U.S. patent application number 15/140033 was filed with the patent office on 2017-01-19 for air spring with a sensor arrangement.
The applicant listed for this patent is STEMCO Kaiser Incorporated. Invention is credited to Lutz May.
Application Number | 20170018124 15/140033 |
Document ID | / |
Family ID | 47323875 |
Filed Date | 2017-01-19 |
United States Patent
Application |
20170018124 |
Kind Code |
A1 |
May; Lutz |
January 19, 2017 |
AIR SPRING WITH A SENSOR ARRANGEMENT
Abstract
An air spring (100) for a vehicle is provided. The air spring
comprises a first mounting element (110) for being fixed to a
vehicle's chassis (210), a second mounting element (120) for being
fixed to a movable part (220) of a vehicle being movable with
respect to the chassis, a bellow (130) extending from the first
mounting element to the second mounting element and including an
air volume (140), and a sensor arrangement (150) being arranged
within the air volume. The sensor arrangement is adapted for
sensing at least one of a road condition, a vehicle condition and a
pay load condition.
Inventors: |
May; Lutz; (Berg,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
STEMCO Kaiser Incorporated |
Millington |
MI |
US |
|
|
Family ID: |
47323875 |
Appl. No.: |
15/140033 |
Filed: |
April 27, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14061874 |
Oct 24, 2013 |
9327572 |
|
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15140033 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60G 2206/011 20130101;
G07C 5/085 20130101; B60G 17/019 20130101; B60G 2401/28 20130101;
B60G 11/27 20130101; B60G 17/052 20130101; G07C 5/0816 20130101;
H02J 50/10 20160201; B60G 2400/7122 20130101; B60G 2400/10
20130101; B60G 2202/152 20130101; B60G 2401/904 20130101; B60G
2204/111 20130101; G07C 5/0808 20130101; B60G 2400/05 20130101;
B60G 2206/42 20130101 |
International
Class: |
G07C 5/08 20060101
G07C005/08; H02J 50/10 20060101 H02J050/10; B60G 11/27 20060101
B60G011/27 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 29, 2012 |
EP |
12190374.4 |
Claims
1.-20. (canceled)
21. An air spring system comprising: a first mounting element
adapted for being fixed to a chassis of a vehicle; a second
mounting element adapted for being fixed to a movable part of the
vehicle, wherein said movable part is movable with respect to the
chassis of the vehicle; a bellow extending from the first mounting
element to the second mounting element, wherein the bellow includes
an air volume; a sensor arrangement completely contained within the
air volume, wherein the sensor arrangement comprises a plurality of
sensors; a control unit adapted for receiving sensed signals from
the sensor arrangement; and a wireless power supply adapted for
wireless transfer of power to the sensor arrangement.
22. The air spring system of claim 21, wherein the sensor
arrangement further comprises a transmitter for wirelessly
transmitting sensed data to an external receiving unit.
23. The air spring system of claim 21, wherein the wireless power
supply is adapted for wireless transfer of power from outside of
the air volume to inside of the air volume.
24. The air spring system of claim 23, wherein the wireless power
supply comprises an induction loop, wherein the induction loop is
arranged at an outer surface of the bellow.
25. The air spring system of claim 21, wherein the wireless power
supply is positioned within the air volume of the bellow.
26. The air spring system of claim 25, wherein the wireless power
supply comprises an induction loop, wherein the induction loop is
arranged at an inner surface of the bellow.
27. The air spring system of claim 21, wherein the control unit is
further adapted to conduct a signal profile analysis based on the
sensed signals and correlations thereof.
28. The air spring system of claim 21, wherein: the sensor
arrangement includes a first accelerometer and a second
accelerometer, the first accelerometer is fixedly mounted with
respect to the first mounting element and the second accelerometer
is fixedly mounted with respect to the second mounting element, and
the first accelerometer and the second accelerometer are mounted to
allow a differential mode measurement with respect to the first
accelerometer and the second accelerometer.
29. The air spring system of claim 21, wherein: the sensor
arrangement includes a first gyroscope and a second gyroscope, the
first gyroscope is fixedly mounted with respect to the first
mounting element and the second gyroscope is fixedly mounted with
respect to the second mounting element, and the first gyroscope and
the second gyroscope are mounted to allow a differential mode
measurement with respect to the first gyroscope and the second
gyroscope.
30. The air spring system of claim 21, wherein the plurality of
sensors includes at least one temperature sensor and at least one
microphone.
31. The air spring system of claim 21, wherein the control unit is
further adapted for evaluating the sensed signals upon at least one
of a road condition, a vehicle condition and a payload
condition.
32. The air spring system of claim 21, wherein the control unit is
further adapted for: accumulating the sensor signals from each
sensor arrangement in each air spring on the vehicle; and providing
a status of the vehicle based on the sensor signals from each of
the sensor arrangements in each of the air springs on the
vehicle.
