U.S. patent application number 16/427853 was filed with the patent office on 2019-11-14 for vehicle platooning systems and methods.
The applicant listed for this patent is Peloton Technology Inc.. Invention is credited to JOSEPH CHRISTIAN GERDES, JOSHUA P. SWITKES.
Application Number | 20190346863 16/427853 |
Document ID | / |
Family ID | 51538131 |
Filed Date | 2019-11-14 |
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United States Patent
Application |
20190346863 |
Kind Code |
A1 |
SWITKES; JOSHUA P. ; et
al. |
November 14, 2019 |
VEHICLE PLATOONING SYSTEMS AND METHODS
Abstract
Systems and methods for coordinating and controlling vehicles,
for example heavy trucks, to follow closely behind each other, or
linking, in a convenient, safe manner and thus to save significant
amounts of fuel while increasing safety. In an embodiment, on-board
controllers in each vehicle interact with vehicular sensors to
monitor and control, for example, relative distance, relative
acceleration/deceleration, and speed. Additional safety features in
at least some embodiments include providing each driver with one or
more visual displays of forward and rearward looking cameras.
Long-range communications are provided for coordinating vehicles
for linking, and for communicating analytics to fleet managers or
others.
Inventors: |
SWITKES; JOSHUA P.;
(Mountain View, CA) ; GERDES; JOSEPH CHRISTIAN;
(Los Altos, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Peloton Technology Inc. |
Mountain View |
CA |
US |
|
|
Family ID: |
51538131 |
Appl. No.: |
16/427853 |
Filed: |
May 31, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15589124 |
May 8, 2017 |
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16427853 |
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14855044 |
Sep 15, 2015 |
9645579 |
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PCT/US2014/030770 |
Mar 17, 2014 |
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15589124 |
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14292583 |
May 30, 2014 |
9665102 |
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14855044 |
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13542622 |
Jul 5, 2012 |
8744666 |
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14292583 |
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61792304 |
Mar 15, 2013 |
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61505076 |
Jul 6, 2011 |
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61505076 |
Jul 6, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60W 2554/801 20200201;
B60W 10/20 20130101; G08G 1/22 20130101; G05D 1/0295 20130101; B60W
10/04 20130101; G05D 1/0088 20130101; G05D 1/0293 20130101; B60W
2710/20 20130101; G05D 2201/0213 20130101; B60W 30/165 20130101;
B60W 2720/10 20130101; G05D 1/0217 20130101; H04W 4/44 20180201;
H04L 67/12 20130101; B60W 2710/18 20130101; H04W 84/005
20130101 |
International
Class: |
G05D 1/02 20060101
G05D001/02; G05D 1/00 20060101 G05D001/00; G08G 1/00 20060101
G08G001/00; B60W 30/165 20060101 B60W030/165; B60W 10/20 20060101
B60W010/20; B60W 10/04 20060101 B60W010/04; H04L 29/08 20060101
H04L029/08 |
Claims
1. A computerized vehicular convoying control system, useful in
association with a plurality of vehicles to identify one or more
opportunities to form a convoy of a lead vehicle and at least one
following vehicle, the control system comprising, on the at least
one following vehicle: a first computerized controller, responsive
to remotely-transmitted information regarding the lead vehicle and
the at least one following vehicle, and configured to compute a
smooth trajectory for the at least one following vehicle as part of
the identification of the opportunity to convoy, the information
regarding the lead vehicle and the at least one following vehicle
being selected from the group consisting of: vehicle location,
vehicle destination, vehicle load, vehicle type, and trailer type;
a first inter-vehicular transceiver configured to enable
communications between the first computerized controller and a
second computerized controller on the lead vehicle; a first
vehicular separation sensor configured to detect a distance between
the lead vehicle and the at least one following vehicle, and
further configured to detect a relative speed between the lead
vehicle and the at least one following vehicle, and to provide such
distance and relative speed to the first computerized controller;
and a first user interface configured to receive an input from the
first computerized controller and to provide vehicular data to a
driver.
2. The convoying control system of claim 1 further comprising: a
first braking actuation sensor configured to measure brake
actuation and to provide such brake actuation measurements to the
first computerized controller; a first supplemental braking
actuator responsive to inputs from the first computerized
controller to vary braking of the at least one following vehicle; a
first acceleration actuation sensor for measuring acceleration
actuation and providing such measured acceleration to the first
computerized controller; and a first supplemental acceleration
actuator responsive to the first computerized controller to vary
acceleration of the at least one following vehicle.
3. The convoying control system of claim 1, further comprising: a
long-range vehicular transceiver configured to communicate between
a central server and the first computerized controller.
4. The convoying control system of claim 1, further comprising: a
global positioning system (GPS) receiver providing positioning
information to the first computerized controller.
5. The convoying control system of claim 1, additionally
comprising, on the lead vehicle: a second computerized controller
that is responsive to remotely-transmitted information regarding
the lead vehicle and the at least one following vehicle, and
configured to compute a smooth trajectory for the lead vehicle as
part of the identification of the opportunity to convoy, the
information regarding the lead vehicle and the at least one
following vehicle being selected from the group consisting of:
vehicle location, vehicle destination, vehicle load, vehicle type,
and trailer type; a second long-range vehicular transceiver
configured to communicate between a central server and the second
computerized controller; a second user interface configured to
receive an input from the second computerized controller and to
provide vehicular data to a driver; a second inter-vehicular
transceiver configured to enable communications between the second
computerized controller and the first computerized controller; and
a forward-facing camera configured to substantially capture a
substantially frontal image as viewed from the lead vehicle and to
provide such frontal image to the second computerized
controller.
6. The convoying control system of claim 5, wherein the
substantially frontal image is provided to the first computerized
controller via the first and second inter-vehicular
transceivers.
7. The convoying control system of claim 1, wherein the second
inter-vehicular transceiver is coupled to, and further configured
to operate, a rear brake light of the lead vehicle independently of
the lead vehicle's braking system as a transmitter of vehicular
control signals from the lead vehicle to the at least one following
vehicle.
8. The convoying control system of claim 1, wherein the first
inter-vehicular transceiver and the second inter-vehicular
transceiver are configured to communicate using a radio
frequency.
9. The convoying control system of claim 1, wherein the first
computerized controller detects at least one hazardous condition
selected from the group consisting of: lane drift, an obstacle in a
lane of travel, a wet road surface, an icy road surface, a tire
blowout, presence of pedestrians in the lane of travel, and the
presence of a construction zone; and wherein the first computerized
controller safely brakes the at least one following vehicle upon
detection of the at least one hazardous condition, and alerts the
driver upon detection of the at least one hazardous condition.
10. The convoying control system of claim 9, wherein the first
computerized controller alerts the driver by providing a
deceleration impulse.
11. The convoying control system of claim 1, wherein the first
computerized controller computes an ordering of the lead vehicle
and the at least one following vehicle in accordance with at least
one of: a vehicle weight, a vehicle load, weather condition, road
condition, fuel remaining, fuel saving, accrued linking time,
braking technology, brake pad wear, a vehicular linking location,
and a destination address.
12. The convoying control system of claim 1, wherein both the lead
vehicle and the at least one following vehicle are trucks.
13. A computerized vehicular convoying control system, useful in
association with a lead vehicle and at least one follower vehicle
to implement a convoy, the control system comprising, on the at
least one follower vehicle: a first computerized controller,
responsive to remotely-transmitted information regarding the lead
vehicle and the at least one follower vehicle, and configured to
monitor and control acceleration and deceleration of the at least
one follower vehicle, thereby maintaining a safe vehicular spacing
between the lead vehicle and the at least one follower vehicle
while moving, the information regarding the lead vehicle and the at
least one follower vehicle being selected from the group consisting
of: vehicle location, vehicle destination, vehicle load, vehicle
type, and trailer type; a first user interface configured to
receive an input from the lead computerized controller and to
provide vehicular data to a driver; a first inter-vehicular
transceiver configured to communicate between the first
computerized controller and a second computerized controller on the
lead vehicle; a vehicular separation sensor configured to detect a
distance between the lead vehicle and the at least one follower
vehicle, and further configured to detect a relative speed between
the lead vehicle and the at least one follower vehicle, and to
provide such distance and relative speed to the first computerized
controller.
