Simulation analysis method and device for hydraulic power steering system

Abstract

The invention relates to the technical field of simulation, and provides a hydraulic power steering system simulation analysis method and system. The method comprises the following steps: defining simulation conditions, and constructing an equivalent model of the hydraulic power steering system by adopting simulation software based on an initial file of the hydraulic power steering system; introducing an input condition of a bench test into the equivalent model for simulation analysis so as to verify whether the equivalent model is credible; and according to a verification result of the equivalent model, performing parameter simulation and analysis through the equivalent model by taking a target parameter configured by the bench test as a target so as to obtain a mapping relation library of each parameter and performance of the hydraulic power steering system. According to the method, the design contradiction between smoothness and accuracy of the hydraulic power-assisted steering system can be balanced while high simulation accuracy is achieved, and powerful data support is provided for subsequent research and development.

Description

Technical Field

[0001] The present application relates to the field of simulation technology, and in particular to a simulation analysis method and device for a hydraulic power steering system. Background Art

[0002] Existing automotive steering systems primarily consist of components such as the steering wheel, steering shaft, steering gear, steering tie rod, and steering knuckle. The steering system converts the steering wheel's rotational motion into wheel swing according to the driver's steering intent, while also providing steering and road surface information to the driver based on the aforementioned information. Commercial vehicles typically use an integral recirculating ball steering gear, combined with hydraulic components such as a steering pump, oil tank, and oil pipes to provide servo-assisted steering. The characteristics of the hydraulic system directly impact the steering performance of commercial vehicles. The hydraulic characteristics of commercial vehicle steering systems describe the hydraulic system's steering assistance effect on the vehicle's steering system, specifically the hydraulic system's response to steering wheel input angle and torque. These characteristics are fed back to the driver in the form of steering wheel reaction torque and angle changes, allowing the driver to perceive the steering operation's effectiveness and road conditions.

[0003] In terms of hydraulic system characteristics, testing is currently carried out by building a power steering test bench, but the testing process has problems such as high cost, inconvenient debugging, poor repeatability, and low efficiency.

[0004] Based on the above content, the present application provides a hydraulic power steering system simulation analysis method and system to solve at least one of the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a hydraulic power steering system simulation analysis method and system, which can highly simulate the hydraulic power steering system to quickly obtain the direct mapping relationship between various parameters and performance in the hydraulic power steering system, thereby quickly solving the core problems of low efficiency, high cost, and difficulty in covering boundary scenarios in the traditional R&D model. The specific solution is as follows:

[0006] A hydraulic power steering system simulation analysis method, the method comprising the following steps:

[0007] S1: Define simulation conditions and use simulation software to build an equivalent model of the hydraulic power steering system based on the initial files of the hydraulic power steering system;

[0008] S2: Introduce the bench test input conditions into the equivalent model for simulation analysis to verify whether the equivalent model is credible;

[0009] S3: Based on the verification results of the equivalent model, taking the target parameters of the bench test configuration as the target, parameter simulation and analysis are performed through the equivalent model to obtain a mapping relationship library of various parameters and performances of the hydraulic power steering system.

[0010] Optionally, step S1 specifically includes:

[0011] The simulation conditions include: ignoring the friction loss between the steering wheel and the steering shaft, fixing the steering output rocker arm, and inputting an angular displacement input whose displacement changes with time in a sinusoidal curve; and the simulation software is AMESim software;

[0012] Based on the simulation conditions and the initial files of the hydraulic power steering system, the equivalent models of the hydraulic power steering system are constructed using AMESim software; the equivalent models include: a steering wheel model, a power steering control model and a steering output model.

[0013] Optionally, the process of constructing the steering wheel model includes:

[0014] The steering gear input angle is simulated with a sinusoidal signal, which is converted into a torque signal through a signal converter and transmitted to the input end of the torsion bar;

[0015] Wherein, angle sensors are respectively arranged at both ends of the torsion bar; the torsion bar is also provided with an angle difference output port which is connected to the power steering model for communication;

[0016] The construction process of the power steering control model includes:

[0017] The sub-model of AMESim software is used to construct the steering valve, power cylinder, steering pump, mechanical steering gear and hydraulic pipeline of the power steering control model;

