A method, device, equipment and storage medium for adjusting the height of a hydraulic suspension

Abstract

The present application provides a method, device, equipment and storage medium for adjusting the height of a hydraulic suspension, the method comprising: if the conditions for adjusting the height of the hydraulic suspension are determined according to the current state of the vehicle, outputting an action command for a single wheel of the vehicle; determining the target control parameter of the height of the hydraulic suspension according to the action command; and adjusting the height of the hydraulic suspension using a double-loop cascade PID controller based on the target control parameter. In this way, by using a double-loop cascade PID controller to adjust the height of the hydraulic suspension, the outer position loop is used to determine the height change rate of the hydraulic suspension, and the inner speed loop is used to adjust the speed of the hydraulic pump based on the height change rate, so that the height of the hydraulic suspension can change according to the desired height change rate, thereby avoiding oscillation near the desired height, achieving precise control of the height of the hydraulic suspension, and improving the control quality.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle hydraulic suspension systems, and specifically to a method, device, equipment and storage medium for adjusting the height of a hydraulic suspension. Background Art

[0002] The hydraulic suspension is a closed-loop control system composed of sensors and controllers. According to the vehicle's operating status, it sends control commands to the actuator in a timely manner according to the set control rules. The main function of the hydraulic suspension height adjustment is to automatically adjust the vehicle body height according to the vehicle's speed and road conditions, thereby improving driving stability and comfort. The control quality of the hydraulic suspension height adjustment directly affects the user's driving experience. Therefore, it is particularly important to accurately adjust the hydraulic suspension and improve the height control quality of the hydraulic suspension.

[0003] In the related art, the solution for adjusting the height of the hydraulic suspension usually adopts a single proportional-differential-integral (PID) controller to adjust the height of the hydraulic suspension. Using only a single PID controller to control the target height of the hydraulic suspension can easily cause oscillation near the desired height. Even if the proportion and integrator are reduced, the actuator cannot play a good role, because the speed of the hydraulic pump is mapped after the desired speed is changed, and the speed generates different lift or lowering force through the shock absorber, thereby affecting the change of the suspension height. The controlled height is indirectly controlled by the actuator, so accurate height control cannot be achieved. Summary of the invention

[0004] The present application provides a method, device, equipment and storage medium for adjusting the height of a hydraulic suspension. The method can achieve precise control of the height of the hydraulic suspension and improve the control quality.

[0005] The technical solution of this application is implemented as follows:

[0006] An embodiment of the present application provides a method for adjusting the height of a hydraulic suspension, comprising: if it is determined according to the current state of the vehicle that the conditions for adjusting the height of the hydraulic suspension are met, outputting an action command for a single wheel of the vehicle; determining a target control parameter for the height of the hydraulic suspension according to the action command; based on the target control parameter, adjusting the height of the hydraulic suspension using a dual-loop cascade PID controller; wherein the dual-loop cascade PID controller includes an outer position loop for determining the rate of change of the height of the hydraulic suspension, and an inner speed loop for controlling the speed of the hydraulic pump.

[0007] According to the above technical means, the height of the hydraulic suspension is adjusted by using a dual-loop cascade PID controller, the height change rate of the hydraulic suspension is determined by using an outer position loop, and the speed of the hydraulic pump is adjusted based on the height change rate by using an inner speed loop, so that the height of the hydraulic suspension can be changed at a desired height change rate, thereby avoiding oscillations near the desired height, achieving precise control of the height of the hydraulic suspension, and improving the control quality.

[0008] Furthermore, the outer position loop adopts proportional control, and the inner speed loop adopts PID control.

[0009] According to the above technical means, since the outer position loop adopts proportional control, the problem of slow response caused by integral control and noise introduced by differential control can be avoided. Simple proportional control can complete the determination of the height change rate, thereby realizing simple and efficient control. Furthermore, the height change rate output by the outer control loop is input into the inner speed loop. PID control can be used to adjust the height of the hydraulic suspension according to the height change rate, thereby improving the efficiency of the height adjustment of the hydraulic suspension.

[0010] Further, the target control parameters include a target height of the hydraulic suspension; based on the target control parameters, the height of the hydraulic suspension is adjusted using a dual-loop cascade PID controller, including: inputting the target height into the outer position loop to determine the expected height change rate of the hydraulic suspension; inputting the expected height change rate into the inner speed loop, and adjusting the speed of the hydraulic pump based on the expected height change rate, so that the height of the hydraulic suspension changes according to the expected height change rate and reaches the target height.

[0011] According to the above technical means, the expected height change rate of the hydraulic suspension is determined by the outer position loop, and the speed of the hydraulic pump is adjusted according to the expected height change rate by the inner speed loop, so that accurate height change control can be achieved. This structure of outer position loop plus inner speed loop only has one more inner loop than the simple control system. For the same interference, this structure has better robustness and faster response than the single PID, and has higher control quality.

[0012] Further, determining the expected height change rate of the hydraulic suspension includes: acquiring the current height of the hydraulic suspension; determining a first height error corresponding to the current height based on the current height and an expected curve for achieving the target height; the expected curve for achieving the target height is a sine curve; determining the expected height change rate corresponding to the current height based on the first height difference and a proportional control parameter of a dual-loop cascade PID controller.

[0013] According to the above-mentioned technical means, since the expected curve for achieving the target height is a sine curve, the first height error corresponding to the current height can be determined based on the current height of the hydraulic suspension and the expected curve corresponding to the target height. Furthermore, the expected height change rate of the hydraulic suspension from the current height to the first expected height can be quickly determined based on the first height error and the proportional control parameter. Adjustment based on the expected height change rate can ensure that the height change of the hydraulic suspension remains stable at the beginning and end of the adjustment, thereby avoiding the problem of inaccurate height adjustment caused by oscillation.

[0014] Further, the target control parameters include an initial height of the hydraulic suspension; determining a first height error corresponding to the current height based on the current height and an expected curve for achieving the target height comprises: obtaining a current adjusted duration of the hydraulic suspension; determining a first height difference between the initial height and the target height; determining a first expected height based on the adjusted duration, the first height difference and the expected curve for achieving the target height; determining a first height error corresponding to the current height based on the first expected height and the current height.

[0015] According to the above-mentioned technical means, based on the current adjusted time of the hydraulic suspension, the first height difference between the initial height and the target height, and the expected curve for achieving the target height, the first expected height that the hydraulic suspension needs to reach at the next moment can be quickly determined, and the first height error corresponding to the current height can be further determined based on the first expected height and the current height, so as to determine the corresponding expected height change rate based on the first height error.