14. The convoying control system of claim 13, further comprising: a
first braking actuation sensor configured to measure brake
actuation and to provide such brake actuation measurements to the
first computerized controller; a first supplemental braking
actuator responsive to inputs from the first computerized
controller to vary braking of the at least one follower vehicle; a
first acceleration actuation sensor for measuring acceleration
actuation and providing such measured acceleration to the first
computerized controller; a first supplemental acceleration actuator
responsive to the first computerized controller to vary
acceleration of the at least one follower vehicle.
15. The convoying control system of claim 13, wherein the second
computerized controller is responsive to remotely-transmitted
information regarding the lead vehicle and the at least one
follower vehicle, and configured to monitor acceleration and
deceleration of the at least one follower vehicle, thereby
maintaining a safe vehicular spacing between the lead vehicle and
the at least one follower vehicle while moving, the information
regarding the lead vehicle and the at least one follower vehicle
being selected from the group consisting of: vehicle location,
vehicle destination, vehicle load, vehicle type, and trailer type;
the system further comprising, on the lead vehicle: a second user
interface configured to receive an input from the second
computerized controller and to provide vehicular data to a driver;
and a second inter-vehicular transceiver configured to communicate
between the second computerized controller and the first
computerized controller.
16. The convoying control system of claim 13, additionally
comprising: a forward-facing camera configured to substantially
capture a substantially frontal image as viewed from the lead
vehicle and to provide such frontal image to the second
computerized controller; and wherein the substantially frontal
image is provided to the first computerized controller via the
first and second inter-vehicular transceivers.
17. The convoying control system of claim 13, wherein the second
inter-vehicular transceiver is coupled to, and further configured
to operate, a rear brake light of the lead vehicle independently of
the lead vehicle's braking system as a transmitter of vehicular
control signals from the lead vehicle to the at least one following
vehicle.
18. The convoying control system of claim 13, wherein the first
inter-vehicular transceiver and the second inter-vehicular
transceiver are configured to communicate using a radio
frequency.
19. The convoying control system of claim 13 wherein the first
computerized controller computes at least one vehicular trajectory
for smoothly linking the at least one follower vehicle with the
lead vehicle.
20. The convoying control system of claim 13, wherein the first
computerized controller detects at least one hazardous condition
selected from the group consisting of: lane drift, an obstacle in a
lane of travel, a wet road surface, an icy road surface, a tire
blowout, the presence of pedestrians in the lane of travel, and the
presence of a construction zone; and wherein the at least one
computerized controller safely brakes at least one of the lead
vehicle and the at least one follower vehicle upon detection of the
at least one hazardous condition, and alerts the driver upon
detection of the at least one hazardous condition.
21. The convoying control system of claim 20, wherein the first
computerized controller alerts the driver by providing a
deceleration impulse.
22. The convoying control system of claim 13, wherein the first
computerized controller computes an ordering of the lead vehicle
and the at least one follower vehicle in accordance with at least
one of: a vehicle weight, a vehicle load, weather condition, road
condition, fuel remaining, fuel saving, accrued linking time,
braking technology, brake pad wear a vehicular linking location,
and a destination address.
23. The convoying control system of claim 13, wherein both the lead
vehicle and the at least one follower vehicle are trucks.
24. A computerized vehicular convoying control system, useful in
association with a lead vehicle and at least one follower vehicle,
the control system comprising: at least one computerized controller
configured to monitor and control acceleration and deceleration of
one of a lead vehicle and at least one follower vehicle; a user
interface configured to receive an input from the at least one
computerized controller and to provide vehicular data to a driver;
a long-range vehicular transceiver configured to communicate
between a central server and the at least one computerized
controller; an inter-vehicular transceiver configured to
communicate between the computerized controller and at least one of
the lead vehicle and the at least one follower vehicle; and a
vehicular separation sensor configured to detect a distance between
the lead vehicle and the at least one follower vehicle, and further
configured to detect a relative speed between the lead vehicle and
the at least one follower vehicle, and to provide such distance and
relative speed to the at least one computerized controller.
25. The convoying control system of claim 24, further comprising: a
braking actuation sensor configured to measure brake actuation and
to provide such brake actuation measurements to the at least one
computerized controller; a supplemental braking actuator responsive
to inputs from the at least one computerized controller to vary
braking of one of the lead vehicle and the at least one follower
vehicle; an acceleration actuation sensor for measuring
acceleration actuation and providing such measured acceleration to
the at least one computerized controller; a supplemental
acceleration actuator responsive to the at least one computerized
controller to vary acceleration of one of the lead vehicle and the
at least one follower vehicle.
26. The convoying control system of claim 24, further comprising: a
vehicular positioning sensor providing relative positioning
measures to the first computerized controller.
27. The convoying control system of claim 26, wherein the vehicular
positioning sensor is a global positioning system (GPS) sensor.
28. The convoying control system of claim 24, further comprising: a
forward-facing camera configured to substantially capture a
substantially frontal image as viewed from one of the lead vehicle
and the at least one follower vehicle and to provide such frontal
image to the at least one computerized controller.
29. The convoying control system of claim 28, wherein the
forward-facing camera captures a substantially frontal image as
viewed from the lead vehicle, and the substantially frontal image
from the lead vehicle is provided to the at least one follower
vehicle via the inter-vehicular transceiver.
30. The convoying control system of claim 24 wherein the
inter-vehicular transceiver is configured to transmit using a radio
frequency.
31. The convoying control system of claim 24, wherein the
inter-vehicular transceiver is coupled to, and further configured
to operate, a rear brake light of the lead vehicle independently of
the lead vehicle's braking system.
32. The convoying control system of claim 31, wherein the
inter-vehicular transceiver is further configured to operate a rear
brake light of the lead vehicle as a transmitter of vehicular
control signals from the lead vehicle to the at least one follower
vehicle.
33. The convoying control system of claim 24, wherein the at least
one computerized controller is further configured to compute an
estimated gross weight of one of the lead vehicle and the at least
one follower vehicle by measuring or estimating engine torque and
measuring or estimating vehicle acceleration.
34. The convoying control system of claim 24, wherein the at least
one computerized controller computes at least one vehicular
trajectory for smoothly linking the at least one follower vehicle
with the lead vehicle.
35. The convoying control system of claim 24, wherein the at least
one computerized controller safely decelerates at least one of the
lead vehicle and the at least one follower vehicle in the event of
a malfunction of the convoying control system.
36. The convoying control system of claim 24, wherein the at least
one computerized controller detects at least one hazardous
condition from the group consisting of: a lane drift, a lane
obstacle, a road surface hazard due to wet conditions, a road
surface hazard due to icy conditions, a tire blowout, a presence of
pedestrians or animals in the lane of travel, and the presence of a
construction zones; and wherein the at least one computerized
controller brakes at least one of the lead vehicle and the at least
one follower vehicle upon detection of the at least one hazardous
condition, and alerts the driver upon detection of the at least one
hazardous condition.
37. The convoying control system of claim 36, wherein the at least
one computerized controller alerts the driver by providing a
deceleration impulse.
38. The convoying control system of claim 24 wherein the at least
one computerized controller computes an ordering of the lead
vehicle and the at least one follower vehicle in accordance with at
least one of a vehicle weight, a vehicle load, weather condition,
road condition, fuel remaining, fuel saving, accrued linking time,
braking technology, brake pad wear, a vehicular linking location,
and destination address.
39. The convoying control system of claim 24, wherein the at least
one computerized controller optimizes fuel consumption by
activating a grade-aware cruise control algorithm.
40. The convoying control system of claim 24, wherein the at least
one computerized controller optimizes fuel consumption by providing
at least one recommendation to the driver, the at least one
recommendation including at least one of: gear selection, speed
reduction, and a recommended vehicular relative lateral
position.
41. The convoying control system of claim 24, wherein both the
first vehicle and the second vehicle are trucks.
42. In a computerized vehicular convoying control system, a
vehicular convoying method for controlling a lead vehicle and at
least one follower vehicle, the convoying method comprising:
monitoring and controlling acceleration and deceleration of one of
a lead vehicle and at least one follower vehicle; communicating
between a central server and one of the lead vehicle and the at
least one follower vehicle; communicating between the lead vehicle
and the at least one follower vehicle; detecting a distance between
the lead vehicle and the at least one follower vehicle; detecting a
relative speed between the lead vehicle and the at least one
follower vehicle; and providing vehicular data to a driver; and
using the detected distance and the relative speed to maintain a
vehicular spacing between the lead vehicle and the at least one
follower vehicle.