[0018] The steering valve is a three-position, four-way valve, and its equivalent model includes: four connecting pipes, a main connecting pipe connected to one end of the four connecting pipes to form a closed loop, and a variable throttle hole is arranged on each main connecting pipe between the connecting ends of two adjacent connecting pipes; wherein the four connecting pipes are respectively an oil inlet pipe, an oil return pipe, a left cylinder chamber pipe, and a right cylinder chamber pipe;

[0019] The control parameters for setting the steering valve include: the valve port flow area and hydraulic diameter, which change with the relative angle of the torsion bar; the hydraulic diameter can be calculated from the valve port flow area; the flow area is calculated based on the valve size data;

[0020] Construct a power cylinder simulation model based on preset power cylinder parameters;

[0021] AMESim software was used to build a steering pump model and hydraulic piping based on bench test parameters and defined oil properties, including density, viscosity, bulk modulus, gas solubility, and volatility.

[0022] Based on the transmission pair parameters obtained from the initial file of the steering gear, a steering gear model is constructed; wherein the steering gear is a recirculating ball steering gear;

[0023] The construction process of the steering output model includes:

[0024] Construct a high-stiffness spring at the output end of the power steering control model;

[0025] A fixed-end model is constructed at the end of the high-stiffness spring away from the power steering control model.

[0026] Optionally, step S2 specifically includes:

[0027] Adjusting configuration parameters of the hydraulic power steering system simulation model based on bench test input conditions; wherein the input conditions include at least bench steering input conditions, steering load conditions, and hydraulic pipeline conditions; and the configuration parameters include at least excitation input configuration, boundary condition configuration, and physical property configuration;

[0028] Based on the input conditions of the bench test, the adjusted hydraulic power steering system simulation model is run to verify whether the model is reliable;

[0029] If the power steering oil pressure curve of the simulation model has the same trend as the power steering oil pressure curve of the bench test, and the test points of the bench test are distributed on both sides of the simulation curve, and the curve deviation value between the bench test and the simulation model is ≤ the deviation threshold, then the adjusted hydraulic power steering system simulation model is determined to be credible.

[0030] Optionally, step S3 specifically includes:

[0031] For the target parameters of the bench test, multiple sets of variables are configured, and simulation is performed through an equivalent model to output multiple sets of power-assisted oil pressure-hand force characteristic mapping curves.

[0032] Compare and analyze the differences in multiple groups of power-assisting oil pressure-hand force characteristic mapping curves to obtain the target parameter-performance mapping relationship.

[0033] Optionally, the following step S4 is also included, specifically including: based on the mapping relationship library of various parameters and performances, testing and verification are performed through a test sample vehicle. If the verification is inconsistent, the mapping relationship library of various parameters and performances is adjusted based on the test results of the test sample vehicle.

[0034] Optionally, the following steps are also included:

[0035] Connect a driving simulator to the test vehicle and establish real-time communication with the hydraulic power steering system simulation model;

[0036] Create a new fault mode analysis unit in the mapping relationship library of various parameters and performances, preset fault scenarios, and define the boundary conditions for each fault;

[0037] Based on preset fault scenarios, the driving simulator simulates extreme working conditions and simultaneously collects driver operation data;

[0038] Based on the driver's operation data as feedback, the mapping relationship library of various parameters and performance is dynamically iterated.

[0039] A hydraulic power steering system simulation and analysis device, comprising:

[0040] a simulation modeling unit configured to define simulation conditions and construct an equivalent model of the hydraulic power steering system using simulation software based on an initial file of the hydraulic power steering system;

[0041] A verification module is configured to introduce the input conditions of the bench test into the equivalent model for simulation analysis to verify whether the equivalent model is credible;

[0042] The analysis and processing module is configured to perform parameter simulation and analysis through the equivalent model based on the verification results of the equivalent model and the target parameters of the bench test configuration, so as to obtain a mapping relationship library of various parameters and performances of the hydraulic power steering system.

[0043] A computer-readable storage medium stores a computer program / instruction thereon, which implements the steps of the method when executed by a processor.

[0044] A computer program product comprises a computer program / instructions which, when executed by a processor, implement the steps of the method.