33. The air spring system of claim 21, wherein the control unit is
further adapted for comparing the sensed signals and correlations
thereof with known signal profiles to identify and recognize a
current signal profile.
34. An air spring system comprising: a first mounting element
adapted for being fixed to a chassis of a vehicle; a second
mounting element adapted for being fixed to a movable part of the
vehicle, wherein said movable part is movable with respect to the
chassis of the vehicle; a bellow extending from the first mounting
element to the second mounting element, wherein the bellow includes
an air volume; a sensor arrangement completely contained within the
air volume, wherein the sensor arrangement comprises a plurality of
sensors; a control unit adapted for receiving sensed signals from
the sensor arrangement; and a wireless power supply adapted for
wireless transfer of power to the sensor arrangement wherein the
wireless power supply is positioned within the air volume of the
bellow, wherein the wireless power supply comprises an induction
loop, and wherein the induction loop is arranged at an inner
surface of the bellow.
35. The air spring system of claim 34, wherein the plurality of
sensors comprises at least two different types of sensors, wherein
the at least two different types of sensors are selected from the
group consisting of: a gyroscope, a microphone, a temperature
sensor, an air pressure sensor, and an accelerometer.
36. The air spring system of claim 34, wherein the control unit is
further adapted for: accumulating the sensor signals from each
sensor arrangement in each air spring on the vehicle; and providing
a status of the vehicle based on the sensor signals from each of
the sensor arrangements in each of the air springs on the
vehicle.
37. The air spring of claim 34, wherein the control unit is further
adapted for comparing the sensed signals and correlations thereof
with known signal profiles to identify and recognize a current
signal profile.
38. The air spring system of claim 37, wherein the sensor
arrangement includes a first sensor coupled to the first mounting
element and a second sensor coupled to the second mounting element,
wherein conducting the signal profile includes comparing a
measurement from the first sensor with a measurement from the
second sensor.
39. An air spring system comprising: a first mounting element
adapted for being fixed to a chassis of a vehicle; a second
mounting element adapted for being fixed to a movable part of the
vehicle, wherein said movable part is movable with respect to the
chassis of the vehicle; a bellow extending from the first mounting
element to the second mounting element, wherein the bellow includes
an air volume; a sensor arrangement completely contained within the
air volume, wherein the sensor arrangement comprises a plurality of
sensors; a control unit adapted for receiving sensed signals from
the sensor arrangement; and a wireless power supply adapted for
wireless transfer of power to the sensor arrangement wherein the
wireless power supply is positioned outside of the air volume of
the bellow, wherein the wireless power supply is adapted for
wireless transfer of power from outside of the air volume to inside
of the air volume, wherein the wireless power supply comprises an
induction loop, and wherein the induction loop is arranged at an
outer surface of the bellow.
40. An air spring system comprising: a first mounting element
adapted for being fixed to a chassis of a vehicle; a second
mounting element adapted for being fixed to a movable part of the
vehicle, wherein said movable part is movable with respect to the
chassis of the vehicle; a bellow extending from the first mounting
element to the second mounting element, wherein the bellow includes
an air volume; a sensor arrangement completely contained within the
air volume, wherein the sensor arrangement comprises a plurality of
sensors; a control unit adapted for receiving sensed signals from
the sensor arrangement; and a means for wirelessly transferring
power from a power source external to the air volume to the sensor
arrangement internal to the air volume.
Description
[0001] This application claims benefit of European Patent
Application Serial No. EP 12190374.4, filed on Oct. 29, 2012. The
teachings of European Patent Application EP 12190374.4 are
incorporated herein by reference in their entirety.
TECHNICAL FIELD OF THE INVENTION
[0002] The invention relates to an air spring for a vehicle and to
an air spring system comprising a multitude of air springs.
BACKGROUND OF THE INVENTION
[0003] When aiming for vastly improved transportation and means of
transportation of people and goods (like reduced fuel consumption,
improved comfort, reduced overall cost, extended product life time,
etc.) the machinery that will have to achieve this (trucks, cars,
aircraft, trains, ships, etc.) may increase in complexity and
features.
[0004] Almost every aspect of the "machinery" may have to be
tightly monitored and controlled. Constant adaptations may be
required to optimize the performances and efficiency of almost
every moving part while the operational conditions keep changing
within a short period of time or with every motion of the means of
transportation for an arbitrarily short moving distance.
SUMMARY OF THE INVENTION
[0005] It may be seen as an objective technical problem to provide
an air spring with improved capabilities for supplying physical
parameter measurement equipment. In particular, the physical
parameter measurement equipment may be adapted for acquiring
parameters like suspension height, pneumatic air pressure and
temperature.
[0006] The object of the present invention is solved by the subject
matter of the independent claims, wherein further embodiments are
incorporated in the dependent claims and the following
specification.
