Control method of multi-mode controllable suspension based on power flow

Abstract

The invention discloses a multi-mode controllable suspension control method based on power flow. The method comprises the steps that S1, parameter variable setting of a multi-mode controllable suspension switching method based on power flow control is obtained and defined; s2, calculating a sprung mass acceleration threshold value, the net power of the suspension system and the maximum value of the maximum vibration power of the suspension system; s3, judging the system state of the suspension system according to the state parameter at the current t moment; and S4, whether the optimal working state of the suspension system is stable or not is evaluated through a preset system stability judgment module, and the control modes of the suspension system are switched. The method can be used for vibration reduction control of the whole vehicle operation process, impact energy absorption is effectively achieved, sprung mass acceleration and jump are reduced, meanwhile, smooth switching of the suspension among multiple control modes is achieved, and the problems of frequent system switching and mode disorder are solved.

Description

Technical Field

[0001] The present invention relates to the technical fields of power flow control and suspension multi-mode switching, and specifically provides a control method for a multi-mode controllable suspension based on power flow. Background Art

[0002] During the driving process of special-purpose vehicles (such as military vehicles, engineering vehicles, etc.), they are often affected by complex external environments, especially the vibration excitation from the road surface. Vibration excitation is sudden and unpredictable, and relatively few studies have been conducted on its control technology. However, some existing methods have shown good suppression effects. For example, the skyhook damping control method can effectively reduce the impact of vibration on the vehicle and its occupants.

[0003] The development of suspension systems has significantly improved the operating capabilities of vehicles on various terrains. A good suspension system can improve the ride comfort or handling stability of the vehicle. Commonly used damping systems are divided into passive systems, semi-active systems, and active systems. Passive systems have a simple structure and low cost, but their own parameters cannot be adjusted, and the damping effect is limited. Active systems can generate forces with adjustable magnitudes and directions, and have good damping performance. However, due to factors such as high energy consumption, complex structure, and high cost, active systems are difficult to promote. Semi-active systems are between passive systems and active systems, and mainly adjust the damping force through adjustable damping shock absorbers. However, due to the limited mechanical performance range of their actuators, the optimal control effect in the full frequency range is limited.

[0004] However, due to the complexity and variability of the vehicle driving environment, there are significant differences in the requirements for damping performance under different driving conditions, making it difficult for a single control strategy to adapt to all operating conditions. It should be noted that existing control schemes usually optimize vibration or multi-mode switching independently, without fully considering the superposition effect of the two. A single control strategy is difficult to meet the protection requirements under multiple excitation conditions. Existing hybrid control methods mainly rely on whether the suspension stroke is exhausted and touches the limit structure to determine the switching timing of the control mode. This switching strategy is relatively fixed and lacks in-depth consideration of the vibration control effect under different excitation conditions. Due to the relatively simple switching logic, it may cause a sudden change in human body acceleration at the moment of switching, which may have an adverse impact on the safety of vehicle equipment and occupants. Summary of the Invention

[0005] The purpose of the present invention is to provide a control method for a multi-mode controllable suspension based on power flow to solve the above defects.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A control method for a multi-mode controllable suspension based on power flow, comprising the following steps:

[0008] S1. Obtain and define the parameter variable settings for the multi-mode controllable suspension switching method based on power flow control;

[0009] S2. Calculate the sprung mass acceleration threshold The net power P of the suspension system net and the maximum value P of the vibration maximum power of the suspension system vmax ;

[0010] S3. According to the state parameters at the current time t, including the sprung mass acceleration of the suspension system at time t The set sprung mass acceleration threshold The net power P of the suspension system at time t net (t), the maximum value P of the vibration power flow of the suspension system at time t vmax (t), to judge the system state of the suspension system;

[0011] S4. Through a preset system stability determination module, evaluate whether the best working state of the suspension system is stable and perform the switching of the suspension system control mode.

