U.S. patent application number 14/641989 was filed with the patent office on 2016-09-15 for control system having obstacle detection and mapping.
This patent application is currently assigned to CATERPILLAR PAVING PRODUCTS INC.. The applicant listed for this patent is Caterpillar Paving Products Inc.. Invention is credited to Eric S. ENGELMANN, Conwell K. RIFE, JR., Mario J. SOURATY.
Application Number | 20160265174 14/641989 |
Document ID | / |
Family ID | 56800650 |
Filed Date | 2016-09-15 |
United States Patent
Application |
20160265174 |
Kind Code |
A1 |
ENGELMANN; Eric S. ; et
al. |
September 15, 2016 |
CONTROL SYSTEM HAVING OBSTACLE DETECTION AND MAPPING
Abstract
A control system is disclosed for use with a cold planer having
a milling drum. The control system may have an obstacle detection
sensor mountable to the cold planer at a location forward of the
milling drum. The obstacle detection sensor may be configured to
generate a first signal indicative of an object detected within a
work surface. The control system may also have a locating device
mountable to the cold planer and configured to generate a second
signal indicative of a location of the cold planer at a time of
first signal generation, and a controller in communication with the
obstacle detection sensor and the locating device. The cold planer
may be configured to generate an electronic map of a work area
based on the first and second signals, and to selectively adjust
operation of the cold planer based on the electronic map.
Inventors: |
ENGELMANN; Eric S.; (Delano,
MN) ; SOURATY; Mario J.; (Plymouth, MN) ;
RIFE, JR.; Conwell K.; (Wayzata, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Caterpillar Paving Products Inc. |
Minneapolis |
MN |
US |
|
|
Assignee: |
CATERPILLAR PAVING PRODUCTS
INC.
Minneapolis
MN
|
Family ID: |
56800650 |
Appl. No.: |
14/641989 |
Filed: |
March 9, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E01C 23/088
20130101 |
International
Class: |
E01C 23/12 20060101
E01C023/12 |
Claims
1. A control system for a cold planer having a milling drum,
comprising: an obstacle detection sensor mountable to the cold
planer at a location forward of the milling drum and being
configured to generate a first signal indicative of an object
detected within a work surface; a locating device mountable to the
cold planer and configured to generate a second signal indicative
of a location of the cold planer at a time of first signal
generation; and a controller in communication with the obstacle
detection sensor and the locating device, the cold planer being
configured to: generate an electronic map of a work area based on
the first and second signals; and automatically adjust operation of
the cold planer based on the electronic map.
2. The control system of claim 1, wherein the obstacle detection
sensor is a magnetic field detecting sensor.
3. The control system of claim 1, wherein the obstacle detection
sensor is ground penetrating radar receiver.
4. The control system of claim 1, wherein: the cold planer further
includes a traction device; the control system further includes an
actuator associated with the traction device; and the controller is
configured to adjust operation of the cold planer by automatically
causing the actuator to change at least one of a travel speed and a
milling depth of the cold planer.
5. The control system of claim 1, wherein: the control system
further includes an actuator associated with the milling drum; and
the controller is configured to affect operation of the cold planer
by automatically causing the actuator to adjust at least one of a
rotational speed and a depth of the milling drum.
6. The control system of claim 1, wherein: the control system
further includes a communication device; and the controller is
further configured to communicate the electronic map offboard the
cold planer.
7. The control system of claim 1, further including a warning
device, wherein the controller is configured to selectively
activate the warning device based on proximity of the milling drum
to the object.
8. The control system of claim 1, further including a display,
wherein the controller is further configured to show the electronic
map on the display.
9. The control system of claim 1, further including an input
device, wherein the controller is further configured to: prompt an
operator to provide input via the input device regarding the
object; and to selectively allow the milling drum to engage the
object or cause the milling drum to avoid the object based on the
input.
