A controllable suspension control system and method for autonomous vehicles

Abstract

This invention discloses a controllable suspension control system and method for autonomous vehicles, relating to the field of vehicle control technology. The system includes: a path planning layer calculation unit, used to output a first suspension control command based on the vehicle's path planning information; the path planning information includes acceleration and trajectory curvature at various positions along the planned path; a control layer processing unit, used to determine the vehicle's control signal based on the path planning information and output a second suspension control command based on the control signal; and a suspension controller, used to perform a weighted summation of the first and second suspension control commands to obtain suspension control commands at various positions along the planned path. This invention improves the timeliness of suspension control.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, and in particular to a controllable suspension control system and method for autonomous vehicles. Background Technology

[0002] The suspension system is a general term for the device that maintains forces and kinematic relationships between the chassis and axles of various automobiles. Its function is to transmit various forces / torques (such as supporting forces, braking forces, driving forces, and lateral forces) acting between the wheels and the chassis, weaken the impacts transmitted from the real road surface to the chassis, and dampen the resulting vibrations. The suspension system is of great importance in ensuring the basic performance of a vehicle, such as safety, ride comfort, and handling.

[0003] With technological advancements in the automotive industry, people have increasingly higher demands for cars, primarily focusing on ride comfort and handling stability. These two aspects have gradually become core indicators for evaluating a vehicle. Ultimately, these two indicators are reflected in the car's suspension system and its subsystems.

[0004] Currently, advanced suspension technologies are generally concentrated in the fields of semi-active and active suspensions, i.e., controllable suspensions.

[0005] Semi-active suspension technology primarily relies on damping control. Mainstream semi-active suspension technologies with damping control use electro-hydraulic adjustable dampers and magnetorheological dampers as actuators. The most common active suspension technology currently integrates the aforementioned damping control with stiffness control; that is, electro-hydraulic adjustable dampers are used in conjunction with air springs, or magnetorheological dampers are used in conjunction with air springs, simultaneously achieving adjustable stiffness and damping.

[0006] Based on different road conditions and signals from distance sensors, the vehicle's computer determines changes in vehicle height and then controls the air compressor and exhaust valve to automatically compress or extend the springs, thereby adjusting the chassis ground clearance to increase high-speed vehicle stability or passability in complex road conditions.

[0007] Current autonomous driving technologies primarily integrate with drive, braking, and steering systems, but their integration with other systems, such as suspension, is relatively poor. This makes it impossible to adjust the suspension based on real-time road conditions and path planning during autonomous driving. Consequently, the safety and comfort requirements of autonomous driving remain insufficiently met. Summary of the Invention

[0008] The purpose of this invention is to provide a controllable suspension control system and method for autonomous vehicles, which improves the timeliness of suspension control.

[0009] To achieve the above objectives, the present invention provides the following solution:

[0010] A controllable suspension control system for autonomous vehicles includes:

[0011] The path planning layer calculation unit is used to output the first suspension control command based on the vehicle's path planning information; the path planning information includes the acceleration and trajectory curvature at each position on the planned path;

[0012] The control layer processing unit is used to determine the vehicle's control signal based on the vehicle's path planning information, and output a second suspension control command based on the control signal.

[0013] The suspension controller is used to perform a weighted summation of the first suspension control command and the second suspension control command to obtain the suspension control command at each position on the planned path.

[0014] Optionally, the path planning layer calculation unit includes:

[0015] The jerk determination subunit is used to determine the jerk at the i-th position based on the acceleration at the i-th position, the acceleration at the (i+1)-th position, and the time interval between the i-th position and the (i+1)-th position.

[0016] The first damping increment signal determination subunit is used to output the first damping increment signal at the i-th position if the jerk at the i-th position is greater than the first jerk threshold and less than the second jerk threshold. The first damping increment signal is the damping increment signal of the two rear suspensions.

[0017] The second damping increment signal determination subunit is used to output the second damping increment signal at the i-th position if the jerk at the i-th position is greater than the second jerk threshold. The second damping increment signal is the damping increment signal of the two rear suspensions.

[0018] The third damping increment signal determination subunit is used to output the third damping increment signal at the i-th position if the trajectory curvature at the i-th position is greater than the curvature threshold; the third damping increment signal is the damping increment signal of the two suspensions on the outer side of the turn.

[0019] Optionally, the control layer processing unit includes:

[0020] The control signal determination subunit is used to determine the steering wheel rotation angle, steering wheel rotation angular velocity, braking torque, and throttle / electric throttle opening at the i-th position of the vehicle based on the vehicle's path planning information.

[0021] The working condition determination value subunit is used to calculate the working condition determination value based on the steering wheel rotation angle and the vehicle speed if the steering wheel rotation angular velocity is greater than or equal to the steering wheel rotation angular velocity threshold.

[0022] The fourth damping increment signal determination subunit is used to output the fourth damping increment signal at the i-th position if the working condition judgment value is less than the judgment threshold. The fourth damping increment signal is the damping increment signal of the two suspensions on the outside of the turn.

[0023] The fifth damping increment signal determination subunit is used to output the fifth damping increment signal at the i-th position if the working condition judgment value is greater than or equal to the judgment threshold. The fifth damping increment signal is the damping increment signal of each suspension on the vehicle.