[0012] Preferably, in the step S1, the specific steps are as follows:

[0013] S11. Use a displacement sensor to obtain the sprung mass displacement z at time t s (t), the sprung mass velocity at time t The sprung mass acceleration at time t The sprung mass acceleration threshold at time t The excitation displacement z of the unsprung mass at time t 0 (t), the excitation velocity of the unsprung mass at time t The remaining stroke s(t) of the shock absorber;

[0014] S12. Define the state parameters of the multi-mode controllable suspension switching method based on power flow control, including: the state parameter state of the suspension system, the vibration control force F of the suspension system at time t v (t), the desired control force F of the suspension system at time t d (t), the tracking control force F of the suspension system at time t u (t);

[0015] Initialize t = 0, state = 0.

[0016] Preferably, in the step S2, the specific steps are as follows:

[0017] S21. The sprung mass acceleration threshold at time t is the average value of the root mean square value of the sprung mass acceleration obtained from the passive suspension model running on the road surface, and is used as the mode switching control threshold;

[0018] S22. Calculate the net power P of the suspension system at time t using Equation (1): net (t):

[0019]

[0020] S23. Calculate the maximum vibration power flow P of the suspension system at time t using Equation (2): vmax (t):

[0021]

[0022] In Equation (1) and Equation (2), k is the spring stiffness of the suspension system; F vmax is the maximum vibration control force that the current suspension system can provide, and is obtained by outputting the maximum value from the vibration control module of the suspension system; expresses the maximum value of the difference between the response speed and the excitation speed to the current state; c(t) represents the damping coefficient of the shock absorber at time t.

[0023] Preferably, the step S3 is specifically as follows:

[0024] Obtain the sprung mass acceleration at time t through step S11 Obtain the sprung mass acceleration threshold at time t through step S21 Then, through the net power P of the suspension system at time t calculated in steps S22 and S23 net (t), the maximum vibration power flow P of the suspension system at time t vmax (t), to judge the state of the suspension system at time t, specifically as follows:

[0025] When and P net (t) > P vmax (t), it indicates that the suspension system is ready to switch to the passive suspension state, state == 0;

[0026] When and P net (t) > P vmax (t), it indicates that the suspension system is ready to switch to the semi-active suspension state, state == 1;

[0027] When and P net (t) < P vmax (t), it indicates that the suspension system is ready to switch to the pseudo-active suspension state, state == 2;

[0028] When and P net (t) > P vmax (t), it indicates that the suspension system is ready to switch to the active suspension state, and state == 3.

[0029] Preferably, the specific steps of the S3 step are as follows:

[0030] S31. Start inputting Z n , Z n+1 , n = 0, k = 0; where Z n , Z n+1 represent the nth and (n + 1)th input values respectively, and k represents the judgment iteration times;

[0031] S32. Record the sprung mass acceleration measured and calculated at the moment of n = 0 and k = 0, compare the recorded sprung mass acceleration with the set threshold value to determine the best working state of the suspension, and then the system sends the output signal of this working state into the preset system stability determination module;

[0032] S33. The system stability determination module will evaluate the stability of the logical variables in the input working state signal; if the input remains unchanged for 5 consecutive times, this logical variable will be sent to the control module of the multi-mode switching suspension, and then control to change the mode of the suspension; if there is no situation where the input remains unchanged for 5 consecutive times, it is considered that the system is unstable and needs to start counting again.

[0033] Preferably, in the S23 step, the vibration control force of the suspension system is output by the vibration control module of the suspension system and by using the power flow vibration control method to control the vibration of the suspension system.

[0034] Preferably, in step S4, after switching the control mode of the suspension system, the vibration control force of the suspension system in this control mode is output by the vibration control module of the suspension system and by using the power flow vibration control method; the specific steps of using the power flow vibration control method are as follows:

[0035] A. Adopt the skyhook damping control method to achieve the vibration control of the suspension system;

[0036] The skyhook damping control method is specifically: when the absolute velocity of the sprung mass is in the same direction as the relative velocity, adjust the damper damping to the maximum damping C sky ; when the absolute velocity of the sprung mass is in the opposite direction to the relative velocity, adjust the damper damping to the minimum damping 0;

[0037] The skyhook damping control method can be described by formula (3), specifically as follows:

[0038]