43. The convoying method of claim 42, wherein detecting the
distance and the relative speed includes emitting a radar
signal.
44. The convoying method of claim 42, further comprising: providing
one of supplemental braking and supplemental acceleration to one of
the lead vehicle and the at least one follower vehicle to maintain
the vehicular spacing.
45. The convoying method of claim 42, further comprising: capturing
a substantially frontal image as viewed from the lead vehicle and
transmitting the image to the at least one follower vehicle.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 15/589,124, filed May 8, 2017 which is a continuation of U.S.
application Ser. No. 14/855,044, filed Sep. 15, 2015, which is a
371 of International Application PCT/US14/30770, filed Mar. 17,
2014, which in turn is a conversion of U.S. patent application Ser.
No. 61/792,304, filed Mar. 15, 2013, and further is a
continuation-in-part of Ser. No. 14/292,583 filed May 30, 2014,
which is a Division of Ser. No. 13/542,622, filed Jul. 5, 2012, now
U.S. Pat. No. 8,744,666, which in turn is a conversion of
Provisional Application Ser. No. 61/505,076, filed on Jul. 6, 2011,
both entitled "Systems and Methods for Semi-Autonomous Vehicular
Convoying"; and which is also a Division of Ser. No. 13/542,627,
filed Jul. 5, 2012, now U.S. Pat. No. 9,582,006, which in turn is
also a conversion of Ser. No. 61/505,076, filed Jul. 6, 2011.
Applicant claims the benefit of priority of each of the foregoing
applications, al of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This application relates generally to safety and fuel
savings systems for vehicles, and more particularly relates to
systems and methods for enabling at least a second vehicle to
follow, safely, a first vehicle at a close distance, where a
plurality of safety features can be used singly or in combination.
In addition, other aspects of the invention provide analytics
useful for assessing driver performance and determining cost
savings.
BACKGROUND
[0003] The present invention relates to systems and methods for
enabling vehicles to closely follow one another safely through
partial automation. Following closely behind another vehicle has
significant fuel savings benefits, but is generally unsafe when
done manually by the driver. On the opposite end of the spectrum,
fully autonomous solutions require inordinate amounts of
technology, and a level of robustness that is currently not cost
effective.
[0004] Currently the longitudinal motion of vehicles is controlled
during normal driving either manually or by convenience systems,
and, during rare emergencies, it may be controlled by active safety
systems.
[0005] Convenience systems, such as adaptive cruise control,
control the speed of the vehicle to make it more pleasurable or
relaxing for the driver, by partially automating the driving task.
These systems use range sensors and vehicle sensors to then control
the speed to maintain a constant headway to the leading vehicle. In
general these systems provide zero added safety, and do not have
full control authority over the vehicle (in terms of being able to
fully brake or accelerate) but they do make the driving task
easier, which is welcomed by the driver.
[0006] Some safety systems try to actively prevent accidents, by
braking the vehicle automatically (without driver input), or
assisting the driver in braking the vehicle, to avoid a collision.
These systems generally add zero convenience, and are only used in
emergency situations, but they are able to fully control the
longitudinal motion of the vehicle.
[0007] Manual control by a driver is lacking in capability compared
to even the current systems, in several ways. First, a manual
driver cannot safely maintain a close following distance. In fact,
the types of distance to get any measurable gain results in an
unsafe condition, risking a costly and destructive accident.
Second, the manual driver is not as reliable at maintaining a
constant headway as an automated system. Third, a manual driver,
when trying to maintain a constant headway, generally causes rapid
and large changes in command (accelerator pedal position for
example) which result in a loss of efficiency.
[0008] It is therefore apparent that an urgent need exists for
reliable and economical Semi-Autonomous Vehicular Convoying. These
improved Semi-Autonomous Vehicular Convoying Systems enable
vehicles to follow closely together in a safe, efficient,
convenient manner.
SUMMARY
[0009] The system and methods which form the invention described
herein combines attributes of state of the art convenience, safety
systems and manual control to provide a safe, efficient convoying,
or platooning, solution. The present invention achieves this
objective by combining elements of active vehicle monitoring and
control with communication techniques that permit drivers of both
lead and trailing vehicles to have a clear understanding of their
motoring environment, including a variety of visual displays, while
offering increased convenience to the drivers together with the
features and functionality of a manually controlled vehicle.
[0010] To achieve the foregoing and in accordance with the present
invention, systems and methods for a Semi-Autonomous Vehicular
Convoying are provided. In particular the systems and methods of
the present invention provide for: 1) a close following distance to
save significant fuel; 2) safety in the event of emergency
maneuvers by the leading vehicle; 3) safety in the event of
component failures in the system; 4) an efficient mechanism for
vehicles to find a partner vehicle to follow or be followed by; 5)
an intelligent ordering of the vehicles based on several criteria;
6) other fuel economy optimizations made possible by the close
following; 7) control algorithms to ensure smooth, comfortable,
precise maintenance of the following distance; 8) robust failsafe
mechanical hardware; 9) robust failsafe electronics and
communication; 10) other communication between the vehicles for the
benefit of the driver; 11) prevention of other types of accidents
unrelated to the close following mode; and, 12) a simpler
embodiment to enable a vehicle to serve as a lead vehicle without
the full system.
[0011] It will be appreciated by those skilled in the art that the
various features of the present invention described herein can be
practiced alone or in combination. These and other features of the
present invention will be described in more detail below in the
detailed description of the invention and in conjunction with the
following figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In order that the present invention may be more clearly
ascertained, some embodiments will now be described, by way of
illustration, with reference to the accompanying drawings, in
which:
[0013] FIG. 1 shows the airflow around a heavy truck, in accordance
with some embodiments.
[0014] FIG. 2 shows US transportation fuel use.
[0015] FIG. 3A shows typical fleet expenses for a heavy truck
fleet.
[0016] FIG. 3B shows typical heavy truck fuel use from aerodynamic
drag.
[0017] FIG. 4 shows typical fuel savings for a set of linked
trucks.
[0018] FIG. 5 shows fuel savings versus following distance gap for
a set of heavy trucks.
[0019] FIG. 6A shows an example of long range coordination between
two trucks in accordance with one embodiment of the present
invention.
[0020] FIG. 6B illustrates the geofencing capability of the present
invention.
[0021] FIGS. 7A-7C show an example of short range linking between
two trucks, from available to linking to linked.
[0022] FIG. 8A illustrates exemplary long range communications
between trucks.
[0023] FIG. 8B illustrates a variety of factors that a central
server might consider in determining candidates for linking.
[0024] FIG. 9A illustrates an embodiment of short range
communications between trucks.
[0025] FIG. 9B illustrates the communications links which provide
the short range communications of FIG. 9A.
[0026] FIG. 10 illustrates the establishment of a linked pair as
the result of the short range communications between trucks.
[0027] FIG. 11A shows an exemplary installation of system
components for one embodiment of the invention.
[0028] FIG. 11B shows an embodiment in which the view from a
forward looking camera in a lead truck is displayed to the driver
of a following truck.
[0029] FIG. 12 illustrates, in simplified block diagram form, an
embodiment of a vehicular convoying control system in accordance
with the present invention.
[0030] FIGS. 13A-B illustrate, in greater detail than FIG. 12, the
components of the control system which cooperate with the control
processor of FIG. 12.
[0031] FIG. 14 shows exemplary components for a simplified version
of the embodiment of FIG. 12, suitable for a lead vehicle.
[0032] FIGS. 15A-B show, in flow diagram form, an embodiment of a
process for coordination and linking in accordance with the
invention, including consideration of factors specific to the
vehicles.
[0033] FIGS. 16A-B show some additional safety features for some
embodiments.
[0034] FIG. 17 shows one exemplary embodiment of aerodynamic
optimization for use with convoying vehicles.
[0035] FIG. 18 illustrates additional safety features provided by
an embodiment of the present invention, and particularly warnings
and alerts.
[0036] FIG. 19 illustrates a brake test safety feature provided by
an embodiment of the invention.