[0016] Furthermore, the target control parameters include an initial height, a target height, and an expected time for adjusting the target height; the process of creating an expected curve for achieving the target height includes: establishing a functional relationship between the adjusted time for the hydraulic suspension height and the expected adjusted height based on the initial height, the target height, the expected time for adjusting the target height, and the adjusted time for the hydraulic suspension height; and determining a curve corresponding to the functional relationship as the expected curve for achieving the target height.

[0017] According to the above technical means, by determining the functional relationship between the adjusted time of the hydraulic suspension and the expected adjustment height based on the initial height, target height, expected adjustment time of the target height, and the adjusted time of the hydraulic suspension in the target control parameters, the expected curve for achieving the target height can be obtained.

[0018] Further, determining the expected height change rate corresponding to the current height based on the first height difference and the proportional control parameter of the dual-loop cascade PID controller includes: obtaining an acceleration threshold for height adjustment of the hydraulic suspension; and determining the expected height change rate corresponding to the current height based on the acceleration threshold, the proportional control parameter and the first height error.

[0019] According to the above technical means, the height change rate finally determined can be limited according to the acceleration threshold, proportional control parameters and the first height error of the hydraulic suspension system, so that the system safety can be guaranteed and the user's comfort requirements can be met during the process of adjusting the height of the hydraulic suspension.

[0020] Furthermore, the adjusting the rotational speed of the hydraulic pump based on the height change rate includes: determining an expected rotational speed corresponding to the expected height change rate according to a preset correspondence between the height change rate of the hydraulic suspension and the rotational speed of the hydraulic pump; and controlling the rotational speed of the hydraulic pump based on the expected rotational speed.

[0021] According to the above-mentioned technical means, based on the preset correspondence between the height change rate of the hydraulic suspension and the speed of the hydraulic pump, the expected speed corresponding to the expected height change rate can be quickly determined, and the speed of the hydraulic pump can be further controlled based on the expected speed. The height of the hydraulic suspension can be changed according to the expected height change rate in the process of changing to the target height, thereby improving the accuracy of the height adjustment of the hydraulic suspension.

[0022] Further, the adjusting the rotational speed of the hydraulic pump based on the expected height change rate includes: obtaining an adjustment speed threshold of the height of the hydraulic suspension; if the expected height change rate is greater than the adjustment speed threshold, updating the expected height change rate to obtain a new expected height change rate; the new expected height change rate is less than or equal to the adjustment speed threshold; and adjusting the rotational speed of the hydraulic pump based on the new expected height change rate so that the height of the hydraulic suspension changes according to the new expected height change rate and reaches the target height.

[0023] According to the above-mentioned technical means, when it is determined that the expected height change rate is greater than the adjustment speed threshold of the hydraulic suspension height, the expected height change rate can be updated so that the obtained new expected speed meets the adjustment speed threshold. Therefore, in the process of adjusting the speed of the hydraulic pump based on the new expected speed threshold, the speed of the hydraulic pump can be maintained within a safe range, thereby ensuring the safe adjustment of the hydraulic suspension height.

[0024] The embodiment of the present application provides a device for adjusting the height of a hydraulic suspension, comprising:

[0025] A first data output module, configured to output an action instruction for a single wheel of the vehicle if it is determined that a condition for adjusting the height of the hydraulic suspension is met according to the current state of the vehicle;

[0026] A first determination module, used to determine a target control parameter of the height of the hydraulic suspension according to the action instruction;

[0027] The first adjustment module is used to adjust the height of the hydraulic suspension based on the target control parameter using a dual-loop cascade PID controller; wherein the dual-loop cascade PID controller includes an outer position loop for determining the rate of change of the height of the hydraulic suspension, and an inner speed loop for controlling the speed of the hydraulic pump.

[0028] The embodiment of the present application provides a hydraulic suspension height adjustment device, comprising:

[0029] A memory for storing computer programs that can be run on the processor;

[0030] The processor is used to execute the method for adjusting the height of the hydraulic suspension provided in the embodiment of the present application when running the computer program.

[0031] An embodiment of the present application provides a computer-readable storage medium, in which computer-executable instructions are stored. The computer-executable instructions are configured to execute the above-mentioned method for adjusting the height of the hydraulic suspension. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of a flow chart of a method for adjusting the height of a hydraulic suspension provided in an embodiment of the present application;

[0033] Figure 2 A schematic diagram of the relationship between acceleration and height error provided in an embodiment of the present application;

[0034] Figure 3 A flowchart illustrating a method for adjusting the height of a hydraulic suspension provided in an embodiment of the present application;

[0035] Figure 4 A schematic diagram of the structure of a hydraulic suspension height adjustment control system provided in an embodiment of the present application;

[0036] Figure 5 It is a structural schematic diagram of a single PID control loop provided in the related art;

[0037] Figure 6 A schematic diagram of the structure of a dual-loop PID control loop provided in an embodiment of the present application;

[0038] Figure 7 A schematic diagram of a fitting curve of a desired height provided in an embodiment of the present application;

[0039] Figure 8 A schematic diagram of the structure of a hydraulic suspension height adjustment device provided in an embodiment of the present application;

[0040] Fig. 9 A schematic diagram of the composition structure of a hydraulic suspension height adjustment device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0042] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described below in conjunction with the accompanying drawings. The described embodiments should not be regarded as limiting the present application. All other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of this application.

[0043] In the following description, reference is made to “some embodiments\other embodiments”, which describe a subset of all possible embodiments, but it can be understood that “some embodiments\other embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0045] In the related art, a hydraulic device, a suspension system and a vehicle describe a hydraulic suspension system, an oil pump and a reversing valve as an oil supply unit, the reversing valve is divided into at least four routes, each of which is connected to a flow regulating valve and then connected to a shock absorber, the oil pump and the reversing valve control the flow of oil into or out of the shock absorber, and the oil inlet or outlet action of each shock absorber is synchronized. The flow regulating valve of each route is connected to the controller signal, and the size of the valve opening of the flow regulating valve can be controlled by the controller according to the actual situation, thereby adjusting the size of the oil flow in or out of each route of the shock absorber, thereby controlling the lifting and lowering speed of the piston rod of the shock absorber, so that the vehicle body at each wheel can be simultaneously raised or lowered to a predetermined height through the adjustment of the suspension, thereby improving the smoothness of the suspension lifting or lowering. However, the hydraulic suspension system architecture cannot achieve single-wheel control, and the speed adjustment range is limited only by the flow regulating valve.

