A four-wheel hydraulic suspension oil flow rate protection control method and system

Abstract

The present invention discloses a four-wheel hydraulic suspension oil flow rate protection control method and system, which relates to the technical field of suspension systems. The method includes: determining the minimum number of steps required for the flow rate to change to the steady-state target flow rate simultaneously according to the steady-state target flow rate, the target flow rate at the previous moment, and the maximum available flow rate change amount; determining the execution flow rate change amount for the flow rate to change to the steady-state target flow rate simultaneously according to the minimum number of steps required for the flow rate to change to the steady-state target flow rate simultaneously, the steady-state target flow rate, and the target flow rate at the previous moment; determining the target flow rate at the current moment according to the execution flow rate change amount for the flow rate to change to the steady-state target flow rate simultaneously and the target flow rate at the previous moment; updating the target flow rate value at the previous moment to the target flow rate value at the current moment, and repeating the above steps until the difference between the target flow rate at the current moment and the steady-state target flow rate is less than the set value. It solves the problem in the prior art that the oil flow rate changes rapidly, resulting in a low service life of the hydraulic pipeline and being easily damaged.

Description

Technical Field

[0001] The present invention relates to the technical field of suspension systems, and particularly relates to a four-wheel hydraulic suspension oil flow rate protection control method and system. Background Art

[0002] The hydraulic suspension adjusts the oil flow to lock the suspension or adjust the vehicle body height while adjusting the damping coefficient. The bumps caused by uneven road surfaces during vehicle driving may damage the vehicle itself. Therefore, the hydraulic suspension adopts variable damping and automatic adjustment of the vehicle body height to make the vehicle run more precisely and smoothly. The electronically controlled active hydraulic suspension can actively control the vibration of the vehicle according to the mass and acceleration of the suspension, etc., by using hydraulic components.

[0003] In the prior art, the hydraulic suspension adjusts the height and stiffness of the vehicle by controlling the oil flow rate. There are problems that the oil flow rate changes rapidly, resulting in a low service life of the hydraulic pipeline and being easily damaged. Summary of the Invention

[0004] Aiming at the defects existing in the prior art, the purpose of the present invention is to provide a four-wheel hydraulic suspension oil flow rate protection control method and system, which can solve the problems in the prior art that the oil flow rate changes rapidly, resulting in a low service life of the hydraulic pipeline and being easily damaged.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] On the one hand, this solution provides a four-wheel hydraulic suspension oil flow rate protection control method, including:

[0007] Determine the minimum number of steps required for the oil flow rates of each suspension to change to the steady-state target flow rate simultaneously according to the steady-state target flow rate of each suspension oil, the target flow rate of each suspension oil at the previous moment, and the maximum allowable flow rate change of each suspension;

[0008] Determine the execution flow rate change for the oil flow rates of each suspension to change to the steady-state target flow rate simultaneously according to the minimum number of steps required for the oil flow rates of each suspension to change to the steady-state target flow rate simultaneously, the steady-state target flow rate of each suspension oil, and the target flow rate of each suspension oil at the previous moment;

[0009] Determine the target flow rate of each suspension oil at the current moment according to the execution flow rate change for the oil flow rates of each suspension to change to the steady-state target flow rate simultaneously and the target flow rate of each suspension oil at the previous moment;

[0010] Update the target flow rate value of each suspension oil at the previous moment to the target flow rate value of each suspension oil at the current moment, and loop the above steps until the difference between the target flow rate of each suspension oil at the current moment and the steady-state target flow rate of each suspension oil is less than the set value.

[0011] In some alternative solutions, determining the execution flow rate change amount for the hydraulic fluid flow rates of each suspension to simultaneously change to the steady-state target flow rate based on the minimum number of required steps for the hydraulic fluid flow rates of each suspension to simultaneously change to the steady-state target flow rate, the steady-state target flow rates of the hydraulic fluid of each suspension, and the target flow rates of the hydraulic fluid of each suspension at the previous moment includes:

[0012] Determining the maximum available flow rate change amount for the hydraulic fluid flow rates of each suspension to simultaneously change to the steady-state target flow rate based on the minimum number of required steps for the hydraulic fluid flow rates of each suspension to simultaneously change to the steady-state target flow rate, the steady-state target flow rates of the hydraulic fluid of each suspension, and the target flow rates of the hydraulic fluid of each suspension at the previous moment;

[0013] Determining the execution flow rate change amount for the hydraulic fluid flow rates of each suspension to simultaneously change to the steady-state target flow rate based on the maximum available flow rate change amount for the hydraulic fluid flow rates of each suspension to simultaneously change to the steady-state target flow rate and the hydraulic fluid flow rate control coefficient.

[0014] In some alternative solutions, the hydraulic fluid flow rate control coefficient is determined according to the following steps:

[0015] Determining the sum of the ratio of the difference between the steady-state target flow rate and the target flow rate at the previous moment of the hydraulic fluid of each suspension to the steady-state target flow rate of the hydraulic fluid of each suspension;

[0016] Setting the hydraulic fluid flow rate control coefficient according to the sum of the ratio of the difference between the steady-state target flow rate and the target flow rate at the previous moment of the hydraulic fluid of each suspension to the steady-state target flow rate of the hydraulic fluid of each suspension.