[0024] The sixth damping increment signal determination subunit is used to output the sixth damping increment at the i-th position if the braking torque is greater than or equal to the braking torque threshold. The sixth damping increment is the damping increment signal of the two front suspensions.

[0025] The seventh damping increment signal determination subunit is used to output the seventh damping increment if the throttle / electric valve opening is greater than or equal to the throttle / electric valve opening threshold and the vehicle speed is less than the vehicle speed threshold. The seventh damping increment is the damping increment signal of the two rear suspensions.

[0026] The eighth damping increment signal determination subunit is used to output the eighth damping increment if the throttle / electric valve opening is greater than or equal to the throttle / electric valve opening threshold and the vehicle speed is greater than or equal to the vehicle speed threshold. The eighth damping increment is the damping increment signal of each suspension.

[0027] Optionally, the suspension controller includes a suspension control subunit, which is used to, for the j-th suspension, perform a weighted summation of the damping increment signal for the j-th suspension output by the path planning layer calculation unit and the damping increment signal for the j-th suspension output by the control layer processing unit, and use this summation as the final suspension control command for the j-th suspension.

[0028] Optionally, when the vehicle's suspension is a semi-active suspension, the first damping increment signal is represented as:

[0029] ΔC 1= K 1 ( J i - J th1 );

[0030] in, ΔC 1 represents the first damping increment signal. K 1 represents the first coefficient. J i This represents the jerk at the i-th position. J th1 Indicates the first jerk threshold;

[0031] When the vehicle's suspension is an active suspension, the first damping increment signal is represented as:

[0032] ΔC 1= L 1 ( J i - J th1 );

[0033] in, L 1 indicates the second coefficient;

[0034] When the vehicle's suspension is a semi-active suspension, the second damping increment signal is represented as:

[0035] ΔC 1 = K 1 ( J th2 - J th1 )+ K 2 ( J i - J th2 );

[0036] in, ΔC 1 This is the second damping increment signal. K 2 Indicates the third coefficient. J th2 Indicates the second accelerometer threshold;

[0037] When the vehicle's suspension is an active suspension, the second damping increment signal is represented as:

[0038] ΔC 1 = L 1 ( J th2 - J th1 )+ L 2 ( J i - J th2 );

[0039] in, L 2 Indicates the fourth coefficient;

[0040] When the vehicle's suspension is a semi-active suspension, the third damping increment signal is represented as:

[0041] ΔC 2 = K 3 ( k i - k 0 );

[0042] in, ΔC 2 This represents the third damping increment signal. K 3 Indicates the fifth coefficient. k i This represents the trajectory curvature at position i. k 0 Indicates the curvature threshold;

[0043] When the vehicle's suspension is an active suspension, the third damping increment signal is represented as:

[0044] ΔC 2 = L 3 ( k i - k 0 );

[0045] in, L 3 This represents the sixth coefficient.

[0046] Optionally, when the vehicle's suspension is a semi-active suspension, the fourth damping increment signal is represented as:

[0047] ΔC 3 = K 4 ( oh - oh 0 );

[0048] in, ΔC 3 This represents the fourth damping increment signal. K 4 Indicates the seventh coefficient. oh Indicates the angular velocity of the steering wheel rotation. oh 0 Indicates the threshold value for the angular velocity of the steering wheel rotation;

[0049] When the vehicle's suspension is an active suspension, the fourth damping increment signal is represented as:

[0050] ΔC 3 = L 4 ( oh - oh 0 );

[0051] in, L 4 Indicates the eighth coefficient;

[0052] When the vehicle's suspension is a semi-active suspension, the fifth damping increment signal is represented as:

[0053] ΔC 3 = K 4 ( F - F 0 );

[0054] in, ΔC 3 This represents the fifth damping increment signal. K 4 Indicates the ninth coefficient. F Indicates the steering wheel rotation angle. F 0 Indicates the threshold value for steering wheel rotation angle;

[0055] When the vehicle's suspension is an active suspension, the fifth damping increment signal is represented as:

[0056] ΔC 3 = L 4 ( F - F 0 )

[0057] L 4 Indicates the tenth coefficient;

[0058] When the vehicle's suspension is a semi-active suspension, the sixth damping increment signal is represented as:

[0059] ΔC 4 = K 5 ( M B - M B0 );

[0060] in, ΔC 4 This represents the sixth damping increment signal. K5 This represents the eleventh coefficient. M B0 Indicates the braking torque threshold. M B Indicates braking torque;

[0061] When the vehicle's suspension is an active suspension, the sixth damping increment signal is represented as:

[0062] ΔC 4 = L 5 ( M B - M B0 );

[0063] in, L 5 The twelfth coefficient;

[0064] When the vehicle's suspension is a semi-active suspension, the seventh damping increment signal is represented as:

[0065] ΔC 5 = K 6 ( V 0 - V )+ K 7 ( l - l 0 );

[0066] in, ΔC 5 This represents the seventh damping increment signal. K 6 This represents the thirteenth coefficient. K 7 This represents the fourteenth coefficient. V 0 Indicates the vehicle speed threshold. V Indicates vehicle speed. l Indicates the throttle / electric switch opening. l 0 Indicates the threshold for throttle / electric switch opening;

[0067] When the vehicle's suspension is an active suspension, the seventh damping increment signal is represented as:

[0068] ΔC 5 = L 6 ( V 0 -V )+ L 7 ( l - l 0 )

[0069] in, L 6 This represents the fifteenth coefficient. L 7 This represents the sixteenth coefficient.