[0007] According to an aspect of the invention, an air spring for a
vehicle with a first mounting element for being fixed to a
vehicle's chassis, a second mounting element for being fixed to a
movable part of a vehicle being movable with respect to the
chassis, a bellow extending from the first mounting element to the
second mounting element and including an air volume and a sensor
arrangement being arranged within the air volume is provided,
wherein the sensor arrangement is adapted for sensing at least one
of a road condition, a vehicle condition and a payload
condition.
[0008] The vehicle condition may in particular be a condition of
the vehicle outside the air spring, for example vibrations or
oscillations due to a road surface of the street the vehicle is
using.
[0009] The air spring as described above and hereinafter may
provide in particular a protected and secured mounting position for
the sensor arrangement as it is mounted inside the air volume and
thus protected against external influences such as water, dust,
snow, and mechanical influences caused by uneven surfaces.
[0010] As the first mounting element is being fixed to the
vehicle's chassis and the second mounting element is being fixed to
a movable part, for example to a wheel suspension, being movable
with respect to the chassis, vibrations and oscillations of the
chassis on the one hand and of the wheel on the other hand may be
detected. Thus, the status of the chassis and/or the status of the
wheel and the road may be detected independently from each
other.
[0011] According to an embodiment of the invention, the sensor
arrangement comprises a transmitter for transmitting sensed data to
an external receiving unit, wherein the transmitter operates
wireless.
[0012] A wireless operating transmitting unit allows transmission
of data without the necessity of providing wire bound data
transmission and thus having to provide an opening or a
breakthrough in the housing of the air spring for the wire. The
wireless transmission of data from the transmitter to the receiver
may allow a more solid and low-maintenance air spring due to the
lack of an opening for a wire and thus avoiding the intrusion or
penetration of dust, soil and dirt into the air volume of the air
spring. In an alternative embodiment the transmitter may also
operate wire bound.
[0013] According to a further embodiment of the invention, the
sensor arrangement comprises a sensor in form of a first
accelerometer.
[0014] The accelerometer may be adapted to acquire vibration data
for determining a road surface quality, a tire pressure of the
wheel to which an air spring may be assigned, a horizontal level or
tilting of the vehicle, twisting or bending of the frame structure
or of the chassis. Further, the data received from the
accelerometer may help in order to avoid resonance frequencies of
the chassis and may help to detect and to reduce vibrations and
other driving noises of the vehicle as well as to determine the
dampening factor effectiveness of the air spring.
[0015] According to a further embodiment of the invention, the
sensor arrangement comprises a sensor in form of a second
accelerometer, wherein the first accelerometer is fixedly mounted
with respect to the first mounting element and the second
accelerometer is fixedly mounted with respect to the second
mounting element so as to allow a differential mode measurement
with the first and second accelerometers.
[0016] Thus, when used within a vehicle, the first accelerometer
may determine vibrations of the vehicle's chassis and the second
accelerometer may determine vibrations of the wheel or the wheel
suspension. This structural setup may allow in particular to
determine the dampening effectiveness, as, after a sort, the first
and second accelerometer determine an input vibration, i.e. the
vibration of the wheel suspension caused by the surface of the
road, and an output vibration, i.e. the vibration of the vehicle's
chassis.
[0017] According to a further embodiment of the invention, the
sensor arrangement comprises a multitude of sensors in form of
accelerometers for three dimensions.
[0018] The acceleration in the first dimension may be an
acceleration of a vehicle and in particular of the air spring in
moving direction of the vehicle, i.e. in terms of a moving vehicle
back and forth. The acceleration in the second dimension may be an
acceleration perpendicular to the moving direction, i.e. in terms
of a moving vehicle to the left and to the right. Thus, the first
dimension and the second dimension define a planar surface of a
road the vehicle is moving on. The acceleration in the third
dimension may be acceleration orthogonal to the planar surface
defined by the first and the second dimension, i.e. in terms of a
moving vehicle, this vehicle is moving up or down on an inclined
road.
[0019] All of these acceleration in any one of the dimensions may
be caused by a change of direction of the vehicle as well as by an
uneven surface of the road or due to loads which are not secured in
a suitable manner, i.e. perform unintended movements on a loading
or cargo area.
[0020] According to a further embodiment of the invention, the
sensor arrangement comprises a sensor in form of a first
gyroscope.
[0021] The gyroscope enables determination of change of direction
of the vehicle and/or of the wheel or the wheel suspension. The
gyroscope may as well detect vibrations and oscillations of the
wheel suspension, i.e. of the first mounting element, and of the
chassis, i.e. of the second mounting element. The gyroscope may be
used additionally or optionally to the accelerometer.
[0022] According to a further embodiment of the invention, the
sensor arrangement comprises a sensor in form of a second
gyroscope, wherein the first gyroscope is fixedly mounted with
respect to the first mounting element and the second gyroscope is
fixedly mounted with respect to the second mounting element, so as
to allow a differential mode measurement with the first and second
gyroscopes.
