System and method for diagnosing a suspension

Abstract

The present invention relates to systems and methods for diagnosing a suspension. A method of diagnosing a vehicle suspension includes applying a first sequence of forces on a first axle suspension and measuring a first response of the first axle suspension to the first sequence of forces using at least one sensor on the vehicle. The method also includes applying a second sequence of forces on the first axle suspension and measuring a second response of the first axle suspension to the second sequence of forces using the at least one sensor on the vehicle, and measuring a dynamic response of the first axle suspension when one of the first sequence of forces or the second sequence of forces is released. The method further includes determining a condition of the first axle suspension based on at least one of the first response, the second response, or the dynamic response.

Description

Technical Field

[0001] This disclosure generally relates to vehicle suspension diagnostic systems and methods. More specifically, this disclosure relates to an integrated system and method for performing comprehensive diagnostics on a vehicle suspension system. Background Technology

[0002] Diagnosing suspension problems in a vehicle typically involves a mechanic test-driving the vehicle and identifying issues by listening to sounds or observing the vehicle's response when encountering obstacles. However, reproducing certain noises or vehicle responses reported by the owner can be challenging. This can lead to misdiagnosis or the replacement of unnecessary parts. Summary of the Invention

[0003] This document discloses a method for diagnosing a suspension on a vehicle. The method includes: applying a first force sequence to a first axle suspension and measuring a first response of the first axle suspension to the first force sequence using at least one sensor on the vehicle. The method further includes: applying a second force sequence to the first axle suspension and measuring a second response of the first axle suspension to the second force sequence using at least one sensor on the vehicle; and measuring a dynamic response of the first axle suspension when one of the first or second force sequences is released. The method also includes: determining the state of the first axle suspension based on at least one of the first response, the second response, or the dynamic response.

[0004] In one aspect of this disclosure, an active anti-roll bar is used to apply a first sequence of forces, the active anti-roll bar applying a first pair of opposing forces to a first axle suspension along a first pair of rotational directions.

[0005] In one aspect of this disclosure, an active anti-roll bar is used to apply a second force sequence, the active anti-roll bar applying a second pair of opposing forces to the first axle suspension in a second pair of rotational directions opposite to the first pair of rotational directions.

[0006] In one aspect of this disclosure, the active anti-roll bar includes a drive motor configured to rotate a first portion of the active anti-roll bar independently of a second portion of the active anti-roll bar.

[0007] In one aspect of this disclosure, a first portion of the active anti-roll bar is mechanically connected to a first suspension corner of the first axle suspension via a first end link, and a second portion of the active anti-roll bar is connected to a second corner of the first axle suspension via a second end link.

[0008] In one aspect of this disclosure, a first pair of hydraulic actuators are used to apply a first force sequence and a second force sequence, each of the first pair of hydraulic actuators being mechanically connected to an opposite corner of a first axle suspension.

[0009] In one aspect of this disclosure, the dynamic response includes a first dynamic response when a first force sequence is released and a second dynamic response when a second force sequence is released.

[0010] In one aspect of this disclosure, at least one sensor includes a pair of ride height sensors configured to measure suspension travel at opposite corners of the first axle suspension.

[0011] In one aspect of this disclosure, the method includes identifying a broken end link when the suspension travel measured using at least one sensor is less than a predetermined suspension travel.

[0012] In one aspect of this disclosure, at least one sensor includes an inertial measurement unit configured to measure the roll angle and lateral acceleration of the vehicle.

[0013] In one aspect of this disclosure, the method includes identifying a worn damper when the lateral acceleration damping of the vehicle is less than a predetermined damping threshold.

[0014] In one aspect of this disclosure, when the peak lateral acceleration exceeds a predetermined peak lateral acceleration threshold, the state is determined to be that the suspension component is not functioning.