[0070] When the vehicle's suspension is a semi-active suspension, the eighth damping increment signal is represented as:

[0071] ΔC 6 = K 8 ( l - l 0 );

[0072] in, ΔC 6 This represents the eighth damping increment signal. K 8 This represents the seventeenth coefficient;

[0073] When the vehicle's suspension is an active suspension, the eighth damping increment signal is represented as:

[0074] ΔC 6 = L 8 ( l - l 0 );

[0075] in, L 8 This represents the eighteenth coefficient.

[0076] Optionally, the operating condition determination value is expressed as:

[0077] H = a V 2 F ;

[0078] Wherein, H represents the working condition judgment value. a This indicates a given quantity, where V represents the vehicle speed. F This indicates the steering wheel rotation angle.

[0079] This invention also discloses a controllable suspension control method for autonomous vehicles, comprising:

[0080] The first suspension control command is output based on the vehicle's path planning information; the path planning information includes the acceleration and trajectory curvature at each position on the planned path.

[0081] The vehicle's control signal is determined based on the vehicle's path planning information, and a second suspension control command is output based on the control signal.

[0082] The first suspension control command and the second suspension control command are weighted and summed to obtain the suspension control commands at each position on the planned path.

[0083] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0084] This invention outputs a first suspension control command based on information from each position on the vehicle's path planning, and outputs a second suspension control command based on the control signal. The first and second suspension control commands are weighted and summed to obtain the suspension control commands for each position on the planned path. This enables the early determination of suspension control commands, reduces control delay, and thus improves the timeliness of suspension control. Attached Figure Description

[0085] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0086] Figure 1 A schematic diagram of a controllable suspension control system for autonomous vehicles provided in an embodiment of the present invention;

[0087] Figure 2 This is a schematic diagram of the traditional controllable suspension control process;

[0088] Figure 3 A schematic diagram illustrating the workflow of a controllable suspension control system for autonomous vehicles, provided as an embodiment of the present invention;

[0089] Figure 4 This is a schematic diagram of the working logic of the suspension controller provided in an embodiment of the present invention;

[0090] Figure 5 This is a schematic diagram illustrating the working principle of suspension control based on path planning information provided in an embodiment of the present invention;

[0091] Figure 6 This is a schematic diagram illustrating the working principle of semi-active suspension control based on dynamic manipulation information provided in an embodiment of the present invention.

[0092] Figure 7 This is a schematic diagram illustrating the working principle of active suspension control based on dynamic manipulation information provided in an embodiment of the present invention;

[0093] Figure 8 This is a schematic flowchart of a controllable suspension control method for autonomous vehicles provided in an embodiment of the present invention. Detailed Implementation

[0094] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0095] The purpose of this invention is to provide a controllable suspension control system and method for autonomous vehicles, which improves the timeliness of suspension control.

[0096] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0097] Example 1

[0098] Traditional controllable suspension control process such as Figure 2 As shown, onboard sensors monitor the impact on the vehicle's dynamics and send commands to the suspension controller to change suspension parameters. Simultaneously, external stimuli act on the vehicle, indirectly affecting the changes in controllable suspension parameters to cope with constantly evolving driving conditions. While traditional controllable suspensions can adjust the damping coefficient in a stepped or even continuous manner within a certain range, significantly improving vehicle performance compared to passive suspensions, their damping adjustment lags behind changes in the external environment. That is, changes in physical quantities such as vehicle speed, adhesion coefficient, and heading angle precede changes in the controllable suspension's operating mode, making it a passive adaptive mechanism. This invention aims to determine changes in controllable suspension parameters using real-time information from two channels. The first channel is dynamic control commands: these commands come from the control layer, including but not limited to steering wheel angle and braking torque. They are transmitted not only to the corresponding steering, braking, and drive modules but also to the suspension. The purpose of this design is to reduce the response delay of the suspension passively affected by dynamic conditions. The second channel is path planning commands: these commands come from the decision-making and planning layer, including but not limited to trajectory curvature radius and instantaneous vehicle acceleration. The suspension can pre-adjust to adapt to new paths. The commands from both channels are received by the suspension system, but the corresponding control results are not the same. The final control output is obtained by weighting the two control results, and the suspension adjusts its parameters accordingly.

[0099] like Figure 1 and Figure 3 As shown, this embodiment discloses a controllable suspension control system for autonomous vehicles, including:

[0100] The path planning layer calculation unit 101 is used to output a first suspension control command based on the vehicle's path planning information; the path planning information includes the acceleration and trajectory curvature at each position on the planned path.

[0101] The control layer processing unit 102 is used to determine the vehicle's control signal based on the vehicle's path planning information, and output a second suspension control command based on the control signal.

[0102] The suspension controller 103 is used to perform a weighted summation of the first suspension control command and the second suspension control command to obtain the suspension control command at each position on the planned path.