[0023] The gyroscopes may be used additionally or optionally to the
accelerometers and may be adapted to provide an improved
measurement of the vibrations of the first mounting element and the
second mounting element. The above elucidations with respect to the
accelerometers apply in an analog manner to the gyroscopes.
[0024] According to a further embodiment of the invention, the
sensor arrangement comprises a multitude of sensors in form of
gyroscopes for three dimensions.
[0025] One or more gyroscopes may in particular be adapted for
detecting and determining an acceleration, vibration, and/or change
of direction of the first mounting element and/or of the second
mounting element in one of the said three directions,
respectively.
[0026] According to a further embodiment of the invention, the
sensor arrangement comprises a sensor in form of a first
microphone.
[0027] The first microphone may in particular be a body microphone
and may be adapted for detecting body noise and vibration which may
be used to draw conclusions to the road surface, structural
diagnostics, and/or tire pressure. In case the microphone is a body
noise microphone, the signal detection may not be interfered or
disturbed by acoustic noise, i.e. from the surroundings of the air
spring like a vehicle's motor noise or other external acoustic
noise.
[0028] According to a further embodiment of the invention, the
sensor arrangement comprises a sensor in form of a second
microphone, wherein the first microphone is fixedly mounted with
respect to the first mounting element and the second microphone is
fixedly mounted with respect to the second mounting element, so as
to allow a differential mode measurement with the first and second
microphones.
[0029] The explanations given above regarding the first and second
accelerometers and gyroscopes apply in a similar manner to the
first and second microphones, which allow a measurement of noise in
a wheel suspension and a vehicle's chassis, for example.
[0030] According to a further embodiment of the invention, the air
spring comprises a wireless power supply being adapted for wireless
transfer of power from the outside of the air volume to the inside
of the air volume.
[0031] Similar to the transmission of data from the transmitter
being arranged within the air volume to the receiving unit arranged
outside the air volume, the wireless power supply avoids providing
openings in the air spring in order to lead through wires or lines
for the power supply such that the air spring provides a closed air
volume with a reduced number of openings such that the danger of
being intruded with dust or dirt is reduced.
[0032] The wireless power supply may base on the principle of
induction, i.e. the energy is generated when a moving part of the
power supply is moved along a static part, such that the energy is
generated by the said motion. The moving part may be mechanically
attached to the second mounting element such that the motion of the
second mounting element moves the moving part with respect to the
static part and the needed energy is generated. This process may in
particular be kept running when a vehicle with the air spring as
described above and hereinafter moves on.
[0033] Likewise, energy may be transmitted via microwaves from the
outside to the inside of the air volume.
[0034] According to a further embodiment of the invention, at least
one of the first and second mounting element has a mounting opening
and a sensor arrangement carrier, wherein the sensor arrangement
carrier has a sensor mounting portion and an outside portion,
wherein the sensor mounting portion and the outside portion are
separated by a seal line corresponding to the mounting opening, so
that a sensor may be mounted and dismounted within the air
volume.
[0035] The sensor arrangement carrier may be adapted to be used for
opening and closing the air volume when being taken from the
mounting opening and being fitted into the mounting opening,
respectively. Thus, the sensor arrangement carrier performs the
task of carrying the sensor arrangement and closing the air volume.
When being taken from the mounting opening, the sensor arrangement
is taken out of the air volume at the same time and is accessible
in an easy manner for maintenance, for example.
[0036] The seal line may be a rubber lip adapted for sealing the
air volume in a mounted state of the sensor arrangement carrier
such that intrusion of dust, dirt, or the like is reduced or
avoided.
[0037] According to a further aspect of the invention, an air
spring system, and in particular an air spring system for a
vehicle, and in particular for a land vehicle with an air spring as
described above and hereinafter and a control unit is provided,
wherein the control unit is adapted for receiving sensed signals
from the sensor arrangement of the air spring and wherein the
control unit is adapted to evaluate the sensed signals upon at
least one of a road condition, a vehicle condition and a pay load
condition.
[0038] Each of the air springs of the air spring system may be
adapted to damp the vibrations of one wheel or wheel suspension of
a vehicle. The control unit accumulates or joins the sensor signals
of all of the air springs and is thus able to provide an overview
of the vehicle's status. In particular, the load or stress and the
dampening effectiveness of each of the air springs may be detected
in order to obtain an overall status of the vehicle's air spring
system.
[0039] According to an embodiment of the invention, the control
unit is adapted for conducting a signal profile analysis based on
the sensed signals and correlations thereof.
[0040] The sensed signals and correlations thereof may in
particular be compared with known profiles as to identify and
recognize the current signal profile. Such known profiles may be
profiles of inappropriately attached load or inadequately inflated
tires, for example.
