Steering system test bench, steering system test equipment and methods

Abstract

This invention relates to a steering system test bench, steering system testing equipment, and method. The steering system test bench includes a steering gear mounting base, a first actuator mounting base, a column mounting base, and a second actuator mounting base. The steering gear mounting base is used to mount the steering gear assembly. There are two first actuator mounting bases, each positioned on opposite sides of the steering gear mounting base in a first direction. Each first actuator mounting base has a first actuator for connecting to the external tie rod of the steering gear assembly mounted on the steering gear mounting base. The column mounting base is used to mount the steering column assembly. The second actuator mounting base has a second actuator for connecting to the input end of the steering column assembly mounted on the column mounting base, thereby rotating the input end of the steering column assembly. This steering system test bench can test a wider range of items and performance parameters.

Description

Technical Field

[0001] This invention relates to the field of vehicle steering system testing, and specifically to a steering system test bench, steering system testing equipment, and method. Background Technology

[0002] The steering system is a crucial component of a vehicle. During or after the development of the vehicle's steering system, it is necessary to test its various performance aspects. However, existing testing devices and equipment for vehicle steering systems have limited capabilities to test and verify certain items, making it difficult to meet the performance testing needs of the steering system during the overall vehicle development process. Summary of the Invention

[0003] One objective of this invention is to provide a steering system test bench to address the problem that existing technologies cannot support testing a large number of steering system parameters. A second objective is to provide a steering system testing device. A third objective is to provide a steering system testing method.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A steering system test bench includes a steering gear mounting base, a first actuator mounting base, a column mounting base, and a second actuator mounting base. The steering gear mounting base is used to mount a steering gear assembly. There are two first actuator mounting bases, which are respectively disposed on both sides of the steering gear mounting base in a first direction. Each first actuator mounting base is provided with a first actuator, which is used to connect with the outer tie rod of the steering gear assembly mounted on the steering gear mounting base. The column mounting base is used to mount a steering column assembly. The second actuator mounting base is provided with a second actuator, which is used to connect with the input end of the steering column assembly mounted on the column mounting base and to drive the input end of the steering column assembly to rotate.

[0006] According to the above technical solution, a steering system scenario similar to that on an actual vehicle can be simulated using the steering gear mounting seat, the first actuator mounting seat, the column mounting seat, and the second actuator mounting seat. The various parts of the steering system to be tested are respectively mounted on the steering gear mounting seat, the first actuator mounting seat, the column mounting seat, and the second actuator mounting seat. When performing performance tests on the steering system to be tested, the limitations and constraints are fewer, and more testable items and performance parameters are possible. The steering system test bench in this invention can simulate the layout of a real vehicle steering system, perform power steering and non-power steering condition tests, and comprehensively cover the parameter testing requirements for vehicle steering performance development. It allows for preliminary testing of steering system performance parameters in the early stages of vehicle project development, improving the efficiency of policy steering performance development verification and shortening the vehicle development cycle.

[0007] Furthermore, the steering system test bench also includes a base, on which the steering gear mounting seat, the first actuator mounting seat, and the column mounting seat are movably connected, and the second actuator mounting seat is movably connected to the base or fixed to the column mounting seat.

[0008] According to the above technical solution, the steering gear mounting base, the first actuator mounting base, the column mounting base, and the second actuator mounting base are all mounted on the base, and they can form a whole with each other, which facilitates the overall movement, installation, and disassembly; they can better maintain their relative positions during movement, installation, and disassembly, without having to adjust their relative positions after the movement, installation, and disassembly are completed.

[0009] Further, the steering gear mounting bracket includes a first seat body for connecting to the base and a second seat body for connecting and mounting the steering gear assembly. The first seat body is slidably connected to the base in a second direction; the second seat body is slidably connected to the first seat body in a vertical direction. The first actuator mounting bracket includes a third seat body for connecting to the base and a fourth seat body for connecting and mounting the first actuator. The third seat body is slidably connected to the base in a first direction, and the fourth seat body is slidably connected to the third seat body in a second direction. The column mounting bracket includes a fifth seat body for connecting to the base and a sixth seat body for connecting and mounting the steering column assembly. The fifth seat body is slidably connected to the base in a first direction, and the sixth seat body is slidably connected to the fifth seat body in a second direction. The first direction and the second direction are two mutually perpendicular directions in the horizontal plane.

[0010] According to the above technical solution, by adjusting the positions of the second, fourth, and sixth seats in various dimensions, the relative positions between the steering gear assembly, the first actuator, and the steering column assembly can be changed. This allows for diverse and different relative positional relationships between the steering gear assembly, the first actuator, and the steering column assembly, meeting the needs of performance testing for various steering systems under test.

[0011] Furthermore, a rotating bracket is provided on the steering gear mounting base, and a steering gear mounting clamp is provided on the rotating bracket. The steering gear assembly is mounted and fixed on the rotating bracket by the steering gear mounting clamp.

[0012] According to the above technical solution, by setting up a rotating bracket, the steering gear assembly can be rotated and its angle changed when it is installed on the steering gear mounting seat. This allows for more diverse adjustments to the steering gear assembly's posture, better matching the actual state of the steering gear assembly in the vehicle. Simultaneously, a steering gear mounting fixture is provided to secure the steering gear assembly on the rotating bracket. This setup creates an intermediate structure between the steering gear assembly and the rotating bracket, facilitating replacement. In practical scenarios involving testing different steering gear assemblies, only different sizes of steering gear mounting fixtures need to be replaced to mount and secure different steering gear assemblies to the rotating bracket, without needing to replace the entire rotating bracket or other larger components.

[0013] Furthermore, the column mounting base includes a column mounting bracket, and a column mounting clamp is provided on the column mounting bracket. The steering column assembly is fixedly connected to the column mounting bracket through the column mounting clamp.

[0014] According to the above technical solution, the steering column assembly is fixedly mounted on the column mounting bracket using a steering gear mounting clamp. This configuration, consistent with the aforementioned steering gear mounting clamp, forms an intermediate structure between the steering column assembly and the column mounting bracket, facilitating replacement. In practical scenarios involving testing different steering column assemblies, only different sizes of column mounting clamps need to be replaced to mount and fix different steering column assemblies onto the column mounting bracket, without needing to replace the entire column mounting bracket or other larger components.

[0015] Furthermore, the column mounting base also includes a base, a lifting mechanism, and a rotating mounting frame; the lifting mechanism is disposed on the base; the rotating mounting frame is disposed on the lifting mechanism and is driven by the lifting mechanism to move vertically, and the rotating mounting frame is rotatable relative to the lifting mechanism, and the column mounting bracket is fixedly connected to the rotating mounting frame.

[0016] According to the above technical solution, the height of the column mounting bracket and the steering column assembly mounted on the steering column bracket can be adjusted by the lifting mechanism, and the direction and angle of the column mounting bracket and the steering column assembly mounted on the steering column bracket can be adjusted by rotating the mounting bracket. This allows for adjustment of the posture of the steering column assembly in more dimensions, enabling the simulation of more specific scenarios of steering systems in vehicles, and the simulation can be more realistic. This can better meet the diverse and different needs of testing different steering systems.

[0017] A steering system testing device includes the aforementioned steering system test bench, and further includes a data detection module and a data receiving and processing module. The data detection module includes at least one of a steering angle torque sensor and a displacement sensor. The steering angle torque sensor is connected between the second actuator and the input end of the steering column assembly, and is used to acquire the angle of the input end of the steering column assembly and the torque at that angle. The displacement sensor is used to detect the displacement of the end of the first actuator connected to the tie rod of the steering assembly. The data receiving and processing module is used to receive the data information collected by the data detection module, analyze and process the data information, and obtain test results.

[0018] According to the above technical solution, when the steering gear assembly and steering column assembly are respectively installed on the steering system test bench, and the first actuator and the second actuator act on the steering gear assembly and steering column assembly respectively for testing, the steering angle torque sensor can detect the angle of the input end of the steering column assembly and the torque at that angle, and the displacement sensor can detect the displacement of the outer tie rod of the steering gear assembly. The data obtained from these detections can be processed at the data receiving and processing module to obtain corresponding processing results. These processing results reflect the analysis, evaluation, and judgment of the steering system's performance, that is, the results of the steering system performance test.

[0019] Furthermore, the displacement sensor is a laser displacement sensor, which is mounted on the first actuator mounting base; the steering system testing equipment also includes a reflector, which is mounted on the end of the first actuator connected to the steering assembly.

[0020] According to the above technical solution, the laser displacement sensor can detect the distance between the reflector and the laser displacement sensor by emitting laser light towards the reflector and receiving the laser light reflected back by the reflector. The detection process is convenient and quick.

[0021] Furthermore, the steering system testing equipment also includes a road spectrum input module, which is used to input preset road spectrum information to the first actuator.

[0022] According to the above technical solution, the road spectrum input module inputs preset road spectrum information to the first actuator. The first actuator can dynamically adjust the thrust applied to the outer tie rod of the steering assembly according to the preset road spectrum information. This can simulate the real scenario when driving on the road, and the performance test results of the steering system will be more realistic and accurate.

[0023] A steering system testing method, which uses the aforementioned steering system testing equipment to test the steering system to be tested.

[0024] According to the above technical solution, the steering system testing equipment can be used to test a number of test items on the steering system to be tested, thus better meeting the needs of testing the steering system.

[0025] Furthermore, the steering system testing method is used to perform a steering system friction test; the steering system testing method includes:

[0026] Step S11: Set the two first actuators to zero thrust state, control the second actuator to drive the input end of the steering column assembly to reciprocate within the set positive and negative stroke range, and have the angle and torque sensor record the angle and torque information during the rotation process;

[0027] Step S12: Select multiple angle positions and obtain the corresponding torque information.

[0028] Based on the above technical solution, a steering system friction test can be performed on the steering system to be tested.

[0029] Further, in step S11, the starting point of rotation of the input end of the steering column assembly is the midpoint of the input end; and / or

[0030] The defined positive and negative travel intervals are the areas between 95% of the maximum travel from the midpoint to both ends; and / or

[0031] The second actuator controls the input end of the steering column assembly to maintain a constant speed while rotating in the same direction.

[0032] The above technical solution helps to make the test results of the steering system friction test on the steering system under test more realistic and accurate.

[0033] Further, step S12 includes:

[0034] Step S121: Based on the angle and torque information recorded by the angle torque sensor, establish an angle-force coordinate diagram with the angle information as the first coordinate and the torque information as the second coordinate.

[0035] Step S122: Select multiple angular positions in the angle-force coordinate diagram and find the torque information corresponding to these multiple angular positions.

[0036] According to the above technical solution, an angle-force coordinate diagram is first established, which can clearly and intuitively display the torque at different angular positions; it is also simpler and more convenient to find the torque information corresponding to multiple selected angular positions.

[0037] Furthermore, the steering system testing method is used to test the rack travel and gear ratio of the steering gear assembly; the steering system testing method includes:

[0038] Step S21: Set the two first actuators to a zero-thrust state, control the second actuator to drive the input end of the steering column assembly to reciprocate between the extreme positions at both ends, and use a displacement sensor to detect the displacement stroke of the end of the first actuator connected to the steering assembly.

[0039] Step S22: Obtain the left and right limit travels based on the detection data of the displacement sensor, and obtain the rack travel of the steering gear assembly based on the left and right limit travels; and select multiple angular positions to obtain the corresponding displacement travel information, and determine the transmission ratio of the steering gear assembly at the corresponding points through differential calculation.

[0040] Based on the above technical solution, the rack travel and transmission ratio of the steering system to be tested can be measured.

[0041] Further, in step S21, the starting point of rotation of the input end of the steering column assembly is the midpoint of the input end; and / or

[0042] The second actuator controls the input end of the steering column assembly to maintain a constant speed while rotating in the same direction.