[0046] In the related art, a hydraulic suspension lifting control method, device, vehicle control system and vehicle are provided. The hydraulic suspension lifting control method first determines the oil filling and discharging speed formula according to the target height of the hydraulic suspension and the height from the ground at multiple positions; then, according to the oil filling and discharging speed formula, the oil filling and discharging speed at each position is solved; finally, the hydraulic valve on-off frequency at each position is determined according to the oil filling and discharging speed at each position. Since the oil filling and discharging speed formula positively correlates the oil filling and discharging speed with the height of the hydraulic suspension, the hydraulic suspension can quickly reach a balanced level at each position at the same time; in addition, by adjusting the height of each position through the oil filling and discharging speed formula, the hydraulic suspension can be leveled first, and then adjusted to the target height on the basis of leveling, which can ensure the stability of special vehicles during the adjustment process and avoid abnormal vehicle tilt posture, thereby causing panic among drivers. The problem with the hydraulic suspension lifting control method is that it only calibrates a positive proportional coefficient k when processing the oil filling and discharging speed, and the height change rate is not controlled precisely enough.

[0047] Based on the problems existing in the related art, the embodiment of the present application provides a method for adjusting the height of a hydraulic suspension, which can achieve accurate control of the height of the hydraulic suspension and improve the control quality. Figure 1 FIG. 1 is a flow chart of a method for adjusting the height of a hydraulic suspension provided in an embodiment of the present application, the method comprising the following steps:

[0048] S101: If it is determined according to the current state of the vehicle that the conditions for adjusting the height of the hydraulic suspension are met, output an action instruction for a single wheel of the vehicle.

[0049] It should be noted that the condition of the hydraulic suspension height condition may be that the vehicle is currently in a parked or parking state, and the action instruction of a single wheel of the vehicle may be a control instruction for the hydraulic suspension height adjustment of a single wheel. According to the action instruction, the target height (expected height) of the hydraulic suspension height adjustment, the expected completion time, the stroke to be completed under the instruction, etc. can be determined.

[0050] In some embodiments, the hydraulic suspension mode, gear position, vehicle speed, current suspension height, action start, restart, pause and other signals received from the bus can be used to determine whether the hydraulic suspension mode meets the hydraulic suspension height adjustment conditions. For example, if the vehicle's current gear position is P gear, the vehicle speed is 0, the dancing mode is received, and the default height request in the mode is met, then the mode is entered and the timing is started; if a pause command is received, the timer is paused; if the preconditions for entering the mode are not met (the gear position is not P, the vehicle speed is not 0 or the mode is switched), then the mode is exited, the timer is reset, and a reset flag is issued.

[0051] In some embodiments, when it is determined that the current state of the vehicle meets the conditions for adjusting the height of the hydraulic suspension, a specific action instruction that needs to be executed by a single wheel in the current mode can be output to start adjusting the height of the hydraulic suspension for the single wheel. Different action instructions can be sent to different wheels to control the adjustment process of the height of the hydraulic suspension corresponding to different wheels respectively, and the height adjustment of the hydraulic suspension between the wheels does not affect each other.

[0052] S102: Determine a target control parameter of the height of the hydraulic suspension according to the action instruction.

[0053] In some embodiments, the action instruction includes identification information, and different identification information indicates different hydraulic suspension height adjustment targets, and the identification information may be an action instruction serial number. The target control parameter may be a target parameter for hydraulic suspension height adjustment, and the target control parameter may include the target height of the hydraulic suspension adjustment, the expected completion time, the stroke required to be completed under the action instruction (target height minus current height), the initial height, and the adjustment type, and the adjustment type may include three types: rise, fall, and hold. If the adjustment type is the hold type, the expected completion time, the stroke required to be completed under the action instruction, and the initial height are all zero, and only the target height may be obtained.

[0054] In some embodiments, the action database can be searched according to the identification information of the action instruction to determine the corresponding target control parameters. The action database can be a database that stores the identification information of the action instruction and the corresponding hydraulic suspension height adjustment parameters. The correspondence between the identification information of the action instruction and the corresponding hydraulic suspension height adjustment parameters can be pre-created. The hydraulic suspension height adjustment parameters corresponding to different action instruction serial numbers may be different. Therefore, according to the currently received action instruction, the action database can be searched to determine the target control parameters corresponding to the current action instruction.

[0055] S103: Based on the target control parameters, the height of the hydraulic suspension is adjusted using a double-loop cascade PID controller.

[0056] In some embodiments, a dual-loop cascade PID controller may include two control loops, including an outer position loop for determining the height change rate of the hydraulic suspension, and an inner speed loop for controlling the speed of the hydraulic pump. The height change rate determined or output by the outer position loop can be used as an input to the inner speed loop, so that the inner speed loop can adjust and control the height of the hydraulic suspension according to the height change rate.

[0057] In an embodiment of the present application, if the conditions for adjusting the height of the hydraulic suspension are determined to be met according to the current state of the vehicle, an action command for a single wheel of the vehicle is output; the target control parameter of the height of the hydraulic suspension is determined according to the action command; based on the target control parameter, the height of the hydraulic suspension is adjusted using a double-loop cascade PID controller. In this way, by adjusting the height of the hydraulic suspension using a double-loop cascade PID controller, the height change rate of the hydraulic suspension is determined using the outer position loop, and the speed of the hydraulic pump is adjusted based on the height change rate using the inner speed loop, so that the height of the hydraulic suspension can change at the desired height change rate, thereby avoiding oscillation near the desired height, achieving precise control of the height of the hydraulic suspension, and improving the control quality.

[0058] In some embodiments of the present application, the outer position loop adopts proportional control, and the inner speed loop adopts PID control. For the outer position loop, since the requirement for the height change rate (expected speed) is that the height change rate can reduce the position error, and when the position error is zero, the height change rate is zero, so the height change rate can be a curve related to the position error and passing through zero, so a simple proportional (P) control can be achieved. For the inner speed loop, its purpose is to achieve the change amount that can be directly changed by the actuator, so PID control can be considered.

[0059] According to the above technical means, since the outer position loop adopts proportional control, the problem of slow response caused by integral control and noise introduced by differential control can be avoided. Simple proportional control can complete the determination of the height change rate, thereby realizing simple and efficient control. Furthermore, the height change rate output by the outer control loop is input into the inner speed loop. PID control can be used to adjust the height of the hydraulic suspension according to the height change rate, thereby improving the efficiency of the height adjustment of the hydraulic suspension.

[0060] In some embodiments of the present application, the target control parameters include a target height of the hydraulic suspension; based on this, based on the target control parameters, a dual-loop cascade PID controller is used to adjust the height of the hydraulic suspension, that is, step S103 can be implemented by the following steps S1031 to S1032, and each step is described below.

[0061] S1031. Input the target height into the outer position loop to determine the expected height change rate of the hydraulic suspension.

[0062] In some embodiments, the expected height change rate can be the rate of change of the hydraulic suspension height over time, the target height can be the expected height adjusted by the hydraulic suspension system, and the outer position loop can determine the height change rate corresponding to the current height based on the input target height and the current height of the hydraulic suspension.