[0039] In the formula, F skyhook is the ceiling damping control force, and C sky is the ceiling damping coefficient, is the sprung mass velocity, is the excitation velocity;

[0040] B. Energy absorption and release of the suspension system;

[0041] The power P sds (t) of the suspension system dissipating or storing the sprung mass energy at time t is obtained by using Equation (4):

[0042]

[0043] The power P 0ds (t) of the suspension system dissipating or storing the excitation energy at time t is obtained by using Equation (5):

[0044]

[0045] In Equations (4) and (5), c(t) is the damping coefficient of the shock absorber at time t, which can be adjusted in real time according to the state of the suspension system;

[0046] According to Equations (4) and (5), the total power P e (t) of the suspension system dissipating or storing energy at time t is obtained by using Equation (6):

[0047]

[0048] In Equation (6), the tracking force of the suspension system at time t Then: P e (t) = P net (t); In order to consume the energy transmitted to the suspension system, the first term of the net power P t (t) should be maximized;

[0049] C. Judging the damping of the shock absorber of the suspension system according to the value:

[0050] When , it means that the shock absorber of the suspension system is consuming energy, and the damping of the shock absorber is adjusted to the maximum to maximize the energy consumption of the shock absorber of the suspension system;

[0051] When , it means that the shock absorber of the suspension system is releasing energy outward, and the damping of the shock absorber is adjusted to the minimum to minimize the energy released outward by the suspension system;

[0052] D. Adopt a power flow control method to achieve the adjustment of the suspension system damping;

[0053] Use Equation (7) to obtain the vibration control force F of the suspension system at time t: powerflow (t):

[0054]

[0055] In Equation (7), C power is the power flow damping coefficient;

[0056] When the tracking damping force F of the system u is in the same direction as the relative velocity , that is, , the suspension system damping absorbs and dissipates energy. At this time, the suspension system damping should be adjusted to the maximum to maximize the energy consumed by the suspension system; when the tracking damping force F of the system u is in the opposite direction to the relative velocity , that is, , the suspension system damping releases energy outward. At this time, the suspension system damping should be adjusted to the minimum to minimize the energy released by the suspension system outward.

[0057] The beneficial effects of the present invention are as follows:

[0058] (1) The control method of the multi-mode controllable suspension based on power flow of the present invention can quickly identify the change of the excitation, accurately select and switch to the corresponding suspension mode by judging the vibration excitation and the maximum vibration excitation input to the suspension system and comparing the intensity difference of the power flow. It can also improve the switching smoothness of the multi-mode controllable suspension, reduce the step caused by the switching, and improve the system stability;

[0059] (2) The control method of the multi-mode controllable suspension based on power flow of the present invention can achieve better control effects in a wide frequency range by introducing the tracking force of the suspension system, and the vibration isolation effect near the resonance frequency is significantly better than other control effects;

[0060] (3) The control method of the multi-mode controllable suspension based on power flow of the present invention can maximize the absorption of the energy of each motion process when the suspension system is subjected to impact excitation by introducing the power flow method. Compared with other control methods, it can more effectively alleviate the impact of obstacles on the suspension system and make the suspension move with a relatively stable constant acceleration;

[0061] (4) The control method of the multi-mode controllable suspension based on power flow of the present invention can perform adaptive switching among the four modes of active / semi-active / passive / pseudo-active according to the real-time situation, thereby expanding the effective frequency range of vibration reduction, improving the ride comfort and driving smoothness, and improving the vibration control effect;