[0037] FIGS. 20A-B illustrate in block diagram form an aspect of
some embodiments of the invention for providing a variety of
metrics for assessing truck and driver performance, and for routing
appropriate information to the driver and the fleet manager.
DETAILED DESCRIPTION OF THE INVENTION
[0038] The present invention will now be described in detail with
reference to several embodiments thereof as illustrated in the
accompanying drawings. In the following description, numerous
specific details are set forth in order to provide a thorough
understanding of embodiments of the present invention. It will be
apparent, however, to one skilled in the art, that embodiments may
be practiced without some or all of these specific details. In
other instances, well known process steps and/or structures have
not been described in detail in order to not unnecessarily obscure
the present invention. The features and advantages of embodiments
may be better understood with reference to the drawings and
discussions that follow.
[0039] The present invention relates to systems and methods for a
Semi-Autonomous Vehicular Convoying. Such a system enables vehicles
to follow closely behind each other, in a convenient, safe manner.
For convenience of illustration, the exemplary vehicles referred to
in the following description will, in general, be large trucks, but
those skilled in the art will appreciate that many, if not all, of
the features described herein also apply to many other types of
vehicles.
[0040] To facilitate discussion, FIG. 1 shows the airflow around a
typical truck 100, illustrating both the relatively laminar airflow
along the truck's roof and sides and the substantially turbulent
flow at the rear of the truck. It will be appreciated by those
skilled in the art that a vehicle's aerodynamic smoothness, related
to the truck's frontal area and shape, affect total drag. The
system of the present invention is aimed at reducing the drag
caused by this type of airflow. This drag is responsible for the
majority of fuel used in transportation, especially in the Heavy
Truck sector (see FIG. 2). The expense of this fuel is significant
for all private and industrial vehicle users, but especially so for
heavy truck fleets, where the fuel is about 40% of operating
expenses (see FIG. 3A). As shown in FIG. 3B, the wind resistance
for a typical truck 100 is approximately 63% of engine power at
highway speeds. This wind resistance power is approximately
proportional to vehicle speed to the third power, as
Drag_Power=Cd*(Area*0.5*density*Velocity{circumflex over ( )}3),
where Cd is the coefficient of drag and is a function of the
object's shape.
[0041] Embodiments of the present invention enable vehicles to
follow closely together and to achieve significant fuel savings,
both for the lead and the trailing vehicles, as illustrated in FIG.
4 where two heavy trucks are shown following closely. FIG. 5 (from
"Development and Evaluation of Selected Mobility Applications for
VII (a.k.a. IntelliDrive)", Shladover 2009) shows the fuel savings
possible for heavy trucks at various gaps.
[0042] In accordance with the present invention, a key part of the
functionality of one such embodiment is long range coordination
between the vehicles, which, in an embodiment, is managed from a
central location, but, alternatively, can be initiated and managed
by the truck drivers. As shown in FIG. 6A, this serves to allow
vehicles 410 and 420 to find linking partners, where information
concerning each truck such as shown at 615 and 625, is available
to, for example, the central location. In an embodiment, unique
indicia, such as a serial number, is associated with each vehicle
available for linking. The unique indicia can, in an embodiment, be
unique among all vehicles that are potentially available for
linking, whether or not available at a specific time and location;
or, in an alternative embodiment, the indicia can be temporarily
assigned, for example as part of the process of identifying and
selecting candidates for linking, and can be unique only among
vehicles that are candidates for linking at a particular time and
location. In a still further alternative, the permanent or
temporarily unique indicia can be assigned not only to vehicles
available for linking, but to all vehicles proximate to vehicles
having the system of the present invention, such that each such
"neighboring" vehicle is monitored for movements that might require
an evasive maneuver or other safety-related action. Such an
arrangement provides improved situational awareness, and the
movements of such other vehicles can be recorded for safety and
liability purposes. In some embodiments, rear or side view cameras,
lidar or radar can provide improved detection and monitoring of
neighboring vehicles. The system has some knowledge of the location
and/or destination of the self-vehicle and of other equipped
vehicles on the road. The system can thus suggest nearby vehicles
with which to link. Numerous other factors can also be taken into
account before selecting trucks to link, as discussed hereinafter
at least in connection with FIGS. 15A-C. The factors discussed in
connection with FIGS. 15A-15C become relevant, the trucks must be
traveling, or available to be coordinated to travel, on the same
route, in an area where linking will provide the desired fuel
savings and safety benefits. Thus, as shown in FIG. 6A, the two
trucks are traveling on a stretch of major highway, both going the
same direction, and neither is already linked. This provides, at
least initially, some motivation to link the two trucks.
[0043] However, some areas of roadways are not well-suited to
linking. For example, and as shown in FIG. 6B, while the majority
of a highway system may be adequate for enabling linking, indicated
at 630, specific areas may be known to be undesirable for linking
for one reason or another, and thus trucks in those areas are
disabled from linking, indicated at 635. Problem areas, where
linking is disabled, can result from, among other things, a grade
or a downgrade, a city, lack of a divided highway or other adverse
roadway characteristics, weather, military installations, RF or
microwave interference, or, in some cases, low overpasses. For
routes that include low overpasses, the central location can simply
provide different routing for trucks too tall to clear. In the
event that a too-tall truck ends up on a route with a low overpass,
an embodiment of the present invention can apply brakes or
otherwise generate a warning, as discussed in greater detail
hereinafter in connection with FIG. 18.
[0044] Should it be desirable for two trucks to link, the result is
as shown in FIGS. 7A-7C, where trucks 410 and 420 move to within a
few feet of each other, for example in the range of 10 feet to
approximately 500 feet, and the displays 615 and 625 show that a
merge is allowed and that the trucks are available for linking,
then linking, and then linked. In an embodiment of the
semi-autonomous system of the present invention, the trucks are
brought generally proximate to one another through the coordination
of a central system together with long range communication.
[0045] FIGS. 8A-8B show the technology to enable such a system: in
FIG. 8A, a long range communication system 880 and a central server
890 provide a communication link to each of trucks 410 and 420. As
shown in FIG. 8B, the server 890 and/or the system onboard each
vehicle 410, 420, makes decisions and suggestions based on
knowledge of one or more of vehicle location, destination, load,
weather, traffic conditions, vehicle type, trailer type, recent
history of linking, fuel price, driver history, and other factors,
all as shown at 830A-n. When a linking opportunity presents itself,
the driver is notified via driver display 840, discussed in great
detail in FIGS. 11A-B. At that point, the driver can manually
adjust the vehicle speed to reduce the distance between the
vehicles, or the system can automatically adjust the speed. In some
instances, the central server or on-board systems will conclude
that the pair is not suitable for linking, and linking is disabled
as shown at 850.
[0046] These linking opportunities can also be determined while the
vehicle is stationary, such as at a truck stop, rest stop, weigh
station, warehouse, depot, etc. They can also be calculated ahead
of time by the fleet manager or other associated personnel. They
may be scheduled at time of departure, or hours or days ahead of
time, or may be found ad-hoc while on the road, with or without the
assistance of the coordination functionality of the system. In
addition, linking of vehicles within a yard is also possible, and
can improve traffic flow while reducing emissions even as vehicles
operate at low speed.
[0047] The determination of which vehicle to suggest for linking
may take into account several factors, and choose an optimum such
as the vehicle which minimizes a cost function. For example, it may
minimize a weighted cost function of the distance between the
vehicles and the distance between their destinations:
Optimum=min(W.sub.p(Pos.sub.a-Pos.sub.b).sup.2+W.sub.d(Des.sub.a-Des.sub.-
b).sup.2), where W.sub.p and W.sub.d are the weights on the two
cost terms respectively. This cost function could have any of the
factors listed above.
[0048] Once the two vehicles or drivers have decided to coordinate,
either by choice or at the suggestion of the coordination
functionality of the invention, they can manually adjust their
speed, or it can be automatic. If manual, the system may suggest to
the lead driver to slow down, and to the follower to speed up. Or
if the leader is stationary (at a truck stop, rest stop, etc.), it
may suggest that he delay his departure the appropriate amount of
time. These suggestions may be based on vehicle speed, destination,
driver history, or other factors. If the system automatically
controls the speed, it may operate the truck in a Cruise Control or
Adaptive Cruise Control type mode, with the speed chosen to bring
the two vehicles closer together. The system may also operate in a
semi-automatic mode, where it limits the speed of the leading
vehicle, to bring them closer together.