[0043] Based on the above technical solution, it helps to make the test results of the rack travel, i.e., the transmission ratio test of the steering system under test more realistic and accurate.

[0044] Further, step S22 includes:

[0045] Step S221: Based on the angle and displacement travel recorded by the displacement sensor, establish an angle-travel coordinate graph with the angle information as the first coordinate and the displacement travel as the second coordinate.

[0046] Step S222: Select multiple angular positions in the angle-stroke coordinate graph and find the displacement stroke information corresponding to these multiple angular positions;

[0047] Step S223: Determine the transmission ratio of the steering gear assembly at the corresponding point through differential calculation.

[0048] Based on the above technical solution, an angle-stroke coordinate diagram is first established. This clearly and intuitively displays the stroke information at different angular positions, making it simpler and more convenient to find the stroke information corresponding to multiple selected angular positions. The established angle-stroke coordinate diagram can not only be used to find the displacement stroke information corresponding to the selected angular position when determining the transmission ratio of the steering gear assembly, but also to find the right limit stroke and left limit stroke when determining the rack stroke of the steering gear assembly.

[0049] Furthermore, the steering system testing method is used to perform steering system stiffness and clearance tests; the steering system testing method includes:

[0050] Step S31: Set the ends of the two first actuators connected to the steering assembly to a fixed state, and control the second actuator to drive the input end of the steering column assembly to rotate between the angle position corresponding to the set maximum positive torque and the angle position corresponding to the set maximum negative torque.

[0051] Step S32: Select a torque value, obtain the angular position when the positive torque reaches the torque value, and the angular position when the negative torque reaches the torque value, and determine the steering system clearance based on these two angular positions; and

[0052] Select the starting and ending angles of the center sections for positive and negative torques, obtain the corresponding torque values, and determine the steering stiffness of the center sections based on these torque values; and

[0053] Select the starting and ending angles of the non-central section for positive and negative torques, obtain the corresponding torque values, and determine the steering stiffness of the non-central section based on the torque values.

[0054] Based on the above technical solution, the steering system stiffness and clearance can be tested on the steering system to be tested.

[0055] Further, in step S31, the maximum positive torque is 30 Nm, the maximum negative torque is -30 Nm; and / or

[0056] In step S31, the starting point of rotation of the input end of the steering column assembly is the midpoint of the input end; and / or

[0057] The second actuator controls the input end of the steering column assembly to maintain a constant speed while rotating in the same direction.

[0058] The above technical solution helps to make the test results of the steering system stiffness and clearance tests on the steering system under test more realistic and accurate.

[0059] Further, step S32 includes:

[0060] Step S321: Based on the angle and torque information recorded by the angle torque sensor, establish an angle-force coordinate diagram with the angle information as the first coordinate and the torque information as the second coordinate.

[0061] Step S322: Select a torque value in the angle-force coordinate diagram, and find the positive and negative angular positions corresponding to the selected torque value; and

[0062] Determine the starting and ending angles of the central segments of the positive and negative moments in the angle-force coordinate diagram, and find the corresponding moment values; and

[0063] Determine the starting and ending angles of the non-central sections of the positive and negative torques in the angle-force coordinate diagram, and find the corresponding torque values;

[0064] Step S323: Calculate and determine the steering system clearance based on the found positive and negative angular positions; and

[0065] Based on the torque values ​​of the central sections of the positive and negative torques found, according to the formula:

[0066]

[0067] Determine the steering stiffness of the center sections for both positive and negative moments; and

[0068] Based on the torque values ​​of the non-central sections of the positive and negative torques found, according to the formula:

[0069]

[0070] Determine the steering stiffness of the non-central section for both positive and negative moments;

[0071] Wherein, G1 is the stiffness of the central section; G2 is the stiffness of the non-central section; T A - The torque value at the initial angle of the central section; T B- The torque value at the termination angle of the central section; T C - The torque value at the starting angle of the non-central section; T D - The moment value at the termination angle of the non-central section; a A - The starting angle of the central section; a B - The termination angle of the central section; a C - The starting angle of the non-central segment; a D - Termination angle of non-central sections.

[0072] Based on the above technical solution, the steering stiffness of the central section for positive and negative torques, as well as the steering stiffness of the non-central section for positive and negative torques, can be obtained.

[0073] Furthermore, the steering system testing method is used to test the maximum output rack force of the electric power steering system; the steering system testing method includes:

[0074] Step S41: Set one of the first actuators to a zero-thrust state, and set the other first actuator to a fixed state at the end connected to the steering gear assembly; control the second actuator to drive the input end of the steering column assembly to rotate from the center position in one direction until the set maximum positive torque is reached; and rotate in the other direction until the set maximum negative torque is reached; and record the thrust applied by the first actuator with the fixed end connected to the steering gear assembly during this process;

[0075] Step S42: Determine the thrust applied by the first actuator when the maximum positive torque and the maximum negative torque are reached, and determine the maximum output rack force of the electric power steering system based on the magnitude of the found thrust.

[0076] Based on the above technical solution, the maximum output rack force of the electric power steering system can be tested on the steering system to be tested.

[0077] Further, in step S41, the starting point of rotation of the input end of the steering column assembly is the midpoint of the input end; and / or

[0078] The maximum positive torque is 10 Nm, and the maximum negative torque is -10 Nm; and / or

[0079] The second actuator controls the input end of the steering column assembly to maintain a constant speed while rotating in the same direction.

[0080] Based on the above technical solution, it helps to make the test results of the maximum output rack force of the electric power steering system more realistic and accurate.

[0081] Further, step S42 includes:

[0082] Step S421: Based on the torque information recorded by the angle torque sensor and the thrust data information applied by the first actuator, establish a torque-thrust coordinate diagram with the torque information as the first coordinate and the thrust information as the second coordinate.

[0083] Step S422: Locate the thrust data corresponding to the positions of the maximum positive torque and the maximum negative torque in the torque-thrust coordinate graph;

[0084] Step S423: Calculate the average value of the found thrust data as the maximum output rack force of the electric power steering system.

[0085] According to the above technical solution, by establishing a torque-thrust coordinate diagram, the correspondence between torque and thrust at the same location can be clearly and intuitively displayed; thus, the torque information corresponding to the selected maximum positive torque and maximum negative torque can be easily and quickly found.

[0086] Furthermore, the steering system testing method is used to test the catch-up characteristics of electric power steering; the steering system testing method includes:

[0087] Step S51: Execute the first simulated working condition. Under the first simulated working condition, the two first actuators jointly apply a first thrust to the steering gear assembly, and the second actuator drives the input end of the steering column assembly to rotate within a set positive and negative stroke range at a first rotation speed; and the angle and torque sensor records the angle and torque information during this rotation process.

[0088] Step S52: Compare the maximum torque recorded by the angle torque sensor with the set torque value. If the maximum torque recorded by the angle torque sensor exceeds the set torque value, it indicates that the catch-up characteristic under the first simulated working condition does not meet the requirements. If the maximum torque recorded by the angle torque sensor does not exceed the set torque value, it indicates that the catch-up characteristic under the first simulated working condition meets the requirements.

[0089] Step S53: Following steps S51 to S52, execute the subsequent second to nth simulated working conditions respectively to determine whether the catch-up characteristics under the second to nth simulated working conditions meet the requirements; wherein, the first thrust decreases from the first thrust to the nth thrust, and the first rotation speed increases from the first rotation speed to the nth rotation speed.

[0090] Based on the above technical solution, the catch-up characteristics of electric power steering can be tested on the steering system to be tested.

[0091] Further, in step S51, the electric power steering is set to an assist state at a vehicle speed of 0; and / or

[0092] In step S51, the starting point of rotation of the input end of the steering column assembly is the midpoint of the input end; after rotating to the endpoints of the positive and negative travel ranges, the input end of the steering column assembly returns to the midpoint of the input end; and / or

[0093] The defined positive and negative travel intervals are the areas between 90% of the maximum travel from the midpoint to both ends; and / or

[0094] The second actuator controls the input end of the steering column assembly to maintain a constant speed while rotating in the same direction.

[0095] Based on the above technical solution, it helps to make the test results of the electric power steering catch-up characteristics of the steering system under test more realistic and accurate.

[0096] Furthermore, the ratio of the first thrust to the maximum rack force of the steering system under static conditions is 95%, and the first rotational speed is 180° / s;

[0097] The ratio of the nth thrust to the maximum rack force of the steering system under static conditions is 50%, and the nth rotational speed is 600° / s.

[0098] According to the above technical solution, the catch-up characteristics of electric power steering are tested by establishing multiple simulated working conditions. Moreover, the thrust and rotation speed under different simulated working conditions have a specific correlation, which can test the catch-up characteristics of electric power steering more realistically and efficiently.

[0099] Furthermore, the steering system testing method is used to test the overheat protection performance of electric power steering; and the steering system testing method is based on the aforementioned steering system testing equipment with a road spectrum input module; the steering system testing method includes:

[0100] Step S61: Control the second actuator to drive the input end of the steering column assembly to reciprocate between the extreme positions at both ends, and the angle and torque sensor records the angle and torque information during the rotation; and during the rotation, the first actuator adjusts the thrust applied to the steering assembly in response to the preset road spectrum information provided by the road spectrum input module.

[0101] Step S62: Based on the angle and torque information recorded by the steering torque sensor, select an angle position and find the torque value corresponding to the selected angle position during the rotation of the input end of the steering column assembly.

[0102] Step S63: Compare the determined torque value with the set standard value. If it exceeds the set standard value, it indicates that the overheat protection performance of the electric power steering does not meet the requirements. If it does not exceed the set standard value, it indicates that the overheat protection performance of the electric power steering meets the requirements.

[0103] Based on the above technical solution, the overheat protection performance of the electric power steering system to be tested can be evaluated.

[0104] Further, in step S61, the second actuator drives the input end of the steering column assembly to rotate multiple cycles, each cycle including: rotating from the center position of the input end toward the first end to the limit position, and then rotating toward the second end to the limit position; rotating from the limit position in the second end toward the first end to the limit position and holding it for a predetermined time; rotating from the limit position in the first end toward the second end to the limit position and holding it for a predetermined time; rotating from the limit position in the second end to the center position of the input end; and / or

[0105] The second actuator controls the input end of the steering column assembly to maintain a constant speed while rotating in the same direction.

[0106] Based on the above technical solution, it helps to make the test results of the overheat protection performance of the electric power steering system under test more realistic and accurate.

[0107] Further, step S62 includes:

[0108] Step S621: Based on the angle and torque information recorded by the angle and torque sensor during rotation, establish an angle-force coordinate diagram with the angle information as the first coordinate and the torque information as the second coordinate.

[0109] Step S622: Select an angle position in the angle-force coordinate diagram and find the torque information corresponding to each rotation to the selected angle position.

[0110] Based on the above technical solution, an angle-force coordinate diagram is first established, which can clearly and intuitively display the torque at different angular positions; it is also simpler and more convenient to find the torque information corresponding to the selected angular position.

[0111] Further, in step S62, the selected angular position is 95% of the extreme positions of the first end direction and the second end direction; and / or

[0112] The set standard value is determined to be 10 Nm.

[0113] Based on the above technical solution, the standard used to test the overheat protection performance of electric power steering is more in line with the actual vehicle scenario.

[0114] Further, in step S63, the maximum value among the multiple torque values ​​corresponding to the selected angular position is compared with a set standard value, or the torque value corresponding to the last rotation to the selected angular position is compared with a set standard value; based on the comparison result, it is determined whether the overheat protection performance of the electric power steering meets the requirements.

[0115] According to the above technical solution, by comparing the maximum value among multiple torques with the set standard value, or by taking the torque value corresponding to the last rotation to the selected angle position as the maximum value and comparing it with the set standard value, the test results of the overheat protection performance of electric power steering will be more accurate.

