Passive hydraulic load control method and device, rear wheel steering gear and vehicle

Abstract

The invention provides a passive hydraulic load control method and device, a rear wheel steering gear and a vehicle, the method is applied to the vehicle, and the method comprises the steps that displacement data of the rear wheel steering gear during testing and passive hydraulic load data of a hydraulic valve are obtained; generating a target load threshold according to the displacement data and the passive hydraulic load data; and controlling the hydraulic valve to output a passive hydraulic load signal according to the target load threshold value. According to the method, the target load threshold value can be generated according to the displacement data during testing of the rear wheel steering gear and the passive hydraulic load data of the hydraulic valve, then the hydraulic valve is controlled to output the passive hydraulic load signal according to the target load threshold value, and output of the passive hydraulic load signal of the hydraulic valve is accurately controlled. The deviation between the actual load and the set load is minimized, the stability and consistency of load signals are ensured, and the test reliability is improved.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and more particularly, to a passive hydraulic load control method, device, rear wheel steering gear and vehicle in the field of vehicles. Background Art

[0002] There are currently two types of loads for testing RWS (Rear wheel steering) wire-controlled steering products: one is an active hydraulic load, which can actively load the load force and has high hydraulic control stability. It can also change the load force in different forms and conditions according to the test conditions through pressure regulation, overflow and pressure feedback, but it is relatively expensive.

[0003] The other is a passive hydraulic load. Although it is cheap, it can only achieve the purpose of passive load by setting a threshold. The actual value and the threshold setting value cannot be completely consistent. The actual deviation is about 1KN, which seriously affects the reliability of RWS performance testing. Summary of the invention

[0004] The present application provides a passive hydraulic load control method, device, rear-wheel steering gear and vehicle. The method can generate a target load threshold based on the displacement data during the rear-wheel steering gear test and the passive hydraulic load data of the hydraulic valve, and then control the hydraulic valve to output a passive hydraulic load signal according to the target load threshold, accurately control the output of the passive hydraulic load signal of the hydraulic valve, ensure that the deviation between the actual load and the set load is minimized, ensure the stability and consistency of the load signal, and improve the reliability of the test.

[0005] In a first aspect, a passive hydraulic load control method is provided, the method comprising the following steps: obtaining displacement data during a rear-wheel steering gear test and passive hydraulic load data of a hydraulic valve; generating a target load threshold value based on the displacement data and the passive hydraulic load data; and controlling the hydraulic valve to output a passive hydraulic load signal based on the target load threshold value.

[0006] Through the above technical scheme, the embodiment of the present application can generate a target load threshold based on the displacement data during the rear-wheel steering gear test and the passive hydraulic load data of the hydraulic valve, and then control the hydraulic valve to output a passive hydraulic load signal according to the target load threshold, accurately control the output of the passive hydraulic load signal of the hydraulic valve, ensure that the deviation between the actual load and the set load is minimized, ensure the stability and consistency of the load signal, and improve the reliability of the test.

[0007] In combination with the first aspect, in some possible implementations, a target load threshold is generated based on displacement data and passive hydraulic load data, including: calculating a load compensation value based on the displacement data and passive hydraulic load data; and determining the target load threshold based on a set load threshold of the hydraulic valve and the load compensation value.

[0008] Through the above technical scheme, the embodiment of the present application can calculate the load compensation value based on the displacement data and the passive hydraulic load data, and further determine the target load threshold value based on the set load threshold value and the load compensation value of the hydraulic valve. By increasing the load compensation value of the hydraulic valve, the target load threshold value is determined using the set load threshold value and the load compensation value, thereby avoiding the discrepancy between the actual value and the set value of the passive load of the hydraulic valve, improving the stability of the load control, and thereby improving the reliability of the test of the rear wheel steering gear.

[0009] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the load compensation value is calculated based on the displacement data and the passive hydraulic load data, including: determining the median displacement based on the displacement data and rounding the median displacement; calculating the load compensation value based on the rounded median displacement and the passive hydraulic load data.

[0010] Through the above technical scheme, the embodiment of the present application can determine the median displacement based on the displacement data, round the median displacement data, and calculate the load compensation value based on the rounded median displacement and passive hydraulic load data. By rounding the median displacement data, the integer displacement data can correspond to more load compensation points, thereby improving the reliability of load signal compensation.

[0011] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the load compensation value is calculated based on the rounded median displacement and the passive hydraulic load data, including: identifying the actual number of sampling points in the passive hydraulic load data corresponding to the rounded median displacement; determining the target number of sampling points based on the actual number of sampling points, and selecting multiple passive hydraulic loads near the passive hydraulic load corresponding to the rounded median displacement based on the target number of sampling points; and calculating the load compensation value based on the multiple passive hydraulic loads.