[0017] In some alternative solutions, according to the formula:

[0018] Determining the minimum number of required steps for the hydraulic fluid flow rates of each suspension to simultaneously change to the steady-state target flow rate;

[0019] where N(k) fl is the minimum number of required steps for the hydraulic fluid flow rate of the left front suspension to change to the steady-state target flow rate, N(k) fr is the minimum number of required steps for the hydraulic fluid flow rate of the right front suspension to change to the steady-state target flow rate, N(k) rl is the minimum number of required steps for the hydraulic fluid flow rate of the left rear suspension to change to the steady-state target flow rate, N(k) rr is the minimum number of required steps for the hydraulic fluid flow rate of the right rear suspension to change to the steady-state target flow rate, Δv(k) fl is the difference between the steady-state target flow rate and the target flow rate at the previous moment of the hydraulic fluid of the left front suspension, Δv(k) fr is the difference between the steady-state target flow rate and the target flow rate at the previous moment of the hydraulic fluid of the right front suspension, Δv(k) rl is the difference between the steady-state target flow rate and the target flow rate at the previous moment of the hydraulic fluid of the left rear suspension, Δv(k)rr is the difference between the steady-state target flow rate of the right rear suspension oil and the target flow rate of the right rear suspension at the previous moment, Δv(k) flmax is the maximum available flow rate change of the left front suspension, Δv(k) frmax is the maximum available flow rate change of the right front suspension, Δv(k) rlmax is the maximum available flow rate change of the left rear suspension, Δv(k) rrmax is the maximum available flow rate change of the right rear suspension, N(k) max is the minimum number of steps required for the oil flow rates of each suspension to simultaneously change to the steady-state target flow rate.

[0020] In some alternative solutions, according to the formula: determine the maximum available flow rate change for the oil flow rates of each suspension to simultaneously change to the steady-state target flow rate;

[0021] where, Δv1(k) fl is the maximum available flow rate change for the oil flow rate of the left front suspension to simultaneously change to the steady-state target flow rate, Δv1(k) fr is the maximum available flow rate change for the oil flow rate of the right front suspension to simultaneously change to the steady-state target flow rate, Δv1(k) rl is the maximum available flow rate change for the oil flow rate of the left rear suspension to simultaneously change to the steady-state target flow rate, Δv1(k) rr is the maximum available flow rate change for the oil flow rate of the right rear suspension to simultaneously change to the steady-state target flow rate, Δv(k) fl is the difference between the steady-state target flow rate of the left front suspension oil and the target flow rate of the left front suspension at the previous moment, Δv(k) fr is the difference between the steady-state target flow rate of the right front suspension oil and the target flow rate of the right front suspension at the previous moment, Δv(k) rl is the difference between the steady-state target flow rate of the left rear suspension oil and the target flow rate of the left rear suspension at the previous moment, Δv(k) rr is the difference between the steady-state target flow rate of the right rear suspension oil and the target flow rate of the right rear suspension at the previous moment, N(k) max is the minimum number of steps required for the oil flow rates of each suspension to simultaneously change to the steady-state target flow rate.

[0022] In some alternative solutions, according to the formula:

[0023] determine the sum of the ratios of the differences between the steady-state target flow rates of the oil of each suspension and the target flow rates at the previous moment to the steady-state target flow rates of the oil of each suspension;

[0024] According to the formula: determine the suspension oil flow rate control coefficient;

[0025] Among them, γ(k) is the sum of the ratios of the differences between the steady-state target flow rates of the suspension oils and the target flow rates at the previous moment to the steady-state target flow rates of the suspension oils, and Δv(k) fl is the difference between the steady-state target flow rate of the left front suspension oil and the target flow rate at the previous moment of the left front suspension, and Δv(k) fr is the difference between the steady-state target flow rate of the right front suspension oil and the target flow rate at the previous moment of the right front suspension, and Δv(k) rl is the difference between the steady-state target flow rate of the left rear suspension oil and the target flow rate at the previous moment of the left rear suspension, and Δv(k) rr is the difference between the steady-state target flow rate of the right rear suspension oil and the target flow rate at the previous moment of the right rear suspension, and v fl is the steady-state target flow rate of the left front suspension oil, and v fr is the steady-state target flow rate of the right front suspension oil, and v rl is the steady-state target flow rate of the left rear suspension oil, and v rr is the steady-state target flow rate of the right rear suspension oil. β(k) is the suspension oil flow rate control coefficient, β1 is the maximum control coefficient of the suspension oil flow rate, β0 is the minimum control coefficient of the suspension oil flow rate, γ1 is the upper limit of the sum of the ratios of the differences between the steady-state target flow rates of the suspension oils and the target flow rates at the previous moment to the steady-state target flow rates of the suspension oils, and γ0 is the lower limit of the sum of the ratios of the differences between the steady-state target flow rates of the suspension oils and the target flow rates at the previous moment to the steady-state target flow rates of the suspension oils.

[0026] In some alternative solutions, according to the formula: Determine the execution flow rate change amount for the suspension oil flow rates to simultaneously change to the steady-state target flow rates;

[0027] Among them, Δv2(k) fl is the execution flow rate change amount for the left front suspension oil flow rate to simultaneously change to the steady-state target flow rate, and Δv2(k) fr is the execution flow rate change amount for the right front suspension oil flow rate to simultaneously change to the steady-state target flow rate, and Δv2(k) rl is the execution flow rate change amount for the left rear suspension oil flow rate to simultaneously change to the steady-state target flow rate, and Δv2(k) rr is the execution flow rate change amount for the right rear suspension oil flow rate to simultaneously change to the steady-state target flow rate, and Δv1(k) fl is the maximum available flow rate change amount for the left front suspension oil flow rate to simultaneously change to the steady-state target flow rate, and Δv1(k) fr is the maximum available flow rate change amount for the right front suspension oil flow rate to simultaneously change to the steady-state target flow rate, and Δv1(k) rl is the maximum available flow rate change amount for the left rear suspension oil flow rate to simultaneously change to the steady-state target flow rate, and Δv1(k) rr$\Delta v_2(k)$ is the maximum available flow rate change for the right rear suspension oil flow rate to simultaneously change to the steady-state target flow rate, and $\beta(k)$ is the suspension oil flow rate control coefficient.