[0116] The beneficial effects of this invention are:

[0117] The steering system test bench, testing equipment, and method provided by this invention can simulate a steering system scenario similar to that of an actual vehicle using a steering gear mounting base, a first actuator mounting base, a column mounting base, and a second actuator mounting base. The various components of the steering system to be tested are respectively mounted on these mounting bases. When performing performance tests on the steering system, the limitations and constraints are reduced, allowing for a wider range of test items and performance parameters. Specifically, these tests can include steering system friction testing, steering gear assembly rack travel and transmission ratio testing, steering system stiffness and clearance testing, maximum output rack force of the electric power steering system, electric power steering catch-up characteristics, and electric power steering overheat protection performance.

[0118] When performing the above tests on the steering system under test, the steering gear assembly and steering column assembly of the steering system under test are respectively installed on the steering system test bench. When the first actuator and the second actuator act on the steering gear assembly and the steering column assembly respectively for testing, the steering angle torque sensor can detect the angle of the input end of the steering column assembly and the torque at that angle, and the displacement sensor can detect the displacement of the tie rod of the steering gear assembly. The data obtained from these detections can be processed at the data receiving and processing module to obtain the corresponding processing results. These processing results reflect the analysis, evaluation and judgment of the performance of the steering system, that is, the results of the performance test of the steering system.

[0119] In summary, this invention can simulate the layout of a real vehicle steering system, perform power steering and non-power steering system tests, comprehensively cover the parameter testing requirements for vehicle steering performance development, and conduct preliminary testing of steering system performance parameters in the early stages of vehicle project development, thereby improving the efficiency of steering performance development verification and shortening the vehicle development cycle. Attached Figure Description

[0120] Figure 1 This is a schematic diagram of the structure of the steering system test bench in an embodiment of the present invention;

[0121] Figure 2 for Figure 1 The diagram shown is a structural schematic of the steering system test bench with the steering mounting bracket hidden.

[0122] Figure 3 for Figure 1 A schematic diagram of the steering gear mounting base of the steering system test bench shown;

[0123] Figure 4 for Figure 3 A schematic diagram of the structure after the steering gear assembly is installed on the steering gear mounting bracket;

[0124] Figure 5 for Figure 1 The diagram shows the structure of the column mounting base, the second actuator mounting base, and the installed steering column assembly and second actuator in the steering system test bench.

[0125] Figure 6 This is a schematic diagram of the steering system test equipment in an embodiment of the present invention;

[0126] Figure 7 for Figure 6 The diagram shows the process flow for performing steering system friction tests using the steering system testing equipment shown.

[0127] Figure 8 for Figure 6 The diagram shows the process flow of the steering system testing equipment for testing the rack formation and transmission ratio of the steering gear assembly;

[0128] Figure 9 for Figure 6 The diagram shows the process of using the steering system testing equipment to test the stiffness and clearance of the steering system.

[0129] Figure 10 for Figure 9 A detailed flowchart of step S32 is shown below;

[0130] Figure 11 for Figure 6 The diagram shown illustrates the process of using the steering system testing equipment to measure the maximum output rack force of the electric power steering system.

[0131] Figure 12 for Figure 6 The diagram shows the process of performing catch-up characteristic tests on electric power steering using the steering system testing equipment shown.

[0132] Figure 13 for Figure 6 The diagram shows the process of testing the overheat protection performance of electric power steering using the steering system testing equipment shown.

[0133] in:

[0134] 1-Steering system test bench;

[0135] 10-Base;

[0136] 11-Steering gear mounting base; 111-First mounting body; 112-Second mounting body; 113-Rotating bracket; 114-Steering gear mounting clamp;

[0137] 12-First actuator mounting base; 121-Third mounting body; 122-Fourth mounting body;

[0138] 13-Tube column mounting base; 131-Fifth mounting body; 132-Sixth mounting body; 133-Tube column mounting bracket; 134-Tube column mounting clamp; 135-Base; 136-Lifting mechanism; 137-Rotating mounting frame;

[0139] 14-Second actuator mounting base;

[0140] 2-Steering gear assembly;

[0141] 3-First actuator; 31-Connecting end;

[0142] 4-Steering column assembly; 41-Intermediate shaft assembly;

[0143] 5-Second actuator; 51-Coupling;

[0144] 6-Angle torque sensor;

[0145] 7-Displacement sensor; 71-Reflector;

[0146] 8-Route spectrum input module;

[0147] 9-Data receiving and processing module; 91-Multi-channel data acquisition unit; 92-Computer; 93-First power supply. Detailed Implementation

[0148] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0149] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0150] In one embodiment of the steering system test bench of the present invention, such as Figures 1-6 As shown, the steering system test bench 1 includes a steering gear mounting base 11, a first actuator mounting base 12, a column mounting base 13, and a second actuator mounting base 14. The steering gear mounting base 11 is used to mount the steering gear assembly 2. There are two first actuator mounting bases 12, which are respectively arranged on both sides of the steering gear mounting base 11 in a first direction. Each first actuator mounting base 12 is provided with a first actuator 3, and the first actuator 3 is used to connect with the outer tie rod of the steering gear assembly 2 mounted on the steering gear mounting base 11. The column mounting base 13 is used to mount the steering column assembly 4. The second actuator mounting base 14 is provided with a second actuator 5, which is used to connect with the input end of the steering column assembly 4 mounted on the column mounting base 13, and to drive the input end of the steering column assembly 4 to rotate.

[0151] In this embodiment, a steering assembly 2 is mounted on a steering assembly mounting base 11, and first actuators 3 are mounted on two first actuator mounting bases 12 respectively. The connecting end 31 of the first actuator 3 is connected to the outer tie rod of the steering assembly 2. The first actuator 3 can apply a force to the outer tie rod of the steering assembly 2 through its connecting end 31. This force can be an inward thrust (towards the steering assembly 2) or an outward pull (away from the steering assembly 2). For ease of description, it will generally be referred to as thrust in the following description. The first actuators 3 on both sides of the steering assembly 2 can be used to simulate the wheels connected to the steering assembly 2 in an actual vehicle. The force they apply to the steering assembly 2 is equivalent to the force exerted by the wheels on the steering assembly 2 in an actual vehicle.

[0152] In this embodiment, a steering column assembly 4 is mounted on the column mounting base 13. The steering column assembly 4 is connected to the steering gear assembly 2 via an intermediate shaft assembly 41. A second actuator 5 is mounted on the second actuator mounting base 14. The second actuator 5 is connected to the input end of the steering column assembly 4 via, for example, a coupling 51, and drives the input end of the steering column assembly 4 to rotate. The second actuator 5 can be used to simulate the steering wheel connected to the steering column assembly 4 in an actual vehicle. The rotational force applied by the second actuator 5 to the input end of the steering column assembly 4 is equivalent to the force applied by the driver to the steering wheel in an actual vehicle, and then applied to the steering column assembly 4 through the steering wheel.

[0153] Based on the above description, in this embodiment, the steering system scenario similar to that on an actual vehicle can be simulated using the steering gear mounting seat 11, the first actuator mounting seat 12, the column mounting seat 13, and the second actuator mounting seat 14. The various parts of the steering system to be tested are respectively mounted on the steering gear mounting seat 11, the first actuator mounting seat 12, the column mounting seat 13, and the second actuator mounting seat 14. When performing performance testing on the steering system to be tested, the limitations and constraints are fewer, and more testable items and performance parameters are possible. The steering system test bench in this embodiment can simulate the layout of a real vehicle steering system, perform power steering and non-power steering condition tests, and comprehensively cover the parameter testing requirements for vehicle steering performance development. Performance parameters of the steering system can be tested early in the vehicle project development phase, improving the efficiency of policy steering performance development verification and shortening the vehicle development cycle.

[0154] In one embodiment of the steering system test bench, the steering system test bench 1 further includes a base 10, the steering gear mounting seat 11, the first actuator mounting seat 12, and the column mounting seat 13 are movably connected to the base 10, and the second actuator mounting seat 14 is movably connected to the base 10 or fixed to the column mounting seat 13.

[0155] In this embodiment, the steering gear mounting base 11, the first actuator mounting base 12, the column mounting base 13, and the second actuator mounting base 14 are all disposed on the base 10, and can form an integral whole with each other, which facilitates the overall movement, installation, and disassembly; it can better maintain their relative positions during movement, installation, and disassembly, without having to adjust their relative positions after the movement, installation, and disassembly are completed.

[0156] In this embodiment, the positions of the steering gear mounting seat 11, the first actuator mounting seat 12, and the column mounting seat 13 on the base 10 are movable, specifically in the form of sliding. Figure 1 and Figure 2 As shown, a sliding groove is provided on the base 10, and sliding rails are respectively provided on the steering gear mounting seat 11, the first actuator mounting seat 12, and the column mounting seat 13, allowing them to move relative to the base 10 along the sliding groove. By moving the positions of the steering gear mounting seat 11, the first actuator mounting seat 12, and the column mounting seat 13 on the base 10, different relative positional relationships can be formed between them to match different steering systems, thereby facilitating performance testing of different steering systems.

[0157] In this embodiment, the second actuator mounting base 14 is movably connected to the base 10, or it can be fixed to the column mounting base 13.

[0158] When the second actuator mounting seat 14 is movably connected to the base 10, it is similar to the steering gear mounting seat 11, the first actuator mounting seat 12, and the column mounting seat 13 described above, and will not be repeated here. However, it should be noted that since the second actuator 5 mounted on the second actuator mounting seat 14 needs to be connected to the input end of the steering column assembly 4 mounted on the column mounting seat 13, to meet this requirement, the column mounting seat 13 and the second actuator mounting seat 14, which are independently mounted on the base 10, must maintain a relatively fixed positional relationship. When the relative positional relationship between the two is initially established or deviates after establishment, it is generally necessary to control the column mounting seat 13 and the second actuator mounting seat 14 to move on the base 10 to change to the correct relative positional relationship. When the second actuator mounting seat 14 is fixed on the column mounting seat 13, the second actuator mounting seat 14 and the column mounting seat 13 form a whole, and the two move as a whole on the base 10 without changing their relative positional relationship. Figure 1 and Figure 5 As shown, in the following description, the second actuator mounting base 14 is fixed on the column mounting base 13 as an example, and the case where the second actuator mounting base 14 is independently set on the base 10 will not be described in detail.

[0159] In this embodiment, when the first actuator 3 is connected to the outer tie rod of the steering gear assembly 2, the coaxiality tolerance between the first actuator 3 and the outer tie rod of the steering gear assembly 2 is controlled within ±10mm. The purpose of this setting is to make the first actuator 3 and the outer tie rod of the steering gear assembly 2 tend to be coaxial, so that when an interaction force is generated between the two, it helps to reduce the force in the radial direction.

[0160] When the second actuator 5 is connected to the input end of the steering column assembly 4, the coaxiality tolerance between the second actuator 5 and the input end of the steering column assembly 4 is controlled within ±2mm. The purpose of this setting is to ensure that when the input end of the steering column assembly 4 is driven by the second actuator 5 to rotate, it is not subjected to radial force or the radial force it bears is small.

[0161] In one embodiment of the steering system test bench, the steering gear mounting base 11 includes a first seat body 111 for connecting to a base 10 and a second seat body 112 for connecting and mounting a steering gear assembly 2. The first seat body 111 is slidably connected to the base 10 in a second direction; the second seat body 112 is slidably connected to the first seat body 111 in a vertical direction. The first actuator mounting base 12 includes a third seat body 121 for connecting to the base 10 and a fourth seat body 122 for connecting and mounting a first actuator 3. The third seat body 121 is slidably connected to the base 10 in a first direction, and the fourth seat body 122 is slidably connected to the third seat body 121 in a second direction. The column mounting base 13 includes a fifth seat body 131 for connecting to the base 10 and a sixth seat body 132 for connecting and mounting a steering column assembly 4. The fifth seat body 131 is slidably connected to the base 10 in a first direction, and the sixth seat body 132 is slidably connected to the fifth seat body 131 in a second direction. The first direction and the second direction are two mutually perpendicular directions in the horizontal plane.