[0041] According to a further embodiment of the invention, the air
spring system comprises a plurality of air springs, wherein the
control unit is adapted for conducting a signal profile analysis
based on sensed signals from each air spring of the plurality of
air springs.
[0042] In a similar manner as for one air spring, the signal
profile analysis may be carried out for the signals of a multitude
of air springs and the according signals as well as comparing the
measured signal profiles with known and prior recorded signal
profiles.
[0043] It should be noted that the invention is not limited to the
use of accelerometers, gyroscopes, and microphones. In one
embodiment, any kind of physical parameter sensor may be located
inside of an air spring's air volume, for example earth magnetic
field sensors, mechanical shock sensors, temperature sensors, and
all other acceleration, vibration and motion sensors.
[0044] The output signals of these sensors may be provided to the
control unit or to any other kind of evaluation unit in an
untreated, analogue format or in a processed format, including
using means for digital signal processing.
[0045] These and other aspects of the present invention will become
apparent from and elucidated with reference to the embodiments
described hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] FIG. 1 illustrates an air spring according to an exemplary
embodiment of the invention.
[0047] FIG. 2 illustrates a sensor arrangement for an air spring
according to an exemplary embodiment of the invention.
[0048] FIG. 3 illustrates an air spring according to an exemplary
embodiment of the invention.
[0049] FIG. 4 illustrates a wheel suspension with an air spring
according to an exemplary embodiment of the invention.
[0050] FIG. 5 illustrates an air spring system according to an
exemplary embodiment of the invention.
[0051] FIG. 6A illustrates an air spring according to an exemplary
embodiment of the invention.
[0052] FIG. 6B illustrates an air spring according to an exemplary
embodiment of the invention.
[0053] FIG. 6C illustrates an air spring according to an exemplary
embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0054] FIG. 1 illustrates an air spring 100 with a first mounting
element 110, a second mounting element 120, and a bellow 130. The
first mounting element in form of a top plate, the second mounting
element in form of a bottom plate, and the bellow contain or
include a volume and in particular the air volume 140.
[0055] In an operating mode of the air spring, the top plate and
the bottom plate may move towards each other along the direction
arrow 105 by movements of the bottom plate and/or by movements of
the top plate.
[0056] Inside of the air spring, i.e. within the air volume 140, a
sensor arrangement 150 is located such that a first sensor
arrangement unit 150A is arranged at the first mounting element 110
and a second sensor arrangement unit 150B is arranged at the second
mounting element 120. Both sensor arrangement units may be
functionally linked to each other, i.e. electrically interconnected
and/or share a common data transmission channel for transmitting
and/or receiving signals, data, and information from and to each
other, respectively.
[0057] The first sensor arrangement unit 150A is adapted for
measuring vibrations, oscillations, and/or accelerations of the
first mounting element, i.e. of the top plate, wherein the second
sensor arrangement unit 150B is adapted for measuring vibrations,
oscillations, and/or accelerations of the second mounting element,
i.e. the bottom plate. As both sensor arrangement units 150A, 150B
are located inside the air volume 140 of the air spring 100 and
transmit the measured physical parameters wireless to a receiver
(not shown in FIG. 1) located outside of the air volume, no
wire-bound connection may be led from the air volume outside of the
air spring. Thus, no additional openings for such wires may be
required and the air volume is protected against intrusion of dust,
water, and other dirt particles.
[0058] It should be noted, that the sensor arrangement may comprise
a single sensor arrangement unit mounted to the first mounting
element or the second mounting element as well as a multitude of
sensor arrangement units, of which a plurality of sensor
arrangement units may be mounted to each one of the first mounting
element and the second mounting element.
[0059] Inside of the air volume 140, a wireless power supply 190 is
arranged at the first mounting element for providing electrical
energy to the sensor arrangement 150. The wireless power supply 190
may in particular be an energy receiver for receiving energy
transmitted via microwaves or may base on the principle of
induction, wherein the energy is generated by the movements of the
power supply 190 and/or by the movements of the first mounting
element.
[0060] Alternatively, the power supply may be mounted to the second
mounting element as well as more than one power supply units may be
used. Further, an induction loop may be arranged at an inner
surface or at an outer surface of the bellow 130.
[0061] FIG. 2 illustrates a sensor arrangement 150, and in
particular a sensor arrangement unit, comprising a sensor 155 with
a first accelerometer 156A, a first gyroscope 157A, and a first
microphone 158A, each adapted for measuring physical parameters as
described above and hereinafter. The sensor arrangement further
comprises a transmitter 151 for transmitting data, i.e. the signals
corresponding to the measured physical parameters, to a receiver
270, which may in particular be located outside of the air volume
140 of the air spring 100. The signal transmission is carried out
wireless, which is indicated by arrow 151A.