[0103] To achieve real-time adjustment of the vehicle's attitude during autonomous driving, suspension control commands are calculated from lateral and longitudinal vehicle dynamics commands in both channels to simultaneously improve ride comfort and handling stability.

[0104] The suspension control commands are obtained from the control layer, and the information sources include, but are not limited to, steering wheel angle, drive and braking torque. The output commands from the control layer include, but are not limited to, steering wheel angle. F、 Steering wheel rotation angular velocity oh Braking torque M B And throttle / electric throttle opening (throttle opening or electric throttle opening) l Based on the numerical analysis of the above multiple state variables, the dynamic conditions of the vehicle in the longitudinal and lateral directions are determined, and the roll and pitch of the vehicle are reduced simultaneously by adjusting the suspension damping or suspension force.

[0105] Control commands are obtained from the decision-making and planning layer, and the information sources include, but are not limited to, the trajectory curvature radius and the instantaneous acceleration of the entire vehicle. The output commands of the decision-making and planning layer include, but are not limited to, the vehicle's longitudinal position (x), lateral position (y), and heading angle at future moments. and the curvature of the vehicle's trajectory at that location Based on the numerical analysis of the above multiple state variables, the dynamic conditions of the vehicle in the longitudinal and lateral directions are determined, and the roll and pitch of the vehicle are reduced simultaneously by adjusting the suspension damping or suspension force.

[0106] The suspension controller performs weighted processing on the control commands obtained from path planning information and control commands obtained from dynamic manipulation information to solve for the final control output command (suspension control command) to control the suspension to complete parameter adjustments.

[0107] In this invention, the two modules that input control information to the suspension controller are a control layer processing unit and a path planning layer calculation unit. The control layer processing unit originates from... Figure 3 The control layer and path planning layer computation units in the middle come from Figure 3 The decision-making and planning layer in the middle.

[0108] The path planning layer calculation unit 101 mainly includes an arithmetic logic unit (ALU) for calculating trajectory curvature and instantaneous acceleration. During path planning, the desired path consists of several coordinate points connected sequentially to form a smooth curve. Simultaneously, the expected acceleration vectors of the vehicle as it passes these points are pre-calculated by the vehicle's computer. When the acceleration vectors corresponding to two or more adjacent points differ significantly, the ALU calculating instantaneous acceleration will determine it as a rapid acceleration or deceleration condition. When the curvature at a certain point on the desired path exceeds an allowable threshold, the ALU calculating trajectory curvature will determine it as a sharp turn condition. Rapid acceleration and sharp turn conditions can be considered sudden events, and the signals describing them are connected to the input of the suspension controller via the CAN bus.

[0109] like Figure 5 As shown, the path planning layer calculation unit from the autonomous driving decision planning layer determines whether it is a sharp turn or a sharp acceleration condition at a certain coordinate point based on the expected acceleration vector and trajectory curvature at several coordinate points on the expected path, and transmits the information describing the condition, i.e., the path planning information, to the suspension control.

[0110] Each coordinate point on the pre-planned desired path corresponds to a desired acceleration vector of the vehicle when it passes that point in the future. Let the vehicle's current coordinate point be denoted as... X 0 The coordinates of the subsequent times are as follows: X 1 、X 2 、X 3 …X n。 Among them, the first i The acceleration vector of each point is denoted as . a i。 Then from X i arrive X i+1 accelerometer in the displacement element A i It can be regarded as: J i = .in t The planning time interval is given here. A first jerk threshold is also provided. J th1 Second accelerometer threshold Jth2 The car is assumed to be moving forward.

[0111] The path planning layer calculation unit 101 includes:

[0112] The jerk determination subunit is used to determine the jerk at the i-th position based on the acceleration at the i-th position, the acceleration at the (i+1)-th position, and the time interval between the i-th position and the (i+1)-th position (coordinate point).

[0113] When 0 < J i < J th1 At this point, the driving conditions are normal, and the path planning layer calculation unit does not make any additional intervention to the suspension.

[0114] The first damping increment signal determination subunit is used to determine if the jerk at the i-th position is greater than the first jerk threshold and less than the second jerk threshold. J th1 < J i < J th2 If the time at position i is a state of intense acceleration, the first damping increment signal at position i is output. The first damping increment signal is the damping increment signal of the two rear suspensions.

[0115] The second damping increment signal determination subunit is used to determine if the jerk at the i-th position is greater than the second jerk threshold. J i > J th2 If the time at position i is a dangerous acceleration condition, the second damping increment signal at position i is output. The second damping increment signal is the damping increment signal of the two rear suspensions.

[0116] The control method based on the first derivative of the desired acceleration in the first and second damping increment signal determination subunits is used to improve the "nose-up phenomenon" during rapid acceleration.

[0117] As mentioned earlier, the desired path is a smooth curve formed by connecting several desired coordinate points in sequence. Although path planning is based on sufficient safety, there will still be some desired coordinate points with excessive curvature, causing the vehicle to veer sharply when passing near these points. Let the curvature of the i-th coordinate point be denoted as . k i。 Given a curvature threshold k 0 .

[0118] when ki <k 0 The area near this coordinate point is for normal steering. The path planning layer calculation unit does not make any additional intervention to the suspension.