[0045] Through the above solution, the following beneficial technical effects are achieved:

[0046] The present application provides a simulation and analysis method and device for a hydraulic power steering system. By constructing an equivalent model of the hydraulic power steering system, parameter simulation can be quickly completed, thereby outputting a parameter and performance relationship curve. The input conditions of the bench test are imported into the simulation model, and the credibility of the model is verified by comparing the simulation model with the test data. Furthermore, guided by the target parameters of the bench test, batch simulation is performed by changing the key parameters of the simulation model, and the relationship between parameters and performance is analyzed to form a mapping relationship library, which can balance the design contradiction between the smoothness and accuracy of the hydraulic power steering system, provide guidance for later R&D improvements, and shorten the R&D cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 Flowchart of the hydraulic power steering system simulation analysis method provided in this application;

[0048] Figure 2 Schematic diagram of the equivalent model structure for hydraulic power steering system simulation;

[0049] Figure 3 Schematic diagram of the equivalent model structure of the steering valve;

[0050] Figure 4 The model diagram of the variable throttle hole;

[0051] Figure 5 This is a schematic diagram of the power cylinder model;

[0052] Figure 6 is a schematic diagram of the torsion bar model;

[0053] Figure 7 The displacement-time curve of the steering input in the bench test;

[0054] Figure 8 This is a comparison chart of the simulated power-assisting oil pressure and the experimental power-assisting oil pressure. DETAILED DESCRIPTION

[0055] To make the objectives, technical solutions, and advantages of this application more clear, this application will be further described in detail below with reference to the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0056] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0057] It should be noted in particular that any symbols and / or numbers in the specification that are not marked in the accompanying drawings are not drawing marks.

[0058] The optional embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0059] Figure 1 A hydraulic power steering system simulation analysis method is shown, the method comprising the following steps:

[0060] S1: Define simulation conditions and use simulation software to build an equivalent model of the hydraulic power steering system based on the initial files of the hydraulic power steering system;

[0061] S2: Introduce the bench test input conditions into the equivalent model for simulation analysis to verify whether the equivalent model is credible;

[0062] S3: Based on the verification results of the equivalent model, taking the target parameters of the bench test configuration as the target, parameter simulation and analysis are performed through the equivalent model to obtain a mapping relationship library of various parameters and performances of the hydraulic power steering system.

[0063] Figure 2 As shown, the present application can quickly complete parameter simulation by constructing an equivalent model of the hydraulic power steering system, thereby outputting parameter and performance relationship curves, with high efficiency and short cycle, without occupying too many computing resources. Then, the input conditions of the bench test are imported into the simulation model, and the credibility of the model is verified by comparing the simulation model with the test data. Further, guided by the target parameters of the bench test, batch simulation is carried out by changing the key parameters of the simulation model, and the relationship between parameters and performance is analyzed, thereby forming a mapping relationship library, which can balance the design contradiction between the smoothness and accuracy of the hydraulic power steering system, and provide guidance for later R&D improvements, shorten the R&D cycle, and reduce R&D costs.

[0064] In one specific embodiment, the step S1: defining simulation conditions and constructing an equivalent model of the hydraulic power steering system using simulation software based on an initial file of the hydraulic power steering system, specifically includes:

[0065] The simulation conditions include: ignoring the friction loss between the steering wheel and the steering shaft, fixing the steering output rocker arm, and inputting an angular displacement input whose displacement changes with time in a sinusoidal curve; and the simulation software is AMESim software;

[0066] Based on the simulation conditions and the initial files of the hydraulic power steering system, the equivalent models of the hydraulic power steering system are constructed using AMESim software; the equivalent models include: a steering wheel model, a power steering control model and a steering output model.

[0067] Specifically, this application ignores the friction loss between the steering wheel and the steering shaft, and focuses on the core characteristics of the hydraulic power assist; the rocker arm is fixed equivalent to infinite stiffness, thereby isolating the dynamic influence of mechanical structures such as the steering tie rod, so as to focus on the pressure-flow characteristic analysis of the hydraulic power cylinder, and utilizing the hydraulic-mechanical multi-domain collaborative simulation capabilities of the AMESim software to automatically process physical effects such as oil compressibility and pipeline resistance, simplify the problem of balancing modeling and accuracy, and at the same time solve the design problem of the contradiction between complex modeling efficiency and accuracy, thereby improving the simulation accuracy as a whole.