[0012] Through the above technical scheme, the embodiment of the present application can identify the actual number of sampling points in the passive hydraulic load data corresponding to the rounded median displacement, and determine the target number of sampling points based on the actual number of sampling points, and select multiple passive hydraulic loads near the passive hydraulic load corresponding to the rounded median displacement based on the target number of sampling points, and then calculate the load compensation value based on the multiple passive hydraulic loads. By amplifying the number of actual sampling points, it is ensured that there are enough data points for analysis, thereby increasing the reliability of the load compensation value.

[0013] In combination with the first aspect and the above-mentioned implementations, in some possible implementations, determining the median displacement based on the displacement data includes: identifying the maximum displacement and the minimum displacement of the displacement data within the target stroke range; and determining the median displacement based on the maximum displacement and the minimum displacement.

[0014] Through the above technical solution, in order to ensure the reliability of load compensation, the embodiment of the present application can identify the maximum displacement and the minimum displacement of the displacement data within the target stroke range, and then determine the median displacement based on the maximum displacement and the minimum displacement.

[0015] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, after controlling the hydraulic valve to output a passive hydraulic load signal according to the target load threshold, it also includes: obtaining a target test displacement of the rear-wheel steering gear, and setting a target control displacement according to the target test displacement, identifying the displacement data of the rear-wheel steering gear to obtain an actual displacement, wherein the target control displacement is less than the target test displacement; if the actual displacement reaches the target control displacement, the hydraulic valve is controlled to release pressure to a first preset pressure, and if the actual displacement reaches the target test displacement, the hydraulic valve is controlled to release pressure to a second preset pressure, wherein the first preset pressure is greater than the second preset pressure.

[0016] Through the above technical scheme, the embodiment of the present application can set a target control displacement according to the target test displacement of the rear-wheel steering gear to achieve more precise control and identify the actual displacement of the rear-wheel steering gear. When the actual displacement reaches the target control displacement, the hydraulic valve is controlled to release pressure to the first preset pressure, that is, to release pressure in advance, so as to reduce the impact when the hydraulic valve is switched at the end, and ensure the smooth transition of the load signal. When the actual displacement reaches the target test displacement, the hydraulic valve is controlled to release pressure for the second time, and the pressure is released to the second preset pressure to ensure that the load force drops rapidly at the maximum displacement, that is, by releasing pressure in advance and then releasing pressure to build up pressure when the end is switched, load overshoot can be avoided.

[0017] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, after controlling the hydraulic valve to release pressure to the second preset pressure, it also includes: if the actual displacement reaches the first preset displacement, controlling the hydraulic valve to increase the pressure to the first preset pressure; if the actual displacement reaches the second preset displacement, controlling the hydraulic valve to increase the pressure to the pressure before pressure relief, wherein the first preset displacement and the second preset displacement are set according to the target control displacement.

[0018] Through the above technical scheme, the embodiment of the present application can control the hydraulic valve to increase the pressure to the first preset pressure when the actual displacement reaches the first preset displacement, and increase the pressure in advance when the actual displacement retreats to a level close to the target test displacement to ensure that the load force is gradually restored and avoid sudden impact. When the actual displacement reaches the second preset displacement, the hydraulic valve is controlled to increase the pressure to the pressure before pressure relief to ensure that the load force is fully restored and maintain the stability and reliability of the test.

[0019] In a second aspect, a passive hydraulic load control device is provided, which includes: an acquisition module for acquiring displacement data and passive hydraulic load data of a hydraulic valve during a rear-wheel steering gear test; a generation module for generating a target load threshold based on the displacement data and the passive hydraulic load data; and a control module for controlling the hydraulic valve to output a passive hydraulic load signal based on the target load threshold.

[0020] In combination with the second aspect, in some possible implementations, the generation module is further used to: calculate a load compensation value based on the displacement data and the passive hydraulic load data; and determine a target load threshold based on a set load threshold of the hydraulic valve and the load compensation value.

[0021] In combination with the second aspect and the above-mentioned implementations, in some possible implementations, the generation module is further used to: determine the median displacement based on the displacement data, and round the median displacement; and calculate the load compensation value based on the rounded median displacement and the passive hydraulic load data.

[0022] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, the generation module is further used to: identify the actual number of sampling points in the passive hydraulic load data corresponding to the rounded median displacement; determine the target number of sampling points based on the actual number of sampling points, and select multiple passive hydraulic loads near the passive hydraulic load corresponding to the rounded median displacement based on the target number of sampling points; calculate the load compensation value based on multiple passive hydraulic loads.