[0162] In this embodiment, for the steering gear mounting base 11, its first seat 111 is connected to the base 10 and can slide relative to the base 10 in a second direction, while the first seat 111 and the second seat 112 are slidably connected in the vertical direction, thus allowing the second seat 112 to move in both the second and vertical directions. The steering gear assembly 2 is mounted on the second seat 112, therefore it can move and change its position along both the second and vertical directions. For the first actuator mounting base 12, its third seat 121 is connected to the base 10 and can slide relative to the base 10 in a first direction, while the fourth seat 122 is slidable to the third seat 121 in the second direction, thus allowing the fourth seat 122 to move in both the first and second directions. The first actuator 3 is mounted on the fourth seat 122, therefore it can move and change its position along both the first and second directions. For the column mounting base 13, its fifth seat 131 is connected to the base 10 and can slide relative to the base 10 in a first direction, while the sixth seat 132 can slide relative to the fifth seat 131 in a second direction. Thus, the sixth seat 132 can move in both the first and second directions. The steering column assembly 4 is mounted on the sixth seat 132, so it can move and change its position along both the first and second directions.

[0163] In this embodiment, by adjusting the positions of the second seat 112, the fourth seat 122, and the sixth seat 132 in various dimensions, the relative positions between the steering gear assembly 2, the first actuator 3, and the steering column assembly 4 can be changed. This allows for diverse and different relative positional relationships between the steering gear assembly 2, the first actuator 3, and the steering column assembly 4, meeting the needs of performance testing for various steering systems under test.

[0164] In one embodiment of the steering system test bench, a rotating bracket 113 is provided on the steering gear mounting base 11, and a steering gear mounting fixture 114 is provided on the rotating bracket 113. The steering gear assembly 2 is mounted and fixed on the rotating bracket 113 by the steering gear mounting fixture 114.

[0165] In this embodiment, by setting the rotating bracket 113, when the steering assembly 2 is installed on the steering mounting base 11, the steering assembly 2 can also be rotated by means of the rotating bracket 113 to change the angle of the steering assembly 2, thereby making more diverse adjustments to the posture of the steering assembly 2 so as to better match the state of the steering assembly 2 in the actual vehicle.

[0166] In this embodiment, a steering gear mounting fixture 114 is also provided, which is used to mount and fix the steering gear assembly 2 on the rotating bracket 113. This arrangement provides an intermediate structure between the steering gear assembly 2 and the rotating bracket 113, making replacement easier. In practical scenarios where different steering gear assemblies 2 are tested, only different sizes of steering gear mounting fixtures 114 need to be replaced to mount and fix different steering gear assemblies 2 onto the rotating bracket 113, without needing to replace the entire rotating bracket 113 or other larger components.

[0167] In one embodiment of the steering system test bench, the column mounting base 13 includes a column mounting bracket 133, and a column mounting clamp 134 is provided on the column mounting bracket 133. The steering column assembly 4 is fixedly connected to the column mounting bracket 133 through the column mounting clamp 134.

[0168] In this embodiment, the steering column assembly 4 is fixedly mounted on the column mounting bracket 133 via the steering gear mounting clamp 114. This configuration is consistent with the aforementioned steering gear mounting clamp 114, forming an intermediate structure between the steering column assembly 4 and the column mounting bracket 133. This intermediate structure facilitates replacement. In practical scenarios where different steering column assemblies 4 are tested, only different sizes of column mounting clamps 134 need to be replaced to mount and fix different steering column assemblies 4 onto the column mounting bracket 133, without needing to replace the entire column mounting bracket 133 or other larger components.

[0169] In one embodiment of the steering system test bench, the column mounting base 13 further includes a base 135, a lifting mechanism 136, and a rotating mounting frame 137; the lifting mechanism 136 is disposed on the base 135; the rotating mounting frame 137 is disposed on the lifting mechanism 136 and is driven by the lifting mechanism 136 to move vertically, and the rotating mounting frame 137 is rotatable relative to the lifting mechanism 136, and the column mounting bracket 133 is fixedly connected to the rotating mounting frame 137.

[0170] In this embodiment, the height of the column mounting bracket 133 and the steering column assembly 4 mounted on the steering column bracket 133 can be adjusted by the lifting mechanism 136, and the direction and angle of the column mounting bracket 133 and the steering column assembly 4 mounted on the steering column bracket 133 can be adjusted by the rotating mounting bracket 137. This allows for adjustment of the posture of the steering column assembly 4 in more dimensions, enabling the simulation of more specific scenarios of steering systems on vehicles, and the simulation can be more realistic. This can better meet the diverse and different needs of testing different steering systems.

[0171] In one embodiment of the steering system testing equipment of the present invention, such as Figure 6 As shown, the steering system testing equipment includes the steering system test bench described in the above embodiments, and also includes a data detection module and a data receiving and processing module. The data detection module includes at least one of a steering angle torque sensor 6 and a displacement sensor 7. The steering angle torque sensor 6 is connected between the second actuator 5 and the input end of the steering column assembly 4, and is used to acquire the angle of the input end of the steering column assembly 4 and the torque at that angle. The displacement sensor 7 is used to detect the displacement of the end of the first actuator 3 connected to the outer tie rod of the steering gear assembly 2. The data receiving and processing module 9 is used to receive the data information collected by the data detection module, analyze and process the data information, and obtain test results.

[0172] In this embodiment, the steering torque sensor 6 can be coaxially arranged with the input end of the second actuator 5 and the steering column assembly 4, specifically between the input end of the steering column assembly 4 and the coupling 51. The displacement sensor 7 can be specifically arranged on different parts of the first actuator mounting base 12 or the first actuator 3.

[0173] In this embodiment, the data receiving and processing module 9 may specifically include a multi-channel data acquisition unit 91 and a computer 92. In addition, it may also include other devices such as a first power supply 93 for supplying power to the computer 92.

[0174] In this embodiment, when the steering gear assembly 2 and the steering column assembly 4 are respectively installed on the steering system test bench, and the first actuator 3 and the second actuator 5 act on the steering gear assembly 2 and the steering column assembly 4 respectively for testing, the steering angle torque sensor 6 can detect the angle of the input end of the steering column assembly 4 and the torque at that angle, and the displacement sensor 7 can detect the displacement of the tie rod of the steering gear assembly 2. The data obtained from these detections can be collected by the multi-channel data acquisition unit 91 and acquired by the computer 92. The computer 92 is equipped with corresponding processing software. With the help of the installed processing software, the computer 92 can process the received data and obtain the corresponding processing results. These processing results reflect the analysis, evaluation and judgment of the performance of the steering system, that is, the results of the performance test of the steering system.

[0175] In one embodiment of the steering system testing equipment, the displacement sensor 7 is a laser displacement sensor, which is disposed on the first actuator mounting base 12; the steering system testing equipment also includes a reflector 71, which is disposed on the end of the first actuator 3 that is connected to the steering assembly 2, i.e., on the connection end 31.

[0176] In this embodiment, the laser displacement sensor can detect the distance between the reflector 71 and the laser displacement sensor by emitting a laser in the direction of the reflector 71 and receiving the laser reflected back by the reflector 71. The detection process is convenient and quick.

[0177] Since the connecting end 31 of the first actuator 3 is always connected to the outer tie rod of the steering assembly 2, the reflector 71 mounted on the connecting end 31 and the outer tie rod of the steering assembly move in the same spatial direction. Therefore, the displacement between the reflector 71 and the laser displacement sensor is equal to the displacement of the outer tie rod of the steering assembly 2. The displacement of the reflector 71 detected by the laser displacement sensor is the displacement of the outer tie rod of the steering assembly 2.

[0178] In one embodiment of the steering system testing equipment, the steering system testing equipment further includes a road spectrum input module 8, which is used to input preset road spectrum information to the first actuator 3.

[0179] In this embodiment, the road spectrum input module 8 inputs preset road spectrum information to the first actuator 3. The first actuator 3 can dynamically adjust the thrust applied to the outer tie rod of the steering assembly 2 according to the preset road spectrum information. This can simulate the real scenario when driving on the road, and the results of the performance test of the steering system will be more realistic and accurate.

[0180] In one embodiment of the steering system testing method of the present invention, the steering system testing method uses the steering system testing equipment described in the above embodiments to test the steering system to be tested.

[0181] In this embodiment, the steering system testing equipment described in the above embodiments can be used to test multiple performance characteristics of the steering system, such as steering system friction testing, testing of the rack travel and transmission ratio of the steering gear assembly, steering system stiffness and clearance testing, testing of the maximum output rack force of the electric power steering system, testing of the catch-up characteristics of the electric power steering, and testing of the overheat protection performance of the electric power steering.

[0182] When performing a steering system friction test using the steering system testing method of the present invention, the steering system testing method includes the following steps S11 to S12, as follows: Figure 7 As shown.

[0183] Step S11: Set the two first actuators 3 to zero thrust state, control the second actuator 5 to drive the input end of the steering column assembly 4 to reciprocate within the set positive and negative stroke range, and have the angle and torque sensor 6 record the angle and torque information during the rotation process.

[0184] In step S11, the first actuator 3 is set to a zero-thrust state, which means that the first actuator 3 does not apply any thrust to the outer tie rod of the steering assembly 2. The outer tie rod of the steering assembly 2 can remain stationary or move autonomously in the first direction, and is not subjected to thrust applied by the first actuator 3 during the displacement process.

[0185] In step S11, when the second actuator 5 drives the input end of the steering column assembly 4 to rotate, the starting point of rotation of the input end of the steering column assembly 4 can be set to the middle position of the input end, that is, the middle position of the rotatable range of the input end.

[0186] In step S11, the set positive and negative travel range can specifically be the area between 95% of the maximum travel from the center position to both ends. For example, if the maximum travel from the center position of the input end to the left is 500°, then in step S11, the second actuator 5 drives the input end of the steering column assembly 4 to move 475° to the left from the center position, and then stops at that angle without continuing to rotate to the left.

[0187] In step S11, the second actuator 5 controls the input end of the steering column assembly 4 to maintain a constant speed while rotating in the same direction. Specifically, the speed at which the input end of the steering column assembly 4 rotates can be 45° / s.

[0188] It should be noted that during the process of the second actuator 5 controlling the rotation of the input end of the steering column assembly 4, when rotating to the stop point on the left or right (i.e., the endpoint of the positive and negative travel intervals), it is necessary to stop and steer. At this time, the input end of the steering column assembly 4 will naturally have a process of decelerating to zero and then accelerating in the opposite direction. However, this deceleration and acceleration process is brief. During the main rotation process after accelerating to the target speed, and during the main rotation process before deceleration, the speed of the steering column assembly 4 does not change, but remains at the target speed and rotates at a constant speed. Therefore, in this step S11, the rotation of the input end of the steering column assembly 4 is limited to a constant speed rotation, which means that the input end of the steering column assembly 4 maintains a constant speed during the main rotation process.

[0189] Based on the above limitations, in step S11, the specific process by which the second actuator 5 drives the input end of the steering column assembly 4 to rotate can be as follows:

[0190] First, adjust the initial position of the input end of the steering column assembly 4 to the center position.

[0191] Subsequently, the second actuator 5 drives the input end of the steering column assembly 4 to move to the right (the stroke from the center position to the right is the positive stroke, and correspondingly, the stroke from the center position to the left is the negative stroke). During this process, the input end of the steering column assembly 4 first undergoes a brief acceleration process, accelerating to a rotational speed of 45° / s; then it maintains this rotational speed and rotates at a constant speed until it reaches the end of the positive stroke range, that is, 95% of the limit position of rotation to the right; before reaching the end of this positive stroke range, the input end of the steering column assembly 4 undergoes a brief deceleration process, reducing the rotational speed to 0, and stops at the end of this positive stroke range.