[0015] This document discloses a non-transitory computer-readable storage medium containing programming instructions that, when executed by a processor, can be used to perform a method. The method includes: applying a first force sequence to a first axle suspension of a vehicle and measuring a first response of the first axle suspension to the first force sequence using at least one sensor on the vehicle. The method further includes: applying a second force sequence to the first axle suspension, measuring a second response of the first axle suspension to the second force sequence using at least one sensor on the vehicle, and measuring a dynamic response of the first axle suspension when one of the first or second force sequences is released. The method also includes: determining a state of the first axle suspension based on at least one of the first response, the second response, or the dynamic response.

[0016] This document discloses a vehicle. The vehicle includes: a body defining a passenger compartment; a first suspension corresponding to a first axle and configured to support the body; a second suspension corresponding to a second axle and configured to support the body; a first suspension actuator associated with the first axle; a second suspension actuator associated with the second axle; and at least one sensor configured to measure movement of the first axle, the second axle, or the body. The vehicle also includes a controller that communicates with the first suspension actuator, the second suspension actuator, and the at least one sensor. The controller is configured to apply a first force sequence to the first axle suspension and measure a first response of the first axle suspension to the first force sequence using at least one sensor on the vehicle. The controller is further configured to apply a second force sequence to the first axle suspension, measure a second response of the first axle suspension to the second force sequence using at least one sensor on the vehicle, and measure a dynamic response of the first axle suspension when one of the first or second force sequences is released. The controller is also configured to determine a state of the first axle suspension based on at least one of the first response, the second response, or the dynamic response.

[0017] The present invention provides the following technical solutions.

[0018] Technical Solution 1. A method for diagnosing the suspension of a vehicle, the method comprising:

[0019] A first force sequence is applied to the first axle suspension;

[0020] The first response of the first axle suspension to the first force sequence is measured using at least one sensor on the vehicle.

[0021] A second force sequence is applied to the first axle suspension;

[0022] The first axle suspension is measured in response to the second force sequence using at least one sensor on the vehicle.

[0023] When one of the first force sequence or the second force sequence is released, the dynamic response of the first axle suspension is measured; and

[0024] The state of the first axle suspension is determined based on at least one of the first response, the second response, or the dynamic response.

[0025] Technical Solution 2. The method according to Technical Solution 1, wherein an active anti-roll bar is used to apply the first force sequence, and the active anti-roll bar applies a first pair of opposing forces to the first axle suspension along a first pair of rotational directions.

[0026] Technical Solution 3. The method according to Technical Solution 2, wherein the active anti-roll bar is used to apply the second force sequence, and the active anti-roll bar applies a second pair of opposing forces to the first axle suspension along a second pair of rotation directions opposite to the first pair of rotation directions.

[0027] Technical Solution 4. The method according to Technical Solution 3, wherein the active anti-roll bar includes a drive motor, the drive motor being configured to rotate the first part of the active anti-roll bar independently of the second part of the active anti-roll bar.

[0028] Technical Solution 5. The method according to Technical Solution 4, wherein a first portion of the active anti-roll bar is mechanically connected to a first suspension corner of the first axle suspension via a first end link, and a second portion of the active anti-roll bar is connected to a second corner of the first axle suspension via a second end link.

[0029] Technical Solution 6. The method according to Technical Solution 1, wherein the first force sequence and the second force sequence are applied using a first pair of hydraulic actuators, each of the first pair of hydraulic actuators being mechanically connected to an opposite corner of the first axle suspension.

[0030] Technical Solution 7. The method according to Technical Solution 1, wherein the dynamic response includes a first dynamic response when the first force sequence is released and a second dynamic response when the second force sequence is released.

[0031] Technical Solution 8. The method according to Technical Solution 1, wherein the at least one sensor includes a pair of ride height sensors configured to measure suspension travel at opposite corners of the first axle suspension.

[0032] Technical Solution 9. The method according to Technical Solution 8, which includes identifying a broken end link when the suspension travel measured using the at least one sensor is less than a predetermined suspension travel.