[0028] In some alternative solutions, according to the formula:

[0029] Determine the target flow rate of each suspension oil at the current moment;

[0030] where $v(k)$ fl is the target flow rate of the left front suspension oil at the current moment, $v(k)$ fr is the target flow rate of the right front suspension oil at the current moment, $v(k)$ rl is the target flow rate of the left rear suspension oil at the current moment, $v(k)$ rr is the target flow rate of the right rear suspension oil at the current moment, $v(k - 1)$ fl is the target flow rate of the left front suspension oil at the previous moment, $v(k - 1)$ fr is the target flow rate of the right front suspension oil at the previous moment, $v(k - 1)$ rl is the target flow rate of the left rear suspension oil at the previous moment, $v(k - 1)$ rr is the target flow rate of the right rear suspension oil at the previous moment, $\Delta v_2(k)$ fl is the execution flow rate change for the left front suspension oil flow rate to simultaneously change to the steady-state target flow rate, $\Delta v_2(k)$ fr is the execution flow rate change for the right front suspension oil flow rate to simultaneously change to the steady-state target flow rate, $\Delta v_2(k)$ rl is the execution flow rate change for the left rear suspension oil flow rate to simultaneously change to the steady-state target flow rate, $\Delta v_2(k)$ rr is the execution flow rate change for the right rear suspension oil flow rate to simultaneously change to the steady-state target flow rate.

[0031] In some alternative solutions, determine the maximum available flow rate change for each suspension according to the maximum available flow rate change per unit time of each suspension and the task execution cycle.

[0032] On the other hand, this solution also provides a four-wheel hydraulic suspension oil flow rate control system, including:

[0033] A minimum step number determination module, which is used to determine the minimum number of steps required for the flow rate of each suspension oil to simultaneously change to the steady-state target flow rate according to the steady-state target flow rate of each suspension oil, the target flow rate of each suspension oil at the previous moment, and the maximum available flow rate change of each suspension.

[0034] An execution flow rate change amount determination module is configured to determine an execution flow rate change amount for the hydraulic oil flow rates of each suspension to simultaneously change to a steady-state target flow rate according to the minimum number of steps required for the hydraulic oil flow rates of each suspension to simultaneously change to the steady-state target flow rate, the steady-state target flow rates of the hydraulic oil of each suspension, and the target flow rates of the hydraulic oil of each suspension at the previous moment;

[0035] A current moment target flow rate determination module is configured to determine the target flow rates of the hydraulic oil of each suspension at the current moment according to the execution flow rate change amount for the hydraulic oil flow rates of each suspension to simultaneously change to the steady-state target flow rate and the target flow rates of the hydraulic oil of each suspension at the previous moment;

[0036] A judgment module is configured to update the target flow rate values of the hydraulic oil of each suspension at the previous moment to the target flow rate values of the hydraulic oil of each suspension at the current moment, and loop the above steps until the difference between the target flow rates of the hydraulic oil of each suspension at the current moment and the steady-state target flow rates of the hydraulic oil of each suspension is less than a set value.

[0037] Compared with the prior art, the advantages of the present invention are as follows: According to the steady-state target flow rates of the hydraulic oil of each suspension, the target flow rates of the hydraulic oil of each suspension at the previous moment, and the maximum available flow rate change amount of each suspension, the minimum number of steps required for the hydraulic oil flow rates of each suspension to simultaneously change to the steady-state target flow rate is determined; According to the minimum number of steps required for the hydraulic oil flow rates of each suspension to simultaneously change to the steady-state target flow rate, the steady-state target flow rates of the hydraulic oil of each suspension, and the target flow rates of the hydraulic oil of each suspension at the previous moment, the execution flow rate change amount for the hydraulic oil flow rates of each suspension to simultaneously change to the steady-state target flow rate is determined; According to the execution flow rate change amount for the hydraulic oil flow rates of each suspension to simultaneously change to the steady-state target flow rate and the target flow rates of the hydraulic oil of each suspension at the previous moment, the target flow rates of the hydraulic oil of each suspension at the current moment are determined; The target flow rate values of the hydraulic oil of each suspension at the previous moment are updated to the target flow rate values of the hydraulic oil of each suspension at the current moment, and the above steps are looped until the difference between the target flow rates of the hydraulic oil of each suspension at the current moment and the steady-state target flow rates of the hydraulic oil of each suspension is less than a set value. The problem in the prior art that the hydraulic oil flow rate changes rapidly, resulting in a low service life of the hydraulic pipeline and easy damage, is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0039] Figure 1 It is a schematic flowchart of a four-wheel hydraulic suspension oil flow rate protection control method in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some, but not all, of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts shall fall within the scope of protection of this application.

[0041] The following further elaborates on the embodiments of the present invention with reference to the accompanying drawings.

[0042] As Figure 1 shown, on the one hand, the present invention provides a method for protecting the hydraulic fluid flow rate of a four-wheel hydraulic suspension, including:

[0043] S01: According to the formula: Determine the difference between the steady-state target flow rate of the hydraulic fluid of each suspension and the target flow rate of each suspension at the previous moment.

[0044] Where, Δv(k) fl is the difference between the steady-state target flow rate of the hydraulic fluid of the left front suspension and the target flow rate of the left front suspension at the previous moment, Δv(k) fr is the difference between the steady-state target flow rate of the hydraulic fluid of the right front suspension and the target flow rate of the right front suspension at the previous moment, Δv(k) rl is the difference between the steady-state target flow rate of the hydraulic fluid of the left rear suspension and the target flow rate of the left rear suspension at the previous moment, Δv(k) rr is the difference between the steady-state target flow rate of the hydraulic fluid of the right rear suspension and the target flow rate of the right rear suspension at the previous moment, v fl is the steady-state target flow rate of the hydraulic fluid of the left front suspension, v fr is the steady-state target flow rate of the hydraulic fluid of the right front suspension, v rl is the steady-state target flow rate of the hydraulic fluid of the left rear suspension, v rr is the steady-state target flow rate of the hydraulic fluid of the right rear suspension, v(k - 1) fl is the target flow rate of the hydraulic fluid of the left front suspension at the previous moment, v(k - 1) fr is the target flow rate of the hydraulic fluid of the right front suspension at the previous moment, v(k - 1) rl is the target flow rate of the hydraulic fluid of the left rear suspension at the previous moment, v(k - 1) rr is the target flow rate of the hydraulic fluid of the right rear suspension at the previous moment.