10. The control system of claim 1, wherein the controller is
further configured to: determine features of the object based on
the first signal; make a comparison of the features with features
of known objects; and selectively represent the object in the
electronic map as one of the known objects based on the
comparison.
11. The control system of claim 10, wherein the controller is
configured to selectively allow the milling drum to engage the
object or cause the milling drum to avoid the object based on the
comparison.
12. The control system of claim 10, wherein the controller is
configured to automatically assign a clearance zone around the
object based on the comparison.
13. A method of operating a. cold planer having a milling drum,
comprising: detecting an object in a work surface being milled by
the milling drum; determining a location of the cold planer when
the object is detected; generating an electronic map of a work area
based on detection of the object and the location of the cold
planer; and automatically adjusting operation of the cold planer
based on the electronic map.
14. The method of claim 13, wherein detecting the object includes
detecting a change in a magnetic field within the work surface.
15. The method of claim 13, wherein detecting the object includes
detecting a change in energy waves reflected off the object.
16. The method of claim 13, wherein automatically adjusting
operation of the cold planer includes automatically adjusting a
travel speed of the cold planer.
17. The method of claim 13, wherein automatically affecting
operation of the cold planer includes automatically adjusting at
least one of a rotational speed and a depth of the milling
drum.
18. The method of claim 13, further including: displaying the
electronic map inside an operator station of the cold planer; and
communicating the electronic map offboard the cold planer.
19. The method of claim 13, further including activating a warning
device based on proximity of the milling drum to the object.
20. A cold planer, comprising: a frame; a traction device connected
to the frame and configured to propel the cold planer; an engine
mounted to the frame and configured to drive the traction device; a
milling drum connected to the frame; a conveyor located adjacent
the milling drum; a first actuator associated with the traction
device and configured to affect at least one of a speed the
traction device and a depth of the milling drum; a second actuator
associated with the milling drum and configured to affect at least
one of rotational speed and the depth of the milling drum; an
operator station supported by the frame at a side opposite the
milling drum; a display disposed in the operator station; an
obstacle detection sensor mounted forward of the milling drum and
being configured to generate a first signal indicative of an object
detected within a work surface; a locating device configured to
generate a second signal indicative of a location of the cold
planer at a time of first signal generation; and a controller in
communication with the obstacle detection sensor, the locating
device, the display, and at least one of the first and second
actuators, the controller being configured to: generate an
electronic map of a work area based on the first and second
signals; and show the electronic map on the display; and
automatically adjust operation of the at least one of the first and
second actuators based on the electronic map.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to a control system
for a cold planer and, more particularly, to a cold planer control
system having obstacle detection and mapping functionality.
BACKGROUND
[0002] Asphalt-surfaced roadways are built to facilitate vehicular
travel. Depending upon usage density, base conditions, temperature
variation, moisture levels, and/or physical age, the surfaces of
the roadways eventually become misshapen and unable to support
wheel loads. In order to rehabilitate the roadways for continued
vehicular use, spent asphalt is removed in preparation for
resurfacing.
[0003] Cold planers, sometimes also called road mills or
scarifiers, are used to break up and remove layers of an asphalt
roadway. A cold planer typically includes a frame propelled by
tracked or wheeled drive units. The frame supports an engine, an
operator's station, a milling drum, and conveyors. The milling
drum, fitted with cutting tools, is rotated through a suitable
interface with the engine to break up the surface of the roadway.
The broken up roadway material is deposited by the milling drum
onto the conveyors for removal from the machine.
[0004] It may be possible, in some situations, for hard objects to
be located within the asphalt material being reclaimed by the cold
planer. When the cutting tools of the milling drum engage these
objects, the cutting tools can he quickly dulled or broken. In some
situations, the objects may be difficult to see and avoid, or even
hidden below the surface of the asphalt material.