[0033] Technical Solution 10. The method according to Technical Solution 1, wherein the at least one sensor includes an inertial measurement unit configured to measure the roll angle of the vehicle and the lateral acceleration of the vehicle.

[0034] Technical Solution 11. The method according to Technical Solution 10, which includes identifying a worn damper when the lateral acceleration damping of the vehicle is less than a predetermined damping threshold.

[0035] Technical Solution 12. The method according to Technical Solution 10, wherein when the peak value of lateral acceleration exceeds a predetermined peak value of lateral acceleration threshold, the state includes being determined as the suspension component is not functioning.

[0036] Technical Solution 13. A non-transitory computer-readable storage medium comprising programming instructions that, when executed by a processor, are operable to perform a method comprising:

[0037] A first sequence of forces is applied to the first axle suspension of the vehicle;

[0038] The first response of the first axle suspension to the first force sequence is measured using at least one sensor on the vehicle.

[0039] A second force sequence is applied to the first axle suspension;

[0040] The first axle suspension is measured in response to the second force sequence using at least one sensor on the vehicle.

[0041] When one of the first force sequence or the second force sequence is released, the dynamic response of the first axle suspension is measured; and

[0042] The state of the first axle suspension is determined based on at least one of the first response, the second response, or the dynamic response.

[0043] Technical Solution 14. The non-transitory computer-readable storage medium according to Technical Solution 13, wherein the first force sequence is applied using an active anti-roll bar, the active anti-roll bar applying a first pair of opposing forces to the first axle suspension along a first pair of rotational directions.

[0044] Technical Solution 15. The non-transitory computer-readable storage medium according to Technical Solution 14, wherein the second force sequence is applied using the active anti-roll bar, the active anti-roll bar applying a second pair of opposing forces to the first axle suspension along a second pair of rotational directions opposite to the first pair of rotational directions.

[0045] Technical Solution 16. The non-transitory computer-readable storage medium according to Technical Solution 15, wherein the active anti-roll bar includes a drive motor configured to rotate a first portion of the active anti-roll bar independently of a second portion of the active anti-roll bar, and the first portion of the active anti-roll bar is mechanically connected to a first suspension corner of the first axle suspension via a first end link, and the second portion of the active anti-roll bar is connected to a second corner of the first axle suspension via a second end link.

[0046] Technical Solution 17. A vehicle comprising:

[0047] The vehicle body is limited to the passenger compartment;

[0048] A first suspension corresponding to the first axle and configured to support the vehicle body;

[0049] A second suspension corresponding to the second axle and configured to support the vehicle body;

[0050] A first suspension actuator associated with the first axle;

[0051] The second suspension actuator associated with the second axle;

[0052] At least one sensor configured to measure movement of the first axle, the second axle, or the vehicle body;

[0053] A controller that communicates with the first suspension actuator, the second suspension actuator, and the at least one sensor, wherein the controller is configured to:

[0054] A first sequence of forces is applied to the first axle suspension;

[0055] The first response of the first axle suspension to the first force sequence is measured using at least one sensor on the vehicle.

[0056] A second force sequence is applied to the first axle suspension;

[0057] The first axle suspension is measured in response to the second force sequence using at least one sensor on the vehicle.

[0058] When one of the first force sequence or the second force sequence is released, the dynamic response of the first axle suspension is measured; and

[0059] The state of the first axle suspension is determined based on at least one of the first response, the second response, or the dynamic response.

[0060] Technical Solution 18. The vehicle according to Technical Solution 17, wherein an active anti-roll bar is used to apply the first force sequence, the active anti-roll bar applying a first pair of opposing forces to the first axle suspension along a first pair of rotational directions.

[0061] Technical Solution 19. The vehicle according to Technical Solution 18, wherein the second force sequence is applied using the active anti-roll bar, the active anti-roll bar applying a second pair of opposing forces to the first axle suspension along a second pair of rotational directions opposite to the first pair of rotational directions.