[0063] S1032: Input the desired height change rate into the inner speed loop, and adjust the rotation speed of the hydraulic pump based on the desired height change rate, so that the height of the hydraulic suspension changes according to the desired height change rate and reaches the target height.

[0064] In some embodiments, after the desired height change rate is determined by the outer position loop, the rotational speed of the hydraulic pump can be determined according to the desired height change rate by the inner speed loop, and the hydraulic pump can be controlled by the motor to rotate at the rotational speed, so that at this rotational speed, the height of the hydraulic suspension can change according to the desired height change rate and finally reach the target height.

[0065] According to the above technical means, the expected height change rate of the hydraulic suspension is determined by the outer position loop, and the speed of the hydraulic pump is adjusted according to the expected height change rate by the inner speed loop, so that accurate height change control can be achieved. This structure of outer position loop plus inner speed loop only has one more inner loop than the simple control system. For the same interference, this structure has better robustness and faster response than the single PID, and has higher control quality.

[0066] In some embodiments of the present application, "determining the expected height change rate of the hydraulic suspension" in step S1031 can be implemented through the following steps S201 to S203, and each step is described below.

[0067] S201. Obtain the current height of the hydraulic suspension.

[0068] In some embodiments, the current height of the hydraulic suspension may be the height of the hydraulic suspension determined when a single-wheel action command is received, or it may be the height after the height of the hydraulic suspension is adjusted one or more times after the action command is received. The current height of the hydraulic suspension may be the same as or different from the initial height according to the action command.

[0069] S202: Determine a first height error corresponding to the current height according to the current height and an expected curve for achieving the target height.

[0070] In some embodiments, the target height realization expected curve may be a pre-established curve of the hydraulic suspension height changing over time from zero to the target height, and the realization expected curve may be a sine curve. The first height error may be the height difference between the current height and the first expected height corresponding to the current moment, and the first expected height may be less than or equal to the target height. Based on the current height of the hydraulic suspension and the target height realization expected curve, the first height error corresponding to the current height may be determined.

[0071] S203: Determine an expected altitude change rate corresponding to the current altitude according to the first altitude difference and a proportional control parameter of the dual-loop cascade PID controller.

[0072] In some embodiments, after the first height error is determined, the expected height change rate corresponding to the current height can be determined based on the first height difference and the proportional control parameter.

[0073] According to the above-mentioned technical means, since the expected curve for achieving the target height is a sine curve, the first height error corresponding to the current height can be determined based on the current height of the hydraulic suspension and the expected curve corresponding to the target height. Furthermore, the expected height change rate of the hydraulic suspension from the current height to the first expected height can be quickly determined based on the first height error and the proportional control parameter. Adjustment based on the expected height change rate can ensure that the height change of the hydraulic suspension remains stable at the beginning and end of the adjustment, thereby avoiding the problem of inaccurate height adjustment caused by oscillation.

[0074] In some embodiments of the present application, the target control parameters include the initial height of the hydraulic suspension. Based on this, the first height error corresponding to the current height is determined according to the current height and the expected curve for achieving the target height, that is, step S202 can be implemented by the following steps S2021 to S2024, and each step is described below.

[0075] S2021. Obtain the current adjusted duration of the hydraulic suspension.

[0076] In some embodiments, the current adjusted time length of the hydraulic suspension may be the length of time taken to adjust the height of the hydraulic suspension from the time the single-wheel action command is received to the current moment. If the height of the hydraulic suspension has not been adjusted after the single-wheel action command is received, the adjusted time length may be zero.

[0077] S2022: Determine a first height difference between the initial height and the target height.

[0078] In some embodiments, the initial height may be determined according to the target height determined by the action instruction and the initial height, that is, the absolute value of the difference between the initial height and the target height may be used to determine the first height difference.

[0079] S2023: Determine a first expected height based on the first duration, the first height difference, and the expected curve for achieving the target height.

[0080] In some embodiments, the first expected height may be the next height that the hydraulic suspension needs to adjust from the current height at the current moment. The expected curve for achieving the target height can be determined by a mathematical function expression. Therefore, after determining the current adjusted time of the hydraulic suspension and the first height difference, the adjusted height and the first height difference can be combined with the mathematical function expression corresponding to the expected curve to determine the first expected height.

[0081] S2024. Determine a first height error corresponding to the current height according to the first expected height and the current height.

[0082] In some embodiments, the first altitude error may be determined based on an absolute value of a difference between the first desired altitude and the current altitude.

[0083] According to the above-mentioned technical means, based on the current adjusted time of the hydraulic suspension, the first height difference between the initial height and the target height, and the expected curve for achieving the target height, the first expected height that the hydraulic suspension needs to reach at the next moment can be quickly determined, and the first height error corresponding to the current height can be further determined based on the first expected height and the current height, so as to determine the corresponding expected height change rate based on the first height error.

[0084] In some embodiments of the present application, the target control parameters include the target height and the expected time for adjusting the target height. Based on this, the process of creating the expected curve for achieving the target height can be achieved through the following steps S301 to S302, and each step is described below.

[0085] S301. Establish a functional relationship between the adjusted time of the hydraulic suspension height and the expected adjusted height according to the initial height, the target height, the expected time after the target height is adjusted, and the adjusted time of the hydraulic suspension height.

[0086] In some embodiments, after receiving a single-wheel action command, the functional relationship between the adjusted time of the hydraulic suspension height and the expected adjusted height can be determined based on the target control parameters determined by the action command, wherein the adjusted time of the hydraulic suspension height can be the independent variable of the functional relationship, and the first error between the initial height and the target height and the expected time to complete the target height adjustment can be fixed parameters of the functional relationship.

[0087] For example, the functional relationship between the adjusted height duration of the hydraulic suspension and the desired adjusted height can be expressed by formula (1):

[0088]

[0089] Among them, CtrlTarHeiCurve, HeightGapInit, CtrlTotalTime, CurrentTime, and HeightOrig respectively represent the expected adjustment height, target height and expected height difference (first height difference), expected time for target height adjustment, expected time for target height adjustment, and the actual height at the beginning of hydraulic suspension adjustment.

[0090] S302: Determine the curve corresponding to the functional relationship as the desired curve for achieving the target height.

[0091] In some embodiments, after determining the functional relationship between the adjusted time of the height of the hydraulic suspension and the desired adjusted height, a curve corresponding to the functional relationship may be plotted to obtain an expected realization curve corresponding to the target height.

[0092] According to the above technical means, by determining the functional relationship between the adjusted time of the hydraulic suspension and the expected adjustment height based on the initial height, target height, expected adjustment time of the target height, and the adjusted time of the hydraulic suspension in the target control parameters, the expected curve for achieving the target height can be obtained.

[0093] In some embodiments of the present application, the expected altitude change rate corresponding to the current altitude is determined based on the first altitude difference and the proportional control parameters of the dual-loop cascade PID controller, that is, the above-mentioned step S203 can be implemented by the following steps S2031 to S2032, and each step is described separately below.