[0062] The sensor arrangement 150 may comprise any one of the
sensor types named above and hereinafter additionally or optionally
to the first accelerometer 156A, the first gyroscope 157A, and the
first microphone 158A shown in FIG. 2.
[0063] FIG. 3 illustrates another exemplary embodiment of the air
spring, wherein the first mounting element 110 comprises a mounting
opening 160 for providing access to the air volume in case mounting
steps and/or repairing steps have to be carried out. A sensor
arrangement carrier 165 is provided for covering and uncovering the
mounting opening 160, i.e. to close or open the air volume 140,
respectively. In order to bring the sensor arrangement carrier 165
from an uncovering state to a covering state of the mounting
opening 160, the sensor arrangement carrier is to be moved towards
the arrow 169.
[0064] The sensor arrangement carrier 165 comprises a sensor
mounting portion 166 and an outside portion 167, wherein the sensor
mounting portion 166 comprises a surface of the sensor arrangement
carrier 165 directed towards the air volume 140 in the covering
state, and wherein the outside portion comprises a surface of the
sensor arrangement carrier 165 directed opposite to the air volume
in the covering state.
[0065] Further, the sensor arrangement carrier 165 comprises a seal
line 168 which is adapted to seal the air volume against intrusion
of particles from the surroundings of the air springs, i.e. to
tightly close the air volume in the covering state of the sensor
arrangement carrier. The seal line may in particular be a rubber
lip and/or may comprise other plastically and/or elastically
malleable materials.
[0066] A sensor arrangement 150 is mounted to the sensor mounting
portion 166. Thus, when moving the sensor arrangement carrier 165
from the covering state to the uncovering state, a direct access to
the sensor arrangement 150 for maintenance purposes is possible
without the requirement to work inside the air volume. However, an
access to the inside of the air volume is also possible through the
mounting opening, in case a further sensor arrangement unit may be
arranged at the second mounting portion.
[0067] FIG. 4 illustrates a wheel suspension 220 and a vehicle's
chassis 210, which are mechanically linked to each other and have
an air spring 100 for dampening vibrations of the wheel 225 due to
uneven road condition, wherein one of the mounting elements of the
air spring is mounted to the wheel suspension 220 and the other one
of the mounting elements of the air spring is mounted to the
vehicle's chassis 210.
[0068] The wheel suspension 220 may move along the arrow 222 when
the road rolls over an uneven street and, as a result of the
vibrations of the wheel 225 and of the wheel suspension 220, the
mounting elements of the air spring are moving frequently towards
and away from each other like indicated by arrow 105. The air
spring and in particular the air volume within the air spring is
adapted to dampen the vibrations of both the wheel suspension and
the vehicle's chassis as to not transfer or transmit these
vibrations from one of these parts to the other one,
respectively.
[0069] The vibrations of the wheel suspension 220 are detected by
the second accelerometer 156B which is mounted to the bottom plate
of the air spring and the vibrations of the vehicle's chassis 210
are detected by the first accelerometer 156A which is mounted to
the top plate of the air spring.
[0070] Accordingly, the detected signals of the physical parameter
acceleration measured by the first and second accelerometers 156A,
156B are indicated by the signal patterns 159A and 159B. The signal
pattern 159B belongs to the second accelerometer 156B which is
mechanically attached via the bottom plate to the wheel suspension
220 and thus subjected to vibrations caused by an uneven road, for
example. The signal pattern 159A belongs to the first accelerometer
156A which is mechanically attached via the top plate to the
vehicle's chassis 210 and thus subjected to vibrations of the
chassis which are damped or muffled by the air spring.
[0071] The signal pattern 159A is smoothed and damped with respect
to the signal pattern 159B. In other words, the signal pattern 159B
may be considered as an input signal which is to be damped by the
air spring and the signal pattern 159A may be considered as an
output signal transmitted to the vehicle's chassis and caused by
the input signal 159B.
[0072] FIG. 5 illustrates an air spring system 300, comprising four
air springs 100 which transmit the data measured by the sensor
arrangement of each of the air springs to a control unit 310. The
shown link between the air springs and the control unit 310 is a
data link which may be either wire-bound or wireless. The data link
may also be directed from the sensor arrangement of the air springs
directly to the control unit, as well as first transmitted from the
sensor arrangement to a receiving unit as shown in FIG. 2 which
then transmits the data to the control unit.
[0073] The air spring system 300 may be mounted in a vehicle such
that at least one air spring is assigned to one wheel or one wheel
suspension. FIG. 5 illustrates this principle with a four-wheeled
vehicle. It should be understood that the air spring system as
described above and hereinafter may comprise more or less than four
air springs and may also be used in vehicles comprising more or
less than four wheels or wheel suspensions.
[0074] FIGS. 6A, 6B, and 6C illustrate the possible locations of a
sensor arrangement, wherein both the first and second mounting
elements 110, 120 are ring-shaped plates within the air volume of
the air spring.