[0062] Technical Solution 20. The vehicle according to Technical Solution 19, wherein the active anti-roll bar includes a drive motor configured to rotate a first portion of the active anti-roll bar independently of a second portion of the active anti-roll bar, and the first portion of the active anti-roll bar is mechanically connected to a first suspension corner of the first axle suspension via a first end link, and the second portion of the active anti-roll bar is connected to a second corner of the first axle suspension via a second end link. Attached Figure Description

[0063] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the present disclosure and, together with the specification, explain the principles of the present disclosure.

[0064] Figure 1 A vehicle with a system for performing vehicle suspension diagnostics is illustrated schematically.

[0065] Figure 2 This is a flowchart of a method for performing vehicle suspension diagnostics.

[0066] Figure 3 The diagram shows... Figure 1 A graphical representation of the vehicle's roll angle relative to the applied torque.

[0067] Figure 4 The diagram shows... Figure 1 A graphical representation of the dynamic response of a vehicle's roll angle after being damped by the vehicle's suspension.

[0068] Figure 5 The figure illustrates a graphical representation of the Fast Fourier Transform (FFT) based on the output of the Inertial Measurement Unit (IMU). Detailed Implementation

[0069] Those skilled in the art will recognize that terms such as “above,” “below,” “upward,” “downward,” “top,” “bottom,” “left,” and “right” are used only to describe the drawings and do not imply a limitation on the scope of this disclosure, as defined by the appended claims. Furthermore, the teachings may be described herein in the form of functional and / or logical block components and / or various processing steps.

[0070] Figure 1An example of a vehicle 10 including a body 12 is illustrated, which defines a passenger compartment supported by a pair of front wheels 16 and a pair of rear wheels 18. A steering system 14 includes a steering wheel 14H configured to form a road angle with the pair of front wheels 16, allowing selective steering of the vehicle 10 in a desired direction via a steering rack 14R. The pair of front wheels 16 are mechanically connected to a front axle suspension 20 having a left front corner suspension 20FL and a right front corner suspension 20FR. The pair of rear wheels 18 are mechanically connected to a rear axle suspension 22 having a left rear corner suspension 22RL and a right rear corner suspension 22RR. In this disclosure, the front axle suspension 20 and the rear axle suspension 22 may comprise independent suspensions or live axle suspensions, depending on the type of vehicle 10.

[0071] The front axle suspension 20 includes a first active anti-roll bar 30 having a first portion 30-1 and a second portion 30-2. The first portion 30-1 is attached to the left front corner suspension 20FL via a first end link 32-1, and the second portion 30-2 is attached to the right front corner suspension 20FR via a second end link 32-2. The first portion 30-1 and the second portion 30-2 are mechanically connected to an actuator 33 having a gearbox 34 driven by at least one drive motor 36, allowing the first portion 30-1 and the second portion 30-2 to move or rotate independently of each other. This allows the vehicle 10 to actively control the front axle suspension 20 during vehicle roll, as will be discussed in more detail below.

[0072] The left front suspension corner 20FL includes a left front suspension component 38FL that connects the sprung mass of the vehicle body 12 to the unsprung mass of a corresponding one of the pair of front wheels 16. The right front suspension corner 20FR includes a right front suspension component 38FR that connects the unsprung mass of the vehicle body 12 to a corresponding one of the pair of front wheels 16. The left suspension component 38FL and the right suspension component 38FR have spring stiffness and provide damping. In this disclosure, the left suspension component 38FL and the right suspension component 38FR may include at least one of a shock absorber and spring, strut, hydraulic actuator, or other combination of suspension components that provide spring stiffness and damping. In particular, this disclosure applies to hydraulic actuators that can raise or lower opposite sides of the vehicle 10, as will be discussed in more detail below.