[0094] S2031. Obtain an acceleration threshold for height adjustment of the hydraulic suspension.

[0095] In some embodiments, the acceleration threshold of the height adjustment of the hydraulic suspension may be an acceleration / deceleration limit value of the height adjustment determined according to a bench test and performance parameters of the hydraulic pump. Different hydraulic suspension systems may have different corresponding acceleration thresholds.

[0096] S2032: Determine an expected altitude change rate corresponding to the current altitude according to the acceleration threshold, the proportional control parameter and the first altitude difference.

[0097] In some embodiments, the expected altitude change rate can be calculated based on the first altitude difference between the initial altitude and the target altitude. However, due to the limitation of system acceleration, in the process of determining the expected altitude change rate, the expected altitude change rate needs to be limited in combination with the acceleration threshold.

[0098] For example, the altitude change rate can be determined according to formula (2):

[0099] TarAdjustSpd=KpHeight 2 *(CtrlTarHeiCurve-CtrlActHei) (2);

[0100] Among them, TarAdjustSpd, KpHeigh and CtrlTarHeiCurve-CtrlActHei represent the height change rate, KpHeigh value and real-time height error (first height error) respectively. According to formula (2), it can be seen that when the error converges to 0, the acceleration is not constant, but proportional to the square of KpHeigh. However, the acceleration capacity of the system is limited. Therefore, we expect that during the entire operation process, the given reference acceleration cannot exceed the acceleration threshold. When the error exceeds a certain value, the acceleration cannot increase linearly with the error, but remains at a constant value, such as Figure 2 According to formula (2), the position error is less than AdjustAccMax / KpHeigh 2 When the first height error is greater than AdjustAccMax / KpHeight 2 When the first height error is greater than AdjustAccMax / KpHeight 2 According to the uniform acceleration equation v-v0 2 =2as we can get formula (3):

[0101]

[0102] Therefore, the relationship between the first height error and the acceleration threshold is as shown in formula (4):

[0103] TarAdjustSpd=(2*AdjustAccMax*HeightGap-(AdjustAccMax / KpHeigh)^2)^0.5 (4);

[0104] Therefore, when HeightGap<=AdjustAccMax / (KpHeigh*KpHeigh), the height change rate can be expressed by formula (5):

[0105] TarAdjustSpd=KpHeigh*HeightGap (5);

[0106] When HeightGap>AdjustAccMax / (KpHeigh*KpHeigh), the height change rate can be expressed by formula (6):

[0107] TarAdjustSpd=(2*AdjustAccMax*HeightGap-(AdjustAccMax / KpHeigh)^2)^0.5 (6);

[0108] Therefore, the expected altitude change rate corresponding to the current altitude may be determined according to the acceleration threshold, the proportional control parameter and the first altitude difference.

[0109] According to the above technical means, the height change rate finally determined can be limited according to the acceleration threshold, proportional control parameters and the first height error of the hydraulic suspension system, so that the system safety can be guaranteed and the user's comfort requirements can be met during the process of adjusting the height of the hydraulic suspension.

[0110] In some embodiments of the present application, "adjusting the rotation speed of the hydraulic pump based on the height change rate" in step S1032 can be implemented through the following steps S401A to S402A, and each step is described below.

[0111] S401A: Determine an expected rotational speed corresponding to an expected height change rate according to a preset correspondence between a height change rate of the hydraulic suspension and a rotational speed of the hydraulic pump.

[0112] In some embodiments, a preset correspondence between the height change rate of the hydraulic suspension and the rotational speed of the hydraulic pump may be created in advance, and the rotational speeds of the hydraulic pumps corresponding to different height change rates may be different. The preset relationship may be stored in a preset correspondence table between the height change rate of the hydraulic suspension and the rotational speed of the hydraulic pump. Therefore, after determining the expected height change rate, the corresponding expected rotational speed may be determined from the preset relationship table.

[0113] S402A: Control the speed of the hydraulic pump based on the desired speed.

[0114] In some embodiments, after the rotation speed of the hydraulic pump is determined, the working parameters of the motor can be controlled to achieve control of the rotation speed of the hydraulic pump so that the hydraulic pump reaches the desired rotation speed.

[0115] According to the above-mentioned technical means, based on the preset correspondence between the height change rate of the hydraulic suspension and the speed of the hydraulic pump, the expected speed corresponding to the expected height change rate can be quickly determined, and the speed of the hydraulic pump can be further controlled based on the expected speed. The height of the hydraulic suspension can be changed according to the expected height change rate in the process of changing to the target height, thereby improving the accuracy of the height adjustment of the hydraulic suspension.

[0116] In some embodiments of the present application, "adjusting the rotation speed of the hydraulic pump based on the height change rate" in step S1032 can be implemented through the following steps S401B to S403B, and each step is described below.

[0117] S401B, obtaining a hydraulic suspension height adjustment speed threshold.

[0118] In some embodiments, the adjustment speed threshold of the hydraulic suspension height may be a maximum height adjustment speed determined based on bench tests and performance parameters of the hydraulic pump, and different hydraulic suspension systems may correspond to different adjustment speed thresholds.

[0119] S402B: If the expected altitude change rate is greater than the adjustment speed threshold, update the expected altitude change rate to obtain a new expected altitude change rate.

[0120] In some embodiments, if the expected height change rate is greater than the adjustment speed threshold, height adjustment based on the expected height change rate may cause safety problems for the hydraulic suspension system. Therefore, when it is determined that the expected height change rate is greater than the adjustment speed threshold, the expected height change rate may be updated or corrected to obtain a new expected height change rate.

[0121] S403B: adjusting the rotation speed of the hydraulic pump based on the new expected height change rate, so that the height of the hydraulic suspension changes according to the new expected height change rate and reaches the target height.

[0122] In some embodiments, after determining a new expected height change rate, if it is determined that the new expected height change rate is less than or equal to an adjustment speed threshold, the expected speed corresponding to the new expected height change rate can be determined based on a preset correspondence between the height change rate of the hydraulic suspension and the speed of the hydraulic pump, thereby adjusting the speed of the hydraulic pump according to the expected speed, so that the height of the hydraulic suspension changes according to the new expected height change rate and finally reaches the target height.

[0123] According to the above-mentioned technical means, when it is determined that the expected height change rate is greater than the adjustment speed threshold of the hydraulic suspension height, the expected height change rate can be updated so that the obtained new expected speed meets the adjustment speed threshold. Therefore, in the process of adjusting the speed of the hydraulic pump based on the new expected speed threshold, the speed of the hydraulic pump can be maintained within a safe range, thereby ensuring the safe adjustment of the hydraulic suspension height.