[0075] According to FIG. 6A, a first sensor arrangement unit 150A,
for example in form of an accelerometer, is located on the first
mounting element 110 which is a ring-shaped top plate within the
air spring. The first mounting element may be adapted for being
attached close to a vehicle's chassis such that a location of the
first sensor arrangement unit close to the chassis may enable
measurement of a resonance frequency of the vehicle's chassis and
measurements due to leveling settings of the vehicle.
[0076] According to FIG. 6B, a second sensor arrangement unit 150B,
for example in form of an accelerometer, is located on the second
mounting element 120. The second mounting element may be adapted
for being attached to a wheel suspension such that the location of
the second sensor arrangement unit close to the wheel suspension
may enable road surface analysis and system diagnosis.
[0077] According to FIG. 6C, a first sensor arrangement unit 150A
and a second sensor arrangement unit 150B, for example each in form
of an accelerometer, are located on the first mounting element and
the second mounting element, respectively. When operated separate
from each other, i.e. each sensor arrangement unit individually,
the sensor arrangement units may be operated as described in
connection with FIGS. 6A, 6B. Furthermore, when comparing the
measured signals from the sensor arrangement units, a differential
mode measurement may be enabled.
[0078] In particular, the first sensor arrangement unit 150A and
the second sensor arrangement unit 150B may be arranged such that
the move directly towards each other in case the bottom plate moves
towards the top plate, i.e. the sensor arrangement units 150A, 150B
have a common moving axis parallel to the moving direction of the
top plate and the bottom plate in an operating state of the air
spring. In other words, in one exemplary embodiment the first and
the second sensor arrangement unit may not have any lateral
displacement or misalignment, i.e. the first sensor arrangement and
the second sensor arrangement are with respect to the moving
direction of the top and bottom plate above/below each other.
[0079] The sensor arrangement may be placed either at a top of the
air spring or at the bottom. When differential signal measurements
are required or signal comparisons then the sensor arrangement may
be placed at both the top and the bottom (like when calculating the
damping factor or when trying to reduce vehicle vibrations caused
by the combinations of the effects from the road surface, vehicle
speed, and tire pressure, for example).
[0080] The wheel of a vehicle is mechanically connected to the
bottom part of an air spring. The frame-work of the vehicle's
chassis is resting at the top of the air spring unit. In this
specific example two accelerometer sensor units are mounted in the
top (Ay) and bottom part (By) of the Air-Spring unit mechanics.
When the vehicle is rolling over a road covered with gravel, then a
certain type of "vibration"-noise signal will be generated by the
Accelerometer By. The vibration type of signal is mainly caused by
the uneven road (road is not smooth). The accelerometer sensor Ay
that is mounted near to the vehicle's chassis structure (in the top
part of the air spring) will be muffled and dampened in comparison
to the signal from By. Of course, in a standard suspension system a
shock absorber is used as well, but is not discussed here any
further. Driving over a smooth road surface will result in a far
less noisy signal. Each of the two signals can be analyzed on its
own (By, and Ay), or they can be compared to each other (building
the differential-signal) depending on the objective of the signal
analysis.
[0081] The information required to make definite and reliable
statements about the measured physical parameters may be measured
either directly (like the absolute axle tilting of the vehicle),
indirectly through data-comparison (like the bending of the trailer
main platform: differential signal by comparing the values of at
least two gyroscopes placed at two different locations on the
vehicle), or by advances signal analysis (like when determine the
tire air pressure or the axle bearing performance: signal profile
and signal frequency spectrum).
[0082] The air spring as described above and hereinafter may
integrate a specific sensor array, i.e. sensor arrangement, onto
already existing electronics of an air spring solution and may use
an on-board computer for the processing of the signals from this
sensor array.
[0083] The sensor arrangement may be placed at the most ideal
location for the intended measurement: where the forces coming from
the wheels and the axles act onto the main-system-frame (chassis,
for example). The fast amount of additional measurement information
will then be made available through one-and-the-same electrical
connector that an air spring unit may already have or which is to
be provided. The sensor arrangement may not require an additional
housing and protection from the environment as it is placed onto an
electronics board within the air volume of the air spring.
[0084] Depending on the physical parameters that have to be
detected and measured and depending on the targeted signal quality,
a number of different sensor types may be installed into the
structure of the air spring. The minimum of recommended sensors to
install may be 2 (accelerometers) at the top and bottom of the
Air-Spring unit, respectively, and the advisable maximum number of
sensors may be 12.
[0085] The possible combination of the sensor arrangement that may
be installed in one air spring may be relatively high (>40).
Some types of sensors may be categorized as "optional", like a
temperature sensor, an air pressure sensor, and a microphone. For
an overview of the exemplary sensors, Table 1 is provided. These
sensors may be placed elsewhere in a vehicle and may not have to be
placed in or near the air spring. However, in case the air spring
has already an electronic data acquisition system and a
digital-serial bus interface included, it may be reasonable to add
these "optional" sensors.