[0023] In combination with the second aspect and the above implementations, in some possible implementations, the generation module is further used to: identify the maximum displacement and the minimum displacement of the displacement data within the target stroke range; and determine the median displacement based on the maximum displacement and the minimum displacement.

[0024] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, it also includes: a first control module, which is used to obtain the target test displacement of the rear-wheel steering gear after controlling the hydraulic valve to output a passive hydraulic load signal according to the target load threshold, and set the target control displacement according to the target test displacement, identify the displacement data of the rear-wheel steering gear to obtain the actual displacement, wherein the target control displacement is less than the target test displacement; if the actual displacement reaches the target control displacement, the hydraulic valve is controlled to release pressure to a first preset pressure, and if the actual displacement reaches the target test displacement, the hydraulic valve is controlled to release pressure to a second preset pressure, wherein the first preset pressure is greater than the second preset pressure.

[0025] In combination with the second aspect and the above-mentioned implementation methods, in some possible implementation methods, it also includes: a second control module, which is used to control the hydraulic valve to increase the pressure to the first preset pressure if the actual displacement reaches the first preset displacement after controlling the hydraulic valve to release pressure to the second preset pressure, and to control the hydraulic valve to increase the pressure to the pressure before pressure relief if the actual displacement reaches the second preset displacement, wherein the first preset displacement and the second preset displacement are set according to the target control displacement.

[0026] In a third aspect, a rear wheel steering gear is provided, and the rear wheel steering gear is tested based on the passive hydraulic load control method in any possible implementation of the first aspect or the first aspect.

[0027] In a fourth aspect, a vehicle is provided, comprising the rear wheel steering gear of the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a flow chart of a passive hydraulic load control method provided in an embodiment of the present application;

[0029] Figure 2 is a flow chart of a hydraulic valve passive load automatic compensation strategy provided by an embodiment of the present application;

[0030] Figure 3 is a diagram of a displacement signal processing process provided by an embodiment of the present application;

[0031] Figure 4 is a diagram of a hydraulic load processing process provided by an embodiment of the present application;

[0032] Figure 5 is a flow chart of a multi-stage load setting strategy for a passive load provided in an embodiment of the present application;

[0033] Figure 6 is a schematic diagram of a passive hydraulic load control device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0035] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0036] Figure 1 It is a schematic flow chart of a passive hydraulic load control method provided in an embodiment of the present application.

[0037] For example, Figure 1 As shown, the passive hydraulic load control method includes the following steps:

[0038] In step S101 , displacement data of the rear wheel steering gear during testing and passive hydraulic load data of the hydraulic valve are acquired.

[0039] The displacement data includes the displacement data of the RWS during the test and the passive hydraulic load data of the hydraulic valve, so as to realize the control of the passive hydraulic load later.

[0040] It should be noted that RWS is a rear-wheel steering product. Unlike the EPS front-wheel steering, it has no angle signal and only a displacement signal when actuated.

[0041] In step S102 , a target load threshold is generated according to the displacement data and the passive hydraulic load data.

[0042] It can be understood that the embodiment of the present application can generate a target load threshold based on displacement data and passive hydraulic load data, so as to subsequently control the hydraulic valve to output a passive hydraulic load signal based on the target load threshold, wherein the method for generating the target load threshold is specifically as follows.

[0043] In an embodiment of the present application, a target load threshold is generated based on displacement data and passive hydraulic load data, including: calculating a load compensation value based on the displacement data and passive hydraulic load data; and determining the target load threshold based on a set load threshold of the hydraulic valve and the load compensation value.

[0044] It can be understood that the embodiments of the present application can calculate the load compensation value based on the displacement data and the passive hydraulic load data, and further determine the target load threshold value based on the set load threshold value and the load compensation value of the hydraulic valve. By increasing the load compensation value of the hydraulic valve, the target load threshold value is determined using the set load threshold value and the load compensation value, thereby avoiding the actual value of the passive load of the hydraulic valve from being inconsistent with the set value, improving the stability of the load control, and thereby improving the reliability of the test of the rear-wheel steering gear.

[0045] In an embodiment of the present application, the load compensation value is calculated based on the displacement data and the passive hydraulic load data, including: determining the median displacement based on the displacement data and rounding the median displacement; and calculating the load compensation value based on the rounded median displacement and the passive hydraulic load data.