[0124] In the embodiment of the present application, if the condition for adjusting the height of the hydraulic suspension is determined to be met according to the current state of the vehicle, an action command for a single wheel of the vehicle is output; the target control parameter of the height of the hydraulic suspension is determined according to the action command; based on the target control parameter, the height of the hydraulic suspension is adjusted using a double-loop cascade PID controller. In this way, by using a double-loop cascade PID controller to adjust the height of the hydraulic suspension, the height change rate of the hydraulic suspension is determined using the outer position loop, and the speed of the hydraulic pump is adjusted based on the height change rate using the inner speed loop, so that the height of the hydraulic suspension can change at the desired height change rate, thereby avoiding oscillation near the desired height, achieving precise control of the height of the hydraulic suspension, and improving the control quality.

[0125] Next, the implementation process of the application embodiment in the actual application scenario is introduced.

[0126] The embodiment of the present application provides a method for controlling the height adjustment of a hydraulic suspension. Figure 3 The hydraulic suspension height adjustment control system 500 is implemented by the bus module 501, module 1 502, module 2 503, module 3 504, module 4 505 and actuator 505 shown in the figure. Figure 4 The hydraulic suspension height adjustment control method is described, and the hydraulic suspension height adjustment control method includes:

[0127] S601, bus module 501 sends signals such as hydraulic suspension mode, gear position, vehicle speed, current suspension height, action start, restart, pause, etc. to module 1 502.

[0128] S602, module 1 502 integrates the above signals to judge the mode precondition (equivalent to the "condition for hydraulic suspension height adjustment" in other embodiments, as well as pause, exit, etc.), and outputs the action instruction sequence number (equivalent to the "action instruction" in other embodiments).

[0129] For example, when the P gear is engaged and the vehicle speed is 0, the dancing mode is received and the default height request in this mode is met, the mode is entered and the timing is started; if a pause command is received, the timer is paused; if the following prerequisites for entering this mode are not met (the gear is not P, the vehicle speed is not 0 or the mode is switched), the mode is exited, the timer is cleared, and a reset flag is issued; the specific action instructions and the number of repetitions for a single wheel or multiple wheels can be flexibly arranged according to the time points; when the timer is paused, the module will retain the current action instruction state; when the timer is cleared, all action instructions issued by the module are 0; the specific action instruction sequence number and the number of repetitions that need to be executed at different time points for each wheel in the current mode, as well as the timer reset signal, are output.

[0130] S603, module 2 503 receives the single-wheel action instruction and the number of cycles, the single-wheel height adjustment completion status and the timer reset signal, and controls the single-wheel target height, the expected completion time, the stroke to be completed under the instruction, the initial height and the adjustment type (equivalent to the "target control parameters" in other embodiments).

[0131] Search the action library according to the action instruction sequence number of a single round, and output the specific control target height, expected completion time, the stroke required to be completed under the instruction (target height minus current height), initial height and adjustment type (ascend, descend, hold) corresponding to the instruction. If it is the hold type, the expected time, the stroke required to be completed under the instruction, and the initial height are 0, and only the expected height is sent;

[0132] The action library can be a single action (such as ascend, descend, and hold) or an action group (such as ascend descend, descend ascend, and hold);

[0133] According to the completion status of the height adjustment, it is determined whether to proceed / loop the next action; after the current action instruction is completed, before the next instruction, it will enter the hold module by default and maintain the target height of the previous action until the next action instruction is input. If a termination or restart signal is received midway, the current loop will be jumped out and all instructions will be set to 0.

[0134] Output single-wheel control target height, expected completion time, travel required to be completed under this instruction, initial height, and adjustment type.

[0135] S604, module 3 504 receives the single-wheel control target height, expected completion time, the stroke to be completed under the instruction, the initial height and the adjustment type, the maximum speed and acceleration and deceleration limits, the tolerance threshold for height adjustment completion, and the PID adjustment parameter Kp value, and determines the expected height change rate.

[0136] Regarding specific motion control, referring to the motion control algorithms of drones and autonomous driving, a dual-loop cascade PID method is used to achieve motion control of the hydraulic suspension system. Because for the hydraulic suspension system, if only PID is used to control the target height, it is easy to cause oscillation near the desired height. Even if the proportion and integrator are adjusted down, the actuator will not work well, because the speed of the electric hydraulic pump is mapped after the desired speed is changed, and the speed generates different lift or lowering forces through the shock absorber, thereby affecting the change of the suspension height. The height of the controlled quantity is indirectly controlled by the actuator.

[0137] Therefore, the output of the actuator cannot directly control the target physical quantity (position height), but the actuator can control the change (speed) of the physical quantity (position height). Then, by controlling the differential of the target physical quantity (position height) and changing it according to a certain curve, the purpose of indirectly controlling the target physical quantity can be achieved. However, this curve must satisfy two points. When there is an error in the target physical quantity, a change that reduces the error should be produced, and when there is no error, the change should also be 0. Therefore, the simplest P control can be achieved, so the control of the outer position loop uses P control. The purpose of the inner speed loop is to achieve the change that can be directly changed by the actuator. PID control can be considered. The purpose of the outer loop is to find a suitable curve to guide the differential change (speed change) of the control target (position height) to achieve the effect of indirect control. Specifically, the outer position loop outputs the desired height change rate, and this output of the outer loop serves as the input of the inner speed loop. This control architecture is structurally only smaller than the inner speed loop. Figure 5 The simple control system shown in the figure has an additional inner loop. However, for the same disturbance, the dual-loop PID of the position loop and speed loop has better robustness and faster response than the single PID, and the control quality is higher. The dual-loop PID control architecture is as follows: Figure 6 shown.

[0138] Planning of the desired height trajectory: In the acceleration and deceleration movement of the actuator, in order to make the actuator transition smoothly when starting and stopping, and the speed is smoother, the commonly used sinusoidal curve fitting method is used for the overall height realization path. The sinusoidal curve corresponding to the overall height realization path is as follows: Figure 7 shown.

[0139] The desired speed is controlled by P according to the height error. The reason for not using PID is mainly because adding the integral term will cause the response to slow down, and adding the differential term will easily introduce noise. Only P control is simple and efficient. Our requirement for the desired speed is that the desired speed must be able to reduce the position error, and when the position error is 0, the desired speed is 0. Therefore, the desired speed should be a curve related to the position error and passing through 0. And there are two constraints when constructing this curve, one is the limit on the maximum acceleration of the hydraulic suspension system, and the other is the limit on the maximum speed of the hydraulic suspension system. Here, the APM square root controller Sqrt_Controller commonly used in aircraft control is used to construct the desired speed curve.