[0062] (5) The control method of a multi-mode controllable suspension based on power flow according to the present invention has a damping effect much higher than that of passive and semi-active systems, and the vertical acceleration of the vehicle body, the dynamic deflection of the suspension, and the dynamic load of the tire are all significantly reduced. When the vehicle is driving on a good road surface and there is no need to improve the ride comfort of the vehicle, after analysis by the stability module, in order to reduce energy loss, the multi-mode controllable suspension switches to the passive mode. If the dynamic deflection of the vehicle suspension increases abnormally at this time, it indicates that the road surface condition is poor, and the stability module evaluates and switches to the semi-active mode to improve its ride comfort. When the acceleration of the sprung mass increases abnormally and the ride comfort of the vehicle is poor, to improve its comfort, the stability module evaluates and adopts the pseudo-active mode. When both the acceleration of the sprung mass and the dynamic deflection of the suspension are too large, the ride comfort rather than energy consumption is considered first, and through the stability module, it switches to the active mode to improve comfort. The energy consumption and cost of the control method of the multi-mode controllable suspension based on power flow are comparable to those of the semi-active suspension system, and it works stably and reliably, and the vibration isolation effect is significantly improved, making this control method applicable to more scenarios. This method has both the advantages of high reliability and low energy consumption of the traditional semi-active system and the advantages of high damping performance of the active actuator. Description of the Drawings

[0063] Figure 1 is the flowchart of the method of the present invention;

[0064] Figure 2 is the flowchart of the operation of the system stability determination module in the method of the present invention;

[0065] Figure 3 is the structural schematic diagram of the active / semi-active suspension. Detailed Embodiments

[0066] The following further illustrates the present invention in conjunction with embodiments. It should be noted that this is only an example and explanation of the concept of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined by the claims of the present invention, they should be regarded as falling within the protection scope of the present invention.

[0067] Embodiment 1:

[0068] The control method of a multi-mode controllable suspension based on power flow according to the present invention is applied to a vehicle equipped with a suspension system. Figure 3 is the structural schematic diagram of the active / semi-active suspension, as Figure 3As shown in the figure, the suspension system includes a vehicle frame 1, a displacement sensor 2, a shock absorber 3, a spring 4, an axle 5, and a tire 6. A plurality of displacement sensors 2 are provided and are respectively installed on both sides of the vehicle frame 1 and at the axle 5, and are respectively used to collect the remaining stroke of the shock absorber, the displacement, speed signal, and acceleration signal of the unsprung mass and the sprung mass.

[0069] A control method for a multi-mode controllable suspension based on power flow according to the present invention, as Figure 1 shown, includes the following steps:

[0070] S1. Obtain and define the parameter variable setting of the multi-mode controllable suspension switching method based on power flow control. The specific steps are as follows:

[0071] S11. Use the displacement sensor 2 to obtain the sprung mass displacement z s (t) at time t, the sprung mass speed at time t the sprung mass acceleration at time t the sprung mass acceleration threshold at time t the excitation displacement z of the unsprung mass at time t 0 (t), the excitation speed of the unsprung mass at time t the remaining stroke s(t) of the shock absorber;

[0072] S12. Define the state parameters of the multi-mode controllable suspension switching method based on power flow control, including: the state parameter state of the suspension system, the vibration control force F v (t) of the suspension system at time t, the desired control force F d (t) of the suspension system at time t, the tracking control force F u (t) of the suspension system at time t;

[0073] Initialize t = 0, state = 0.

[0074] S2. Calculate the sprung mass acceleration threshold the net power P of the suspension system net and the maximum value P of the vibration maximum power of the suspension system vmax , the specific steps are as follows:

[0075] S21. The sprung mass acceleration threshold at time t is the average value of the root mean square value of the sprung mass acceleration obtained from the passive suspension model traveling on the road surface, and is used as the mode switching control threshold;

[0076] S22. Use Equation (1) to calculate the net power P net (t) of the suspension system at time t:

[0077]

[0078] S23. Calculate the maximum vibration power flow P of the suspension system at time t using Equation (2): vmax (t):

[0079]

[0080] In Equations (1) and (2), k is the spring stiffness of the suspension system; F vmax is the maximum vibration control force that the current suspension system can provide, which is obtained by outputting and taking the maximum value from the vibration control module of the suspension system; expresses the maximum value of the difference between the response speed and the excitation speed to the current state; c(t) represents the damping coefficient of the shock absorber at time t.

[0081] The vibration control force of the suspension system is output by performing vibration control on the suspension system through the vibration control module of the suspension system and using the power flow vibration control method.