[0192] Subsequently, the second actuator 5 drives the input end of the steering column assembly 4 to move to the left. During this movement, the input end of the steering column assembly 4 undergoes a brief acceleration process, accelerating to a rotational speed of 45° / s; then it maintains this rotational speed and rotates at a constant speed, passing through the midpoint and continuing to rotate until it reaches the end of the negative travel range, that is, 95% of the extreme position of rotation to the left; before reaching the end of the negative travel range, the input end of the steering column assembly 4 undergoes a brief deceleration process, reducing the rotational speed to 0, and stops at the end of the negative travel range.

[0193] Finally, the second actuator 5 drives the input end of the steering column assembly 4 to move to the right. During this process, the input end of the steering column assembly 4 will first undergo a brief acceleration process, accelerating to a rotational speed of 45° / s; then it will maintain this rotational speed and rotate at a constant speed until it reaches the neutral position; before reaching the neutral position, the input end of the steering column assembly 4 will undergo a brief deceleration process, reducing the rotational speed to 0 and stopping at the neutral position.

[0194] During the aforementioned rotation process, the steering angle torque sensor 6 continuously records the input end of the steering column assembly 4 at each position it rotates to, and the torque applied by the second actuator 5 to the input end of the steering column assembly 4 at each position it rotates to.

[0195] It should be noted that the above process is only an illustrative description. In actual implementation, it is not required to follow the above process exactly. For example, the input end of the steering column assembly 4 can be controlled to move to the left first; and the travel from the center position to the right can also be set as the negative travel, and correspondingly, the travel from the center position to the left can be set as the positive travel.

[0196] Step S12: Select multiple angle positions and obtain the corresponding torque information.

[0197] Specifically, when selecting multiple angle positions, torque can be selected at multiple angle positions such as 0° (rotation through the midpoint), 90° (rotation 90° from the midpoint to the positive travel range), -90° (rotation 90° from the midpoint to the negative travel range), 180° (rotation 180° from the midpoint to the positive travel range), -180° (rotation 180° from the midpoint to the negative travel range), and maximum angle * 0.98 (the maximum angle is the angle position corresponding to the endpoint of the positive and negative travel ranges).

[0198] When analyzing and evaluating the friction test of the steering system, the torque at the selected multiple angular positions is used as a reference to provide the evaluation results.

[0199] As described in step S11 above, the steering column assembly 4 will pass through a certain angular position multiple times during its rotation. Based on this, in step S12, multiple torques corresponding to the multiple rotations to a certain angular position can be calculated, and their average value can be obtained. Specifically, torques at multiple angular positions such as 180°, -180°, 360°, and -360° can be selected, and their average values ​​can be obtained. When analyzing and evaluating the friction test of the steering system, the average value of the torques at one or more positions can also be referenced.

[0200] In one specific embodiment, step S12 may include the following steps S121 to S122.

[0201] Step S121: Based on the angle and torque information recorded by the angle and torque sensor, establish an angle-force coordinate diagram with the angle information as the first coordinate and the torque information as the second coordinate.

[0202] Step S122: Select multiple angular positions in the angle-force coordinate diagram and find the torque information corresponding to these multiple angular positions.

[0203] In this specific embodiment, an angle-force coordinate graph is first established, which can clearly and intuitively display the torque at different angular positions; it is also simpler and more convenient to find the torque information corresponding to the selected multiple angular positions.

[0204] When testing the rack travel and transmission ratio of the steering gear assembly using the steering system testing method of the present invention, the steering system testing method includes the following steps S21 to S22, as follows: Figure 8 As shown.

[0205] Step S21: Set the two first actuators 3 to a zero-thrust state, control the second actuator 5 to drive the input end of the steering column assembly 4 to reciprocate between the extreme positions at both ends, and the displacement sensor 7 detects the displacement stroke of the end of the first actuator 3 connected to the steering assembly 2.

[0206] In step S21, the second actuator 5 drives the input end of the steering column assembly 4 to rotate so that the starting point of the rotation of the input end of the steering column assembly 4 can be set to the middle position of the input end, that is, the middle position of the rotation range of the input end.

[0207] In step S21, the second actuator 5 controls the input end of the steering column assembly 4 to maintain a constant speed while rotating in the same direction. Specifically, the speed at which the input end of the steering column assembly 4 rotates can be 45° / s.

[0208] In step S21, the rotation of the input end of the steering column assembly 4 is limited to uniform rotation, which is the same as in step S11 above. The input end of the steering column assembly 4 maintains a uniform speed during the main rotation process.

[0209] Based on the above limitations, in step S21, the specific process by which the second actuator 5 drives the input end of the steering column assembly 4 to rotate can be as follows:

[0210] First, adjust the initial position of the input end of the steering column assembly 4 to the center position.

[0211] Subsequently, the second actuator 5 drives the input end of the steering column assembly 4 to move to the right (the stroke from the center position to the right is the positive stroke, and correspondingly, the stroke from the center position to the left is the negative stroke). During this process, the input end of the steering column assembly 4 will first undergo a brief acceleration process, accelerating to a rotational speed of 45° / s; then it will maintain this rotational speed and rotate at a constant speed until it reaches the limit position in the right direction; before reaching this limit position in the right direction, the input end of the steering column assembly 4 may undergo a brief deceleration process, reducing the rotational speed to 0 and stopping at the limit position in the right direction.

[0212] Subsequently, the second actuator 5 drives the input end of the steering column assembly 4 to move to the left. During this movement, the input end of the steering column assembly 4 undergoes a brief acceleration process, accelerating to a rotational speed of 45° / s; then it maintains this rotational speed and rotates at a constant speed, passing through the midpoint and continuing to rotate until it reaches the extreme position in the left direction; before reaching this extreme position in the left direction, the input end of the steering column assembly 4 may undergo a brief deceleration process, reducing the rotational speed to 0 and stopping at the extreme position in the left direction.

[0213] Finally, the second actuator 5 drives the input end of the steering column assembly 4 to move to the right. During this process, the input end of the steering column assembly 4 will first undergo a brief acceleration process, accelerating to a rotational speed of 45° / s; then it will maintain this rotational speed and rotate at a constant speed until it reaches the neutral position; before reaching the neutral position, the input end of the steering column assembly 4 will undergo a brief deceleration process, reducing the rotational speed to 0 and stopping at the neutral position.

[0214] During the aforementioned rotation process, the steering angle torque sensor 6 continuously records the torque applied by the second actuator 5 to the input end of the steering column assembly 4 at each position it rotates to. Meanwhile, the displacement sensor 7 continuously records the displacement of the tie rod of the steering gear assembly 2.

[0215] It should be noted that the above process is only an illustrative description. In actual implementation, it is not required to follow the above process exactly.

[0216] Step S22: Obtain the left and right limit travels based on the detection data of the displacement sensor 7, and obtain the rack travel of the steering gear assembly 2 based on the left and right limit travels; and select multiple angular positions to obtain the corresponding displacement travel information, and determine the transmission ratio of the steering gear assembly 2 at the corresponding points through differential calculation.

[0217] In step S22, when the input end of the steering column assembly 4 is rotated to its right and left limit positions, the outer tie rod of the steering gear assembly 2 will undergo right and left displacements, with the displacement being the maximum. This displacement is the right limit travel and left limit travel. The rack travel of the steering gear assembly 2 can be calculated according to the following formula:

[0218] y = y max -y min

[0219] The right limit travel and left limit travel are obtained by performing mathematical operations.

[0220] Where y is the rack stroke of steering gear assembly 2, y max For the right limit travel, y min This is the left limit travel.

[0221] In step S22, the angle position selected when determining the gear ratio of the steering gear assembly 2 can be, for example, multiple angle positions such as 20°, -20°, 90°, -90°, 180°, -180°, 360°, and -360°. The gear ratio for each angle position can be determined according to the following formula:

[0222]

[0223] The gear ratio of steering gear assembly 2 at the selected angular position is determined by calculation.

[0224] Where ratio is the gear ratio of steering assembly 2, a is the angular position, and y is the rack travel of steering assembly 2.

[0225] In one specific embodiment, when determining the transmission ratio of the steering gear assembly 2 at the corresponding point in step S22, the following steps S221 to S223 may be included.

[0226] Step S221: Based on the angle and displacement travel recorded by the displacement sensor 7, establish an angle-travel coordinate graph with the angle information as the first coordinate and the displacement travel as the second coordinate.

[0227] Step S222: Select multiple angular positions in the angle-stroke coordinate graph and find the displacement stroke information corresponding to these multiple angular positions.

[0228] Step S223: Determine the transmission ratio of the steering gear assembly 2 at the corresponding point through differential calculation.

[0229] In this specific embodiment, an angle-stroke coordinate graph is first established, which clearly and intuitively displays the stroke information at different angular positions; this makes it simpler and more convenient to find the stroke information corresponding to multiple selected angular positions. The established angle-stroke coordinate graph can not only be used to find the displacement stroke information corresponding to the selected angular position when determining the transmission ratio of the steering gear assembly 2, but also to find the right limit stroke and left limit stroke when determining the rack stroke of the steering gear assembly 2.

[0230] When performing steering system stiffness and clearance tests using the steering system testing method of the present invention, the steering system testing method includes the following steps S31 to S32, as follows: Figure 9 As shown.

[0231] Step S31: Set the ends of the two first actuators 3 connected to the steering assembly 2 to a fixed state, and control the second actuator 5 to drive the input end of the steering column assembly 4 to rotate between the angle position corresponding to the set maximum positive torque and the angle position corresponding to the set maximum negative torque.

[0232] In step S31, the end of the first actuator 3 connected to the steering assembly 2, i.e., the connection end 31, is set in a fixed state. This means that the first actuator 3 applies a thrust to the outer tie rod of the steering assembly 2. The applied thrust is not used to cause the outer tie rod of the steering assembly 2 to displace. Instead, when the outer tie rod of the steering assembly 2 tends to displace on its own, it overcomes the force that causes the outer tie rod of the steering assembly 2 to tend to displace, so that the connection end 31 of the first actuator 3 and the outer tie rod of the steering assembly 2 connected to the connection end 31 do not displace during the entire test process.

[0233] In step S31, the maximum positive torque is 30 Nm, and the maximum negative torque is -30 Nm. After the values ​​of the maximum positive torque and the maximum negative torque are determined, the torque value at the current angular position can be monitored in real time as the second actuator 5 rotates the input end of the steering column assembly 4. During the rotation of the input end of the steering column assembly 4 to the right (with the positive torque range from the center position to the right as the positive torque range), when the steering angle torque sensor 6 detects that the torque has reached the maximum positive torque, the second actuator 5 controls the input end of the steering column assembly 4 to stop at that angular position and ceases to rotate to the right. Similarly, during the rotation of the input end of the steering column assembly 4 to the left, when the steering angle torque sensor 6 detects that the torque has reached the maximum negative torque, the second actuator 5 controls the input end of the steering column assembly 4 to stop at that angular position and ceases to rotate to the left.

[0234] In step S31, when the second actuator 5 drives the input end of the steering column assembly 4 to rotate, the starting point of rotation of the input end of the steering column assembly 4 can be set to the middle position of the input end, that is, the middle position of the rotatable range of the input end.

[0235] In step S31, the second actuator 5 controls the input end of the steering column assembly 4 to maintain a constant speed while rotating in the same direction. Specifically, the speed at which the input end of the steering column assembly 4 rotates can be 0.5° / s.

[0236] In step S31, the rotation of the input end of the steering column assembly 4 is limited to uniform rotation, which is the same as in step S11 above. The input end of the steering column assembly 4 maintains a uniform speed during the main rotation process.

[0237] Based on the above limitations, in step S31, the specific process by which the second actuator 5 drives the input end of the steering column assembly 4 to rotate can be as follows:

[0238] First, adjust the initial position of the input end of the steering column assembly 4 to the center position.