[0086] In most simple terms, the sensor arrangement or sensor
arrays as described above and hereinafter, may be placed and
mounted inside of the mechanics of the air spring, and can be
placed and mounted from the outside of the air spring. The sensor
arrangement has to be firmly attached to the mechanical structure
of the air spring (the bottom piston or/and the top plate, also
called the upper bit). The term "firmly" attached means that a good
mechanical signal transfer has to be achieved as otherwise the
electrical output signal from the sensor will be distorted, damped,
and of poor quality. When mounting the sensors inside the air
spring, i.e. within the air volume, the sensor arrangement cannot
be seen from the outside, may be better protected from the
environments (water, dust, and stones, others . . . ). In reverse,
when mounting the sensor arrangement from the outside of the air
volume, then they can be retro fitted, can be more easily
maintained, repaired and serviced.
[0087] A signal processing stage for improving the signal quality
may include the following features: automatic compensation of
unwanted effects caused by changes of the environmental operating
conditions, like temperature and supply voltage; signal filtering
stages to improve the signal-to-noise ratio which may be built
using discrete passive and/or active components, using advanced
analogue filter ICs, programmable digital filter IC, or software
operated digital filter systems (using a microprocessor, for
example); customisation of the signal output format (analogue,
serial digital, . . . ), wherein typical serial-digital signal
interfaces may be formats like RS232, RS485, CAN, Lin Bus, Basic
CAN; advanced methods to reduce or even to eliminate the unwanted
effects of electro-magnetic interferences (often called: EMI),
which may include also certain types of differential mode signal
processing, frequency hopping, and plausibility signal analysis;
signal frequency spectrum analyser functions when aiming to provide
a signal-profile analysis (for diagnostic purposes, for example).
Most likely, an advanced signal processing function may require the
use of a micro-controller (for example in the form of a single chip
RISC processor, or a low cost DSP).
TABLE-US-00001 TABLE 1 Measurement Number of Orientation and
Importance/ sensors that Sensor Device Purpose Explanations
Priority could be used Accelerometer X axis Measuring in driving
Accelerating and 3 1 direction (horizontal) decelerating forces
Accelerometer Y axis Measuring in vertical Vibrations caused by 1
2-differential direction road surface, Tire mode Pressure,
Diagnostics, Resonances Accelerometer Z axis Measuring in
left-right Centrifugal forces/ 2 1 direction (horizontal) curves
Gyro X Axis Measuring in driving Allows vector 3 1 direction
(horizontal) calculations Gyro Y Axis Measuring in vertical Vehicle
leveling/tilting 2 2-differential direction in two axis/structural
mode warping Gyro Z Axis Measuring in left-right Allows vector 3 1
direction (horizontal) calculations Microphone Measuring body Road
Surface, Structural Optional/Cost 1 noise/vibration Diagnostics,
Tire reduction pressure Temperature Air Temperature Assists in
calculating Air Optional 1 (outside) Pressure, Diagnostics
Temperature (inside) Compressed Air Assists in calculating Air
Optional 1 Temperature Pressure, Diagnostics Pressure Compressed
Air Optional 1 Pressure Advisable Max number of sensors per
Air-Spring 1
LIST OF REFERENCE NUMERALS USED IN THE DRAWINGS
[0088] 100 air spring [0089] 105 suspension direction [0090] 110
first mounting element [0091] 120 second mounting element [0092]
130 bellow [0093] 140 air volume [0094] 150 sensor arrangement
[0095] 150A first sensor arrangement unit [0096] 150B second sensor
arrangement unit [0097] 151 transmitter [0098] 151A wireless
transmission path [0099] 155 sensor [0100] 156A first accelerometer
[0101] 156B second accelerometer [0102] 157A first gyroscope [0103]
157B second gyroscope [0104] 158A first microphone [0105] 158B
second microphone [0106] 159A first signal pattern [0107] 159B
second signal pattern [0108] 160 mounting opening [0109] 165 sensor
arrangement carrier [0110] 166 sensor mounting portion [0111] 167
outside portion [0112] 168 seal line [0113] 169 mounting direction
[0114] 190 wireless power supply [0115] 210 vehicle's chassis
[0116] 220 movable part of the vehicle's chassis, wheel suspension
[0117] 222 moving direction [0118] 225 wheel [0119] 300 air spring
system [0120] 310 control system
[0121] This application claims benefit of European Patent
Application Serial No. EP 12190374, filed on Oct. 29, 2012. While
certain representative embodiments and details have been shown for
the purpose of illustrating the subject invention, it will be
apparent to those skilled in this art that various changes and
modifications can be made therein without departing from the scope
of the subject invention.
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