[0073] The rear axle suspension 22 includes a second active anti-roll bar 40 having a first portion 40-1 and a second portion 40-2. The first portion 40-1 is attached to the left rear corner suspension 22RL via a first end link 42-1, and the second portion 40-2 is attached to the right rear corner suspension 22RR via a second end link 42-2. The first portion 40-1 and the second portion 40-2 are mechanically connected to an actuator 43 having a gearbox 44 driven by at least one drive motor 46, allowing the first portion 40-1 and the second portion 40-2 to move or rotate independently of each other. This allows the vehicle 10 to actively control the roll of the rear axle suspension 22 during vehicle roll conditions, as will be discussed in more detail below.

[0074] The left rear suspension corner 22RL includes a right rear suspension component 48RL that connects the sprung mass of the vehicle body 12 to the unsprung mass of a corresponding rear wheel of the pair of rear wheels 18. The right rear suspension corner 22RR includes a right rear suspension component 48RR that connects the unsprung mass of the vehicle body 12 to a corresponding rear wheel of the pair of rear wheels 18. The left rear suspension component 48RL and the right rear suspension component 48RR have spring stiffness and provide damping. In this disclosure, the left rear suspension component 48RL and the right rear suspension component 48RR may include at least one of a shock absorber and spring, strut, hydraulic actuator, or other combination of suspension components that provide spring stiffness and damping. In particular, this disclosure applies to hydraulic actuators that can raise or lower opposite sides of the vehicle 10, as will be discussed in more detail below.

[0075] Vehicle 10 includes an ECU 60 for controlling various operations of the vehicle, including actuating drive motors 36 or 46 on the front active anti-roll bar 30 and the rear active anti-roll bar 40, respectively, to control the roll of the body 12 during vehicle 10 operation. The ECU 60 also communicates electrically with an inertial motion unit (IMU) 62 and ride height sensors 64 at each corner of vehicle 10 to measure suspension height changes at each suspension corner of vehicle 10, respectively.

[0076] In this disclosure, the ECU 60 may be equipped with one or more processors (P) (such as logic circuits, combinational logic circuits, application-specific integrated circuits (ASICs), electronic circuits, central processing units (CPUs), semiconductor integrated circuits (ICs), etc.), as well as input / output (I / O) circuits, appropriate signal conditioning and buffering circuits, and additional components such as a high-speed clock. The ECU 60 also includes a non-transitory computer-readable storage medium (i.e., memory (M)), which encompasses read-only memory, programmable read-only memory, random access memory, hard disk drives, etc., and may be resident memory, remote memory, or a combination of both. The memory M may contain instructions for performing the method 100 discussed below.

[0077] Figure 2 The illustration shows an example method 100 for performing suspension diagnostics on vehicle 10. Method 100 begins at block 102 (“Start”). In one example, method 100 begins when a technician performing suspension diagnostics on vehicle 10 puts vehicle 10 into diagnostic mode. While vehicle 10 is in diagnostic mode, its driving performance may be limited until the suspension diagnostics are complete and vehicle 10 exits diagnostic mode. After the suspension diagnostics begin at block 102, method 100 continues to block 104.

[0078] In block 104 (“Vehicle Attitude?”), method 100 determines whether the attitude of vehicle 10 is within a predetermined range of values. For example, method 100 may utilize IMU 62 to determine whether the tilt and yaw angle of vehicle 10 are within predetermined acceptable ranges. A feature of ensuring the attitude of vehicle 10 is within the predetermined acceptable range is ensuring a common starting point is obtained for analyzing the acquired measurements, as discussed in more detail below. This improves the reliability of the diagnosis by keeping vehicle 10 level to compare actual vehicle movement with predicted vehicle movement. Additionally, technicians can confirm that there are no loose items in vehicle 10 (such as a spare tire) and that the fuel tank is full to maintain consistency between tests.

[0079] If the vehicle attitude is not within the predetermined range, method 100 proceeds to block 106 (“Repositioning the Vehicle”) and instructs a technician to reposition the vehicle 10 to ensure that the tilt and yaw are within the predetermined acceptable range. Method 100 can then re-verify the vehicle's attitude at the new position at block 104. If the vehicle attitude is within the predetermined acceptable range, method 100 continues to block 108.