[0049] In an embodiment, once the vehicles are sufficiently close
together, communications between the vehicles is controlled
locally, as shown in FIGS. 9A-B, rather than by the long range
coordination system of FIG. 8A. This ensures more accurate control
of relative speed and distance between the vehicles. In one
implementation, each of trucks 410 and 420 has an on-board control
processor 900 and associated communications interface 905. In
addition, each vehicle senses various characteristics of vehicle
performance, such as speed, relative distance to the other truck,
braking application and/or pressure, engine or drivetrain torque,
system faults, and other characteristics, and those characteristics
are communicated as appropriate to the other control processor. In
an embodiment, the control processor in the lead truck takes
control of the rear vehicle 420 and controls it to a close
following distance behind the front vehicle 410. Alternatively, and
as discussed in more detail in connection with FIG. 13B, the
control processor in the lead truck communicates its status to the
control processor in the trailing truck, and vice versa, to cause
the trucks to move into close proximity to one another while each
remains under the control of its on-board control processor. In
some embodiments, communications more critical to safety can be
given prior over other types of communication among the vehicles.
For example, brake application data or commands can be given
priority over video transmission.
[0050] As a further alternative, one of the drivers may use an
input to the system, which input can be by means of a touch
sensitive display with a graphical user interface (GUI), for
example, to activate this transition. As discussed above, key
technology to allow this linking comprises primarily a
distance/relative speed sensor, and a communication link. The type
of functionality of this link is shown in FIG. 10, where
information about a braking event is sent from the front vehicle
410 to the rear vehicle 420. Other information may include
accelerometer data (filtered or unfiltered), brake pressure, tire
pressure, information about obstacles or other vehicles in front of
the lead truck. Also, any of the above data may be passed from the
front truck 410 to the rear truck 420 that relates to trucks in
front of the pair (for example, to allow safe platoons of three or
more trucks.) During the linked, close-following mode, the system
controls the engine torque and braking, with no driver intervention
required. In some embodiments, the driver is still steering the
vehicle; in others, autonomous steering can be used.
[0051] The linking event can comprise a smooth transition to the
close distance following. This may take the form of a smooth target
trajectory, with functionality in a controller that tries to follow
this trajectory. Using D.sub.m as the safe relative distance in
manual mode, and D.sub.a as the desired distance in semi-autonomous
following mode, and a time T.sub.t for the transition to occur, the
target distance may be
D.sub.g=D.sub.m+(D.sub.a-D.sub.m)*(1-cos(pi*t/T.sub.d))/2 for t
less than or equal to T.sub.d. Thus in this way the change in gap
per time is smallest at the beginning and the end of the
transition, and largest in the middle, providing a smooth response.
Other possible forms of this equation include exponentials,
quadratics or higher powers, hyperbolic trigonometric functions, or
a linear change. This shape can also be calculated dynamically,
changing while the maneuver is performed based on changing
conditions or other inputs.
[0052] The driver can deactivate the system in several ways.
Application of the brake pedal can restore conventional manual
control, or can trigger a mode where the driver's braking is simply
added to the system's braking. Applying the accelerator pedal can
also deactivate the system, returning to a manual mode. Other
driver inputs that can trigger a system deactivation, depending
upon the implementation, include: Turn signal application, steering
inputs larger or faster than a threshold, clutch pedal application,
a gear change, Jake (compression) brake application, trailer brake
application, ignition key-off, and others. The driver can also
deactivate the system by selecting an option on the GUI screen or
other input device.
[0053] In the event of any system malfunction, including but not
limited to component failures, software failures, mechanical
damage, etc., the system may react in one of several safe ways. In
general the trailing truck will reduce engine torque and/or start
braking to ensure a safe gap is maintained. This braking may
continue until the trailing truck has come to a complete stop, or
it may continue only until a nominally safe distance is achieved
(safe without automated control), or it may continue only until the
malfunction has been identified. Additionally, one of several
alerts may be used to notify the driver of the malfunction and
subsequent action of the control system: A braking jerk, consisting
of a small braking command, an audible tone, a seat vibration, a
display on the GUI or other display, flashing the instrument
cluster or other interior lights, increasing or decreasing engine
torque momentarily, activation of the "Jake" (compression) brake,
or other useful alerts.
[0054] To enable some or all of the described functionality, the
system may have some or all of the following components shown in
FIG. 11A: an accelerator pedal interceptor 1140, either on the
communications and control bus found in most modern trucks, or
sensed and modified as a range or set of analog voltages, to be
used to command torque from the engine in a manner which resembles
a highly refined cruise control; a modified brake valve 1150, which
allows the system to command braking even in the absence of driver
command; a forward-looking RADAR or LIDAR unit 1130 which senses
distance to and relative speed with respect to the vehicle in front
410; a user interface 1120, which may also house a forward looking
camera, by which the driver can interact with and control the
system; an antenna array 1110, used for the short and long range
communication systems; and a GPS receiver, which can be a precision
GPS, differential GPS, or other GNSS device.
[0055] The benefit of the forward looking camera, available either
as part of interface 1120 or independently, provides a significant
safety benefit, which can be appreciated from FIG. 11B. FIG. 11B
shows, at 1160, the view seen by the driver of the trailing truck
in a linked pair: the driver sees mostly the back of the lead
truck, as well as some space to each side of the lead truck.
However, in an embodiment, a display 1170 of the forward-looking
camera 1120 in the lead truck is provided to the driver of the
trailing truck, thus providing the driver of the trailing truck an
unobstructed view of what is ahead of the linked pair of trucks.
This permits the driver of the second truck to operate the trailing
vehicle with the same knowledge of the road ahead as the lead
vehicle, including observing unexpected developments, hazards,
traffic, etc. The display 1170 can be visor or dash mounted, or in
any other convenient location, and can also comprise a touch screen
user interface, as discussed in greater detail in connection with
FIG. 12.
[0056] FIG. 12 shows the system architecture for one embodiment
1200. The user 1210 interacts with the system through a user
interface, which may be a Graphical User Interface 1220, and which
is typically, although not necessarily, integrated with a control
processor 1230. Alternatively, the user interface can comprise an
additional electronics unit, such as a tablet-style computer which
can be mounted in any convenient location, such as the dash or the
visor. Such tablets typically include graphical user interfaces,
although such an interface is not necessary and any convenient
interface will do. Such tablets often also include a cellular
modem, thus permitting long range communications and coordination,
as well as a GPS. In some implementations, these features can be
provided separately. For purposes of simplicity in the present
disclosure, it will be assumed that the user interface 1220 is a
tablet with such features, including a graphical user interface and
touch screen. In an alternative embodiment, a smartphone can be
substituted for the tablet. In other embodiments, the processing
capability required by the system of FIG. 12 can be provided by the
tablet or smartphone. In appropriate embodiments, such tablets or
smartphones can serve as the core controller, the user interface
panel, or can provide some or all of the vehicle-to-vehicle link
through either cellular connectivity, Bluetooth, WiFi, or other
suitable connection. Such devices can also be connected to the rest
of the system, such as a CAN or J1939 bus, or vehicle ECU's.
[0057] The user 1210 receives information (a) from visual and or
auditory alerts, and can make system requests (e.g., for linking or
coordination). The user interface 1220 communicates with a long
range data link 1240 (b), such as through a cellular modem or other
service. The user interface 1220 is responsible for managing this
data link, sending data via the link, and receiving data via the
link. A control processor 1230 (which may be alternatively
integrated with the GUI box) receives sensor information 1250 (c),
short range data link 1260 information (e), and controls the
actuators 1270 (f). It receives information from the user interface
1220 via a wired or wireless link (d), and sends information to the
user interface 1220 to be relayed to the driver and/or long range
communication link 1240. Alternately, the long range communication
link 1240 can connect directly to the control box 1230. In this
case, the user interface 1220 may be an extremely simple (low cost)
device, or may even be eliminated from the system entirely.
[0058] FIG. 13A shows one embodiment of a vehicle control unit 1300
in accordance with the present invention while FIG. 13B shows in
process flow form the exchange of information between the vehicle
control units 1300 of both the lead and trailing trucks. In
particular, and with reference to FIG. 13A, the unit 1300 comprises
at least one control processor 1230, which communicates with
various core sensors such as radar/lidar 1310, accelerometers 1320,
data links 1360, and also communicates with actuators such as brake
valve 1340 and accelerator command unit 1390. Via connection (a),
typically but not necessarily a CAN interface, the control
processor 1230 configures the radar unit 1310 and receives data.