[0140] Sqrt_controller is essentially an optimized version of P control. The expected speed is TarAdjustSpd, the target height curve is CtrlTarHeiCurve, the actual height is CtrlActHei, and the real-time height error is:

[0141] Descending: HeightGap=min((CtrlTarHeiCurve-CtrlActHei),0);

[0142] Rising: HeightGap=max((CtrlTarHeiCurve-CtrlActHei),0).

[0143] Furthermore, by limiting the speed and acceleration of the desired height adjustment rate output according to the maximum speed and acceleration and deceleration limits of the height adjustment determined by bench tests and the performance parameters of the electric hydraulic pump, the safety and comfort requirements of the system can be ensured.

[0144] The state of completion of the height adjustment is judged according to the tolerance threshold of the completion of the height adjustment, and a flag bit of the completion of the height adjustment is output.

[0145] Output the expected rate of final height change in a single round and the height adjustment completion flag.

[0146] S605 , module 4 505 receives the expected rate of final height change of a single round, and controls the working state of the actuator 506 .

[0147] Module 4 505 performs PID control on the altitude change rate, and uses the error between the actual altitude change rate and the expected altitude change rate to output a speed request for the electric hydraulic pump, thereby achieving target control of the altitude change rate, which is the inner speed loop. Actuator 506 may be an electric hydraulic pump, and may output a speed request for the electric hydraulic pump according to the expected altitude change rate.

[0148] The hydraulic suspension height adjustment control method provided in the embodiment of the present application defines an instruction library of single-wheel action instructions, realizes the decoupling of the four-wheel action of the requesting end, and unitizes the action instructions to facilitate repeated calls; designs action instructions for single or multiple wheels according to the time series, which is convenient for arranging complex continuous action combinations, and sets timers to facilitate the pause and restart processing of actions; refers to the motion control algorithm of unmanned aerial vehicles and automatic driving, and adopts a dual-loop cascade PID method to realize the motion control of the hydraulic suspension system, which has better robustness and faster response than simple control systems, and has higher control quality; plans the target height adjustment process according to the sine curve, so that the actuation adjustment process is smoother and more stable; adopts the APM square root controller commonly used in aircraft control to construct the speed expectation curve, limits the expected speed within the range of the system's maximum acceleration and speed, and ensures simple and effective position loop P control.

[0149] The embodiment of the present application provides a device for adjusting the height of a hydraulic suspension. Figure 8 A schematic diagram of the structure of a hydraulic suspension height adjustment device provided in an embodiment of the present application is shown in FIG. Figure 8As shown, the hydraulic suspension height adjustment device 800 includes:

[0150] The first data output module 801 is used to output the action instruction of the single wheel of the vehicle if it is determined that the condition for adjusting the height of the hydraulic suspension is met according to the current state of the vehicle;

[0151] A first determination module 802, configured to determine a target control parameter of the height of the hydraulic suspension according to the action instruction;

[0152] The first adjustment module 803 is used to adjust the height of the hydraulic suspension based on the target control parameter using a dual-loop cascade PID controller; wherein the dual-loop cascade PID controller includes an outer position loop for determining the rate of change of the height of the hydraulic suspension, and an inner speed loop for controlling the speed of the hydraulic pump.

[0153] In some embodiments, the outer position loop adopts proportional control, and the inner speed loop adopts PID control.

[0154] In some embodiments, the target control parameter includes a target height of the hydraulic suspension; the first adjustment module 803 includes:

[0155] a first determination submodule, configured to input the target height into the outer position loop to determine a desired height change rate of the hydraulic suspension;

[0156] The first regulating submodule is used to input the expected height change rate into the inner speed loop, and regulate the rotation speed of the hydraulic pump based on the expected height change rate, so that the height of the hydraulic suspension changes according to the expected height change rate and reaches the target height.

[0157] In some embodiments, the first determining submodule includes:

[0158] A first acquisition unit, used for acquiring a current height of the hydraulic suspension;

[0159] A first determining unit is used to determine a first height error corresponding to the current height according to the current height and an expected curve for achieving the target height; the expected curve for achieving the target height is a sine curve;

[0160] The second determining unit is used to determine the expected altitude change rate corresponding to the current altitude according to the first altitude difference and a proportional control parameter of a dual-loop cascade PID controller.

[0161] In some embodiments, the target control parameter includes an initial height of the hydraulic suspension; and the first determining unit includes:

[0162] A first acquisition subunit is used to acquire the current adjustment time of the hydraulic suspension;

[0163] A first determining subunit, configured to determine a first height difference between the initial height and the target height;

[0164] A second determining subunit is used to determine a first expected height based on the adjusted time, the first height difference and the expected curve of achieving the target height;

[0165] The third determining subunit is used to determine a first height error corresponding to the current height according to the first expected height and the current height.

[0166] In some embodiments, the target control parameters include an initial height, a target height, and an expected time for adjusting the target height; the hydraulic suspension height adjustment device 800 further includes:

[0167] A first creation module is used to establish a functional relationship between the adjusted time of the hydraulic suspension height and the expected adjusted height according to the initial height, the target height, the expected time after the target height is adjusted, and the adjusted time of the hydraulic suspension height;

[0168] The second determination module is used to determine the curve corresponding to the functional relationship as the expected curve for achieving the target height.

[0169] In some embodiments, the second determining unit includes:

[0170] A second acquisition subunit is used to acquire an acceleration threshold value for height adjustment of the hydraulic suspension;

[0171] The fourth determination subunit is used to determine the expected altitude change rate corresponding to the current altitude according to the acceleration threshold, the proportional control parameter and the first altitude error.

[0172] In some embodiments, the first regulation submodule includes:

[0173] a third determining unit, configured to determine an expected speed corresponding to the expected height change rate according to a preset correspondence between the height change rate of the hydraulic suspension and the speed of the hydraulic pump;

[0174] A first control unit is configured to control a rotation speed of the hydraulic pump based on the desired rotation speed.

[0175] In some embodiments, the first regulating submodule further includes:

[0176] A third acquisition subunit is used to acquire an adjustment speed threshold of the height of the hydraulic suspension;

[0177] A rate update subunit, configured to update the expected altitude change rate to obtain a new expected altitude change rate if the expected altitude change rate is greater than the adjustment speed threshold; the new expected altitude change rate is less than or equal to the adjustment speed threshold;

[0178] The speed regulating subunit is used to regulate the speed of the hydraulic pump based on the new expected height change rate, so that the height of the hydraulic suspension changes according to the new expected height change rate and reaches the target height.

[0179] It should be noted that the description of the hydraulic suspension height adjustment device in the embodiment of the present application is similar to the description of the corresponding method embodiment above, and has similar beneficial effects as the method embodiment, so it is not repeated here. For technical details not disclosed in this embodiment, please refer to the description of the method embodiment of the present application for understanding.