[0046] Due to the requirements of RWS products, the sampling frequency of general equipment is relatively high. In order to ensure the reliability of load signal compensation, integer displacement data can correspond to more load compensation points and be more accurate. Therefore, the embodiment of the present application can determine the median displacement based on all displacement data, and round the median displacement, and then calculate the load compensation value based on the rounded median displacement and passive hydraulic load data.

[0047] For example, when the RWS is actuated for the first time, displacement data of 1.1, 1.2, and 1.3 are collected. If only the displacement data of 1.1 is used to find the corresponding value, only one valid value can be provided. However, three valid values ​​can be found by rounding, where rounding means directly removing the value after the decimal point.

[0048] In an embodiment of the present application, determining the median displacement according to the displacement data includes: identifying the maximum displacement and the minimum displacement of the displacement data within the target stroke range; and determining the median displacement according to the maximum displacement and the minimum displacement.

[0049] Among them, the target travel range can be set according to specific circumstances and is not specifically limited.

[0050] Due to the passive load characteristics, the load force rises in an arc form at startup. To ensure the reliability of load compensation, the embodiment of the present application can identify the maximum displacement and minimum displacement of the displacement data within the target stroke range, and then determine the median displacement based on the maximum displacement and the minimum displacement.

[0051] Specifically, the processing of displacement data in this application is as follows: Figure 2 As shown, including:

[0052] During the test, the RWS obtains the displacement data during the operation and sets the automatic compensation range of the load data according to the rack travel (RWS single-side rack travel is sufficient). The displacement data in this range will be used to calculate the load compensation value. For example, if the single-side rack travel of the RWS is 30mm, then a range, such as 25mm to 30mm, can be set as the automatic compensation range.

[0053] In an embodiment of the present application, a load compensation value is calculated based on the rounded median displacement and the passive hydraulic load data, including: identifying the actual number of sampling points in the passive hydraulic load data corresponding to the rounded median displacement; determining the target number of sampling points based on the actual number of sampling points, and selecting multiple passive hydraulic loads near the passive hydraulic load corresponding to the rounded median displacement based on the target number of sampling points; and calculating the load compensation value based on the multiple passive hydraulic loads.

[0054] The target number of sampling points can be obtained by increasing the actual number of sampling points. The target number of sampling points = increase coefficient × actual number of sampling points. The increase coefficient is positively correlated with the sampling rate, that is, the higher the sampling rate, the greater the increase coefficient.

[0055] It can be understood that the embodiments of the present application can identify the actual number of sampling points in the passive hydraulic load data corresponding to the rounded median displacement, and determine the target number of sampling points based on the actual number of sampling points, select multiple passive hydraulic loads near the passive hydraulic load corresponding to the rounded median displacement based on the target number of sampling points, and then calculate the load compensation value based on the multiple passive hydraulic load data. By amplifying the number of actual sampling points, it is ensured that there are enough data points for analysis, thereby increasing the reliability of the load compensation value.

[0056] Among them, the number of actual sampling points corresponding to the median displacement in the identification displacement data can be determined by positive and negative indexes. The median displacement is an integer and corresponds to only one point, which affects the reliability of the final compensation value. In order to obtain the number of load force points corresponding to the final median integer, the positive index is used to retrieve the data (passive hydraulic load data) to find a median point, and the reverse index is used to retrieve the data (passive hydraulic load data) to find another median point. The subtraction obtains the "number of sampling points" of the median of the passive hydraulic load data, that is, the actual number of sampling points.

[0057] It should be noted that the passive hydraulic load data is within the displacement range set by the RWS, and the corresponding passive hydraulic load data is determined within the displacement range based on the displacement data.

[0058] For example, the median displacement after rounding is 15 mm, the actual number of sampling points is 4, and the increase coefficient is 5, then the target number of sampling points is 20. Select multiple passive hydraulic loads near the passive hydraulic load corresponding to the median displacement after rounding, such as L1, L2, ..., L20. By calculating the load compensation value through the passive hydraulic load, a more accurate and stable load compensation value can be obtained, thereby improving the reliability and data quality of subsequent RWS tests.

[0059] In step S103 , the hydraulic valve is controlled to output a passive hydraulic load signal according to the target load threshold.

[0060] It can be understood that the embodiment of the present application can control the hydraulic valve to output a passive hydraulic load signal according to the target load threshold, thereby avoiding the discrepancy between the actual value and the set value of the passive hydraulic load, ensuring the stability and accuracy of the load signal, and thus improving the reliability and accuracy of the RWS test.