Connection (b) to accelerometers 1320, which can be wireless, gives
the control box acceleration information in 1, 2 or 3 axes as well
as rotation rate information about 1, 2 or 3 axes. In some
embodiments, gyros can be substituted for accelerometers,
especially for, for example, rotation rate. The data link 1360,
shown at (c) and illustrated in greater detail below as indicated
by the dashed lines, provides information about relevant
characteristics of the leading truck 410, including its
acceleration, or is used to provide the same or similar information
to a following truck 420. The brake valve 1340 (d) provides data on
brake pressure, and is used to apply pressure via a command from
the control processor 1230. The accelerator command 1390 is sent
via an analog voltage or a communications signal (CAN or
otherwise). The control processor performs calculations to process
the sensor information, information from the GUI, and any other
data sources, and determine the correct set of actuator commands to
attain the current goal (example: maintaining a constant following
distance to the preceding vehicle). The data links 1360 can
comprise a link to the truck manufacturer's engine control unit
1370, a wireless link 1375 for communications and a link to other
aspects of the vehicle as shown at 1365. Each of these links can,
depending upon the embodiment, be bidirectional.
[0059] The operation of the vehicle control unit 1300 of the
present invention can be better appreciated from FIG. 13B, which
shows, for an embodiment, the general flow between the vehicle
control units 1300 of two linked vehicles. Two modes of operation
are possible: in a first mode, the front truck's control unit 1300
issues commands to the back truck's control unit, and those
commands are, in general, followed, but can be ignored in
appropriate circumstances, such as safety. In a second mode, the
front truck's control unit sends data to the second truck, advising
the trailing truck of the data sensed by the lead truck and the
actions being taken by the lead truck. The second truck's control
unit then operates on that data from the front truck to take
appropriate action. As shown at 1305, the following or trailing
truck sends data about its operation to the front or lead truck. At
1315, the lead truck receives the data from the trailing truck, and
senses motion and/or external objects and/or communication inputs.
The lead truck then decides upon actions for the lead truck, shown
at 1325, and, if operating in the first mode, also decides upon
actions for the back truck, shown at 1330. Then, depending upon
whether operating in first or second mode, the lead truck either
sends commands (1335) to the trailing truck (first mode), or sends
data (1345) to the trailing truck (second mode). If operating in
the first mode, the second truck receives the commands and performs
them at 1350, with the caveat that the second truck can also chose
to ignore such commands in some embodiments. If operating in the
second mode, the second truck receives the data at 1355, and
decides what actions to perform. Because the control programs for
both units 1300 are the same, in most cases the resulting control
of the second truck will be identical regardless of operating mode.
Finally, the second truck communicates to the front truck what
actions it has taken, so that each truck knows the state of the
other. In at least some embodiments, this process is repeated
substantially continually to ensure that each truck has the current
state of the other truck, thus ensuring safe and predictable
operation of each truck, even when operating in close-order
formation at highway speeds.
[0060] FIG. 15A shows one embodiment of the coordination and
linking functionality. First, the system identifies a vehicle
available for coordination 1510 (example: within a certain range,
depending on the route of the two vehicles). Once one of the
vehicles has accepted 1522 or 1524, the other can then accept,
meaning that the pair has agreed to coordinate for possible linking
1530. Depending on vehicle positioning, weight of load, vehicle
equipment, and other factors, a vehicle within linking range may be
identified as a Following Vehicle Available for Linking 1542 or a
Leading Vehicle Available for Linking 1544. If neither of these is
the case, the system returns to coordination mode. Once a Following
Vehicle Available for Coordination has Accepted the link 1552, the
Self Vehicle then also accepts the link 1553, initiating the link.
Upon completion of the link, the vehicles are now linked 1562.
Similarly, once a Leading Vehicle Available for Coordination has
Accepted the link 1554, the Self Vehicle then also accepts the link
1555, initiating the link. Upon completion of the link, the
vehicles are now linked 1564.
[0061] FIG. 15B illustrates an embodiment of a process by which the
vehicle mass of the truck is taken into account to determine
whether a particular truck pair is suitable for linking and, if so,
which truck should lead, and at what gap. In FIG. 15B, engine
torque and acceleration are sensed at 1576. Because, in at least
some embodiments, the vehicle control unit 1300 knows a variety of
details about the truck on which the system is installed (including
either torque, engine speed, and acceleration, or power and
acceleration) the engine torque and acceleration permits vehicle
mass to be calculated, shown at 1578. Based upon that calculation
for each truck in the pair, the trucks are determined either to be
suitable for linking, or not. If they are suitable for linking,
shown at 1580, a determination as to which truck should lead is
made at 1582, using the factors mentioned above. In some instances,
the characteristics of the truck, such as load, etc., may cause the
control units 1300 of the respective trucks to adjust the gap
between the trucks, or the algorithm by which distance is adjusted
with speed, as shown at 1584. Other operating characteristics that
can, depending upon the embodiment, influence the adjustment of
distance can include type of brakes installed, recent brake use,
time/distance since maintenance, tire life, type of tires, and
temperature. Further, if an exit, interchange, or other road
feature or condition is encountered, or is being approached (for
example, as detected by vehicle sensors or communicated from an
external source such as the fleet office) then the distance can be
increased to provide visibility to the rear driver. Additionally
for an upcoming exit the rear truck or both trucks can be set to
coast to avoid braking at the off-ramp. In some embodiments, the
following distance can also be adjusted based on other upcoming
features of the road or greater environment, to ensure safety, make
the driver more comfortable, or for other reasons. Dangerous low
overpasses, inspection stations, road grade, or areas identified as
dangerous, can all be used to adjust the following distance. These
features can be identified from map data, internet data, or other
source. Other features can be detected by either or both trucks,
either from their on-board sensors, or from the sensors added for
the system. These include upcoming road curvature, current or
upcoming road grade. Current or upcoming traffic can also be
identified through radar sensors, the internet, machine vision, or
other methods. In some embodiments, the following distance can also
be set based on driver activity. A lack of steering input can
signify inattention and cause an increase in following distance.
Similarly, aggressive behavior, shown by aggressive motion of the
steering wheel, pedals or other input, can be used to set a desired
distance. The turn signal can also change the distance, for example
to allow space between the vehicles for exiting the road. The
driver can also select the following distance in some embodiments.
Still further, the current fuel economy, the amount of fuel
onboard, the projected range, or other fuel-related parameters may
be used to set the following distance. For example the driver may
want to follow more closely when the fuel level is low, to help
reach a destination. As another example, the fleet or the driver
may have a target fuel economy, and the adjustment of following
distance can be used to meet this target, within limits appropriate
to ensuring safety.
[0062] In the event the leading vehicle 410 is required to make
emergency maneuvers, safety is ensured by the use of the
communications link between the two vehicles. This link may send
some or all of the following: Brake application pressure, brake air
supply reservoir pressure, engine torque, engine RPM, compression
(Jake) brake application, accelerator pedal position, engine
manifold pressure, computed delivered torque, vehicle speed, system
faults, battery voltage, vehicle acceleration, driver inputs,
diagnostic information, braking system condition, and radar/lidar
data.
[0063] The data link 1260 has very low latency (approximately 10 ms
in one embodiment), and high reliability. This could be, but is not
limited to, WiFi, DSRC (802.11p), radio modem, Zigbee, or other
industry standard format. This link could also be a
non-industry-standard format. In the event of a data link loss, the
trailing vehicles are typically instructed to immediately start
slowing, to ensure that if the front vehicle happens to brake
immediately when the link is lost, the gap can be maintained
safely.
[0064] In addition to safe operation during the loss of the data
link 1260, the system should be safe in the event of failure of
components of the system. For most failures, the trailing vehicles
420 start braking, until the driver takes control or other sensors
determine that the situation is safe at which point braking can be
decreased as appropriate. This ensures that, in the worst case
where the front vehicle 410 starts to brake immediately when a
system component fails, the system is still safe. The modified
brake valve 1340 is also designed such that in the event of a
complete failure, the driver can still brake the vehicle.