[0005] One attempt to increase longevity of a cold planer is
disclosed in U.S. Patent Application No. 2014/0348584 of Fritz et
al. that published on Nov. 27, 2014 ("the '584 publication"). In
particular, the '584 publication discloses a milling machine having
a drum supported from a frame. The '584 publication also discloses
a detection system configured to determine a location of the drum
in an external reference system, a location indicator system
configured to store location information of an. area to be avoided,
and a controller configured to compare the drum location to the
avoidance area location. Based on the comparison, the controller
provides output corresponding to the proximity of the drum to the
avoidance area. The output includes a warning provided to an
operator of the milling machine, and/or automated control (e.g.,
stopping or drum raising) of the milling machine.
[0006] The location indicator system of the '584 publication is
provided with object location information from a field rover. The
field rover is moved to the location of a known object, and an
operator of the rover inputs corner points, outlines, and
clearances associated with the object. This information is then
uploaded to the location indicator system for use in comparison
with the drum location.
[0007] While effective in some applications, the milling machine of
the '584 publication may be less than optimal. Specifically, there
may be situations where the location of the object is unknown
and/or the object is at least partially buried within the asphalt.
In these situations, the field rover may not be able to generate
the object information required by the milling machine for proper
avoidance of the object.
[0008] The control system of the present disclosure solves one or
more of the problems set forth above and/or other problems in the
art.
SUMMARY
[0009] In one aspect, the present disclosure is related to a
control system for a cold planer having a milling drum. The control
system may include an obstacle detection sensor mountable to the
cold planer at a location forward of the milling drum. The obstacle
detection sensor may be configured to generate a first signal
indicative of an object detected within a work surface. The control
system may also include a locating device mountable to the cold
planer and configured to generate a second signal indicative of a
location of the cold planer at a time of first signal generation,
and a controller in communication with the obstacle detection
sensor and the locating device. The controller may be configured to
generate an electronic map of a work area based on the first and
second signals, and to automatically. adjust operation of the cold
planer based on the electronic map.
[0010] In another aspect, the present disclosure is related to a
method of operating a cold planer having a milling drum. The method
may include detecting an object in a work surface being milled by
the milling drum, and determining a location of the cold planer
when the object is detected. The method may further include
generating an electronic map of a work area based on detection of
the object and the location of the cold planer, and automatically
adjusting operation of the cold planer based on the electronic
map.
[0011] In yet another aspect, the present disclosure is directed to
a cold planer. The cold planer may include a frame, a traction
device connected to the frame and configured to propel the cold
planer, and an engine mounted to the frame and configured to drive
the traction device. The cold planer may also include a milling
drum connected to the frame, a first actuator associated with the
traction device and configured to affect at least one of a speed of
the traction device and a depth of the milling drum, and a second
actuator associated with the milling drum and configured to affect
at least one of a rotational speed of the milling drum and the
depth of the milling drum. The cold planer may further include an
operator station supported by the frame at a side opposite the
milling drum, a display disposed in the operator station, an
obstacle detection sensor mounted forward of the milling drum, and
a locating device. The obstacle detection sensor may be configured
to generate a first signal indicative of an object detected within
a work surface. The locating device may be configured to generate a
second signal indicative of a location of the cold planer at a time
of first signal generation. The cold planer may additionally
include a controller in communication with the obstacle detection
sensor, the locating device, the display, and at least one of the
first and second actuators. The controller may be configured to
generate an electronic map of a work area based on the first and
second signals, and to show the electronic map on the display. The
controller may also be configured to automatically adjust operation
of the at least one of the first and second actuators based on the
electronic map.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a cutaway view illustration of an exemplary
disclosed cold planer; and
[0013] FIG. 2 is a diagrammatic illustration of an exemplary
disclosed control system that may be used in conjunction. with the
cold planer of FIG. 1.