[0068] Furthermore, the construction process of the steering wheel model includes:

[0069] The steering gear input angle is simulated with a sinusoidal signal, which is converted into a torque signal through a signal converter and transmitted to the input end of the torsion bar;

[0070] Wherein, angle sensors are respectively arranged at both ends of the torsion bar; the torsion bar is also provided with an angle difference output port which is connected to the power steering model for communication;

[0071] in, Figure 6 This is a schematic diagram of a torsion bar model. Angle sensors are connected to both ends of the torsion bar to measure the bar's rotational angle. The difference between the two angle signals is output to the rotary valve via port 3. Port 2 receives the steering wheel angle signal input, while port 1 receives the load through the mechanical steering gear.

[0072] First, a sinusoidal signal (model code: SIN0) with an amplitude of 5 and a frequency of 0.2 Hz is input to the steering gear input to simulate the driver's steering operation. The sinusoidal signal is connected to a PID controller, where it is dynamically compensated to suppress high-frequency noise and optimize phase delay. The signal is then output to a signal converter. A signal converter (e.g., a torquecon element) is then used to convert the model input signal into torque. The steering wheel's moment of inertia and the friction at the top of the steering gear torsion bar are also factored in. Angle sensors are then placed at both ends of the torsion bar to measure the angle difference, which serves as the input for the rotary valve opening control.

[0073] It can be understood that the steering wheel model designed in this application takes into account the dynamic equations of moment of inertia and friction, so that the model can capture the inertial delay and friction nonlinearity of the steering wheel, thereby improving the simulation accuracy.

[0074] Furthermore, the construction process of the power steering control model includes:

[0075] The sub-model of AMESim software is used to construct the steering valve, power cylinder, steering pump, mechanical steering gear and hydraulic pipeline of the power steering control model;

[0076] Figure 3 Description of the accompanying drawings: 1-steering pump, 4-oil inlet line, 5 and 6 are the left and right cylinder chamber lines, respectively, and lead to the left and right chambers of the power cylinder, respectively, 7 indicates the return oil line leading to the oil tank, 3 represents the relative rotation angle of the steering wheel input to the torsion bar, 2 represents the signal transmission line, in which the forked arrow represents that the signal is copied into two copies, 8 is the power cylinder, 9 represents the main connecting pipe; 10, steering valve; 12, high-rigidity spring; 13, fixed end; 14, torsion bar; 15, steering gear; 16, variable throttle hole.

[0077] like Figure 3As shown, the steering valve is a three-position four-way valve, and its equivalent model includes: four connecting pipes, a main connecting pipe connected to one end of the four connecting pipes to form a closed loop, and a variable throttle hole is arranged on each main connecting pipe between the connecting ends of each two adjacent connecting pipes; wherein the four connecting pipes are respectively an oil inlet pipe, an oil return pipe, a left cylinder chamber pipe, and a right cylinder chamber pipe;

[0078] The control parameters for setting the steering valve include: the valve port flow area and hydraulic diameter, which change with the relative angle of the torsion bar; the hydraulic diameter can be calculated from the valve port flow area; the flow area is calculated based on the valve size data;

[0079] Construct a power cylinder simulation model based on preset power cylinder parameters;

[0080] AMESim software was used to build a steering pump model and hydraulic piping based on bench test parameters and defined oil properties, including density, viscosity, bulk modulus, gas solubility, and volatility.

[0081] Based on the transmission pair parameters obtained from the initial file of the steering gear, a steering gear model is constructed; wherein the steering gear is a recirculating ball steering gear;

[0082] Combine Figure 4 As shown, the opening and closing of the steering valve is controlled by a variable throttle hole; Figure 3 In the figure, ports 2 and 3 of the variable throttle have oil pressure input and flow rate output, while port 1 is used to change the cross-sectional area of ​​the throttle. It can be understood that by appropriately setting the opening cross-sectional area value of the throttle that changes with signal 1 in the variable throttle sub-model, the opening and closing of the valve can be controlled by the torsion bar angle signal input at port 1, thereby realizing the function of the rotary valve.

[0083] Control parameter setting of steering valve: Due to the complex structure of steering valve, accurate simulation in AMESim requires self-built model. After completing the construction of three-position four-way valve, AMESim is required to provide valve attribute dat file to reflect the change of valve port flow area and hydraulic diameter with the relative angle of torsion bar. Among them, hydraulic diameter can be directly calculated from valve port flow area. The flow area file needs to be calculated after measuring the physical valve size data.