[0119] The third damping increment signal determination subunit is used to determine if the trajectory curvature at the i-th position is greater than the curvature threshold. k i > k 0 If the coordinate point is near a sharp turn, the third damping increment signal at the i-th position is output; the third damping increment signal is the damping increment signal of the two suspensions on the outer side of the turn.

[0120] The third damping increment signal determination sub-unit's control method based on desired curvature is used to improve roll and yaw phenomena during sharp turns.

[0121] When the vehicle's suspension is a semi-active suspension, the first damping increment signal is represented as:

[0122] ΔC 1= K 1 ( J i - J th1 );

[0123] in, ΔC 1 represents the first damping increment signal. K 1 represents the first coefficient. J i This represents the acceleration at the i-th position. J th1 This represents the first jerk threshold.

[0124] When the vehicle's suspension is an active suspension, the first damping increment signal is represented as:

[0125] ΔC 1= L 1 ( J i - J th1 );

[0126] in, L 1 represents the second coefficient.

[0127] When the vehicle's suspension is a semi-active suspension, the second damping increment signal is represented as:

[0128] ΔC 1 = K 1 ( Jth2 - J th1 )+ K 2 ( J i - J th2 );

[0129] in, ΔC 1 This is the second damping increment signal. K 2 Indicates the third coefficient. J th2 This indicates the second jerk threshold.

[0130] When the vehicle's suspension is an active suspension, the second damping increment signal is represented as:

[0131] ΔC 1 = L 1 ( J th2 - J th1 )+ L 2 ( J i - J th2 );

[0132] in, L 2 This represents the fourth coefficient.

[0133] When the vehicle's suspension is a semi-active suspension, the third damping increment signal is represented as:

[0134] ΔC 2 = K 3 ( k i - k 0 );

[0135] in, ΔC 2 This represents the third damping increment signal. K 3 Indicates the fifth coefficient. k i This represents the trajectory curvature at position i. k 0 This represents the curvature threshold.

[0136] When the vehicle's suspension is an active suspension, the third damping increment signal is represented as:

[0137] ΔC 2 = L 3 ( k i - k 0 );

[0138] in, L 3 This represents the sixth coefficient.

[0139] The control layer processing unit 102 solves the problem based on the prediction results of the decision-planning layer, and sends control commands to the braking module, drive module, and steering module to adjust state quantities such as braking torque, throttle / electric throttle opening, and steering wheel angle. In addition, the control layer processing unit also integrates the commands from these three aspects, predicting the vehicle motion state at the next sampling instant from the three dimensions of braking, drive, and steering, thereby directly issuing control commands to the suspension and reducing the suspension response delay. In this invention, the control layer processing unit is connected to the input terminal of the suspension controller via a CAN bus.

[0140] In conventional controllable suspensions, damping and suspension force adjustments lag behind changes in the external environment. This invention aims to influence changes in controllable suspension parameters using real-time commands from the control layer. These commands primarily include steering wheel angle. F、 Steering wheel rotation angular velocity oh Braking torque M B and throttle / electric throttle opening l . λ∈ (0, 1). Let the instantaneous vehicle speed be... V .

[0141] The control layer processing unit 102 includes:

[0142] The control signal determination subunit is used to determine the steering wheel rotation angle, steering wheel rotation angular velocity, braking torque, and throttle / electric throttle opening at the i-th position of the vehicle based on the vehicle's path planning information.

[0143] The specific control logic of the control layer processing unit 102 is as follows: Figure 6 and Figure 7 As shown.

[0144] when oh < oh 0 At this time, the control layer processing unit does not make any additional intervention to the suspension.

[0145] The condition determination subunit is used to determine the steering wheel rotation angular velocity if the steering wheel rotation angular velocity is greater than or equal to a steering wheel rotation angular velocity threshold. oh ≥ oh 0 The operating condition judgment value is calculated based on the steering wheel rotation angle and vehicle speed.

[0146] The operating condition determination value is expressed as follows:

[0147] H = a V 2 F ;

[0148] Wherein, H represents the working condition judgment value. a This indicates a given quantity, where V represents the vehicle speed. F This indicates the steering wheel rotation angle.

[0149] The fourth damping increment signal determination subunit is used for if oh ≥ oh 0 And the condition determination value is less than the determination threshold. H < H 0 If the current working condition is determined to be that the vehicle is turning at low speed to perform actions such as reversing into a parking space, then smoothness should be given priority over handling stability. The fourth damping increment signal at the i-th position is output, and the fourth damping increment signal is the damping increment signal of the two suspensions on the outer side of the turn.

[0150] The fifth damping increment signal determination subunit is used for if oh ≥ oh 0 And the condition determination value is greater than or equal to the determination threshold ( H ≥ H 0 If the current operating condition is determined to be that the vehicle is turning at high speed to perform emergency obstacle avoidance or other actions, then the handling stability should be given priority over ride comfort. The fifth damping increment signal at the i-th position is output, and the fifth damping increment signal is the damping increment signal of each suspension on the vehicle.

[0151] when M B <M B0 At this time, the control layer processing unit does not make any additional intervention to the suspension.