[0080] In block 108 (“Verifying the Surrounding Environment”), method 100 requires a technician performing suspension diagnostics to verify that vehicle 10 is spaced at least a predetermined distance from other objects (such as other vehicles or people). When the technician confirms that vehicle 10 is spaced at the predetermined distance from other objects or people, method 100 proceeds to block 110.

[0081] In block 110 (“Applying the First Force Sequence”), method 100 applies opposing forces to the corners of the suspension being diagnosed (such as front axle suspension 20 or rear axle suspension 22). In this disclosure, the suspension corresponding to each axle on the vehicle is tested one at a time. A feature of this testing method is avoiding the application of reaction forces between the axles on vehicle 10. In one example, the first force sequence is applied to the suspension being diagnosed using a corresponding one of active anti-roll bars 30 or 40. Method 100 applies the first force sequence by means of the front active anti-roll bar 30 or the rear active anti-roll bar 40 by sending control signals to drive motors 36 and 46 via controller 60 to rotate the first portion 30-1 or 40-1 in the opposite direction to the second portion 30-2 or 40-2, respectively, to initiate testing for a given suspension. This creates opposing forces between the suspension corners. The first force sequence includes a first time period during which the forces increase in opposite directions before reaching maximum force at each opposing suspension corner.

[0082] In another example, hydraulic actuators, acting as suspension components 38 and 48, are used to apply a first force sequence to the front axle suspension 20 and the rear axle suspension 22, respectively. The hydraulic actuators raise one of the suspension corners of the diagnosed suspension while lowering the other, to generate relative forces between the suspension corners on the front axle suspension 20 or the rear axle suspension 22. Once the first force sequence is complete, method 100 proceeds to block 112.

[0083] In block 112 (“Measurement of First Response”), method 100 analyzes data from sensors on vehicle 10, such as ride height sensor 64 or IMU 62 associated with the diagnosed axle, when the first force sequence is applied and fully applied. IMU 62 is characterized in that, in addition to measuring the change in lateral acceleration of vehicle 10 when the first force sequence is applied, it also measures the amount of roll experienced by vehicle 10 during the application of the first force sequence.

[0084] Figure 3 This is a graphical representation 200 of the vehicle roll angle measured by IMU 62 with respect to the input torque applied during the first force sequence. The x-axis of the graphical representation 200 includes the torque (τ), and the y-axis includes the roll angle in degrees. The graphical representation includes: a first region 202, which has a roll angle with an acceptable gradient relative to the input torque; a second region 204, which has a gradient exceeding the limit; and a third region 206, where the roll angle produced by the input torque is insufficient. When the result is in the first region 202, this may indicate damage to a suspension component (such as a spring); when the result is in the third region, this may indicate damage to the end link 32. After a response is measured, method 100 proceeds to block 114.

[0085] In block 114 (“Applying the Second Force Sequence”), a second force sequence is applied to the suspension being diagnosed. In one example, the second force sequence is applied to the suspension being diagnosed using a corresponding active anti-roll bar 30 or 40. Method 100 applies the second force sequence via the front active anti-roll bar 30 or the rear active anti-roll bar 40 by sending a control signal from controller 60 to drive motor 36 or 46 to rotate the first portion 30-1 or 40-1 in the opposite direction to the second portion 30-2 or 40-2, respectively. This creates opposing forces between the suspension corners. The second force sequence includes a second time period during which the force increases at each opposing suspension corner before reaching its maximum force in the opposite direction to the first force sequence. Method 100 then proceeds to block 116.

[0086] In block 116 (“Measuring the Second Response”), method 100 analyzes data from sensors on vehicle 10, such as ride height sensor 64 or IMU 62 associated with the diagnosed axle, when the second force sequence is applied or fully applied. As discussed above with respect to block 112, IMU 62 is characterized in that, in addition to measuring the change in lateral acceleration of vehicle 10 when the second force sequence is applied, it also measures the amount of roll experienced by vehicle 10 when the second force sequence is applied. After measuring the second response, method 100 proceeds to block 118.