[0045] In this embodiment, as can be seen from the above formula, when Δv(k) fl = 0, the steady-state target flow rate of the hydraulic fluid of the left front suspension is equal to the target flow rate of the hydraulic fluid of the left front suspension at the previous moment, and the flow rate has reached a stable value and does not need to be adjusted. Δv(k) flWhen >0, the steady-state target flow rate of the left front suspension oil is greater than the target flow rate of the left front suspension oil at the previous moment, and the flow rate of the left front suspension oil should continue to increase; Δv(k) fl When <0, the steady-state target flow rate of the left front suspension oil is less than the target flow rate of the left front suspension oil at the previous moment, and the flow rate of the left front suspension oil should continue to decrease. The same applies to the right front suspension, the left rear suspension, and the right rear suspension.

[0046] S02: Determine the maximum available flow rate change of each suspension according to the maximum available flow rate change of each suspension per unit time and the task execution cycle.

[0047] In some alternative embodiments, according to the formula:

[0048] Determine the maximum available flow rate change of each suspension;

[0049] where, Δv(k) flmax is the maximum available flow rate change of the left front suspension, Δv(k) frmax is the maximum available flow rate change of the right front suspension, Δv(k) rlmax is the maximum available flow rate change of the left rear suspension, Δv(k) rrmax is the maximum available flow rate change of the right rear suspension, Δv(k) flmaxone is the maximum available flow rate change of the left front suspension per unit time, Δv(k) frmaxone is the maximum available flow rate change of the right front suspension per unit time, Δv(k) rlmaxone is the maximum available flow rate change of the left rear suspension per unit time, Δv(k) rrmaxone is the maximum available flow rate change of the right rear suspension per unit time, and Δt is the task execution cycle. The task execution cycle is the time used to execute a change in the oil flow rate.

[0050] In this embodiment, it can be seen from the above formula that is equivalent to By limiting the maximum available flow rate change of the oil in each suspension, the oil pipelines of each suspension are protected from being damaged or having their service life reduced due to too rapid changes in the flow rate.

[0051] S1: Determine the minimum number of steps required for the oil flow rate of each suspension to change to the steady-state target flow rate simultaneously according to the steady-state target flow rate of the oil in each suspension, the target flow rate of the oil in each suspension at the previous moment, and the maximum available flow rate change of the oil in each suspension.

[0052] In this embodiment, the number of steps refers to the number of times of oil flow rate change required to change from the target flow rate of the oil at the previous moment to the steady-state target flow rate of the oil.

[0053] In some alternative embodiments, according to the formula:

[0054] Determine the minimum number of steps required for the oil flow rates of each suspension to simultaneously change to the steady-state target flow rate;

[0055] where N(k) fl is the minimum number of steps required for the oil flow rate of the left front suspension to change to the steady-state target flow rate, N(k) fr is the minimum number of steps required for the oil flow rate of the right front suspension to change to the steady-state target flow rate, N(k) rl is the minimum number of steps required for the oil flow rate of the left rear suspension to change to the steady-state target flow rate, N(k) rr is the minimum number of steps required for the oil flow rate of the right rear suspension to change to the steady-state target flow rate, Δv(k) fl is the difference between the steady-state target flow rate of the oil in the left front suspension and the target flow rate at the previous moment of the left front suspension, Δv(k) fr is the difference between the steady-state target flow rate of the oil in the right front suspension and the target flow rate at the previous moment of the right front suspension, Δv(k) rl is the difference between the steady-state target flow rate of the oil in the left rear suspension and the target flow rate at the previous moment of the left rear suspension, Δv(k) rr is the difference between the steady-state target flow rate of the oil in the right rear suspension and the target flow rate at the previous moment of the right rear suspension, Δv(k) flmax is the maximum available flow rate change of the oil in the left front suspension, Δv(k) frmax is the maximum available flow rate change of the oil in the right front suspension, Δv(k) rlmax is the maximum available flow rate change of the oil in the left rear suspension, Δv(k) rrmax is the maximum available flow rate change of the oil in the right rear suspension, N(k) max is the minimum number of steps required for the oil flow rates of each suspension to simultaneously change to the steady-state target flow rate.

[0056] In this embodiment, according to the above formula, it can be seen that

[0057] S2: Determine the execution flow rate change for the oil flow rates of each suspension to simultaneously change to the steady-state target flow rate according to the minimum number of steps required for the oil flow rates of each suspension to simultaneously change to the steady-state target flow rate, the steady-state target flow rate of the oil in each suspension, and the target flow rate of the oil in each suspension at the previous moment.

[0058] Step S2 specifically includes:

[0059] S21: Determine the maximum available flow rate change for the oil flow rates of each suspension to simultaneously change to the steady-state target flow rate according to the minimum number of steps required for the oil flow rates of each suspension to simultaneously change to the steady-state target flow rate, the steady-state target flow rate of the oil in each suspension, and the target flow rate of the oil in each suspension at the previous moment.