[0082] S3. According to the state parameters at the current time t, including the sprung mass acceleration of the suspension system at time t the set sprung mass acceleration threshold the net power P of the suspension system at time t net (t), the maximum vibration power flow P of the suspension system at time t vmax (t), to judge the system state of the suspension system. The specific steps are as follows:

[0083] Obtain the sprung mass acceleration at time t through step S11 Obtain the sprung mass acceleration threshold at time t through step S21 Then, through the net power P of the suspension system at time t calculated in steps S22 and S23 net (t), the maximum vibration power flow P of the suspension system at time t vmax (t), to judge the state of the suspension system at time t, specifically as follows:

[0084] When and P net (t) > P vmax (t), it indicates that the suspension system is ready to switch to the passive suspension state, state == 0;

[0085] When and P net (t) > P vmax (t), it indicates that the suspension system is ready to switch to the semi-active suspension state, state == 1;

[0086] When and P net (t) < P vmaxAt time (t), it indicates that the suspension system is ready to switch to the pseudo-active suspension state, state == 2;

[0087] When and P net (t) > P vmax (t), it indicates that the suspension system is ready to switch to the active suspension state, state == 3.

[0088] S4. Through a preset system stability determination module, evaluate whether the optimal working state of the suspension system is stable and perform the switching of the suspension system control mode. As Figure 2 shown, the specific steps are as follows:

[0089] S31. Start inputting Z n , Z n+1 , n = 0, k = 0; where Z n , Z n+1 represent the nth and (n + 1)th input values respectively, and k represents the judgment iteration times;

[0090] S32. Record the sprung mass acceleration measured and calculated at the moment of n = 0, k = 0, compare the recorded sprung mass acceleration with the set threshold to determine the optimal working state of the suspension, and then the system sends the output signal of this working state into the preset system stability determination module;

[0091] S33. The system stability determination module will evaluate the stability of the logical variables in the input working state signal; if the input remains unchanged for 5 consecutive times, this logical variable will be sent to the control module of the multi-mode switching suspension, and then control to change the mode of the suspension; if there is no case where the input remains unchanged for 5 consecutive times, it is considered that the system is unstable and the counting needs to start over.

[0092] After switching to the required passive suspension state, semi-active suspension state, pseudo-active suspension state or active suspension state among the four suspension system control modes, then through the vibration control module of the suspension system, and adopt the power flow vibration control method in the semi-active suspension state, pseudo-active suspension state or active suspension state to output the vibration control force for the suspension system in this control mode.

[0093] The power flow vibration control method, the specific steps are as follows:

[0094] A. Adopt the skyhook damping control method to achieve the vibration control of the suspension system;

[0095] The skyhook damping control method is specifically: when the absolute velocity and relative velocity of the sprung mass are in the same direction, adjust the damper damping to the maximum damping C sky;When the absolute velocity of the sprung mass is in the opposite direction to the relative velocity, adjust the damper damping to the minimum damping 0;

[0096] The skyhook damping control method can be described by Equation (3) as follows:

[0097]

[0098] In the formula, F skyhook is the skyhook damping control force, C sky is the skyhook damping coefficient, is the sprung mass velocity, is the excitation velocity;

[0099] B. Energy absorption and release of the suspension system;

[0100] Use Equation (4) to obtain the power P sds (t) of the suspension system dissipating or storing the sprung mass energy at time t:

[0101]

[0102] Use Equation (5) to obtain the power P 0ds (t) of the suspension system dissipating or storing the excitation energy at time t:

[0103]

[0104] In Equations (4) and (5), c(t) is the damping coefficient of the shock absorber at time t, which can be adjusted in real time according to the suspension system state;

[0105] According to Equations (4) and (5), use Equation (6) to obtain the power P e (t) of the suspension system for the total dissipated or stored energy at time t:

[0106]

[0107] In Equation (6), the tracking force of the suspension system at time t Then there is: P e (t) = P net (t); In order to consume the energy transmitted to the suspension system, the first term of the net power P t (t) should be maximized.

[0108] For periodic vibration excitation, the energy transmitted to the suspension system should be consumed in a timely manner within this period. And the energy stored in the spring potential energy will ultimately be transmitted to the sprung mass. Therefore, the first term of P net should be maximized which is the power of the suspension damping consuming energy; For the current suspension system, i.e., the tracking damping force F of the current system u , and is the relative velocity between the sprung mass and the unsprung mass of the current system.