[0239] Subsequently, the second actuator 5 drives the input end of the steering column assembly 4 to move to the right (the stroke from the center position to the right is the positive stroke, and the stroke from the center position to the left is the negative stroke). During this rotation, the steering angle torque sensor 6 continuously and in real time monitors the torque at the current angular position. During this process, the input end of the steering column assembly 4 will first undergo a brief acceleration process, accelerating to a rotational speed of 0.5° / s; then it will maintain this rotational speed at a constant speed until the steering angle torque sensor 6 detects that the torque reaches 30Nm, that is, the maximum positive torque has been reached. The second actuator 5 then controls the input end of the steering column assembly 4 to stop at the angular position corresponding to the maximum positive torque.

[0240] Subsequently, the second actuator 5 drives the input end of the steering column assembly 4 to move to the left. During this movement, the input end of the steering column assembly 4 undergoes a brief acceleration process, accelerating to a rotational speed of 0.5° / s; then it maintains this rotational speed and rotates at a constant speed, passing through the center position and continuing to rotate until the steering angle torque sensor 6 detects that the torque reaches -30Nm, that is, the maximum negative torque is reached. The second actuator 5 then controls the input end of the steering column assembly 4 to stop at the angle position corresponding to the maximum negative torque.

[0241] Finally, the second actuator 5 drives the input end of the steering column assembly 4 to move to the right. During this process, the input end of the steering column assembly 4 first undergoes a brief acceleration process, accelerating to a rotational speed of 0.5° / s; then it maintains this rotational speed and rotates at a constant speed until it reaches the neutral position; before reaching the neutral position, the input end of the steering column assembly 4 undergoes a brief deceleration process, reducing the rotational speed to 0 and stopping at the neutral position.

[0242] It should be noted that the above process is only an illustrative description. In actual implementation, it is not required to follow the above process exactly.

[0243] Step S32: Select a torque value, obtain the angular position when the positive torque reaches the torque value, and the angular position when the negative torque reaches the torque value, and determine the steering system clearance based on these two angular positions; and

[0244] Select the starting and ending angles of the center sections for positive and negative torques, obtain the corresponding torque values, and determine the steering stiffness of the center sections based on these torque values; and

[0245] Select the starting and ending angles of the non-central section for positive and negative torques, obtain the corresponding torque values, and determine the steering stiffness of the non-central section based on the torque values.

[0246] In step S32, when selecting a torque value, for example, a torque of 2 Nm or -2 Nm can be selected. Based on the angular position and torque information recorded by the angular torque sensor 6, the angular positions corresponding to 2 Nm and -2 Nm are found using the following formula:

[0247] a=a1+a2

[0248] This allows you to determine the steering system clearance.

[0249] Where a is the steering system clearance, a1 is the angular position corresponding to a torque of 2 Nm, and a2 is the angular position corresponding to a torque of -2 Nm.

[0250] When determining the steering stiffness of the center section for both positive and negative moments, the following formula can be used:

[0251]

[0252] The results of the steering stiffness of the center section with positive and negative torques are obtained.

[0253] When determining the steering stiffness of the non-central section under positive and negative moments, the following formula can be used:

[0254]

[0255] The results of the steering stiffness of the non-central section with positive and negative torques are obtained.

[0256] In the above formula, G1 is the stiffness of the central section; G2 is the stiffness of the non-central section; T A - The torque value at the initial angle of the central section; T B - The torque value at the termination angle of the central section; T C - The torque value at the starting angle of the non-central section; T D - The moment value at the termination angle of the non-central section; a A - The starting angle of the central section; a B - The termination angle of the central section; a C - The starting angle of the non-central segment; a D - Termination angle of non-central sections.

[0257] In one specific embodiment, step S32 may include the following steps S321 to S323, such as... Figure 10 As shown.

[0258] Step S321: Based on the angle and torque information recorded by the angle torque sensor 6, establish an angle-force coordinate diagram with the angle information as the first coordinate and the torque information as the second coordinate.

[0259] Step S322: Select a torque value in the angle-force coordinate diagram, and find the positive and negative angular positions corresponding to the selected torque value; and

[0260] Determine the starting and ending angles of the central segments of the positive and negative moments in the angle-force coordinate diagram, and find the corresponding moment values; and

[0261] Determine the starting and ending angles of the non-central sections of the positive and negative torques in the angle-force coordinate diagram, and find the corresponding torque values.

[0262] Step S323: Calculate and determine the steering system clearance based on the found positive and negative angular positions; and

[0263] Based on the torque values ​​of the central sections of the positive and negative torques found, according to the formula:

[0264]

[0265] Determine the steering stiffness of the center sections for both positive and negative moments; and

[0266] Based on the torque values ​​of the non-central sections of the positive and negative torques found, according to the formula:

[0267]

[0268] Determine the steering stiffness of the non-central section for both positive and negative moments.

[0269] In this specific embodiment, by establishing an angle-force coordinate graph, the torque at different angular positions can be clearly and intuitively displayed; finding the multiple angular positions corresponding to the selected torque value is also simpler and more convenient. Simultaneously, determining the stiffness and clearance of the steering system according to the above formula is a simple, direct, and convenient process.

[0270] When testing the maximum output rack force of an electric power steering system using the steering system testing method of the present invention, the steering system testing method includes the following steps S41 to S42, as follows: Figure 11 As shown.

[0271] Step S41: Set one of the first actuators 3 to a zero thrust state, and set the other end of the first actuator 3 connected to the steering assembly 2 to a fixed state; control the second actuator 5 to drive the input end of the steering column assembly 4 to rotate from the center position in one direction until the set maximum positive torque is reached; and rotate in the other direction until the set maximum negative torque is reached; and record the thrust applied by the first actuator 3 with the end connected to the steering assembly 2 in the fixed state during this process.

[0272] In step S41, the electric power steering system is connected to the CAN communication module and the EPS power supply module. The EPS power supply module is used to provide power to the electric power steering system, and the CAN communication module is used to input signals to the electric power steering system to set the power steering system to the 0 vehicle speed power steering state (i.e., the power steering state corresponding to the actual vehicle speed being 0).

[0273] In step S41, when the second actuator 5 drives the input end of the steering column assembly 4 to rotate, the starting point of rotation of the input end of the steering column assembly 4 can be set to the middle position of the input end, that is, the middle position of the rotatable range of the input end.

[0274] In step S41, the maximum positive torque is 10 Nm, and the maximum negative torque is -10 Nm. After the values ​​of the maximum positive torque and the maximum negative torque are determined, the torque value at the current angular position can be monitored in real time as the second actuator 5 rotates the input end of the steering column assembly 4. During the rotation of the input end of the steering column assembly 4 to the right (with the positive torque range from the center position to the right as the positive torque range), when the steering angle torque sensor 6 detects that the torque has reached the maximum positive torque, the second actuator 5 controls the input end of the steering column assembly 4 to stop at that angular position and ceases to rotate to the right. Similarly, during the rotation of the input end of the steering column assembly 4 to the left, when the steering angle torque sensor 6 detects that the torque has reached the maximum negative torque, the second actuator 5 controls the input end of the steering column assembly 4 to stop at that angular position and ceases to rotate to the left.

[0275] In step S41, the second actuator 5 controls the input end of the steering column assembly 4 to maintain a constant speed while rotating in the same direction. Specifically, the speed at which the input end of the steering column assembly 4 rotates can be 0.5° / s.

[0276] In step S41, the rotation of the input end of the steering column assembly 4 is limited to uniform rotation, which is the same as in step S11 above. The input end of the steering column assembly 4 maintains a uniform speed during the main rotation process.

[0277] Based on the above limitations, in step S41, the specific process by which the second actuator 5 drives the input end of the steering column assembly 4 to rotate can be as follows:

[0278] First, adjust the initial position of the input end of the steering column assembly 4 to the center position.

[0279] Subsequently, the second actuator 5 drives the input end of the steering column assembly 4 to move to the right (the stroke from the center position to the right is the positive stroke, and the stroke from the center position to the left is the negative stroke). During this rotation, the steering angle torque sensor 6 continuously and in real time monitors the torque at the current angular position. During this process, the input end of the steering column assembly 4 will first undergo a brief acceleration process, accelerating to a rotational speed of 0.5° / s; then it will maintain this rotational speed and rotate at a constant speed until the steering angle torque sensor 6 detects that the torque reaches 10Nm, that is, the maximum positive torque has been reached. The second actuator 5 then controls the input end of the steering column assembly 4 to stop at the angular position corresponding to the maximum positive torque.

[0280] Subsequently, the second actuator 5 drives the input end of the steering column assembly 4 to move to the left. During this movement, the input end of the steering column assembly 4 undergoes a brief acceleration process, accelerating to a rotational speed of 0.5° / s; then it maintains this rotational speed and rotates at a constant speed, passing through the center position and continuing to rotate until the steering angle torque sensor 6 detects that the torque reaches -10Nm, that is, the maximum negative torque is reached. The second actuator 5 then controls the input end of the steering column assembly 4 to stop at the angle position corresponding to the maximum negative torque.

[0281] Finally, the second actuator 5 drives the input end of the steering column assembly 4 to move to the right. During this process, the input end of the steering column assembly 4 first undergoes a brief acceleration process, accelerating to a rotational speed of 0.5° / s; then it maintains this rotational speed and rotates at a constant speed until it reaches the neutral position; before reaching the neutral position, the input end of the steering column assembly 4 undergoes a brief deceleration process, reducing the rotational speed to 0 and stopping at the neutral position.

[0282] It should be noted that the above process is only an illustrative description. In actual implementation, it is not required to follow the above process exactly.

[0283] Step S42: Determine the thrust applied by the first actuator 3 at the maximum positive torque and the maximum negative torque, and determine the maximum output rack force of the electric power steering system based on the magnitude of the found thrust.

[0284] In one specific embodiment, step S42 may include the following steps S421 to S423.

[0285] Step S421: Based on the torque information recorded by the angle torque sensor 6 and the thrust data information applied by the first actuator 3, a torque-thrust coordinate diagram is established with the torque information as the first coordinate and the thrust information as the second coordinate.

[0286] Step S422: Locate the thrust data corresponding to the positions of the maximum positive torque and the maximum negative torque in the torque-thrust coordinate graph.

[0287] Step S423: Calculate the average value of the found thrust data as the maximum output rack force of the electric power steering system.

[0288] In this specific embodiment, by establishing a torque-thrust coordinate graph, the correspondence between torque and thrust at the same location can be clearly and intuitively displayed; thus, the torque information corresponding to the selected maximum positive torque and maximum negative torque can be easily and quickly found.

[0289] Let P be the maximum positive torque found. max Let P be the maximum negative torque found. min According to the following formula:

[0290] P = (P max -P min ) / 2

[0291] Calculate the average of the two values, which is the maximum output rack force of the electric power steering system.

[0292] In the above formula, P represents the maximum output rack force of the electric power steering system. And in the above formula, P... min Since it is a negative value, P max -P min That is, P max The absolute value of P min The sum of the absolute values ​​of .

[0293] When testing the catch-up characteristics of electric power steering (an indicator for evaluating whether the assistance of electric power steering is sufficient) using the steering system testing method of the present invention, the steering system testing method includes the following steps S51 to S53, as follows: Figure 12 As shown.

[0294] Step S51: Execute the first simulated working condition. Under the first simulated working condition, the two first actuators 3 jointly apply a first thrust to the steering assembly 2, and the second actuator 5 drives the input end of the steering column assembly 4 to rotate at a first rotation speed within a set positive and negative stroke range; and the angle and torque sensor 6 records the angle and torque information during this rotation process.

[0295] In step S51, the first simulated working condition and subsequent second simulated working conditions, nth simulated working conditions, etc. are preset, which mainly include the following aspects: the thrust applied by the first actuator 3 to the outer tie rod of the steering gear assembly 2, and the rotational speed at which the input end of the steering column assembly 4 is rotated by the second actuator 5.