[0060] In some alternative embodiments, according to the formula: Determine the maximum available flow rate change for the suspension hydraulic fluid flow rates to simultaneously change to the steady-state target flow rates;

[0061] where, Δv1(k) fl is the maximum available flow rate change for the left front suspension hydraulic fluid flow rate to simultaneously change to the steady-state target flow rate, Δv1(k) fr is the maximum available flow rate change for the right front suspension hydraulic fluid flow rate to simultaneously change to the steady-state target flow rate, Δv1(k) rl is the maximum available flow rate change for the left rear suspension hydraulic fluid flow rate to simultaneously change to the steady-state target flow rate, Δv1(k) rr is the maximum available flow rate change for the right rear suspension hydraulic fluid flow rate to simultaneously change to the steady-state target flow rate, Δv(k) fl is the difference between the steady-state target flow rate of the left front suspension hydraulic fluid and the target flow rate at the previous moment of the left front suspension, Δv(k) fr is the difference between the steady-state target flow rate of the right front suspension hydraulic fluid and the target flow rate at the previous moment of the right front suspension, Δv(k) rl is the difference between the steady-state target flow rate of the left rear suspension hydraulic fluid and the target flow rate at the previous moment of the left rear suspension, Δv(k) rr is the difference between the steady-state target flow rate of the right rear suspension hydraulic fluid and the target flow rate at the previous moment of the right rear suspension, N(k) max is the minimum number of steps required for the suspension hydraulic fluid flow rates to simultaneously change to the steady-state target flow rates.

[0062] In this embodiment, it can be seen from the above formula that Combined with step S1, it can be seen that The maximum available flow rate change for the suspension hydraulic fluid flow rates to simultaneously change to the steady-state target flow rates does not exceed the maximum available flow rate change of each suspension.

[0063] S22: Determine the execution flow rate change for the suspension hydraulic fluid flow rates to simultaneously change to the steady-state target flow rates according to the maximum available flow rate change for the suspension hydraulic fluid flow rates to simultaneously change to the steady-state target flow rates and the suspension hydraulic fluid flow rate control coefficient.

[0064] In some alternative embodiments, the suspension hydraulic fluid flow rate control coefficient is determined according to the following steps:

[0065] S221: Determine the sum of the difference between the steady-state target flow rate of each suspension hydraulic fluid and the target flow rate at the previous moment of each suspension hydraulic fluid and the ratio of the steady-state target flow rate of each suspension hydraulic fluid.

[0066] S222: Set the suspension hydraulic fluid flow rate control coefficient according to the sum of the difference between the steady-state target flow rate of each suspension hydraulic fluid and the target flow rate at the previous moment of each suspension hydraulic fluid and the ratio of the steady-state target flow rate of each suspension hydraulic fluid.

[0067] In some alternative embodiments, according to the formula:

[0068] Determine the sum of the ratios of the difference between the steady-state target flow rate of each suspension oil and the target flow rate at the previous moment to the steady-state target flow rate of each suspension oil;

[0069] According to the formula: Determine the suspension oil flow rate control coefficient;

[0070] where γ(k) is the sum of the ratios of the difference between the steady-state target flow rate of each suspension oil and the target flow rate at the previous moment to the steady-state target flow rate of each suspension oil, and Δv(k) fl is the difference between the steady-state target flow rate of the left front suspension oil and the target flow rate of the left front suspension at the previous moment, and Δv(k) fr is the difference between the steady-state target flow rate of the right front suspension oil and the target flow rate of the right front suspension at the previous moment, and Δv(k) rl is the difference between the steady-state target flow rate of the left rear suspension oil and the target flow rate of the left rear suspension at the previous moment, and Δv(k) rr is the difference between the steady-state target flow rate of the right rear suspension oil and the target flow rate of the right rear suspension at the previous moment, v fl is the steady-state target flow rate of the left front suspension oil, v fr is the steady-state target flow rate of the right front suspension oil, v rl is the steady-state target flow rate of the left rear suspension oil, v rr is the steady-state target flow rate of the right rear suspension oil, β(k) is the suspension oil flow rate control coefficient, β1 is the maximum control coefficient of the suspension oil flow rate, β0 is the minimum control coefficient of the suspension oil flow rate, γ1 is the upper limit of the sum of the ratios of the difference between the steady-state target flow rate of each suspension oil and the target flow rate at the previous moment to the steady-state target flow rate of each suspension oil, and γ0 is the lower limit of the sum of the ratios of the difference between the steady-state target flow rate of each suspension oil and the target flow rate at the previous moment to the steady-state target flow rate of each suspension oil.

[0071] In this embodiment, the larger γ(k) is, the greater the difference between the target flow rate of the suspension oil at the previous moment and the steady-state target flow rate of the suspension oil; when γ(k) = 0, it means that the target flow rate of the suspension oil at the previous moment is equal to the steady-state target flow rate of the suspension oil. In order to ensure the smoothness of the suspension oil flow rate change process, a suspension oil flow rate control coefficient is set. Among them, β1 > β0, γ1 > γ0, 0 < β0 ≤ β(k) ≤ β1 ≤ 1, and the values of β1, β0, γ1, and γ0 are obtained through experimental calibration.

[0072] In some alternative embodiments, according to the formula:

[0073] Determine the execution flow rate change amount when the flow rates of each suspension oil change to the steady-state target flow rate simultaneously;

[0074] Among them, Δv2(k) fl is the execution flow velocity change amount when the oil flow velocity of the left front suspension simultaneously changes to the steady-state target flow velocity, and Δv2(k) fr is the execution flow velocity change amount when the oil flow velocity of the right front suspension simultaneously changes to the steady-state target flow velocity, and Δv2(k) rl is the execution flow velocity change amount when the oil flow velocity of the left rear suspension simultaneously changes to the steady-state target flow velocity, and Δv2(k) rr is the execution flow velocity change amount when the oil flow velocity of the right rear suspension simultaneously changes to the steady-state target flow velocity, and Δv1(k) fl is the maximum available flow velocity change amount when the oil flow velocity of the left front suspension simultaneously changes to the steady-state target flow velocity, and Δv1(k) fr is the maximum available flow velocity change amount when the oil flow velocity of the right front suspension simultaneously changes to the steady-state target flow velocity, and Δv1(k) rl is the maximum available flow velocity change amount when the oil flow velocity of the left rear suspension simultaneously changes to the steady-state target flow velocity, and Δv1(k) rr is the maximum available flow velocity change amount when the oil flow velocity of the right rear suspension simultaneously changes to the steady-state target flow velocity, and β(k) is the suspension oil flow velocity control coefficient.