[0109] C. According to the value, judge the damping of the shock absorber of the suspension system:

[0110] When , it means that the shock absorber of the suspension system is consuming energy, and the damping of the shock absorber is adjusted to the maximum to maximize the energy consumption of the shock absorber of the suspension system;

[0111] When , it means that the shock absorber of the suspension system is releasing energy outward, and the damping of the shock absorber is adjusted to the minimum to minimize the energy released outward by the suspension system;

[0112] D. Adopt the power flow control method to realize the adjustment of the damping of the suspension system;

[0113] Use equation (7) to obtain the vibration control force F powerflow (t) of the suspension system at time t:

[0114]

[0115] In equation (7), C power is the power flow damping coefficient;

[0116] When the tracking damping force F u of the system is in the same direction as the relative velocity , i.e., , the damping of the suspension system is absorbing and dissipating energy. At this time, the damping of the suspension system should be adjusted to the maximum to maximize the energy consumed by the suspension system; when the tracking damping force F u of the system is in the opposite direction to the relative velocity , i.e., , the damping of the suspension system is releasing energy outward. At this time, the damping of the suspension system should be adjusted to the minimum to minimize the energy released outward by the suspension system.

[0117] In the three different suspension system control modes of semi-active suspension state, pseudo-active suspension state, and active suspension state, the vibration control module of the suspension system adopts the power flow vibration control method to obtain the vibration control force F powerflow (t) of the suspension system at different times t, and uses the generated F powerflow (t) for the vibration control of the suspension system, adjusts the dynamic response between the wheel and the body, reduces vibration, suppresses the change of the body posture, and thus optimizes the driving performance and riding comfort of the vehicle under different suspension system control modes.

[0118] A control method for a multi-mode controllable suspension based on power flow. Based on the power flow vibration control method, aiming at different requirements for suspension performance under different driving conditions, the working modes of the suspension are divided into passive mode, semi-active mode, pseudo-active mode and active mode. A multi-mode switching control strategy is designed according to the characteristics of each mode, corresponding switching rules and switching parameter thresholds are established, and a stability module is introduced, which can be used for vibration reduction control throughout the vehicle operation process, effectively realizing the absorption of impact energy, reducing the acceleration and jerk of the sprung mass; at the same time, smooth switching between the four control methods of passive mode, semi-active mode, pseudo-active mode and active mode of the suspension is achieved, solving the problems of frequent system switching and mode disorder.

[0119] A control method for a multi-mode controllable suspension based on power flow. By judging the vibration excitation and the maximum vibration excitation input into the suspension system and comparing the intensity difference of the power flow, it can not only quickly identify the change of the excitation, accurately select and switch to the corresponding suspension mode, but also improve the switching smoothness of the multi-mode controllable suspension, reduce the step caused by the switching, and improve the system stability.

[0120] A control method for a multi-mode controllable suspension based on power flow. By introducing the tracking force of the suspension system, this control method can achieve better control effects in a wide frequency range, and the vibration isolation effect near the resonance frequency is significantly better than other control effects.

[0121] A control method for a multi-mode controllable suspension based on power flow. By introducing the power flow method, when the suspension system is subjected to impact excitation, the energy of each motion process is maximally absorbed. Compared with other control methods, it more effectively realizes the mitigation of the impact of obstacles on the suspension system, and makes the suspension move with a relatively stable constant acceleration.

[0122] A control method for a multi-mode controllable suspension based on power flow. It can perform adaptive switching among the four modes of active / semi-active / passive / pseudo-active according to the real-time situation, thereby expanding the effective frequency range of vibration reduction, improving the ride comfort and driving smoothness, and improving the vibration control effect.