[0084] Combine Figure 5 As shown, power cylinder modeling: The modeling of the power cylinder is based on existing components. Figure 4 In the power cylinder model, ports 1 and 2 are connected to the left and right chambers, respectively, and port 3 receives resistance input from the ground (such as tire self-centering resistance). When the model is working, hydraulic oil controlled by the steering valve flows into or out of ports 1 and 2. Due to the incompressibility of the oil, a pressure difference is generated, which drives the piston to overcome the resistance from port 3, completing the steering action.

[0085] Steering pump modeling: Since the speed of the steering pump of the actual vehicle is variable, it is difficult to simulate this change in the bench test. Moreover, the change in the steering pump speed has little effect on the performance of the steering system. Therefore, combined with the bench test, the steering pump speed is taken as 1200r / min, the flow rate is 21L / min, and the unloading valve opening pressure is 15.5MPa.

[0086] Steering Circuit Modeling: To align with the test plan, the model replaced the steel tubing used in the actual vehicle hydraulic circuit with rubber tubing, eliminating the elbows and reductions typically found in the actual vehicle piping. The difference lies in the pressure drop. The inlet and return lines are both 1.5m long, 18mm diameter rubber tubing. A fixed orifice is located at the end of each to simulate the pressure loss caused by the elbows and reductions in the rubber tubing. After the hydraulic oil passes through this element, the throttling effect causes some pressure loss.

[0087] Fluid Properties: The hydraulic fluid property model defines the hydraulic fluid properties for the entire system, including density, viscosity, and bulk modulus. It also considers the effects of dissolved gases and volatilization on the fluid. For the purposes of this analysis, the basic hydraulic fluid model is sufficient; that is, only the density, viscosity, and bulk modulus are set, with all other parameters remaining at default values. For example, the density is 868 kg / m³, the kinematic viscosity is 7.8 cSt, and the bulk modulus is 17,000 bar. Since temperature effects are not considered, these parameters are fixed.

[0088] It should be noted that since the friction between the steering wheel and the torsion bar is difficult to measure and the value is very small, it has little impact on the system. In the subsequent model verification process, the bench test input is also directly loaded on the torsion bar. Therefore, the friction between the steering wheel and the torsion bar is not considered, and the steering wheel angle input is directly transmitted and loaded on the torsion bar.

[0089] Mechanical steering gear model construction: Based on the fact that the recirculating ball steering gear is a two-stage transmission pair, including a screw-nut transmission pair and a rack-and-pinion transmission pair, and the transmission ratio from the steering gear secondary transmission pair to the steering wheel is approximately 1, the screw-nut transmission pair in the steering gear structure only needs to be considered. Therefore, based on the transmission ratio between the screw-nut transmission pair and the rack-and-pinion transmission pair, the gear radius of the rack-and-pinion transmission pair is calculated to complete the modeling.

[0090] It can be understood that the three-position four-way valve equivalent model and variable throttle orifice design are used to transform the complex steering valve structure into a parameterized control module, and the throttling area is dynamically adjusted by the torsion bar angle signal to accurately simulate the nonlinear relationship between the valve core displacement and the flow area; the power cylinder model introduces the ground resistance input port, and combines the steering valve pressure difference drive logic to realize the coupled simulation of hydraulic thrust and mechanical load; the steering pump is based on the fixed speed parameter of the bench test, which simplifies the simulation conditions while retaining the core flow-pressure characteristics; the hydraulic pipeline uses rubber tubes equivalent to steel pipes and simulates the elbow resistance through fixed throttle orifices to balance the model complexity and pressure loss accuracy; the oil property adopts a constant basic model to improve the simulation efficiency while ignoring the temperature influence; the mechanical steering gear is simplified to a screw-nut transmission pair, and the secondary transmission characteristics are retained by the transmission ratio equivalent, which not only ensures the simulation accuracy of key performance, but also greatly reduces the consumption of computing resources and the difficulty of model debugging.

[0091] Furthermore, the construction process of the steering output model includes:

[0092] Construct a high-stiffness spring at the output end of the power steering control model;

[0093] A fixed-end model is constructed at the end of the high-stiffness spring away from the power steering control model.