[0061] In an embodiment of the present application, after controlling the hydraulic valve to output a passive hydraulic load signal according to a target load threshold, it also includes: obtaining a target test displacement of the rear-wheel steering gear, setting a target control displacement according to the target test displacement, identifying the displacement data of the rear-wheel steering gear to obtain an actual displacement, wherein the target control displacement is less than the target test displacement; if the actual displacement reaches the target control displacement, the hydraulic valve is controlled to release pressure to a first preset pressure, and if the actual displacement reaches the target test displacement, the hydraulic valve is controlled to release pressure to a second preset pressure, wherein the first preset pressure is greater than the second preset pressure.

[0062] Among them, the target test displacement is the maximum displacement that needs to be achieved in the rear-wheel steering gear test, and the target control displacement is smaller than the target test displacement, which is used to perform more precise control when approaching the target test displacement. The first preset pressure and the second preset pressure can be set according to the specific situation, and there is no specific limitation on this.

[0063] It can be understood that the embodiment of the present application can set a target control displacement according to the target test displacement of the rear-wheel steering gear to achieve more precise control and identify the actual displacement of the rear-wheel steering gear. When the actual displacement reaches the target control displacement, the hydraulic valve is controlled to release pressure to the first preset pressure, that is, to release pressure in advance, so as to reduce the impact during the terminal switching of the hydraulic valve and ensure the smooth transition of the load signal. When the actual displacement reaches the target test displacement, the hydraulic valve is controlled to release pressure for the second time to the second preset pressure to ensure that the load force drops rapidly at the maximum displacement, that is, by releasing pressure in advance and then releasing pressure to build up pressure during the terminal switching, load overshoot can be avoided.

[0064] For example, the target test displacement is 30mm, the target control displacement is 29mm, the first preset pressure is 2.5KN, and the second preset pressure is 0KN: when the actual displacement reaches 29mm, the hydraulic valve is controlled to release the pressure to 2.5KN; when the actual displacement reaches 30mm, the hydraulic valve is controlled to release the pressure to 0KN.

[0065] This ensures that the load force gradually decreases when approaching the maximum displacement, avoiding sudden impact and overshoot, and improving the stability and reliability of the test.

[0066] In an embodiment of the present application, after controlling the hydraulic valve to release pressure to the second preset pressure, it also includes: if the actual displacement reaches the first preset displacement, controlling the hydraulic valve to increase the pressure to the first preset pressure; if the actual displacement reaches the second preset displacement, controlling the hydraulic valve to increase the pressure to the pressure before pressure relief, wherein the first preset displacement and the second preset displacement are set according to the target control displacement.

[0067] Among them, the first preset displacement and the second preset displacement are set according to the target control displacement, and can be set according to specific circumstances. There is no specific limitation on this. The first preset displacement and the second preset displacement are both smaller than the target test displacement.

[0068] It can be understood that the embodiment of the present application can control the hydraulic valve to increase the pressure to the first preset pressure when the actual displacement reaches the first preset displacement, and increase the pressure in advance when the actual displacement retreats to a level close to the target test displacement to ensure that the load force is gradually restored and avoid sudden impact. When the actual displacement reaches the second preset displacement, the hydraulic valve is controlled to increase the pressure to the pressure before pressure relief to ensure that the load force is fully restored and maintain the stability and reliability of the test.

[0069] It should be noted that since the passive load undergoes two pressure reliefs during the test, the first time when the actual displacement reaches the target control displacement, the pressure is relieved to the first preset pressure, and the second time when the actual displacement reaches the target test displacement, the pressure is relieved to the second preset pressure, and then pressure is built up again. Therefore, the embodiment of the present application can set the first preset displacement and the second preset displacement according to the target control displacement, so as to ensure the gradual recovery of the load force during the pressure building process and avoid sudden impact.

[0070] For example, the first preset displacement is 1mm, the second preset displacement is 2mm, the first preset pressure is 2.5KN, and the pressure before pressure relief is 5KN: when the actual displacement reaches 1mm, the hydraulic valve is controlled to increase the pressure to 2.5KN; when the actual displacement reaches 2mm, the hydraulic valve is controlled to increase the pressure to 5KN.

[0071] The passive hydraulic load control method of the present application is described below through a specific embodiment, which is mainly divided into two parts: hydraulic valve passive load automatic compensation strategy and passive load multi-stage load setting strategy. The passive hydraulic load bench collects data: RWS displacement data, hydraulic valve passive hydraulic load data, processes it and outputs the threshold load force, that is, the target load threshold.

[0072] 1. Hydraulic valve passive load automatic compensation strategy, the specific process is as follows Figure 2 shown.