[0123] A control method for a multi-mode controllable suspension based on power flow. Its vibration damping effect is much higher than that of passive and semi-active systems, and the body vertical acceleration, suspension dynamic deflection, and tire dynamic load are all significantly reduced. When the vehicle is driving on a good road surface and there is no need to improve the ride comfort of the vehicle, after analysis by the stability module, in order to reduce energy loss, the multi-mode controllable suspension switches to the passive mode. If the suspension dynamic deflection of the vehicle increases abnormally at this time, it indicates that the road surface condition is poor. The stability module evaluates and switches to the semi-active mode to improve its ride comfort. When the sprung mass acceleration increases abnormally and the ride comfort of the vehicle is poor, to improve its comfort, the stability module evaluates and adopts the pseudo-active mode. When both the sprung mass acceleration and the suspension dynamic deflection are too large, the ride comfort during driving is given priority over energy consumption. Through the stability module, it switches to the active mode to improve comfort. The energy consumption and cost of the control method for the multi-mode controllable suspension based on power flow are comparable to those of the semi-active system. It works stably and reliably, and the vibration isolation effect is significantly improved, enabling this control method to be applicable to more scenarios. This method not only has the advantages of high reliability and low energy consumption of traditional semi-active systems but also has the advantage of high vibration damping performance of active actuators.

[0124] The above is an exemplary description of the invention. Obviously, the specific implementation of the present invention is not limited by the above methods. As long as such non-substantial improvements are made by adopting the method concept and technical solution of the present invention, or the concept and technical solution of the invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A control method for a multi-mode controllable suspension based on power flow, characterized in that: The following steps are involved: S1. Obtain and define parameter variable settings of a multi-mode controllable suspension switching method based on power flow control; S2. Calculate the sprung mass acceleration threshold Net power of the suspension system P net and the maximum vibration power of the suspension system P vmax ; S3, based on the current state parameters at time t, including the sprung mass acceleration of the suspension system at time t Set sprung mass acceleration threshold The net power P of the suspension system at time t net (t), the maximum vibration power flow of the suspension system at time t P vmax (t), to determine the system status of the suspension system; S4. Evaluate whether the optimal working state of the suspension system is stable through a preset system stability determination module, and switch the control mode of the suspension system.

2. The control method of a multi-mode controllable suspension based on power flow according to claim 1, characterized in that: The specific steps of step S1 are as follows: S11. Use the displacement sensor to obtain the sprung mass displacement z at time t. s (t), sprung mass velocity at time t The sprung mass acceleration at time t The sprung mass acceleration threshold at time t The excitation displacement z0(t) of the unsprung mass at time t and the excitation velocity of the unsprung mass at time t are Shock absorber remaining travel s(t); S12, define the state parameters of the multi-mode controllable suspension switching method based on power flow control, including: the state parameter state of the suspension system, the vibration control force F of the suspension system at time t v (t), the expected control force F of the suspension system at time t d (t), the tracking control force F of the suspension system at time t u (t); Initialize t=0, state=0.

3. The control method of a multi-mode controllable suspension based on power flow according to claim 2, characterized in that: The specific steps of step S2 are as follows: S21, sprung mass acceleration threshold at time t is the average of the RMS values ​​of the sprung mass acceleration obtained from the passive suspension model driving on the road and serves as the mode switching control threshold; S22. Calculate the net power P of the suspension system at time t using formula (1): net (t): S23. Calculate the maximum vibration power flow P of the suspension system at time t using formula (2): vmax (t): In formula (1) and formula (2), k is the spring stiffness of the suspension system; F vmax is the maximum vibration control force that the current suspension system can provide, which is obtained by taking the maximum value of the output of the vibration control module of the suspension system; It expresses the maximum value of the difference between the response speed and the excitation speed of the current state; c(t) represents the damping coefficient of the shock absorber at time t.

4. The control method of a multi-mode controllable suspension based on power flow according to claim 3, characterized in that: The specific steps of step S3 are as follows: The sprung mass acceleration at time t is obtained by step S11 The sprung mass acceleration threshold at time t is obtained by step S21 Then, the net power P of the suspension system at time t obtained by calculation in steps S22 and S23 is net (t), the maximum vibration power flow of the suspension system at time t P vmax (t), to determine the state of the suspension system at time t, as follows: when And P net (t)>P vmax (t), indicating that the suspension system is ready to switch to the passive suspension state, state==0; when And P net (t)>P vmax (t), indicating that the suspension system is ready to switch to the semi-active suspension state, state == 1; when And P net (t)<P vmax (t), indicating that the suspension system is ready to switch to the pseudo-active suspension state, state == 2; when And P net (t)>P vmax (t), it indicates that the suspension system is ready to switch to the active suspension state, state==3.