[0094] Specifically, in a complete steering system, the steering load comes from the resistance of the ground to the wheels. However, in the test standard for measuring the hand-force characteristic curve, the assist pressure is assumed to be fixed with the steering arm fixed, meaning that the steering output is rigidly fixed during straight-line driving. Therefore, to obtain the hand-force characteristic curve, the output of the model is fixed. Since AMESim software itself does not allow the fixed end to be directly connected to a moving element (the input and output of the element cannot be connected if they do not match), even rigid fixation during steering bench testing theoretically cannot achieve complete immobility. Therefore, a very stiff spring, for example, with a stiffness of 5e9N / m, is connected to the steering output. This extremely stiff spring, connecting the steering output and the fixed end, circumvents the AMESim software limitation of directly fixing moving elements. It also accurately replicates the boundary conditions of the fixed steering arm in bench testing through near-rigid mechanical properties (deformation ≤ 0.001mm), ensuring simulation accuracy.

[0095] In a specific embodiment, the step S2 specifically includes:

[0096] Adjusting configuration parameters of the hydraulic power steering system simulation model based on bench test input conditions; wherein the input conditions include at least bench steering input conditions, steering load conditions, and hydraulic pipeline conditions; and the configuration parameters include at least excitation input configuration, boundary condition configuration, and physical property configuration;

[0097] Based on the input conditions of the bench test, the adjusted hydraulic power steering system simulation model is run to verify whether the model is reliable;

[0098] If the power steering oil pressure curve of the simulation model has the same trend as the power steering oil pressure curve of the bench test, and the test points of the bench test are distributed on both sides of the simulation curve, and the curve deviation value between the bench test and the simulation model is ≤ the deviation threshold, then the adjusted hydraulic power steering system simulation model is determined to be credible.

[0099] For example, the bench test input is a triangular wave with a period of 280 seconds and a peak value of 700°, with time as the horizontal axis and input angle as the vertical axis. The test input parameters are shown in Table 2.3: Test Input Parameter Values.

[0100] Amplitude (°) Angular velocity V ((°) / s) Period T(s) Load W (Nm) Input speed N (rpm) 700 10 280 -3000 1200

[0101] The entire test lasted 320 seconds, with no steering input for the first 20 seconds and the last 20 seconds, resulting in a zero angle input to the torsion bar. The test lasted 280 seconds, representing a complete cycle. The input angle varied linearly with time using a triangular wave, with an amplitude of 700°. The load on the steering knuckle was 3000 Nm, and the input speed of the motor-driven steering pump was 1200 rpm. Bench test data was measured by various sensors, and the following results are available: 1. As previously mentioned, the input angle was a triangular wave with a period of 280 seconds and a peak value of 700°.

[0102] After the model modified the load and input conditions based on the bench test conditions, the simulation was run according to the test conditions. The simulation time was set to 320 seconds, of which the first and second 20 seconds were without input, which was the system stabilization time, and the middle 280 seconds was a triangle wave input cycle. The obtained simulation curve and test curve were plotted on the same graph, as shown in Figure 1. Figure 8 .

[0103] Furthermore, in step S3, based on the verification results of the equivalent model, with the target parameters of the bench test configuration as the target, parameter simulation and analysis are performed through the equivalent model to obtain a mapping relationship library of various parameters and performances of the hydraulic power steering system, specifically including:

[0104] For the target parameters of the bench test, multiple sets of variables are configured, and simulation is performed through an equivalent model to output multiple sets of power-assisted oil pressure-hand force characteristic mapping curves.

[0105] Compare and analyze the differences in multiple groups of power-assisting oil pressure-hand force characteristic mapping curves to obtain the target parameter-performance mapping relationship.

[0106] Among them, the vertical axis of the power-assist oil pressure-hand force characteristic mapping curve is the power-assist oil pressure, and the horizontal axis is the input torque, which is used to indicate whether the power-assist matching of the hydraulic power steering system meets the design goals.

[0107] The target parameters include at least the following: steering valve related parameters, power cylinder related parameters, steering pump and oil parameters, mechanical structure parameters (torsion bar stiffness, steering gear transmission pair mechanical parameters) and constraint parameters (such as pipe size, material, fixed end constraint parameters).