[0075] In this embodiment, according to the above formula and in combination with steps S222 and S21, it can be known that the execution flow velocity change amounts when the oil flow velocities of each suspension simultaneously change to the steady-state target flow velocity are all less than or equal to the maximum available flow velocity change amounts of the corresponding suspensions, avoiding the problems of damage to the suspension hydraulic pipelines and reduction of the working life, and improving the reliability of the system.

[0076] S3: Determine the current target flow velocity of the oil of each suspension according to the execution flow velocity change amount when the oil flow velocity of each suspension simultaneously changes to the steady-state target flow velocity and the target flow velocity of the oil of each suspension at the previous moment.

[0077] In some alternative embodiments, according to the formula:

[0078] Determine the current target flow velocity of the oil of each suspension;

[0079] Among them, v(k) fl is the current target flow velocity of the oil of the left front suspension, and v(k) fr is the current target flow velocity of the oil of the right front suspension, and v(k) rl is the current target flow velocity of the oil of the left rear suspension, and v(k) rr is the current target flow velocity of the oil of the right rear suspension, and v(k - 1) fl is the target flow velocity of the oil of the left front suspension at the previous moment, and v(k - 1) fr is the target flow velocity of the oil of the right front suspension at the previous moment, and v(k - 1) rlis the target flow rate of the left rear suspension oil at the previous moment, v(k-1) rr is the target flow rate of the right rear suspension oil at the previous moment, Δv2(k) fl is the change in the execution flow rate for the left front suspension oil to simultaneously change to the steady-state target flow rate, Δv2(k) fr is the change in the execution flow rate for the right front suspension oil to simultaneously change to the steady-state target flow rate, Δv2(k) rl is the change in the execution flow rate for the left rear suspension oil to simultaneously change to the steady-state target flow rate, Δv2(k) rr is the change in the execution flow rate for the right rear suspension oil to simultaneously change to the steady-state target flow rate.

[0080] In this embodiment, by adding the change in the execution flow rate for the suspension oil to simultaneously change to the steady-state target flow rate to the target flow rate of the suspension oil at the previous moment, the target flow rate of the suspension oil at the current moment is obtained, and a change in the oil flow rate is completed.

[0081] S4: Update the target flow rate values of the suspension oils at the previous moment to the target flow rate values of the suspension oils at the current moment, and loop the above steps until the difference between the target flow rate of the suspension oil at the current moment and the steady-state target flow rate of the suspension oil is less than the set value.

[0082] In this embodiment, by repeating the process of obtaining the target flow rate of each suspension oil at the current moment by performing the oil flow rate change on the target flow rate of each suspension oil at the previous moment until the difference between the target flow rate of each suspension oil at the current moment and the steady-state target flow rate of each suspension oil is less than the set value. The smooth transition of the flow rate of each suspension oil to the steady-state target flow rate is achieved.

[0083] In summary, the present invention determines the minimum number of steps required for the oil flow rates of each suspension to simultaneously change to the steady-state target oil flow rate according to the steady-state target oil flow rate of each suspension, the target oil flow rate of each suspension at the previous moment, and the maximum allowable change amount of the oil flow rate of each suspension; determines the execution oil flow rate change amount for the oil flow rates of each suspension to simultaneously change to the steady-state target oil flow rate according to the minimum number of steps required for the oil flow rates of each suspension to simultaneously change to the steady-state target oil flow rate, the steady-state target oil flow rate of each suspension, and the target oil flow rate of each suspension at the previous moment; determines the target oil flow rate of each suspension at the current moment according to the execution oil flow rate change amount for the oil flow rates of each suspension to simultaneously change to the steady-state target oil flow rate and the target oil flow rate of each suspension at the previous moment; updates the target oil flow rate value of each suspension at the previous moment to the target oil flow rate value of each suspension at the current moment, and loops the above steps until the difference between the target oil flow rate of each suspension at the current moment and the steady-state target oil flow rate of each suspension is less than the set value. This solves the problem in the prior art that the oil flow rate changes rapidly, resulting in a low service life and easy damage of the hydraulic pipeline. During the dynamic control process of the oil flow rate of the hydraulic suspension, the change amount of the oil flow rate is always required to be less than or equal to the maximum allowable change amount of the hydraulic system characteristics, avoiding the problems of damage to the hydraulic suspension pipeline and low working life, and improving the durability of the working life of the suspension system.

[0084] On the other hand, the present invention also provides a four-wheel hydraulic suspension oil flow rate control system, including:

[0085] A minimum number of steps determination module, which is used to determine the minimum number of steps required for the oil flow rates of each suspension to simultaneously change to the steady-state target oil flow rate according to the steady-state target oil flow rate of each suspension, the target oil flow rate of each suspension at the previous moment, and the maximum allowable change amount of the oil flow rate of each suspension;

[0086] An execution oil flow rate change amount determination module, which is used to determine the execution oil flow rate change amount for the oil flow rates of each suspension to simultaneously change to the steady-state target oil flow rate according to the minimum number of steps required for the oil flow rates of each suspension to simultaneously change to the steady-state target oil flow rate, the steady-state target oil flow rate of each suspension, and the target oil flow rate of each suspension at the previous moment;

[0087] A current moment target oil flow rate determination module, which is used to determine the target oil flow rate of each suspension at the current moment according to the execution oil flow rate change amount for the oil flow rates of each suspension to simultaneously change to the steady-state target oil flow rate and the target oil flow rate of each suspension at the previous moment;

[0088] A judgment module, which is used to update the target oil flow rate value of each suspension at the previous moment to the target oil flow rate value of each suspension at the current moment, and loop the above steps until the difference between the target oil flow rate of each suspension at the current moment and the steady-state target oil flow rate of each suspension is less than the set value.