DETAILED DESCRIPTION
[0014] For the purpose of this disclosure, the term "asphalt" is
defined as a mixture of aggregate and asphalt cement. Asphalt
cement is a brownish-black solid or semi-solid mixture of bitumens
obtained as a byproduct of petroleum distillation. The asphalt
cement can be heated and mixed with the aggregate for use in paving
roadway surfaces, where the mixture hardens upon cooling. A "cold
planer" is defined as a machine used to remove layers of hardened
asphalt from an existing roadway. It is contemplated that the
disclosed cold planer may also or alternatively be used to remove
cement and other roadway surfaces, or to remove non-roadway surface
material such as in a mining operation.
[0015] FIG. 1 illustrates an exemplary cold planer 10 having a
frame 14 supported by one or more traction devices 16, a milling
drum 12 rotationally supported under a belly of frame 14, and an
engine 18 mounted to frame 14 and configured to drive milling drum
12 and traction devices 16. Traction devices 16 may include either
wheels or tracks connected to actuators 19 that are adapted to
controllably raise and lower frame 14 relative to a ground surface.
It should be noted that, in the disclosed embodiment, raising and
lowering of frame 14 may also function to vary a penetration depth
of milling drum 12 into the ground surface. In some embodiments,
the same or different actuators 19 may also be used to steer cold
planer 10 and or to adjust a travel speed of traction devices 16
(e.g., to speed up or brake traction devices 16), if desired. One
or more additional actuators 20 may be associated with milling drum
12 and configured to adjust a rotational speed and/or the depth of
milling drum 12 independent of, or in conjunction with, actuators
19. A conveyor system 22 may be connected at a leading end to frame
14 and configured to transport material away from milling drum 12
and into a waiting haul vehicle 24.
[0016] Frame 14 may also support an operator station. 26 at a side
opposite milling drum 12. Operator station 26 may house any number
of interface devices 28 used to control cold planer 10. In the
disclosed example, interface devices 28 include, among other
things, a display 28a, a warning device 28b, and an input device
28c (28a-c shown only in FIG. 2). Display 28a may be configured to
render the location of cold planer 10 (e.g., of milling drum 12)
relative to objects 30 found within the surface being milled.
Warning device 28b may be configured to audibly and/or visually
alert the operator of cold planer 10 as to a proximity of milling
drum 12 to objects 30. Input device 28c may be configured to
receive control instructions from the operator of cold planer 10.
Other interface devices (e.g., control devices) may also be
possible, and one or more of the interface devices described above
could be combined into a single interface device, if desired.
[0017] An object detection device ("device") 32 may be mounted to
cold planer 10 at a location forward of milling drum 12, relative
to a normal cutting or working direction. Device 32 may be any type
of device known in the art for detecting a location of objects 30.
In some embodiments, only a 2-D location may be detected. In other
embodiments, a depth of objects 30 within the roadway surface may
also be detected by device 32. For example, device 32 may be a
magnetic field detector having any number of detection sensors
(e.g., magnetometers) 34 arranged across a width of cold planer 10.
In another example, device 32 may be a ground penetrating radar
having any number of detection sensors (e.g., radar receivers) 34.
As will be explained in more detail below, signals generated by
sensors 34 may be used to automatically adjust operation (e.g.,
travel speed, rotational speed, milling depth, etc.) of cold planer
10. Although shown as being connected to conveyor system 22, it is
contemplated that device 32 could alternatively he connected closer
to milling drum 12, for example to a front cover of a drum
enclosure or to frame 14, if desired.
[0018] As illustrated in FIG. 2, a control system 36 may be
associated with cold planer 10 and include elements that cooperate
to map the work area around cold planer 10 and to implement the
automatic adjustments discussed above based on the mapping. These
elements may include actuator 19, actuator 20, interface devices
28, sensors 34, a locating device 38, a communication device 40,
and a controller 42 connected with each of the other elements.
Controller 42 may show the electronic map on display 28a and then
use the electronic map to automatically cause actuators 19 and/or
20 to adjust a travel speed, a drum rotational speed, and/or a
milling depth in order to avoid engagement of milling drum 12 with
objects 30.