[0108] Specifically, by configuring multiple groups of variables to carry out batch simulations, the power steering oil pressure-hand force characteristic curve group is output synchronously to form a visualization matrix of parameter influences, which can intuitively present the gradient influence of key parameters such as torsion bar stiffness and valve port size on steering feel; the mapping relationship library established based on curve difference comparison can accurately quantify the correspondence between parameter adjustment and performance change (for example, for every 0.1mm increase in valve port opening, the small-angle steering torque is reduced by 1.2Nm), providing engineers with reverse design guidance from performance requirements to parameter combinations, avoiding the blindness of traditional empirical design and improving parameter optimization efficiency through simulation batch calculations.

[0109] Furthermore, the present application further comprises the following steps:

[0110] Connect a driving simulator to the test vehicle and establish real-time communication with the hydraulic power steering system simulation model;

[0111] Create a new fault mode analysis unit in the mapping relationship library of various parameters and performances, preset fault scenarios, and define the boundary conditions for each fault;

[0112] Based on preset fault scenarios, the driving simulator simulates extreme working conditions and simultaneously collects driver operation data;

[0113] Based on the driver's operation data as feedback, the mapping relationship library of various parameters and performance is dynamically iterated.

[0114] Specifically, by connecting the driving simulator (such as a six-end free motion platform) with the simulation model through real-time communication, the driver's operation can instantly trigger the simulation model response, thereby enhancing the simulation authenticity; by introducing a fault mode analysis unit, extreme scenarios such as steering pump failure and oil pipe rupture can be preset, and through precise boundary condition definition (such as residual oil pressure), dangerous working conditions that are difficult to reach with traditional tests are covered. Based on the driver's operating data feedback under extreme working conditions, the mapping relationship library is dynamically iterated, which can not only optimize the normal working condition parameters, but also explore the safety boundary of the system under failure mode. This design greatly improves the test efficiency, while reducing the safety risks and costs of extreme vehicle testing, and providing quantitative support for the reliability design of the steering system.

[0115] On the other hand, the present application provides a hydraulic power steering system simulation analysis device, comprising:

[0116] a simulation modeling unit configured to define simulation conditions and construct an equivalent model of the hydraulic power steering system using simulation software based on an initial file of the hydraulic power steering system;

[0117] A verification module is configured to introduce the input conditions of the bench test into the equivalent model for simulation analysis to verify whether the equivalent model is credible;

[0118] The analysis and processing module is configured to perform parameter simulation and analysis through the equivalent model based on the verification results of the equivalent model and the target parameters of the bench test configuration, so as to obtain a mapping relationship library of various parameters and performances of the hydraulic power steering system.

[0119] On the other hand, the present application provides a computer-readable storage medium having a computer program / instruction stored thereon, which implements the steps of the method when the computer program / instruction is executed by a processor.

[0120] On the other hand, the present application provides a computer program product, comprising a computer program / instruction, which implements the steps of the method when executed by a processor.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A simulation analysis method for a hydraulic power steering system, characterized in that: The method comprises the following steps: S1: Define simulation conditions and use simulation software to build an equivalent model of the hydraulic power steering system based on the initial files of the hydraulic power steering system; S2: Introduce the bench test input conditions into the equivalent model for simulation analysis to verify whether the equivalent model is credible; S3: Based on the verification results of the equivalent model, taking the target parameters of the bench test configuration as the target, parameter simulation and analysis are performed through the equivalent model to obtain a mapping relationship library of various parameters and performances of the hydraulic power steering system.

2. The method according to claim 1, characterized in that Step S1 specifically includes: The simulation conditions include: ignoring the friction loss between the steering wheel and the steering shaft, fixing the steering output rocker arm, and inputting an angular displacement input whose displacement changes with time in a sinusoidal curve; and the simulation software is AMESim software; Based on the simulation conditions and the initial files of the hydraulic power steering system, the equivalent models of the hydraulic power steering system are constructed using AMESim software; the equivalent models include: a steering wheel model, a power steering control model and a steering output model.