[0065] Ordering of the vehicles: In an embodiment, the system
arranges the vehicles on the road to ensure safety. This order may
be determined by vehicle weight/load, weather/road conditions, fuel
savings or linking time accrued, braking technology on the vehicle,
destination or other factors. In such an embodiment, the system
will (graphically or otherwise) tell the drivers which vehicle
should be in the front. For example, to mitigate fatigue, the
system may cause the trucks to exchange positions on a periodic
basis. In embodiments where order is important, such as heavy
trucks, the system will only perform the linking functionality if
the vehicles are in the correct order. The order may be determined
by relative positioning measures like GPS, directional detection of
the wireless communication, driver input, visual (video or still
image) processing, or direct or indirect detection of aerodynamics
through fuel savings or sensors. In another embodiment, the system
can apply steering or other lateral control, combined with control
of engine torque and braking, if needed, to effectuate the desired
order of the vehicles.
[0066] FIG. 16A shows some additional safety features the system
may have to prevent other types of accidents unrelated to the close
following mode. One such feature is to use the video stream from
the front looking camera to detect drifting within or out of the
lane. This is done by looking at the edges or important features on
the leading vehicle 410, and calculating the lateral offset from
that vehicle. When it is detected, the system can react with a
braking jerk (a short braking application to get the driver's
attention), slowing down, or a braking jerk in the leading vehicle.
Alternatively, and as shown in FIG. 16B, a set of registration
marks 1605 can be provided on a display for the driver of the
trailing rig, to permit optimum longitudinal registration between
the vehicles. In embodiments having video, portions of the video
that are not important, or change less frequently, can be highly
compressed or not transmitted at all. For example, when trucks are
linked, the back of the lead vehicle does not change significantly,
and is not critical. The compression can be varied based on known
or commanded movement of the vehicles. For example if it is known
that the vehicles have relative motion laterally, then the image
can be shifted laterally in an efficient way without sending the
raw video.
[0067] The system can also use the front mounted radar to detect
obstacles or stationary vehicles in the road, even when not in
close-following mode. When these are detected, it can apply a
braking jerk, slow the vehicle, or provide visual or auditory
warnings. The system can also use the accelerator pedal signal to
determine when the driver is not engaged with the vehicle (or other
driver states) and react accordingly, such as slowing the vehicle
or disabling the system. These and other warnings and alerts are
discussed hereinafter in connection with FIG. 18.
[0068] To facilitate rapid deployment, a simpler version of the
system enables vehicles to be a leading vehicle, shown in FIG. 14.
The components on this version are a subset of those on the full
system, so there is no automation. There are several embodiments of
this reduced set of functionality, with different subsets of the
components from the full system. One minimal system simply performs
two functions: Transmits sufficient data to the trailing vehicle to
allow dose following, and alerts the front driver to a linking
request and allows him/her to accept or decline it. As such, this
version has only the data link functionality 1460. It connects to
the brake pressure sensor and electrical power. This system may
also have additional components, including an accelerometer 1450
and/or an extremely simply user interface and/or long range data
communication 1440.
[0069] The full system may also provide other fuel economy
optimizations. These may include grade-based cruise control, where
the speed set-point is determined in part by the grade angle of the
road and the upcoming road. The system can also set the speed of
the vehicles to attain a specific fuel economy, given constraints
on arrival time. Displaying the optimum transmission gear for the
driver 1410 can also provide fuel economy benefits.
[0070] The system may also suggest an optimal lateral positioning
of the trucks, to increase the fuel savings. For example, with a
cross wind, it may be preferable to have a slight offset between
the trucks, such that the trailing truck is not aligned perfectly
behind the leading truck. This lateral position may be some
combination of a relative position to the surrounding truck(s) or
other vehicles, position within the lane, and global position. This
lateral position may be indicated by the registration marks
1605.
[0071] The data link between the two vehicles is critical to
safety, so the safety critical data on this link has priority over
any other data. Thus the link can be separated into a safety layer
(top priority) and a convenience layer (lower priority). The
critical priority data is that which is used to actively control
the trailing vehicle. Examples of this may include acceleration
information, braking information, system activation/deactivation,
system faults, range or relative speed, or other data streams
related to vehicle control. The selection of which data is high
priority may also be determined, in whole or in part, by the data
being sent and/or received. For example in an emergency braking
situation, additional data may be included as high priority.
[0072] The lower priority convenience portion of the link can be
used to provide data, voice or video to the drivers to increase
their pleasure of driving. This can include social interaction with
the other drivers, or video from the front vehicle's camera to
provide a view of the road ahead. This link can also be used when
the vehicle is stationary to output diagnostic information gathered
while the vehicle was driving. In addition, other cameras, and thus
other views, can be provided, including providing the driver of the
lead truck with a view from the forward-looking camera on the
trailing rig, or providing both drivers with sufficient camera
views from around each vehicle that all blind spots are eliminated
for each driver.
[0073] Because the system is tracking the movements of the
vehicles, a tremendous amount of data about the individual vehicles
and about the fleet is available. This information can be processed
to provide analysis of fleet logistics, individual driver
performance, vehicle performance or fuel economy, backhaul
opportunities, or others. These and other features are discussed
hereinafter in connection with FIGS. 20A-B.
[0074] In an embodiment, the system includes an "allow to merge"
button to be used when the driver wants another vehicle to be able
to merge in between the two vehicles. The button triggers an
increase in the vehicle gap to a normal following distance,
followed by an automatic resumption of the close following distance
once the merging vehicle has left. The length of this gap may be
determined by the speed of the vehicles, the current gap, an
identification of the vehicle that wishes to merge, the road type,
and other factors. The transition to and from this gap may have a
smooth shape similar to that used for the original linking event.
Using D.sub.v as the relative distance to allow a vehicle to cut
in, and D.sub.a as the desired distance in semi-autonomous
following mode, and a time Tt for the transition to occur, the
target distance may be
D.sub.g=D.sub.a+(D.sub.v-D.sub.a)*(1-cos(pi*t/T.sub.d))/2 for t
less than or equal to T.sub.d.
[0075] For vehicles without an automatic transmission, the system
can sense the application of the clutch pedal by inferring such
from the engine speed and vehicle speed. If the ratio is not close
to one of the transmission ratios of the vehicle, then the clutch
pedal is applied or the vehicle is in neutral. In this event the
system should be disengaged, because the system no longer has the
ability to control torque to the drive wheels. For example this
calculation may be performed as a series of binary checks, one for
each gear Gear_1=abs(RPM/WheelSpeed-Gear1Ratio)<Gear1Threshold
and so on for each gear. Thus if none of these are true, the clutch
pedal is engaged.
[0076] The system can estimate the mass of the vehicle to take into
account changes in load from cargo. The system uses the engine
torque and measured acceleration to estimate the mass. In simplest
form, this says that M_total=Force_Wheels/Acceleration. This may
also be combined with various smoothing algorithms to reject noise,
including Kalman filtering, Luenberger observers, and others. This
estimate is then used in the control of the vehicle for the
trajectory generation, system fail-safes, the tracking controller,
and to decide when full braking power is needed. The mass is also
used to help determine the order of the vehicles on the road.
[0077] Many modifications and additions to the embodiments
described above are possible and are within the scope of the
present invention. For example, the system may also include the
capability to have passenger cars or light trucks following heavy
trucks. This capability may be built in at the factory to the
passenger cars and light trucks, or could be a subset of the
components and functionality described here, e.g., as an
aftermarket product.
[0078] The system may also include an aerodynamic design optimized
for the purpose of convoying, as shown in FIG. 17. This may be the
design of the tractor or trailer, or the design of add-on
aerodynamic aids that optimize the airflow for the convoy mode.
This design may correspond to a specific speed, at which the
airflow will be optimized for the convoy mode.
[0079] For example, a hood may deploy, e.g., slide forward, from
the roof of the follower vehicle. Portions of the hood may be
textured (like an aerodynamic golf ball surface) or may be
transparent so as not to further obscure the follower driver's
view. In another example, the existing aerodynamic cone of a
follower truck may be repositioned, and/or the cone profile
dynamically reconfigured, depending on vehicular speed and weather
conditions. This aerodynamic addition or modification may be on the
top, bottom, sides, front, or back of the trailer or tractor, or a
combination thereof.