[0180] It should be noted that in the embodiments of the present application, if the above-mentioned method for adjusting the height of the hydraulic suspension is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application can be essentially or the part that contributes to the relevant solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods of each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a U disk, a mobile hard disk, a read-only memory (ROM), a magnetic disk or an optical disk. In this way, the embodiments of the present application are not limited to any specific combination of hardware and software.

[0181] Accordingly, an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the method for adjusting the height of the hydraulic suspension provided in the above embodiment is implemented.

[0182] Fig. 9 A schematic diagram of the composition structure of a hydraulic suspension height adjustment device provided in an embodiment of the present application, such as Fig. 9 As shown, the hydraulic suspension height adjustment device 900 includes: a memory 901, a processor 902, a communication interface 903 and a communication bus 904. The memory 901 is used to store instructions for downloading executable vehicle upgrade files; the processor 902 is used to execute the executable hydraulic suspension height adjustment instructions stored in the first memory 901 to implement the hydraulic suspension height adjustment method provided in the above embodiment.

[0183] The description of the above embodiment of the hydraulic suspension height adjustment device is similar to the description of the above method embodiment, and has similar beneficial effects as the method embodiment. For technical details not disclosed in the embodiment of the hydraulic suspension height adjustment device of this application, please refer to the description of the method embodiment of this application for understanding.

[0184] It should be noted that, in this article, the term "comprises" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises at least one ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0185] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0186] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units; they may be located in one place or distributed on multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0187] In addition, all functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may be a separate unit, or two or more units may be integrated into one unit; the above-mentioned integrated units may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0188] A person of ordinary skill in the art can understand that: all or part of the steps of implementing the above-mentioned method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above-mentioned method embodiment; and the aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROM, disks or optical disks.

[0189] Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application can essentially or in other words, the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a product to execute all or part of the methods of each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0190] The above are only implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technical object familiar with the technical field can be easily thought of within the technical scope disclosed in the present application. Changes or substitutions should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for adjusting the height of a hydraulic suspension, characterized in that: include: If it is determined according to the current state of the vehicle that the condition for adjusting the height of the hydraulic suspension is met, outputting an action instruction for the single wheel of the vehicle; Determining a target control parameter of the height of the hydraulic suspension according to the action instruction; Based on the target control parameters, the height of the hydraulic suspension is adjusted using a dual-loop cascade PID controller; wherein the dual-loop cascade PID controller includes an outer position loop for determining the rate of change of the height of the hydraulic suspension, and an inner speed loop for controlling the speed of the hydraulic pump.

2. The method according to claim 1, characterized in that The outer position loop adopts proportional control, and the inner speed loop adopts PID control.

3. The method according to claim 1, characterized in that The target control parameter includes a target height of the hydraulic suspension; The step of adjusting the height of the hydraulic suspension by using a double-loop cascade PID controller based on the target control parameter includes: inputting the target height into the outer position loop to determine a desired rate of change of height of the hydraulic suspension; The desired height change rate is input into the inner speed loop, and the rotation speed of the hydraulic pump is adjusted based on the desired height change rate, so that the height of the hydraulic suspension changes according to the desired height change rate and reaches the target height.

4. The method according to claim 3, characterized in that The determining of the expected height change rate of the hydraulic suspension comprises: Obtaining the current height of the hydraulic suspension; Determine a first height error corresponding to the current height according to the current height and an expected curve for achieving the target height; the expected curve for achieving the target height is a sine curve; The expected altitude change rate corresponding to the current altitude is determined according to the first altitude difference and a proportional control parameter of a dual-loop cascade PID controller.

5. The method according to claim 4, characterized in that The target control parameter includes an initial height of the hydraulic suspension; and determining a first height error corresponding to the current height according to the current height and an expected curve for achieving the target height, comprising: Obtaining the current adjustment time of the hydraulic suspension; determining a first height difference between the initial height and the target height; Determining a first desired altitude based on the adjusted time duration, the first altitude difference, and an expected curve for achieving the target altitude; A first height error corresponding to the current height is determined according to the first expected height and the current height.

6. The method according to claim 4, characterized in that The target control parameters include an initial height, a target height, and an expected time for adjusting the target height; the process of creating an expected curve for achieving the target height includes: Establishing a functional relationship between the adjusted time of the hydraulic suspension height and the expected adjusted height according to the initial height, the target height, the expected time after the target height is adjusted, and the adjusted time of the hydraulic suspension height; The curve corresponding to the functional relationship is determined as the expected curve for achieving the target height.

7. The method according to claim 4, characterized in that The determining the expected altitude change rate corresponding to the current altitude according to the first altitude difference and the proportional control parameter of the dual-loop cascade PID controller includes: Acquiring an acceleration threshold for height adjustment of the hydraulic suspension; An expected altitude change rate corresponding to the current altitude is determined according to the acceleration threshold, the proportional control parameter and the first altitude error.

8. The method according to claim 3, characterized in that The adjusting the rotation speed of the hydraulic pump based on the height change rate includes: Determining an expected speed corresponding to the expected height change rate according to a preset correspondence between the height change rate of the hydraulic suspension and the speed of the hydraulic pump; The rotation speed of the hydraulic pump is controlled based on the desired rotation speed.

9. The method according to claim 3, characterized in that: The adjusting the rotation speed of the hydraulic pump based on the expected altitude change rate comprises: Obtaining a speed threshold for adjusting the height of the hydraulic suspension; If the expected altitude change rate is greater than the adjustment speed threshold, the expected altitude change rate is updated to obtain a new expected altitude change rate; the new expected altitude change rate is less than or equal to the adjustment speed threshold; The rotation speed of the hydraulic pump is adjusted based on the new expected height change rate, so that the height of the hydraulic suspension changes according to the new expected height change rate and reaches the target height.

10. A device for adjusting the height of a hydraulic suspension, characterized in that: include: A first data output module, configured to output an action instruction for a single wheel of the vehicle if it is determined that a condition for adjusting the height of the hydraulic suspension is met according to the current state of the vehicle; A first determination module, used to determine a target control parameter of the height of the hydraulic suspension according to the action instruction; The first adjustment module is used to adjust the height of the hydraulic suspension based on the target control parameter using a dual-loop cascade PID controller; wherein the dual-loop cascade PID controller includes an outer position loop for determining the rate of change of the height of the hydraulic suspension, and an inner speed loop for controlling the speed of the hydraulic pump.

11. A hydraulic suspension height adjustment device, characterized in that: include: processor and memory; wherein, The memory is used to store a computer program that can be run on the processor; The processor is configured to execute the method according to any one of claims 1 to 9 when running the computer program.

12. A computer-readable storage medium, characterized in that: The storage medium stores computer program code, and when the computer program code is executed by a computer, the method according to any one of claims 1 to 9 is executed.

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