[0019] Locating device 38 may be configured to generate a signal
indicative of a geographical position of the cold planer 10
relative to a local reference point, a coordinate system associated
with the work area, a coordinate system associated with. Earth, or
any other type of 2-D or 3-D coordinate system. For example,
locating device 38 may embody an electronic receiver configured to
communicate with one or more satellites, or a local radio or laser
transmitting system used to determine a relative geographical
location of itself. Locating device 38 may receive and. analyze
high-frequency, low-power radio or laser signals from multiple
locations to triangulate a relative 3-D geographical position. A
signal indicative of this geographical position may then be
communicated from locating device 38 to controller 42. The signal
generated by location device 38 may then be correlated with the
object detection signal from sensor 34 (e.g., based on a known
offset distance and/or angle), such that the location of the
detected objects 30 may also be determined and mapped.
[0020] Controller 42 may be configured to manage communications
between cold planer 10 and an offboard entity (e.g., a central
facility or another machine such as a trimming, machine--not
shown). For example, controller 42 may receive signals from sensor
34 and locating device 38, and correlate the signals, filter the
signals, buffer the signals, record the signals, or otherwise
condition the signals before generating the electronic map and
directing the map offboard via communication device 40.
[0021] Communication device 40 may include hardware and/or software
that enables sending and receiving of data messages between.
controller 42 and the offboard entity. The data messages may be
sent and received via a direct data link and/or a wireless
communication link, as desired. The direct data link may include an
Ethernet connection, a connected area network (CAN), or another
data link known in the art, The wireless communications may include
satellite, cellular, infrared, and any other type of wireless
communications that enables communication device 40 to exchange
information.
[0022] Controller 42 may embody a single microprocessor or multiple
microprocessors that include a means for monitoring operator and
sensor input, and responsively adjusting operational
characteristics of cold planer 10 based on the input. For example,
controller 42 may include a memory, a secondary storage device, a
clock, and a processor, such as a central processing unit or any
other means for accomplishing a task consistent with the present
disclosure. Numerous commercially available microprocessors can be
configured to perform the functions of controller 42. It should be
appreciated that controller 42 could readily embody a general
machine controller capable of controlling numerous other machine
functions, Various other known circuits may be associated with
controller 42, including signal-conditioning circuitry,
communication circuitry, and other appropriate circuitry.
Controller 42 may be further communicatively coupled with an
external computer system, instead of or in addition to including a
computer system, as desired.
INDUSTRIAL APPLICABILITY
[0023] The disclosed control system may be used with any cold
planer where object avoidance is important, The disclosed control
system may provide for object avoidance by the associated cold
planer through detecting and mapping out the location of the
object. The disclosed control system may also provide for automated
control of the cold planer based on the mapping, Operation of
control system 36 will now be explained.
[0024] During operation of cold planer 10, sensors 34 may
continuously monitor the work area in front of milling drum 12 to
determine if any objects 30 are present. These objects 30 may be
harder and/or denser than a surrounding environment and, if engaged
by the tools of milling drum 12, could cause damage to milling drum
12. in one example, objects 30 include man-hole covers, pipes,
sewer grates, and rocks. Sensors 34 may generate signals indicative
of changes in magnetic fields and/or reflected energy waves caused
by the inclusion of objects 30. These signals may be directed to
controller 42 for further processing.
[0025] While sensors 34 are generating object detection signals,
locating device 38 may he simultaneously generating location
signals. These signals may be 2-D or 3-D signals, and provide an
indication as to a location of a particular point of cold planer
10. For example, the location signals may be associated with the
location of milling drum 12. Controller 42 may receive the location
signals and correlate the location signals with the object
detection signals. For example, when an object 30 is detected,
controller 42 may determine the location of the object 30 based on
the detected location of milling drum 12 and known kinematics
(e.g., based on a known offset distance. and/or angle of sensors 34
from milling drum 12) of cold planer 10, Controller 42 may then
generate an electronic map of the work area that shows the current
location of milling drum 12 and the location of any detected
objects 30. Controller 42 may continuously update the electronic
map as cold planer 10 moves through the work area.