[0073] It is used to solve the phenomenon that the actual value of the passive load does not match the set value. It adds an automatic compensation strategy for the hydraulic load cylinder to correct the load force in real time to improve the reliability of RWS performance testing. The self-compensation strategy of displacement and load force signals is used to achieve the purpose of stabilizing the load signal output.

[0074] 1. Collect and process displacement signals (displacement data). The specific process is as follows: Figure 3 shown.

[0075] (1) During the test, the RWS obtains displacement data during actuation and sets the automatic compensation range of the load signal according to the rack travel (the rack travel on one side of the RWS is sufficient).

[0076] (2) Take the median value of MAX / MIN: MAX is the maximum value of the set stroke; MIN is the minimum value of the set stroke. Perform the mean calculation to obtain the median displacement. (Due to the passive load characteristics, the load force rises in an arc when starting. To ensure reliable compensation, the value is obtained within the middle stable range.)

[0077] (3) Rounding: Due to the requirements of RWS products, the sampling frequency of general equipment is relatively high. In order to ensure the reliability of load force signal compensation, its integer displacement signal can correspond to more load compensation points and be more accurate. For example, when the first actuation is performed, displacement data of 1.1, 1.2, and 1.3 are taken. If only the displacement data of 1.1 is used to find the corresponding value, only one valid value can be provided, but rounding can find three valid values.

[0078] 2. Collect the load signal and the processed RWS displacement signal and calculate the automatic compensation value. The specific process is as follows: Figure 4 shown.

[0079] (1) Select the corresponding load data within the RWS set displacement range and perform processing and calculation.

[0080] (2) Number of positive and negative indexes: The median displacement is an integer and corresponds to only one point, which affects the reliability of the final compensation value. To obtain the number of load force points corresponding to the final median integer, the positive index (index from left to right) is used to find the number of load force points corresponding to the first median and record its sampling position. The negative index (index from right to left) is used to find the number of load force points corresponding to the first median and record its sampling point position. The two are subtracted to obtain the "sampling point number" of the passive hydraulic load data corresponding to the median displacement.

[0081] (3) Enlarging the range of coefficients: To increase the reliability of the compensation value, the enlarging coefficient is set by oneself. For example, it is set to 5. The assumed 4 median points in (2) are enlarged fivefold to 20 sampling points. A total of 20 sampling points before and after the median are selected for the next step of processing.

[0082] (4) Mean calculation: directly perform mean calculation on the number of sampling points in (3) to obtain the load compensation value.

[0083] (5) According to the set load threshold, the load compensation value within the range is added or subtracted to obtain a stable load force signal.

[0084] 2. Passive load multi-stage load setting strategy, the specific process is as follows Figure 5 shown.

[0085] It is used to solve the instantaneous load overshoot phenomenon during the end reversing and end dwelling of the passive load, change the hydraulic valve software strategy, optimize and cancel the end impact, increase the reliability of the RWS durability test and avoid the impact on product quality. That is, to set a multi-stage program strategy for the displacement and load signals to achieve the purpose of stabilizing the load signal output when the RWS actuates to the end and the reversing actuation after the end pause.

[0086] It should be noted that the strategy of the embodiment of the present application is only applied to the RWS product performance / durability test, and when the RWS actuates to the end and pauses at the end and then switches direction, the load force overshoot signal will appear as an arc rise, which is not completely consistent with the active load.

[0087] This part adds displacement and load multi-segment instructions based on the original load threshold, so that the overshoot of the load force signal disappears when the passive hydraulic valve is switched and paused at the end.

[0088] 1. Displacement strategy: only for RWS products, because the control of RWS is message displacement control, the displacement is fixed during the test, so a displacement instruction is added at the end and connected to the load. Example: RWS test displacement actuation 30mm, add a 29mm section.

[0089] 2. Load strategy: Add a load command based on the load threshold. This command is best set to a normal value, and cooperate with the displacement command to release the hydraulic valve in advance. Example: The threshold is set to 5KN, and the load command is increased to 2.5KN. With the 29mm displacement command, the force is released to 2.5KN when the RWS moves to 29mm, and then to 0KN when it reaches 30mm, so that the hydraulic load will not be overshooted when the RWS moves to the end and stops at the end and then switches to another direction.

[0090] It should be noted that general RWS tests have end-stop and non-stop conditions, but in both conditions, as long as the switching passive load is involved, the pressure will be instantly released from the positive direction to the load force in the reverse direction. For example, the load force is set to 5KN, and the end of the positive direction is 5KN, but it needs to be instantly changed to -5KN during the switching process, which involves a 10KN response process. The passive load cannot meet the requirements at all, so overshoot occurs. This application directly releases the pressure in advance, and then releases the pressure and builds up the pressure when the end is switched, which can meet the response time to eliminate the overshoot.