[0152] The sixth damping increment signal determination subunit is used to determine if the braking torque is greater than or equal to the braking torque threshold ( M B ≥ M B0 If the vehicle's "nodding" tendency is too large, the sixth damping increment at the i-th position is output, and the sixth damping increment is the damping increment signal of the two front suspensions.

[0153] when λ<λ 0 At this time, the control layer processing unit does not make any additional intervention to the suspension.

[0154] The seventh damping increment signal determination subunit is used to determine if the throttle opening is greater than or equal to the throttle opening threshold ( l ≥ l 0 And the vehicle speed is less than the vehicle speed threshold ( V < V 0 If the vehicle is in a state of rapid acceleration from low speed, and the vehicle's "nose-up" tendency is large, the seventh damping increment is output. The seventh damping increment is the damping increment signal of the two rear suspensions.

[0155] The eighth damping increment signal determination subunit is used to determine if the throttle / electric valve opening is greater than or equal to the throttle / electric valve opening threshold, and the vehicle speed is greater than or equal to the vehicle speed threshold. V ≥ V 0 If the vehicle is cruising at high speed, then the vehicle is determined to be cruising at high speed. In this case, handling stability should be given priority over ride comfort, and an eighth damping increment is output. The eighth damping increment is the damping increment signal for each suspension.

[0156] The suspension controller includes a suspension control subunit, which is used to, for the j-th suspension, perform a weighted summation of the damping increment signal for the j-th suspension output by the path planning layer calculation unit and the damping increment signal for the j-th suspension output by the control layer processing unit, and use this summation as the final suspension control command for the j-th suspension.

[0157] When the vehicle's suspension is a semi-active suspension, the fourth damping increment signal is represented as:

[0158] ΔC 3 = K 4 ( oh - oh 0 );

[0159] in, ΔC 3 This represents the fourth damping increment signal. K 4 Indicates the seventh coefficient. oh Indicates the angular velocity of the steering wheel rotation. oh 0 Indicates the threshold value for the angular velocity of the steering wheel rotation;

[0160] When the vehicle's suspension is an active suspension, the fourth damping increment signal is represented as:

[0161] ΔC 3 = L 4 ( oh - oh 0 );

[0162] in, L 4 Indicates the eighth coefficient;

[0163] When the vehicle's suspension is a semi-active suspension, the fifth damping increment signal is represented as:

[0164] ΔC 3 = K 4 ( F - F 0 );

[0165] in, ΔC 3 This represents the fifth damping increment signal. K 4 Indicates the ninth coefficient. F Indicates the steering wheel rotation angle. F 0 Indicates the threshold value for steering wheel rotation angle;

[0166] When the vehicle's suspension is an active suspension, the fifth damping increment signal is represented as:

[0167] ΔC 3 = L 4 ( F - F 0 );

[0168] L 4 Indicates the tenth coefficient;

[0169] When the vehicle's suspension is a semi-active suspension, the sixth damping increment signal is represented as:

[0170] ΔC 4 = K 5 ( M B - M B0 );

[0171] in, ΔC 4 This represents the sixth damping increment signal. K 5 This represents the eleventh coefficient. M B0 Indicates the braking torque threshold. M B Indicates braking torque;

[0172] When the vehicle's suspension is an active suspension, the sixth damping increment signal is represented as:

[0173] ΔC 4 = L 5 ( M B - M B0 );

[0174] in, L 5 The twelfth coefficient;

[0175] When the vehicle's suspension is a semi-active suspension, the seventh damping increment signal is represented as:

[0176] ΔC 5 = K 6 ( V 0 - V )+ K 7 ( l - l 0 );

[0177] in, ΔC 5 This represents the seventh damping increment signal. K 6 This represents the thirteenth coefficient. K 7 This represents the fourteenth coefficient. V 0 Indicates the vehicle speed threshold. V Indicates vehicle speed. l Indicates the throttle / electric switch opening. l 0 Indicates the threshold for throttle / electric switch opening;

[0178] When the vehicle's suspension is an active suspension, the seventh damping increment signal is represented as:

[0179] ΔC5 = L 6 ( V 0 - V )+ L 7 ( l - l 0 )

[0180] in, L 6 This represents the fifteenth coefficient. L 7 This represents the sixteenth coefficient.

[0181] When the vehicle's suspension is a semi-active suspension, the eighth damping increment signal is represented as:

[0182] ΔC 6 = K 8 ( l - l 0 );

[0183] in, ΔC 6 This represents the eighth damping increment signal. K 8 This represents the seventeenth coefficient;

[0184] When the vehicle's suspension is an active suspension, the eighth damping increment signal is represented as:

[0185] ΔC 6 = L 8 ( l - l 0 );

[0186] in, L 8 This represents the eighteenth coefficient.

[0187] This invention determines the changes in controllable suspension parameters based on real-time information from two channels: path planning information and dynamic manipulation information. Suspension control commands are obtained from the control layer, with information sources including, but not limited to, steering wheel angle, drive and braking torque; control commands are also obtained from the decision planning layer, with information sources including, but not limited to, trajectory curvature radius, and instantaneous vehicle acceleration. After receiving suspension control commands from both sources, the suspension controller performs a weighted average to obtain the final suspension control command. This final command controls the suspension to adjust its parameters, reducing the response delay of the suspension passively affected by dynamic states and allowing the suspension to pre-adjust to adapt to new external environments.