[0087] In block 118 (“Release Torque”), method 100 instructs the components applying the second force sequence to release the torque, such as releasing the torque to zero within a predetermined time. This allows vehicle 10 to experience a dynamic response. Method 100 then proceeds to block 120.

[0088] In block 120 (“Measuring Dynamic Response”), method 100 measures the dynamic response after the torque is released in block 118 and the vehicle 10 transitions to a steady-state condition. The dynamic response is measured when the maximum force applied under the first or second force sequence is released, causing the suspension on the vehicle 10 to return to a steady state. As part of block 112, the dynamic response can also be measured after the release of the first force sequence. In this case, at least one sensor (such as IMU 62) measures the roll change of the vehicle 10 until this change is damped to a steady state.

[0089] Figure 4 The figure illustrates the roll angle of vehicle 10 along the y-axis. The graph of time (t) along the x-axis is 300. Figure 4The diagram illustrates four possible responses. Line 302 represents the response where the vehicle damper (such as a shock absorber) is brand new and capable of rapidly damping changes in vehicle roll angle. Line 304 represents the response where the damper on the vehicle is damaged (such as an oil leak). Line 306 represents the response where the damper on vehicle 10 is worn by approximately 25% and the permissible vehicle roll is greater than that of the first line 302. Line 308 represents the response where the damper on vehicle 10 has reached the end of its service life and needs to be replaced.

[0090] Figure 5 The illustration shows a graphical representation 400 of the Fast Fourier Transform (FFT) of converting a time-domain signal from an IMU 62 into a frequency-domain signal. In the graphical representation 400, the frequency is along the x-axis and expressed in terms of g... 2 The units are / Hz along the y-axis, where g represents the acceleration relative to gravity. This allows for a comparison of normal suspension behavior, represented by line 402, with the behavior of damaged suspension components, represented by line 404. Figure 5 As shown, the spike in line 404 indicates the presence of a loose or worn link in the diagnosed suspension. After measuring the dynamic response, method 100 proceeds to block 122.

[0091] At block 122 (“Extra axles?”), method 100 determines whether there are any additional suspension components on vehicle 10 that need to be tested. In the illustrated example, vehicle 10 includes a front suspension 20 and a rear suspension 22, but this disclosure applies to vehicles 10 that have more than one front and rear suspension. Therefore, if one of the suspensions on vehicle 10 has not yet been analyzed, method 100 can return to blocks 110-118 to analyze any additional suspension on vehicle 10. If method 100 determines that there are no additional suspensions on vehicle 10 that need to be analyzed, method 100 proceeds to block 124.

[0092] In block 124 (“Analysis Data”), method 100 analyzes data associated with the first response, second response, and dynamic response of each axle to determine the state of each suspension on vehicle 10. If the data associated with the first or second response of any test suspension indicates that the suspension travel is less than a predetermined threshold, it may indicate that the end links 32-1, 32-2, 42-1, or 42-2 broke during the first or second force sequence using the active anti-roll bar. In particular, if one of the end links 32-1, 32-2, 42-1, or 42-2 breaks, the force applied by the active anti-roll bar 30 or 40 will not be transmitted to the suspension due to the broken link.

[0093] Furthermore, if the damping included in the dynamic response is less than a predetermined threshold (as mentioned above) Figure 4(As discussed), this may indicate that the suspension damper has failed or is about to fail. If the roll of vehicle 10 measured by IMU 62 includes damping less than a predetermined threshold, the damper on vehicle 10 may need to be replaced.

[0094] The terms “a” and “an” do not indicate a limitation of quantity, but rather indicate the presence of at least one of the mentioned items. Unless the context clearly indicates otherwise, the term “or” means “and / or”. When “aspect” is used throughout this specification, it means that a particular element (e.g., a feature, structure, step, or characteristic) described in connection with that aspect is contained in at least one aspect described herein, and may or may not be present in other aspects. Furthermore, it will be understood that the described elements may be combined in appropriate ways within the aspects.