[0091] In summary, the embodiments of the present application achieve:

[0092] 1. By collecting RWS displacement signals and hydraulic load signals and performing compensation processing within the range, the set value and actual load are consistent, making the data reliable during the RWS performance and durability test.

[0093] 2. By adding multiple instructions to the set load threshold, the phenomenon of load overshoot during terminal reversal and pause of passive hydraulic load is realized, so that RWS is fully protected when running to the end and the test process data is reliable.

[0094] 3. By collecting displacement and hydraulic load signals and processing them, this logic can be set as the standard configuration of the test bench, which can match different steering gear products such as RWS and wire control.

[0095] 4. The displacement signal can be converted into an angle signal to perform load compensation and cancel overshoot. The load compensation can also be converted into angle compensation and applied to steering products of servo motor control.

[0096] This solves the problem of unstable passive hydraulic load during RWS testing, as well as the problem of passive hydraulic load overshooting and impacting the end rack during RWS testing. In addition, the displacement and load self-compensation strategies and multi-segment instruction strategies can also be applied to wire-controlled steering products, and can also be used for products requiring angle control, angle compensation, etc. The multi-purpose use of one machine greatly reduces the equipment testing cost.

[0097] According to the passive hydraulic load control method proposed in the embodiment of the present application, a target load threshold can be generated based on the displacement data during the rear-wheel steering gear test and the passive hydraulic load data of the hydraulic valve, and then the hydraulic valve is controlled to output a passive hydraulic load signal based on the target load threshold, thereby accurately controlling the output of the passive hydraulic load signal of the hydraulic valve to ensure that the deviation between the actual load and the set load is minimized, ensure the stability and consistency of the load signal, and improve the reliability of the test.

[0098] Figure 6 It is a structural schematic diagram of a passive hydraulic load control device provided in an embodiment of the present application.

[0099] For example, Figure 6 As shown, the passive hydraulic load control device 10 may include: an acquisition module 100 , a generation module 200 and a control module 300 .

[0100] Among them, the acquisition module 100 is used to obtain the displacement data and passive hydraulic load data of the hydraulic valve during the rear wheel steering gear test; the generation module 200 is used to generate a target load threshold according to the displacement data and the passive hydraulic load data; the control module 300 is used to control the hydraulic valve to output a passive hydraulic load signal according to the target load threshold.

[0101] In the embodiment of the present application, the generation module 200 is further used to: calculate the load compensation value according to the displacement data and the passive hydraulic load data; and determine the target load threshold according to the set load threshold of the hydraulic valve and the load compensation value.

[0102] In the embodiment of the present application, the generation module 200 is further used to: determine the median displacement according to the displacement data, and round the median displacement; and calculate the load compensation value according to the rounded median displacement and the passive hydraulic load data.

[0103] In an embodiment of the present application, the generation module 200 is further used to: identify the actual number of sampling points in the passive hydraulic load data corresponding to the rounded median displacement; determine the target number of sampling points based on the actual number of sampling points, and select multiple passive hydraulic loads near the passive hydraulic load corresponding to the rounded median displacement based on the target number of sampling points; calculate the load compensation value based on the multiple passive hydraulic loads.

[0104] In the embodiment of the present application, the generation module 200 is further used to: identify the maximum displacement and the minimum displacement of the displacement data within the target travel range; and determine the median displacement according to the maximum displacement and the minimum displacement.

[0105] In the embodiment of the present application, the device 10 of the embodiment of the present application further includes: a first control module.

[0106] Among them, the first control module is used to obtain the target test displacement of the rear-wheel steering gear after controlling the hydraulic valve to output a passive hydraulic load signal according to the target load threshold, and set the target control displacement according to the target test displacement, identify the displacement data of the rear-wheel steering gear to obtain the actual displacement, wherein the target control displacement is less than the target test displacement; if the actual displacement reaches the target control displacement, the hydraulic valve is controlled to release pressure to a first preset pressure, and if the actual displacement reaches the target test displacement, the hydraulic valve is controlled to release pressure to a second preset pressure, wherein the first preset pressure is greater than the second preset pressure.

[0107] In the embodiment of the present application, the device 10 of the embodiment of the present application further includes: a second control module.