[0188] The working logic of suspension controller 103 is as follows: Figure 4 As shown. The path planning layer calculation unit and the control layer processing unit transmit the monitored information to the suspension controller via the CAN bus. The system's built-in weighted calculator processes the two types of information according to specified weights to obtain new suspension control parameters. The information from the control layer processing unit has a weight of 1- Oh The weight of information from the path planning layer computation unit is Oh , Ω∈ (0, 1). The new suspension control parameters are directly input to the controllable suspension by the suspension controller.

[0189] Figure 4 The central suspension control system is suspension controller 103. J This indicates a suspension control command. a This indicates the first suspension control command. b This indicates the second suspension control command.

[0190] Example 2

[0191] In order to execute the method corresponding to Embodiment 1 above, and to achieve the corresponding functions and technical effects, such as Figure 8 As shown in the figure, this embodiment also discloses a controllable suspension control method for autonomous vehicles, including the following steps.

[0192] Step 201: Output the first suspension control command based on the vehicle's path planning information; the path planning information includes the acceleration and trajectory curvature at each position on the planned path.

[0193] Step 202: Determine the vehicle's control signal based on the vehicle's path planning information, and output the second suspension control command based on the control signal.

[0194] Step 203: Perform a weighted summation of the first suspension control command and the second suspension control command to obtain the suspension control command at each position on the planned path.

[0195] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The methods disclosed in the embodiments are described simply because they correspond to the systems disclosed in the embodiments; relevant details can be found in the method section.

[0196] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A controllable suspension control system for autonomous vehicles, characterized in that, include: The path planning layer calculation unit is used to output the first suspension control command based on the vehicle's path planning information; The path planning information includes the acceleration and trajectory curvature at each location on the planned path; The control layer processing unit is used to determine the vehicle's control signals based on the vehicle's path planning information, and output a second suspension control command based on the control signals; the control signals include steering wheel angle, steering wheel rotation angular velocity, braking torque, and throttle / electric throttle opening. The suspension controller is used to perform a weighted summation of the first suspension control command and the second suspension control command to obtain the suspension control command at each position on the planned path.

2. The controllable suspension control system for autonomous vehicles according to claim 1, characterized in that, The path planning layer calculation unit includes: The jerk determination subunit is used to determine the jerk at the i-th position based on the acceleration at the i-th position, the acceleration at the (i+1)-th position, and the time interval between the i-th position and the (i+1)-th position. The first damping increment signal determination subunit is used to output the first damping increment signal at the i-th position if the jerk at the i-th position is greater than the first jerk threshold and less than the second jerk threshold. The first damping increment signal is the damping increment signal of the two rear suspensions. The second damping increment signal determination subunit is used to output the second damping increment signal at the i-th position if the jerk at the i-th position is greater than the second jerk threshold. The second damping increment signal is the damping increment signal of the two rear suspensions. The third damping increment signal determination subunit is used to output the third damping increment signal at the i-th position if the trajectory curvature at the i-th position is greater than the curvature threshold; the third damping increment signal is the damping increment signal of the two suspensions on the outer side of the turn.

3. The controllable suspension control system for autonomous vehicles according to claim 2, characterized in that, The control layer processing unit includes: The control signal determination subunit is used to determine the steering wheel rotation angle, steering wheel rotation angular velocity, braking torque, and throttle / electric throttle opening at the i-th position of the vehicle based on the vehicle's path planning information. The working condition determination value subunit is used to calculate the working condition determination value based on the steering wheel rotation angle and the vehicle speed if the steering wheel rotation angular velocity is greater than or equal to the steering wheel rotation angular velocity threshold. The fourth damping increment signal determination subunit is used to output the fourth damping increment signal at the i-th position if the working condition judgment value is less than the judgment threshold. The fourth damping increment signal is the damping increment signal of the two suspensions on the outside of the turn. The fifth damping increment signal determination subunit is used to output the fifth damping increment signal at the i-th position if the working condition judgment value is greater than or equal to the judgment threshold. The fifth damping increment signal is the damping increment signal of each suspension on the vehicle. The sixth damping increment signal determination subunit is used to output the sixth damping increment at the i-th position if the braking torque is greater than or equal to the braking torque threshold. The sixth damping increment is the damping increment signal of the two front suspensions. The seventh damping increment signal determination subunit is used to output the seventh damping increment if the throttle / electric valve opening is greater than or equal to the throttle / electric valve opening threshold and the vehicle speed is less than the vehicle speed threshold. The seventh damping increment is the damping increment signal of the two rear suspensions. The eighth damping increment signal determination subunit is used to output the eighth damping increment if the throttle / electric valve opening is greater than or equal to the throttle / electric valve opening threshold and the vehicle speed is greater than or equal to the vehicle speed threshold. The eighth damping increment is the damping increment signal of each suspension.

4. The controllable suspension control system for autonomous vehicles according to claim 3, characterized in that, The suspension controller includes a suspension control subunit, which is used to, for the j-th suspension, perform a weighted summation of the damping increment signal for the j-th suspension output by the path planning layer calculation unit and the damping increment signal for the j-th suspension output by the control layer processing unit, and use this summation as the final suspension control command for the j-th suspension.