[0080] This aerodynamic design may be to specifically function as a
lead vehicle 1710, specifically as a following vehicle 1720, or an
optimized combination of the two. It may also be adjustable in some
way, either automatically or manually, to convert between optimized
configurations to be a lead vehicle, a following vehicle, both, or
to be optimized for solitary travel.
[0081] The data link between the two vehicles may be accomplished
in one of several ways, including, but not limited to: A standard
patch antenna, a fixed directional antenna, a steerable
phased-array antenna, an under-tractor antenna, an optical link
from the tractor, an optical link using one or more brake lights as
sender or receiver, or others. In at least some embodiments, it is
desirable to ensure that a line of sight is maintained between the
antenna of the lead and following truck, for those types of
communication that require it. Multiple antennas can be used in
such embodiments, by, for example using one antenna on each side
mirror of the vehicle, such that one of these antennas is usually
in line of sight to an antenna on the other vehicle. The selection
between the available antennas can be done based on detected signal
strength, for example. In a platooning or automated system, the
optimal antenna can be predicted through knowledge of the motion of
the vehicles, the commanded motion, or knowledge of the surrounding
vehicles, either from sensing or from communication. In some
embodiments, the placement of antennas on the vehicle may be chosen
specifically for platooning. For example if the predetermined
distance between the vehicles is known to be twenty feet, the
antenna placement may be chosen to ensure that line of sight is
maintained at a twenty foot spacing. It is also possible to
command, through the vehicle control unit, that the vehicles
maintain a line of sight. Such an approach can be combined with
other factors, for example sidewind, to determine an overall
optical relative position between the vehicles. The phase lock loop
in the communications module can be fed the commanded motion of one
or more vehicles, to help predict the Doppler shift.
[0082] The data link, or other components of the system, may be
able to activate the brake lights, in the presence or absence of
brake pedal or brake application.
[0083] Other possible modifications include supplemental visual
aids for drivers of follower vehicles, including optical devices
such as mirrors and periscopes, to enable follower drivers to get a
better forward-looking view which is partially obscured by the lead
vehicle.
[0084] Any portion of the above-described components included in
the system may be in the cab, in the trailer, in each trailer of a
multi-trailer configuration, or a combination of these
locations.
[0085] The components may be provided as an add-on system to an
existing truck, or some or all of them may be included from the
factory. Some of the components may also be from existing systems
already installed in the truck from the factory or as an
aftermarket system.
[0086] The present invention is also intended to be applicable to
current and future vehicular types and power sources. For example,
the present invention is suitable for 2-wheeler, 3-wheelers, 4
wheelers, 6 wheelers, 16-wheelers, gas powered, diesel powered,
two-stroke, four-stroke, turbine, electric, hybrid, and any
combinations thereof. The present invention is also consistent with
many innovative vehicular technologies such as hands-free user
interfaces including head-up displays, speech recognition and
speech synthesis, regenerative braking and multiple-axle
steering.
[0087] The system may also be combined with other vehicle control
systems such as Electronic Stability Control, Parking Assistance,
Blind Spot Detection, Adaptive Cruise Control, Traffic Jam
Assistance, Navigation, Grade-Aware Cruise Control, Automated
Emergency Braking, Pedestrian detection, Rollover-Control,
Anti-Jacknife control, Anti-Lock braking, Traction Control, Lane
Departure Warning, Lanekeeping Assistance, Sidewind compensation.
It may also be combined with predictive engine control, using the
command from the system to optimize future engine inputs. With
reference to FIG. 18, an embodiment by which such warnings and
alerts are generated in accordance with the invention can be better
appreciated. A warning and alert processor 1800, which can either
be integrated with the control processor 1230 or be a separate
processor, receives inputs from the vehicle sensors 1805, as well
as the short range communication link 1810, and various driver
sensors 1815 including, for example, a sobriety sensor. In
addition, the processor 1800 receives input concerning the location
on the road, any applicable grade, and the state of the vehicle, as
shown at 1820. If an unacceptable condition exists, the processor
1800 either causes an alert 1825, which can take the form of sound,
vibration, a visual display, or some other signal intended to be
immediately noticed by the driver, or the processor causes an
action 1830, such as braking and/or reduction in engine torque.
[0088] FIG. 19 illustrates yet another safety feature implemented
in some embodiments of the invention. Braking is a key safety
feature for trucks operating either in linked mode or
independently. The ability to determine brake condition while
underway is of significant value, and can be accomplished by the
method shown in FIG. 19. In particular, while the vehicle is
moving, the driver applies the brakes at 1900. The vehicle control
unit 1300 samples the input from the vehicle sensor to (1) detect
deceleration, shown at 1905; (2) detect wheel slip(s), shown at
1910; and, (3) detect brake air pressure, shown at 1915. Based on
the collective data, brake condition is calculated at 1920. The
result of the calculation can be displayed to the driver or the
fleet manager (through the long range communication link), and can
provide a warning or alert if the brake condition is abnormal.
Additionally, if the truck is available for linking, the result of
the calculation at step 1920 can be used to choose whether to link
as part of a particular pair, shown at 1925. If a link is to be
made, the calculation can be used to determine which truck of the
pair should lead, 1930, or to adjust the gap or algorithm,
1935.
[0089] Referring next to FIGS. 20A-B, an embodiment for collecting
data about the operation of a particular truck, and a fleet as a
whole, can be better appreciated. A variety of measured data
2000A-n, including vehicle speed, fuel consumption, historical
data, braking information, gear information, driver sensors, gap
information, weather, and grade as just some examples, are provided
to the central server or the on-board system 2010. The server or
other processor 2010 calculates a selection of metrics including
miles per gallon, driver efficiency, savings, time linked,
availability of linkings, and numerous variations. From these,
selected metrics can be displayed to the driver, 2020, or the fleet
manager 2030, or can be used to provide driver incentives, 2040. An
exemplary display 2050 for the driver is illustrated in FIG. 20B,
particularly by showing the savings per mile achieved by the
driver.
[0090] Data from the vehicles can provide specific information on
best practices for a variety of aspects of driving. First, the data
must be aggregated to form a database of best practice. This can
take the form of an average (or median) of data traces, or can be
calculated based on a weighted cost function. In one algorithm,
higher fuel economy traces are weighted more heavily, and a
weighted average is then calculated for each control input. In
another, the drive is separated into segments and the single best
drive for each of those segments is identified. Other
considerations can also be factors, for example mechanical
considerations such as engine overheating, brake condition and
others.
[0091] This database of best practices may also be a function of
truck and conditions. In one embodiment, there is a separate best
practice for each model of truck. Once this best practices data is
created, it can be applied to a wide variety of control inputs.
These include gear selection, speed selection, route selection. It
can include the specific means to attain each of these selections,
including pedal application, transmission retarder activation,
compression (jake) brake application. These optimized control
inputs can then be communicated to either the driver or an
automated system, or a combination thereof. If to an automated
system, these can be used to adjust the target speed, or shifting
selection or other parameters of the automation system.
[0092] In some embodiments, various optimal inputs can also be
suggested to the driver by displaying them on the visual display or
other device. In addition, current inputs can be overlayed with
calculated best inputs. We can also show the potential improvement,
for example showing the current miles per gallon and the
anticipated miles per gallon if the suggested choices are
implemented.
[0093] The collected data can also be shown after the drive itself,
either to the fleet manager, the driver, or other interested
parties. This can also be used to adjust various aspects of the
fleet operation, such as which driver drives in which location,
which truck is used for each route, or dispatch times.
[0094] In sum, the present invention provides systems and methods
for a Semi-Autonomous Vehicular Convoying. The advantages of such a
system include the ability to follow closely together in a safe,
efficient, convenient manner.
[0095] While this invention has been described in terms of several
embodiments, there are alterations, modifications, permutations,
and substitute equivalents, which fall within the scope of this
invention. Although sub-section titles have been provided to aid in
the description of the invention, these titles are merely
illustrative and are not intended to limit the scope of the present
invention.
[0096] It should also be noted that there are many alternative ways
of implementing the methods and apparatuses of the present
invention. It is therefore intended that the following appended
claims be interpreted as including all such alterations,
modifications, permutations, and substitute equivalents as fall
within the true spirit and scope of the present invention.
* * * * *