[0095] While the foregoing disclosure has been described with reference to exemplary embodiments, those skilled in the art will understand that various modifications can be made without departing from its scope, and its elements can be substituted with equivalents. Furthermore, various modifications can be made without departing from its scope to adapt particular situations or materials to the teachings of this disclosure. Therefore, this disclosure is not limited to the specific embodiments disclosed, but will include embodiments falling within its scope.

Claims

1. A method for diagnosing the suspension of a vehicle, the method comprising: A first sequence of forces is applied to the first axle suspension; The first response of the first axle suspension to the first force sequence is measured using at least one sensor on the vehicle. A second force sequence is applied to the first axle suspension; The first axle suspension is measured in response to the second force sequence using at least one sensor on the vehicle. When one of the first force sequence or the second force sequence is released, the dynamic response of the first axle suspension is measured; as well as The state of the first axle suspension is determined based on at least one of the first response, the second response, or the dynamic response.

2. The method according to claim 1, wherein, The first force sequence is applied using an active anti-roll bar, which applies a first pair of opposing forces to the first axle suspension along a first pair of rotational directions.

3. The method according to claim 2, wherein, The second force sequence is applied using the active anti-roll bar, which applies a second pair of opposing forces to the first axle suspension along a second pair of rotational directions opposite to the first pair of rotational directions.

4. The method according to claim 3, wherein, The active anti-roll bar includes a drive motor configured to rotate a first portion of the active anti-roll bar independently of a second portion of the active anti-roll bar.

5. The method according to claim 4, wherein, The first part of the active anti-roll bar is mechanically connected to the first suspension corner of the first axle suspension via a first end link, and the second part of the active anti-roll bar is connected to the second corner of the first axle suspension via a second end link.

6. The method according to claim 1, wherein, The first force sequence and the second force sequence are applied using a first pair of hydraulic actuators, each of which is mechanically connected to an opposite corner of the first axle suspension.

7. The method according to claim 1, wherein, The dynamic response includes a first dynamic response when the first force sequence is released and a second dynamic response when the second force sequence is released.

8. The method according to claim 1, wherein, The at least one sensor includes a pair of ride height sensors configured to measure suspension travel at opposite corners of the first axle suspension.

9. A non-transitory computer-readable storage medium comprising programming instructions that, when executed by a processor, are operable to perform a method comprising: A first sequence of forces is applied to the first axle suspension of the vehicle; The first response of the first axle suspension to the first force sequence is measured using at least one sensor on the vehicle. A second force sequence is applied to the first axle suspension; The first axle suspension is measured in response to the second force sequence using at least one sensor on the vehicle. When one of the first force sequence or the second force sequence is released, the dynamic response of the first axle suspension is measured; as well as The state of the first axle suspension is determined based on at least one of the first response, the second response, or the dynamic response.

10. A vehicle comprising: The vehicle body is limited to the passenger compartment; A first suspension corresponding to the first axle and configured to support the vehicle body; A second suspension corresponding to the second axle and configured to support the vehicle body; A first suspension actuator associated with the first axle; The second suspension actuator associated with the second axle; At least one sensor configured to measure movement of the first axle, the second axle, or the vehicle body; A controller that communicates with the first suspension actuator, the second suspension actuator, and the at least one sensor, wherein the controller is configured to: A first sequence of forces is applied to the first axle suspension; The first response of the first axle suspension to the first force sequence is measured using at least one sensor on the vehicle. A second force sequence is applied to the first axle suspension; The first axle suspension is measured in response to the second force sequence using at least one sensor on the vehicle. When one of the first force sequence or the second force sequence is released, the dynamic response of the first axle suspension is measured; and The state of the first axle suspension is determined based on at least one of the first response, the second response, or the dynamic response.

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