[0108] Among them, the second control module is used to control the hydraulic valve to increase the pressure to the first preset pressure if the actual displacement reaches the first preset displacement after the hydraulic valve is controlled to release pressure to the second preset pressure; if the actual displacement reaches the second preset displacement, the hydraulic valve is controlled to increase the pressure to the pressure before pressure relief, wherein the first preset displacement and the second preset displacement are set according to the target control displacement.

[0109] According to the passive hydraulic load control device proposed in the embodiment of the present application, a target load threshold can be generated based on the displacement data during the rear-wheel steering gear test and the passive hydraulic load data of the hydraulic valve, and then the hydraulic valve is controlled to output a passive hydraulic load signal according to the target load threshold, thereby accurately controlling the output of the passive hydraulic load signal of the hydraulic valve, ensuring that the deviation between the actual load and the set load is minimized, ensuring the stability and consistency of the load signal, and improving the reliability of the test.

[0110] The embodiment of the present application also provides a rear wheel steering gear, which is tested based on the above-mentioned passive hydraulic load control method.

[0111] An embodiment of the present application also provides a vehicle, comprising the above-mentioned rear wheel steering gear.

[0112] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0113] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0114] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0115] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one or a combination of multiple of the following technologies known in the art: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array, a field programmable gate array, etc.

[0116] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

Claims

1. A passive hydraulic load control method, characterized in that: The following steps are involved: Obtain displacement data during rear wheel steering gear testing and passive hydraulic load data of hydraulic valves; generating a target load threshold value based on the displacement data and the passive hydraulic load data; The hydraulic valve is controlled to output a passive hydraulic load signal according to the target load threshold.

2. The passive hydraulic load control method according to claim 1, characterized in that: The generating a target load threshold according to the displacement data and the passive hydraulic load data comprises: calculating a load compensation value according to the displacement data and the passive hydraulic load data; The target load threshold is determined according to the set load threshold of the hydraulic valve and the load compensation value.

3. The passive hydraulic load control method according to claim 2, characterized in that: The calculating the load compensation value according to the displacement data and the passive hydraulic load data comprises: Determine a median displacement according to the displacement data, and round the median displacement; A load compensation value is calculated based on the rounded median displacement and the passive hydraulic load data.

4. The passive hydraulic load control method according to claim 3, characterized in that: The calculating of the load compensation value according to the rounded median displacement and the passive hydraulic load data comprises: identifying the number of actual sampling points in the passive hydraulic load data corresponding to the rounded median displacement; Determine the target number of sampling points according to the actual number of sampling points, and select multiple passive hydraulic loads near the passive hydraulic load corresponding to the rounded median displacement according to the target number of sampling points; The load compensation value is calculated based on the plurality of passive hydraulic loads.

5. The passive hydraulic load control method according to claim 3, characterized in that: Determining the median displacement according to the displacement data comprises: Identifying a maximum displacement and a minimum displacement of the displacement data within a target travel range; The median displacement is determined based on the maximum displacement and the minimum displacement.

6. The passive hydraulic load control method according to claim 1, characterized in that: After controlling the hydraulic valve to output a passive hydraulic load signal according to the target load threshold, the method further includes: Acquiring a target test displacement of the rear wheel steering gear, setting a target control displacement according to the target test displacement, identifying displacement data of the rear wheel steering gear to obtain an actual displacement, wherein the target control displacement is smaller than the target test displacement; If the actual displacement reaches the target control displacement, the hydraulic valve is controlled to release pressure to a first preset pressure; if the actual displacement reaches the target test displacement, the hydraulic valve is controlled to release pressure to a second preset pressure, wherein the first preset pressure is greater than the second preset pressure.

7. The passive hydraulic load control method according to claim 6, characterized in that: After controlling the hydraulic valve to release pressure to a second preset pressure, the method further includes: If the actual displacement reaches the first preset displacement, the hydraulic valve is controlled to increase the pressure to the first preset pressure. If the actual displacement reaches the second preset displacement, the hydraulic valve is controlled to increase the pressure to the pressure before pressure relief. The first preset displacement and the second preset displacement are set according to the target control displacement.

8. A passive hydraulic load control device, characterized in that: include: An acquisition module, used for acquiring displacement data during rear wheel steering gear testing and passive hydraulic load data of a hydraulic valve; A generating module, configured to generate a target load threshold value according to the displacement data and the passive hydraulic load data; The control module is used to control the hydraulic valve to output a passive hydraulic load signal according to the target load threshold.

9. A rear wheel steering gear, characterized in that: The rear wheel steering gear is tested based on the passive hydraulic load control method described in any one of claims 1-7.

10. A vehicle, characterized in that: Including the rear wheel steering gear as described in claim 9.

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