5. The controllable suspension control system for autonomous vehicles according to claim 2, characterized in that, When the vehicle's suspension is a semi-active suspension, the first damping increment signal is represented as: ΔC 1= K 1（ J i - J th1 ）； in, ΔC 1 represents the first damping increment signal. K 1 represents the first coefficient. J i This represents the jerk at the i-th position. J th1 Indicates the first jerk threshold; When the vehicle's suspension is an active suspension, the first damping increment signal is represented as: ΔC 1= L 1（ J i - J th1 ）； in, L 1 indicates the second coefficient; When the vehicle's suspension is a semi-active suspension, the second damping increment signal is represented as: in, This is the second damping increment signal. K 2 Indicates the third coefficient. J th2 Indicates the second accelerometer threshold; When the vehicle's suspension is an active suspension, the second damping increment signal is represented as: in, L 2 Indicates the fourth coefficient; When the vehicle's suspension is a semi-active suspension, the third damping increment signal is represented as: ΔC 2 = K 3 （ k i - k 0 ）； in, ΔC 2 This represents the third damping increment signal. K 3 Indicates the fifth coefficient. k i This represents the trajectory curvature at position i. k 0 Indicates the curvature threshold; When the vehicle's suspension is an active suspension, the third damping increment signal is represented as: ΔC 2 = L 3 （ k i - k 0 ）； in, L 3 This represents the sixth coefficient.

6. The controllable suspension control system for autonomous vehicles according to claim 3, characterized in that, When the vehicle's suspension is a semi-active suspension, the fourth damping increment signal is represented as: ΔC 3 = K 4 （ ω - ω 0 ）； in, ΔC 3 This represents the fourth damping increment signal. K 4 Indicates the seventh coefficient. ω Indicates the angular velocity of the steering wheel rotation. ω 0 Indicates the threshold value for the angular velocity of the steering wheel rotation; When the vehicle's suspension is an active suspension, the fourth damping increment signal is represented as: ΔC 3 = L 4 （ ω - ω 0 ）； in, L 4 Indicates the eighth coefficient; When the vehicle's suspension is a semi-active suspension, the fifth damping increment signal is represented as: in, This represents the fifth damping increment signal. Indicates the ninth coefficient. Ф Indicates the steering wheel rotation angle. Ф 0 Indicates the threshold value for steering wheel rotation angle; When the vehicle's suspension is an active suspension, the fifth damping increment signal is represented as: Indicates the tenth coefficient; When the vehicle's suspension is a semi-active suspension, the sixth damping increment signal is represented as: ΔC 4 = K 5 （ M B - M B0 ）； in, ΔC 4 This represents the sixth damping increment signal. K 5 This represents the eleventh coefficient. M B0 Indicates the braking torque threshold. M B Indicates braking torque; When the vehicle's suspension is an active suspension, the sixth damping increment signal is represented as: ΔC 4 = L 5 （ M B - M B0 ）； in, L 5 The twelfth coefficient; When the vehicle's suspension is a semi-active suspension, the seventh damping increment signal is represented as: ΔC 5 = K 6 （ V 0 - V ）+ K 7 （ λ - λ 0 ）； in, ΔC 5 This represents the seventh damping increment signal. K 6 This represents the thirteenth coefficient. K 7 This represents the fourteenth coefficient. V 0 Indicates the vehicle speed threshold. V Indicates vehicle speed. λ Indicates the throttle / electric switch opening. λ 0 Indicates the threshold for throttle / electric switch opening; When the vehicle's suspension is an active suspension, the seventh damping increment signal is represented as: ΔC 5 = L 6 （ V 0 - V ）+ L 7 （ λ - λ 0 ） in, L 6 This represents the fifteenth coefficient. L 7 This represents the sixteenth coefficient. When the vehicle's suspension is a semi-active suspension, the eighth damping increment signal is represented as: ΔC 6 = K 8 （ λ - λ 0 ）； in, ΔC 6 This represents the eighth damping increment signal. K 8 This represents the seventeenth coefficient; When the vehicle's suspension is an active suspension, the eighth damping increment signal is represented as: ΔC 6 = L 8 （ λ - λ 0 ）； in, L 8 This represents the eighteenth coefficient.

7. The controllable suspension control system for autonomous vehicles according to claim 3, characterized in that, The operating condition determination value is expressed as follows: H = a V 2 Ф ； Wherein, H represents the working condition judgment value. a This indicates a given calibrated quantity, where V represents the vehicle speed. Ф This indicates the steering wheel rotation angle.

8. A controllable suspension control method for autonomous vehicles, characterized in that, include: The first suspension control command is output based on the vehicle's path planning information; The path planning information includes the acceleration and trajectory curvature at each location on the planned path; The vehicle's control signals are determined based on the vehicle's path planning information, and a second suspension control command is output based on the control signals; the control signals include steering wheel angle, steering wheel rotation angular velocity, braking torque, and throttle / electric throttle opening. The first suspension control command and the second suspension control command are weighted and summed to obtain the suspension control commands at each position on the planned path.

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