3. The method according to claim 2, characterized in that The construction process of the steering wheel model includes: The steering gear input angle is simulated with a sinusoidal signal, which is converted into a torque signal through a signal converter and transmitted to the input end of the torsion bar; Wherein, angle sensors are respectively arranged at both ends of the torsion bar; the torsion bar is also provided with an angle difference output port which is connected to the power steering model for communication; The construction process of the power steering control model includes: The sub-model of AMESim software is used to construct the steering valve, power cylinder, steering pump, mechanical steering gear and hydraulic pipeline of the power steering control model; The steering valve is a three-position, four-way valve, and its equivalent model includes: four connecting pipes, a main connecting pipe connected to one end of the four connecting pipes to form a closed loop, and a variable throttle hole is arranged on each main connecting pipe between the connecting ends of two adjacent connecting pipes; wherein the four connecting pipes are respectively an oil inlet pipe, an oil return pipe, a left cylinder chamber pipe, and a right cylinder chamber pipe; The control parameters for setting the steering valve include: the valve port flow area and hydraulic diameter, which change with the relative angle of the torsion bar; the hydraulic diameter can be calculated from the valve port flow area; the flow area is calculated based on the valve size data; Construct a power cylinder simulation model based on preset power cylinder parameters; AMESim software was used to build a steering pump model and hydraulic piping based on bench test parameters and defined oil properties, including density, viscosity, bulk modulus, gas solubility, and volatility. Based on the transmission pair parameters obtained from the initial file of the steering gear, a steering gear model is constructed; wherein the steering gear is a recirculating ball steering gear; The construction process of the steering output model includes: Construct a high-stiffness spring at the output end of the power steering control model; A fixed-end model is constructed at the end of the high-stiffness spring away from the power steering control model.

4. The method according to claim 3, characterized in that The step S2 specifically includes: Adjusting the configuration parameters of the hydraulic power steering system simulation model based on the bench test input conditions; wherein the input conditions include at least: bench steering input conditions, steering load conditions, and hydraulic pipeline conditions; and the configuration parameters include at least: excitation input configuration, boundary condition configuration, and physical property configuration; Based on the input conditions of the bench test, the adjusted hydraulic power steering system simulation model is run to verify whether the model is reliable; If the power steering oil pressure curve of the simulation model has the same trend as the power steering oil pressure curve of the bench test, and the test points of the bench test are distributed on both sides of the simulation curve, and the curve deviation value between the bench test and the simulation model is ≤ the deviation threshold, then the adjusted hydraulic power steering system simulation model is determined to be credible.

5. The method according to claim 4, characterized in that The step S3 specifically includes: For the target parameters of the bench test, multiple sets of variables are configured, and simulation is performed through an equivalent model to output multiple sets of power-assisted oil pressure-hand force characteristic mapping curves. Compare and analyze the differences in multiple groups of power-assisting oil pressure-hand force characteristic mapping curves to obtain the target parameter-performance mapping relationship.

6. The method according to claim 5, characterized in that The method further includes the following step S4, specifically comprising: performing test verification on a test vehicle based on the mapping relationship library of various parameters and performances; if the verification is inconsistent, adjusting the mapping relationship library of various parameters and performances based on the test results of the test vehicle.

7. The method according to claim 6, characterized in that The following steps are also included: Connect a driving simulator to the test vehicle and establish real-time communication with the hydraulic power steering system simulation model; Create a new fault mode analysis unit in the mapping relationship library of various parameters and performances, preset fault scenarios, and define the boundary conditions for each fault; Based on preset fault scenarios, the driving simulator simulates extreme working conditions and simultaneously collects driver operation data; Based on the driver's operation data as feedback, the mapping relationship library of various parameters and performance is dynamically iterated.

8. A hydraulic power steering system simulation analysis device, characterized in that: include: a simulation modeling unit configured to define simulation conditions and construct an equivalent model of the hydraulic power steering system using simulation software based on an initial file of the hydraulic power steering system; A verification module is configured to introduce the input conditions of the bench test into the equivalent model for simulation analysis to verify whether the equivalent model is credible; The analysis and processing module is configured to perform parameter simulation and analysis through the equivalent model based on the verification results of the equivalent model and the target parameters of the bench test configuration, so as to obtain a mapping relationship library of various parameters and performances of the hydraulic power steering system.

9. A computer-readable storage medium having a computer program / instruction stored thereon, wherein the computer program / instruction, when executed by a processor, implements the steps of the method according to any one of claims 1 to 7.

10. A computer program product comprising a computer program / instruction, which, when executed by a processor, implements the steps of the method according to any one of claims 1 to 7.

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