[0296] For example, the first simulated working condition set in advance can be as follows: the first thrust applied by the first actuator 3 to the steering assembly 2 is equal to 95% of the maximum output rack force under static conditions (static means the actual vehicle speed is 0, the maximum output rack force can be obtained by testing in the above steps S41 to S42, or by CAE simulation), and the first rotational speed of the second actuator 5 driving the input end of the steering column assembly 4 to rotate is 180° / s.

[0297] In step S51, the electric power steering is set to the power steering state at a vehicle speed of 0. The starting point of rotation of the input end of the steering column assembly 4 is the middle position of the input end. After rotating to the endpoints of the positive travel range and the negative travel range, the input end of the steering column assembly 4 returns to the middle position of the input end.

[0298] In step S51, the set positive and negative travel range can specifically be the area between 90% of the maximum travel from the center position to both ends. For example, if the maximum travel from the center position of the input end to the left is 500°, then in step S11, the second actuator 5 drives the input end of the steering column assembly 4 to move 450° to the left from the center position, and then stops at that angle without continuing to rotate to the left.

[0299] In step S51, the second actuator 5 controls the input end of the steering column assembly 4 to maintain a constant speed during rotation in the same direction, that is, to maintain the first rotation speed during the main rotation process.

[0300] Based on the above limitations, in step S51, the specific process by which the second actuator 5 drives the input end of the steering column assembly 4 to rotate can be as follows:

[0301] First, adjust the initial position of the input end of the steering column assembly 4 to the center position.

[0302] Subsequently, the second actuator 5 drives the input end of the steering column assembly 4 to move to the right (the stroke from the center position to the right is the positive stroke, and correspondingly, the stroke from the center position to the left is the negative stroke). During this process, the input end of the steering column assembly 4 first undergoes a brief acceleration process, accelerating to a rotational speed of 180° / s; then it maintains this rotational speed and rotates at a constant speed until it reaches the end of the positive stroke range, that is, 90% of the limit position of rotation to the right; before reaching the end of this positive stroke range, the input end of the steering column assembly 4 undergoes a brief deceleration process, reducing the rotational speed to 0, and stops at the end of this positive stroke range.

[0303] Subsequently, the second actuator 5 drives the input end of the steering column assembly 4 to move to the left. During this movement, the input end of the steering column assembly 4 undergoes a brief acceleration process, accelerating to a rotational speed of 180° / s; then it maintains this rotational speed and rotates at a constant speed, passing through the midpoint and continuing to rotate until it reaches the end of the negative travel range, that is, 90% of the extreme position of rotation to the left; before reaching the end of the negative travel range, the input end of the steering column assembly 4 undergoes a brief deceleration process, reducing the rotational speed to 0 and stopping at the end of the negative travel range.

[0304] Finally, the second actuator 5 drives the input end of the steering column assembly 4 to move to the right. During this process, the input end of the steering column assembly 4 first undergoes a brief acceleration process, accelerating to a rotational speed of 180° / s; then it maintains this rotational speed and rotates at a constant speed until it reaches the neutral position; before reaching the neutral position, the input end of the steering column assembly 4 undergoes a brief deceleration process, reducing the rotational speed to 0 and stopping at the neutral position.

[0305] During the aforementioned rotation process, the steering angle torque sensor 6 continuously records the input end of the steering column assembly 4 at each position it rotates to, and the torque applied by the second actuator 5 to the input end of the steering column assembly 4 at each position it rotates to.

[0306] It should be noted that the above process is only an illustrative description. In actual implementation, it is not required to follow the above process exactly.

[0307] Step S52: Compare the maximum torque recorded by the angle torque sensor 6 with the set torque value. If the maximum torque recorded by the angle torque sensor 6 exceeds the set torque value, it indicates that the catch-up characteristic under the first simulated working condition does not meet the requirements. If the maximum torque recorded by the angle torque sensor 6 does not exceed the set torque value, it indicates that the catch-up characteristic under the first simulated working condition meets the requirements.

[0308] In step S52, based on the torque information recorded by the steering angle torque sensor 6, the maximum torque value is searched. If this maximum value exceeds the set torque value, it indicates that at the angle position corresponding to the maximum torque value, the force applied by the second actuator 5 to the input end of the steering column assembly 4 (simulating the force applied by the driver to the steering wheel in an actual vehicle) is relatively large. This indicates that the electric power steering provides insufficient assistance, meaning that the electric power steering does not meet the requirements for catch-up characteristics. Conversely, if the maximum torque value found does not exceed the set torque value, it means that the electric power steering catch-up characteristics meet the requirements.

[0309] Step S53: Following steps S51 to S52, execute the subsequent second to nth simulated working conditions respectively to determine whether the catch-up characteristics under the second to nth simulated working conditions meet the requirements; wherein, the first thrust decreases from the first thrust to the nth thrust, and the first rotation speed increases from the first rotation speed to the nth rotation speed.

[0310] In step S53, the catch-up characteristics of electric power steering under the second simulated working condition, the third simulated working condition...the nth simulated working condition are tested according to the methods of steps S51 to S52 above.

[0311] In step S53 and the aforementioned step S51, when setting the first simulated operating condition to the nth module operating condition, the following principle is followed: the thrust applied by the first actuator 3 to the steering assembly 2 is negatively correlated with the rotational speed at which the second actuator 5 drives the input end of the steering column assembly 4 to rotate. That is, in any two pre-set simulated operating conditions, if the thrust of one simulated operating condition is greater than that of the other, then its rotational speed is smaller than that of the other simulated operating condition.

[0312] Taking a value of n of 3 as an example, under the pre-set second simulated operating condition, the second thrust can be set to 70% of the maximum output rack force under static conditions, and the second rotational speed can be set to 360° / s. Under the pre-set third simulated operating condition, the third thrust can be set to 50% of the maximum output rack force under static conditions, and the third rotational speed can be set to 600° / s.

[0313] When the steering system testing method of the present invention is used to test the overheat protection performance of electric power steering, it needs to be based on the above-described embodiment of the steering system testing equipment with a road spectrum input module. In this case, the steering system testing method includes the following steps S61 to S63, as follows: Figure 13 As shown.

[0314] Step S61: Control the second actuator 5 to drive the input end of the steering column assembly 4 to reciprocate between the two extreme positions, and the angle and torque sensor 6 records the angle and torque information during the rotation; and during the rotation, the first actuator 3 adjusts the thrust applied to the steering assembly 2 in response to the preset road spectrum information provided by the road spectrum input module 8.

[0315] In step S61, the electric power steering is set to 0-speed power steering.

[0316] In step S61, the road spectrum input module 8 provides road spectrum information to the first actuator 3. According to the road spectrum information, during the process of the second actuator 5 driving the input end of the steering column assembly 4 to rotate, the thrust applied by the first actuator 3 to the steering assembly 2 is variable and dynamic. This is different from the above-mentioned multiple test items in the test of the overheat protection performance of electric power steering.

[0317] In step S61, the second actuator 5 controls the input end of the steering column assembly 4 to maintain a constant speed while rotating in the same direction. Specifically, the speed at which the input end of the steering column assembly 4 rotates can be 90° / s.

[0318] In step S61, the rotation of the input end of the steering column assembly 4 is limited to uniform rotation, which is the same as in step S11 above. The input end of the steering column assembly 4 maintains a uniform speed during the main rotation process.

[0319] In one specific embodiment, in step S61, the second actuator 5 drives the input end of the steering column assembly 4 to rotate multiple cycles, for example, up to 10 cycles. Each cycle includes:

[0320] First, rotate the device from the center of the input terminal towards the first end to its limit position, and then rotate it towards the second end to its limit position. The first end direction can be, for example, the right side, and the second end direction can be, correspondingly, the left side, or vice versa.

[0321] Subsequently, it rotates from the extreme position at the second end towards the extreme position at the first end and holds for a predetermined time. The predetermined time can be set to 5 seconds.

[0322] Then, rotate from the extreme position in the first direction to the extreme position in the second direction and hold for a predetermined time. This predetermined time can also be set to 5 seconds.

[0323] Finally, rotate from the extreme position in the direction of the second end to the middle position of the input end.

[0324] Step S62: Based on the angle and torque information recorded by the steering torque sensor 6, select an angle position and find the torque value corresponding to the selected angle position during the rotation of the input end of the steering column assembly 4.

[0325] In step S62, the selected angular position can specifically be 95% of the extreme position of rotation to both sides. Based on the angle and torque information recorded by the angular torque sensor 6, the torque value at each rotation to that angular position can be found.

[0326] In one specific embodiment, step S62 may include the following steps S621 to S622.

[0327] Step S621: Based on the angle and torque information recorded by the rotation angle torque sensor 6 during the rotation process, an angle-force coordinate diagram is established with the angle information as the first coordinate and the torque information as the second coordinate.

[0328] Step S622: Select an angle position in the angle-force coordinate diagram and find the torque information corresponding to each rotation to the selected angle position.

[0329] In this specific embodiment, an angle-force coordinate graph is first established, which can clearly and intuitively display the torque at different angular positions; it is also simpler and more convenient to find the torque information corresponding to the selected angular position.

[0330] Step S63: Compare the determined torque value with the set standard value. If it exceeds the set standard value, it indicates that the overheat protection performance of the electric power steering does not meet the requirements. If it does not exceed the set standard value, it indicates that the overheat protection performance of the electric power steering meets the requirements.

[0331] In step S63, the maximum value among the multiple torque values ​​corresponding to the selected angle position can be compared with a set standard value, or the torque value corresponding to the last rotation to the selected angle position (generally, when the input end of the steering column assembly 4 is continuously rotated, the electric power steering will enter overheat protection, and the power assistance provided will gradually decrease. Therefore, the torque value of the last rotation to this angle position is usually the largest) can be compared with a set standard value. Based on the comparison results, it is determined whether the overheat protection performance of the electric power steering meets the requirements.

[0332] Specifically, if the maximum value exceeds the set torque value, it indicates that at the angle position corresponding to the maximum torque value, the force applied by the second actuator 5 to the input end of the steering column assembly 4 (simulating the force applied by the driver to the steering wheel in an actual vehicle) is relatively large. This means that the electric power steering provides insufficient assistance, implying that the electric power steering has entered an overheat protection state after prolonged or high-intensity operation. Under the overheat protection state, the assistance provided is significantly reduced and does not meet the requirements. Conversely, if the maximum value of the torque being searched does not exceed the set torque value, it means that after prolonged or high-intensity operation, the assistance provided by the electric power steering is still sufficient and meets the requirements.

[0333] Specifically, the set standard value can be determined as 10 Nm. That is, if the torque value corresponding to the selected angle position is greater than 10 Nm, it indicates that the overheat protection performance of the electric power steering does not meet the requirements, while if it does not exceed 10 Nm, it indicates that the overheat protection performance of the electric power steering meets the requirements.