[0089] It should be noted that those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the above-described device and each module and unit can refer to the corresponding processes in the foregoing embodiments, and will not be elaborated herein.

[0090] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application. Unless otherwise clearly specified and defined, the terms "mounted", "connected" and "connected" shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0091] It should be noted that in the present application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0092] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A control method for protecting the flow rate of hydraulic oil in a four-wheel hydraulic suspension, characterized in that, Including: S1. Determine the minimum number of steps required for the target flow rates of the suspension oils to change to the steady-state target flow rates simultaneously, based on the steady-state target flow rates of the suspension oils, the target flow rates of the suspension oils at the previous moment, and the maximum available flow rate change amounts of the suspension oils; S2. Determine the execution flow rate change amounts for the target flow rates of the suspension oils to change to the steady-state target flow rates simultaneously, based on the minimum number of steps required for the target flow rates of the suspension oils to change to the steady-state target flow rates simultaneously, the steady-state target flow rates of the suspension oils, and the target flow rates of the suspension oils at the previous moment. This includes: determining the maximum available flow rate change amounts for the target flow rates of the suspension oils to change to the steady-state target flow rates simultaneously, based on the minimum number of steps required for the target flow rates of the suspension oils to change to the steady-state target flow rates simultaneously, the steady-state target flow rates of the suspension oils, and the target flow rates of the suspension oils at the previous moment; determining the execution flow rate change amounts for the target flow rates of the suspension oils to change to the steady-state target flow rates simultaneously, based on the maximum available flow rate change amounts for the target flow rates of the suspension oils to change to the steady-state target flow rates simultaneously and the suspension oil flow rate control coefficient. The determination of the suspension oil flow rate control coefficient includes the following steps: determining the ratio sum of the difference between the steady-state target flow rate and the target flow rate at the previous moment of each suspension oil and the steady-state target flow rate of each suspension oil, based on the steady-state target flow rate and the target flow rate at the previous moment of each suspension oil; setting the suspension oil flow rate control coefficient based on the ratio sum of the difference between the steady-state target flow rate and the target flow rate at the previous moment and the steady-state target flow rate of each suspension oil; S3. Determine the target flow rates of the suspension oils at the current moment, based on the execution flow rate change amounts for the target flow rates of the suspension oils to change to the steady-state target flow rates simultaneously and the target flow rates of the suspension oils at the previous moment; S4. Update the target flow rate values of the suspension oils at the previous moment to the target flow rate values of the suspension oils at the current moment, and loop the above steps until the difference between the target flow rates of the suspension oils at the current moment and the steady-state target flow rates of the suspension oils is less than the set value; Among them, according to the formula: , determine the sum of the ratios of the differences between the steady-state target flow rates of the suspension oils and the target flow rates at the previous moment to the steady-state target flow rates of the suspension oils; according to the formula: ， Determine the suspension oil flow rate control coefficient; where, is the sum of the ratios of the differences between the steady-state target flow rates of the suspension oils and the target flow rates at the previous moment to the steady-state target flow rates of the suspension oils, , , and are respectively the differences between the steady-state target flow rates of the left front, right front, left rear, and right rear suspension oils and the target flow rates at the previous moment of their respective suspensions, , , and are respectively the steady-state target flow rates of the left front, right front, left rear, and right rear suspension oils, is the suspension oil flow rate control coefficient, and are respectively the maximum control coefficient and the minimum control coefficient of the suspension oil flow rate, and are respectively the upper limit and the lower limit of the sum of the ratios of the differences between the steady-state target flow rates of the suspension oils and the target flow rates at the previous moment to the steady-state target flow rates of the suspension oils.

2. The four-wheel hydraulic suspension oil flow rate protection control method according to claim 1, wherein According to the formula: , determine the minimum number of steps required for the fluid flow rates of each suspension to simultaneously change to the steady-state target fluid flow rate; Among them, is the minimum number of steps required for the oil flow rate of the left front suspension to change to the steady-state target flow rate, is the minimum number of steps required for the oil flow rate of the right front suspension to change to the steady-state target flow rate, is the minimum number of steps required for the oil flow rate of the left rear suspension to change to the steady-state target flow rate, is the minimum number of steps required for the oil flow rate of the right rear suspension to change to the steady-state target flow rate, is the difference between the steady-state target flow rate of the oil in the left front suspension and the target flow rate of the left front suspension at the previous moment, is the difference between the steady-state target flow rate of the oil in the right front suspension and the target flow rate of the right front suspension at the previous moment, is the difference between the steady-state target flow rate of the oil in the left rear suspension and the target flow rate of the left rear suspension at the previous moment, is the difference between the steady-state target flow rate of the oil in the right rear suspension and the target flow rate of the right rear suspension at the previous moment, is the maximum available flow rate change of the left front suspension, is the maximum available flow rate change of the right front suspension, is the maximum available flow rate change of the left rear suspension, is the maximum available flow rate change of the right rear suspension, is the minimum number of steps required for the oil flow rates of each suspension to change to the steady-state target flow rate simultaneously.