[0026] Controller 42 may then automatically adjust operation of
cold planer 10 based on the electronic map. For example, controller
42 may automatically adjust a speed of cold planer 10 and/or a
depth of milling drum 12, such that as milling drum 12 approaches a
mapped location of object 30, milling drum 12 may be inhibited from
engagement. In some instances, controller 42 may first alert the
operator of cold planer 10 (e.g., via activation of warning device
28b) before implementing automated functions. For example,
controller 42 may selectively activate warning device 28b based on
a proximity of milling drum 12 to object 30. This may provide the
operator with an opportunity to override the automated functions
(e.g., via input device 28c), if desired. in particular, the
operator may approve of automated avoidance maneuvers or
selectively instruct controller 42 to allow engagement of milling
drum 12 with object 30.
[0027] In some applications, controller 42 may be configured to
automatically classify a particular object 30 as a known object
based on geometry (e.g., a size, shape, density, and/or magnetic
property) detected by sensors 34. For example, when an object 30 is
detected that has a diameter of about two feet, has a round shape,
and is ferrous, controller 42 may compare these features with
corresponding features of known or expected objects and determine
that the detected object 30 is a manhole cover. Controller 42 may
be configured to detect pipes, sewer grates, and other objects in
the same way. In addition, controller 42 may be able to determine
that object 30 is a rock or other type of object when the detected
parameters do not match stored parameters of known objects. When
the detected object 30 is recognized and/or classified as a known
object, the electronic map may be updated to reflect the
classification. For example, corresponding symbols may be placed on
the map at the location of the detected object 30.
[0028] In some applications, controller 42 may vary the type of
control implemented based on the classification of object 30. In
one example, a wide clearance zone may be assigned for use in
controlling milling drum 12 when object 30 is recognized as a first
object type (a manhole cover), and a narrow clearance zone may be
assigned when object 30 is recognized as a second object type (a
sewer grate). in another example, milling drum 12 may be allowed to
chew through object 30 when it is classified as a third type of
object (e.g., a pvc pipe).
[0029] When controlling the movements of cold planer 10 so as to
avoid contact between milling drum 12 and object 30, care should be
taken to remove as much asphalt material from around object 30 as
possible, without causing any damage to the work tools of milling
drum 12. In some instances, this may still leave a significant
amount of material around object 30 that must be removed before
repaving can begin, In. these instances, controller 42 may
communicate the electronic map of objects 30 offboard to another
machine, such as a trimming machine (not shown). The trimming
machine may be more accurately controlled and, thus, more capable
of removing material that is right up against the object 30,
without damaging the machine. In other instances, hand-removal of
the material may be required, and the electronic map may be helpful
in accomplishing this manual task.
[0030] Several advantages may be associated with the disclosed
control system. For example, because sensors 34 may be integrated
into cold planer 10, automated adjustment of cold planer 10 based
on the signals from sensor 34 may allow high-response avoidance of
detected objects 30. In addition, because controller 42 may
generate an electronic map based on the signals from sensors 34,
the map may be communicated offboard for manual use, for use by
other automated machines, and for future reference, Further,
because sensors 34 may be ground penetrating type sensors, in one
embodiment, objects 30 that are not ferrous but that could still
cause damage to cold planer 10 may be detected and avoided.
[0031] It will be apparent to those skilled in the art that various
modifications and variations can be made to the disclosed control
system without departing from the scope of the disclosure. Other
embodiments of the control system will be apparent to those skilled
in the art from consideration of the specification and practice of
the conveyor system disclosed herein. It is intended that the
specification and examples be considered as exemplary only, with a
true scope of the disclosure being indicated by the following
claims and their equivalents.
* * * * *