5. The control method of a multi-mode controllable suspension based on power flow according to claim 4, characterized in that: The specific steps of step S4 are as follows: S31, start inputting Z n , Z n+1 , n=0, k=0; where Z n , Z n+1 They represent the nth and n+1th input values ​​respectively, and k represents the number of judgment iterations; S32, recording the sprung mass acceleration measured and calculated at the moment n=0, k=0, comparing the recorded sprung mass acceleration with a set threshold value to determine the optimal working state of the suspension, and the system then sends an output signal of the working state to a preset system stability determination module; S33, the system stability determination module will evaluate the stability of the logical variable in the input working status signal; if the input remains unchanged for 5 consecutive times, the logical variable will be sent to the control module of the multi-mode switching suspension, and then control the change of the suspension mode; if the input does not remain unchanged for 5 consecutive times, the system is considered unstable and the counting needs to be restarted.

6. The control method of a multi-mode controllable suspension based on power flow according to claim 3, characterized in that: In step S23, the vibration control force of the suspension system is output by controlling the vibration of the suspension system through the vibration control module of the suspension system and adopting the power flow vibration control method.

7. The control method of a multi-mode controllable suspension based on power flow according to claim 1, characterized in that: In step S4, after the control mode of the suspension system is switched, the vibration control module of the suspension system is used to output the vibration control force of the suspension system in this control mode by adopting the power flow vibration control method; The power flow vibration control method comprises the following specific steps: A. Use the ceiling damping control method to achieve vibration control of the suspension system; The ceiling damping control method is as follows: when the absolute speed of the sprung mass is in the same direction as the relative speed, the damper damping is adjusted to the maximum damping C sky ; When the absolute speed of the sprung mass is opposite to the relative speed, adjust the damper damping to the minimum damping 0; The ceiling damping control method can be described as formula (3), as follows: In the formula, F skyhook is the ceiling damping control force, C sky is the ceiling damping coefficient, is the sprung mass velocity, To stimulate speed; B. Energy absorption and release of the suspension system; Using formula (4), we can get the power P of the suspension system dissipating or storing the sprung mass energy at time t: sds (t): Using formula (5), we can get the power P of the suspension system dissipating or storing the excitation energy at time t: 0ds (t): In equations (4) and (5), c(t) is the damping coefficient of the shock absorber at time t, which can be adjusted in real time according to the state of the suspension system; According to equations (4) and (5), the total energy dissipation or storage power P of the suspension system at time t is obtained using equation (6): e (t): In formula (6), the tracking force of the suspension system at time t is Then we have: P e (t) = P net (t); In order to consume the energy transmitted to the suspension system, the net power P t (t) The first item maximum; C. According to Value to judge the damping size of the suspension system shock absorber: when When , it means that the shock absorber of the suspension system is consuming energy, and the damping of the shock absorber is adjusted to the maximum to maximize the energy consumption of the shock absorber of the suspension system; when When , it means that the shock absorber of the suspension system is releasing energy outward, and the damping of the shock absorber is adjusted to the minimum to minimize the energy released outward by the suspension system; D. Use power flow control method to adjust the damping of the suspension system; Using formula (7), we can get the vibration control force F of the suspension system at time t: powerflow (t): In formula (7), C power is the power flow damping coefficient; When the tracking damping force F u With relative speed The same direction, that is When the suspension system damping is absorbing and dissipating energy, the suspension system damping should be adjusted to the maximum to maximize the energy consumed by the suspension system; when the tracking damping force F u With relative speed The opposite direction, that is When the suspension system is in a state of tension, the damping of the suspension system is releasing energy outwards. At this time, the damping of the suspension system should be adjusted to the minimum to minimize the energy released outwards by the suspension system.

Images