3. The four-wheel hydraulic suspension oil flow rate protection control method according to claim 1, characterized in that According to the formula: , determine the maximum available flow rate change when the flow rates of each suspension fluid change to the steady-state target flow rate simultaneously; Among them, is the maximum available flow rate change amount when the left front suspension oil flow rate simultaneously changes to the steady-state target flow rate, is the maximum available flow rate change amount when the right front suspension oil flow rate simultaneously changes to the steady-state target flow rate, is the maximum available flow rate change amount when the left rear suspension oil flow rate simultaneously changes to the steady-state target flow rate, is the maximum available flow rate change amount when the right rear suspension oil flow rate simultaneously changes to the steady-state target flow rate, is the difference between the steady-state target flow rate of the left front suspension oil and the target flow rate of the left front suspension at the previous moment, is the difference between the steady-state target flow rate of the right front suspension oil and the target flow rate of the right front suspension at the previous moment, is the difference between the steady-state target flow rate of the left rear suspension oil and the target flow rate of the left rear suspension at the previous moment, is the difference between the steady-state target flow rate of the right rear suspension oil and the target flow rate of the right rear suspension at the previous moment, is the minimum number of steps required for the oil flow rates of each suspension to simultaneously change to the steady-state target flow rate.

4. The four-wheel hydraulic suspension oil flow rate protection control method according to claim 1, characterized in that According to the formula: , determine the execution flow rate change amount when the suspension oil flow rates change to the steady-state target flow rate simultaneously; Among them, is the execution flow rate change amount when the left front suspension oil flow rate simultaneously changes to the steady-state target flow rate, is the execution flow rate change amount when the right front suspension oil flow rate simultaneously changes to the steady-state target flow rate, is the execution flow rate change amount when the left rear suspension oil flow rate simultaneously changes to the steady-state target flow rate, is the execution flow rate change amount when the right rear suspension oil flow rate simultaneously changes to the steady-state target flow rate, is the maximum available flow rate change amount when the left front suspension oil flow rate simultaneously changes to the steady-state target flow rate, is the maximum available flow rate change amount when the right front suspension oil flow rate simultaneously changes to the steady-state target flow rate, is the maximum available flow rate change amount when the left rear suspension oil flow rate simultaneously changes to the steady-state target flow rate, is the maximum available flow rate change amount when the right rear suspension oil flow rate simultaneously changes to the steady-state target flow rate, is the suspension oil flow rate control coefficient.

5. The four-wheel hydraulic suspension oil flow rate protection control method according to claim 1, characterized in that, According to the formula: , determine the target flow rate of each suspension oil at the current moment; Among them, is the target flow rate of the left front suspension oil at the current moment, is the target flow rate of the right front suspension oil at the current moment, is the target flow rate of the left rear suspension oil at the current moment, is the target flow rate of the right rear suspension oil at the current moment, is the target flow rate of the left front suspension oil at the previous moment, is the target flow rate of the right front suspension oil at the previous moment, is the target flow rate of the left rear suspension oil at the previous moment, is the target flow rate of the right rear suspension oil at the previous moment, is the execution flow rate change amount for the left front suspension oil to simultaneously change to the steady-state target flow rate, is the execution flow rate change amount for the right front suspension oil to simultaneously change to the steady-state target flow rate, is the execution flow rate change amount for the left rear suspension oil to simultaneously change to the steady-state target flow rate, is the execution flow rate change amount for the right rear suspension oil to simultaneously change to the steady-state target flow rate.

6. The four-wheel hydraulic suspension oil flow rate protection control method according to claim 1, characterized in that, Determine the maximum available flow rate change amounts of the suspension oils, based on the maximum available flow rate change amounts per unit time of the suspension oils and the task execution period.

7. A four-wheel hydraulic suspension oil flow rate control system, which applies the four-wheel hydraulic suspension oil flow rate protection control method according to any one of claims 1 to 6, characterized in that, Including: A minimum step determination module, which is used to determine the minimum number of steps required for the target flow rates of the suspension oils to change to the steady-state target flow rates simultaneously, based on the steady-state target flow rates of the suspension oils, the target flow rates of the suspension oils at the previous moment, and the maximum available flow rate change amounts of the suspension oils; An execution flow rate change amount determination module, which is used to determine the execution flow rate change amount for the suspension oil flow rates to simultaneously change to the steady-state target flow rate according to the minimum number of steps required for each suspension oil flow rate to simultaneously change to the steady-state target flow rate, the steady-state target flow rate of each suspension oil, and the target flow rate of each suspension oil at the previous moment. It includes: determining the maximum available flow rate change amount for each suspension oil flow rate to simultaneously change to the steady-state target flow rate according to the minimum number of steps required for each suspension oil flow rate to simultaneously change to the steady-state target flow rate, the steady-state target flow rate of each suspension oil, and the target flow rate of each suspension oil at the previous moment; determining the execution flow rate change amount for each suspension oil flow rate to simultaneously change to the steady-state target flow rate according to the maximum available flow rate change amount for each suspension oil flow rate to simultaneously change to the steady-state target flow rate and the suspension oil flow rate control coefficient; wherein the confirmation of the suspension oil flow rate control coefficient includes the following steps: determining the sum of the ratio of the difference between the steady-state target flow rate and the target flow rate at the previous moment of each suspension oil to the steady-state target flow rate of each suspension oil according to the steady-state target flow rate of each suspension oil and the target flow rate of each suspension oil at the previous moment; setting the suspension oil flow rate control coefficient according to the sum of the ratio of the difference between the steady-state target flow rate and the target flow rate at the previous moment of each suspension oil to the steady-state target flow rate of each suspension oil. A current moment target flow rate determination module, which is used to determine the target flow rate of each suspension oil at the current moment according to the execution flow rate change amount for each suspension oil flow rate to simultaneously change to the steady-state target flow rate and the target flow rate of each suspension oil at the previous moment. A judgment module, which is used to update the target flow rate value of each suspension oil at the previous moment to the target flow rate value of each suspension oil at the current moment, and loop the above steps until the difference between the target flow rate of each suspension oil at the current moment and the steady-state target flow rate of each suspension oil is less than the set value.

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