[0334] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A steering system test bench, characterized in that, The steering system test bench (1) includes a steering gear mounting base (11), a first actuator mounting base (12), a column mounting base (13), and a second actuator mounting base (14). The steering gear mounting bracket (11) is used to mount the steering gear assembly (2); There are two first actuator mounting seats (12), and the two first actuator mounting seats (12) are respectively disposed on both sides of the steering gear mounting seat (11) in the first direction; each first actuator mounting seat (12) is provided with a first actuator (3), and the first actuator (3) is used to connect with the outer tie rod of the steering gear assembly (2) installed on the steering gear mounting seat (11); The column mounting base (13) is used to install the steering column assembly (4); The second actuator mounting base (14) is provided with a second actuator (5), which is used to connect to the input end of the steering column assembly (4) installed on the column mounting base (13) and to drive the input end of the steering column assembly (4) to rotate. The steering system test bench (1) also includes a base (10), the steering gear mounting seat (11), the first actuator mounting seat (12), and the column mounting seat (13) are movably connected to the base (10), and the second actuator mounting seat (14) is movably connected to the base (10) or fixed to the column mounting seat (13). The steering gear mounting base (11) includes a first seat body (111) for connecting to the base (10) and a second seat body (112) for connecting to the steering gear assembly (2). The first seat body (111) is slidably connected to the base (10) in a second direction; the second seat body (112) is slidably connected to the first seat body (111) in a vertical direction. The first actuator mounting base (12) includes a third seat (121) for connecting to the base (10) and a fourth seat (122) for connecting and mounting the first actuator (3). The third seat (121) is slidably connected to the base (10) in a first direction, and the fourth seat (122) is slidably connected to the third seat (121) in a second direction. The column mounting base (13) includes a fifth seat body (131) for connecting to the base (10) and a sixth seat body (132) for connecting and mounting the steering column assembly (4). The fifth seat body (131) is slidably connected to the base (10) in a first direction, and the sixth seat body (132) is slidably connected to the fifth seat body (131) in a second direction. The first direction and the second direction are two mutually perpendicular directions in the horizontal plane.

2. The steering system test bench according to claim 1, characterized in that, A rotating bracket (113) is provided on the steering gear mounting base (11), and a steering gear mounting clamp (114) is provided on the rotating bracket (113). The steering gear assembly (2) is mounted and fixed on the rotating bracket (113) through the steering gear mounting clamp (114).

3. The steering system test bench according to claim 1, characterized in that, The column mounting base (13) includes a column mounting bracket (133), and a column mounting clamp (134) is provided on the column mounting bracket (133). The steering column assembly (4) is fixedly connected to the column mounting bracket (133) through the column mounting clamp (134).

4. The steering system test bench according to claim 3, characterized in that, The column mounting base (13) also includes a base (135), a lifting mechanism (136), and a rotating mounting frame (137). The lifting mechanism (136) is mounted on the base (135); the rotating mounting bracket (137) is mounted on the lifting mechanism (136) and is driven by the lifting mechanism (136) to move vertically. The rotating mounting bracket (137) is rotatable relative to the lifting mechanism (136), and the column mounting bracket (133) is fixedly connected to the rotating mounting bracket (137).

5. A steering system testing device, characterized in that, The steering system testing equipment includes the steering system testing bench (1) as described in any one of claims 1 to 4, and also includes a data detection module and a data receiving and processing module (9). The data detection module includes at least one of an angle torque sensor (6) and a displacement sensor (7); The steering torque sensor (6) is connected between the second actuator (5) and the input end of the steering column assembly (4) to obtain the angle of the input end of the steering column assembly (4) and the torque at that angle; The displacement sensor (7) is used to detect the displacement of the end of the first actuator (3) connected to the outer tie rod of the steering assembly (2); The data receiving and processing module (9) is used to receive the data information collected by the data detection module, and to analyze and process the data information to obtain test results.

6. The steering system testing equipment according to claim 5, characterized in that, The displacement sensor (7) is a laser displacement sensor, which is mounted on the first actuator mounting base (12); The steering system test equipment also includes a reflector (71), which is disposed at the end of the first actuator (3) that is connected to the steering assembly (2).

7. The steering system testing equipment according to claim 5, characterized in that, The steering system testing equipment also includes a road spectrum input module (8), which is used to input preset road spectrum information to the first actuator (3).

8. A method for testing a steering system, characterized in that, The steering system testing method uses the steering system testing equipment described in any one of claims 5 to 7 to test the steering system to be tested.

9. The steering system testing method according to claim 8, characterized in that, The steering system test method is used to perform steering system friction tests; The steering system testing method includes: Step S11: Set the two first actuators (3) to zero thrust state, control the second actuator (5) to drive the input end of the steering column assembly to reciprocate within the set positive and negative stroke range, and have the angle and torque sensor (6) record the angle and torque information during the rotation process; Step S12: Select multiple angle positions and obtain the corresponding torque information.

10. The steering system testing method according to claim 9, characterized in that, In step S11, the starting point of rotation of the input end of the steering column assembly (4) is the midpoint of the input end; and / or The defined positive and negative travel intervals are the areas between 95% of the maximum travel from the midpoint to both ends; and / or The second actuator (5) controls the input end of the steering column assembly (4) to maintain a constant speed while rotating in the same direction.

11. The steering system testing method according to claim 9, characterized in that, Step S12 includes: Step S121: Based on the angle and torque information recorded by the angle torque sensor (6), establish an angle-force coordinate diagram with the angle information as the first coordinate and the torque information as the second coordinate. Step S122: Select multiple angular positions in the angle-force coordinate diagram and find the torque information corresponding to these multiple angular positions.

12. The steering system testing method according to claim 8, characterized in that, The steering system test method is used to test the rack travel and transmission ratio of the steering gear assembly (2); The steering system testing method includes: Step S21: Set the two first actuators (3) to zero thrust state, control the second actuator (5) to drive the input end of the steering column assembly (4) to reciprocate between the extreme positions at both ends, and the displacement sensor (7) detects the displacement stroke of the end of the first actuator (3) connected to the steering assembly (2). Step S22: Obtain the left limit stroke and right limit stroke based on the detection data of the displacement sensor (7), and obtain the rack stroke of the steering assembly (2) based on the left limit stroke and right limit stroke; and select multiple angle positions to obtain the corresponding displacement stroke information, and determine the transmission ratio of the steering assembly (2) at the corresponding point by differential calculation.

13. The steering system testing method according to claim 12, characterized in that, In step S21, the starting point of rotation of the input end of the steering column assembly (4) is the midpoint of the input end; and / or The second actuator (5) controls the input end of the steering column assembly (4) to maintain a constant speed while rotating in the same direction.

14. The steering system testing method according to claim 12, characterized in that, Step S22 includes: Step S221: Based on the angle and displacement travel recorded by the displacement sensor (7), establish an angle-travel coordinate diagram with the angle information as the first coordinate and the displacement travel as the second coordinate. Step S222: Select multiple angular positions in the angle-stroke coordinate graph and find the displacement stroke information corresponding to these multiple angular positions; Step S223: Determine the transmission ratio of the steering gear assembly (2) at the corresponding point by differential calculation.

15. The steering system testing method according to claim 8, characterized in that, The steering system testing method is used to test the stiffness and clearance of the steering system; The steering system testing method includes: Step S31: Set the ends of the two first actuators (3) connected to the steering assembly (2) to a fixed state, and control the second actuator (5) to drive the input end of the steering column assembly (4) to rotate between the angle position corresponding to the set maximum positive torque and the angle position corresponding to the set maximum negative torque. Step S32: Select a torque value, obtain the angular position when the positive torque reaches the torque value, and the angular position when the negative torque reaches the torque value, and determine the steering system clearance based on these two angular positions; and Select the starting and ending angles of the center sections for positive and negative torques, obtain the corresponding torque values, and determine the steering stiffness of the center sections based on these torque values; and Select the starting and ending angles of the non-central section for positive and negative torques, obtain the corresponding torque values, and determine the steering stiffness of the non-central section based on the torque values.

16. The steering system testing method according to claim 15, characterized in that, In step S31, the maximum positive torque is 30 Nm, the maximum negative torque is -30 Nm; and / or In step S31, the starting point of rotation of the input end of the steering column assembly (4) is the midpoint of the input end; and / or The second actuator (5) controls the input end of the steering column assembly (4) to maintain a constant speed while rotating in the same direction.

17. The steering system testing method according to claim 15, characterized in that, Step S32 includes: Step S321: Based on the angle and torque information recorded by the angle torque sensor (6), establish an angle-force coordinate diagram with the angle information as the first coordinate and the torque information as the second coordinate. Step S322: Select a torque value in the angle-force coordinate diagram, and find the positive and negative angular positions corresponding to the selected torque value; and Determine the starting and ending angles of the central segments of the positive and negative moments in the angle-force coordinate diagram, and find the corresponding moment values; and Determine the starting and ending angles of the non-central sections of the positive and negative torques in the angle-force coordinate diagram, and find the corresponding torque values; Step S323: Calculate and determine the steering system clearance based on the found positive and negative angular positions; and Based on the torque values ​​of the central sections of the positive and negative torques found, according to the formula: Determine the steering stiffness of the center sections for both positive and negative moments; and Based on the torque values ​​of the non-central sections of the positive and negative torques found, according to the formula: Determine the steering stiffness of the non-central section for both positive and negative moments; in, - Stiffness of the central section; -Stiffness of non-central sections; - The torque value at the starting angle of the central section; - The torque value at the termination angle of the central section; - The torque value at the starting angle of the non-central section; - The torque value at the termination angle of the non-central section; - The starting angle of the central section; - The termination angle of the central section; - The starting angle of the non-central section; - Termination angle of non-central sections.

18. The steering system testing method according to claim 8, characterized in that, The steering system test method is used to test the maximum output rack force of the electric power steering system. The steering system testing method includes: Step S41: Set one of the first actuators (3) to a zero thrust state, and set the other end of the first actuator (3) connected to the steering gear assembly (2) to a fixed state; control the second actuator (5) to drive the input end of the steering column assembly (4) to rotate from the center position in one direction until the set maximum positive torque is reached; and rotate in the other direction until the set maximum negative torque is reached; and record the thrust applied by the first actuator (3) whose end connected to the steering gear assembly (2) is set to a fixed state during this process; Step S42: Determine the thrust applied by the first actuator (3) when the maximum positive torque and the maximum negative torque are reached, and determine the maximum output rack force of the electric power steering system based on the magnitude of the thrust found.

19. The steering system testing method according to claim 18, characterized in that, In step S41, the starting point of rotation of the input end of the steering column assembly (4) is the midpoint of the input end; and / or The maximum positive torque is 10 Nm, and the maximum negative torque is -10 Nm; and / or The second actuator (5) controls the input end of the steering column assembly (4) to maintain a constant speed while rotating in the same direction.

20. The steering system testing method according to claim 18, characterized in that, Step S42 includes: Step S421: Based on the torque information recorded by the angle torque sensor (6) and the thrust data information applied by the first actuator (3), a torque-thrust coordinate diagram is established with the torque information as the first coordinate and the thrust information as the second coordinate. Step S422: Locate the thrust data corresponding to the positions of the maximum positive torque and the maximum negative torque in the torque-thrust coordinate graph; Step S423: Calculate the average value of the found thrust data as the maximum output rack force of the electric power steering system.

21. The steering system testing method according to claim 8, characterized in that, The steering system test method is used to test the catch-up characteristics of electric power steering; The steering system testing method includes: Step S51, execute the first simulated working condition. Under the first simulated working condition, the two first actuators (3) jointly apply the first thrust to the steering gear assembly (2), and the second actuator drives the input end of the steering column assembly (4) to rotate in the set positive and negative stroke range according to the first rotation speed; and the angle and torque sensor records the angle and torque information during the rotation process. Step S52: Compare the maximum torque recorded by the angle torque sensor (6) with the set torque value. If the maximum torque recorded by the angle torque sensor (6) exceeds the set torque value, it indicates that the catch-up characteristic under the first simulated working condition does not meet the requirements. If the maximum torque recorded by the angle torque sensor (6) does not exceed the set torque value, it indicates that the catch-up characteristic under the first simulated working condition meets the requirements. Step S53: Following steps S51 to S52, execute the subsequent second to nth simulated working conditions respectively to determine whether the catch-up characteristics under the second to nth simulated working conditions meet the requirements; wherein, the first thrust decreases from the first thrust to the nth thrust, and the first rotation speed increases from the first rotation speed to the nth rotation speed.

22. The steering system testing method according to claim 21, characterized in that, In step S51, the electric power steering is set to an assist state at a vehicle speed of 0; and / or In step S51, the starting point of rotation of the input end of the steering column assembly (4) is the midpoint of the input end; after rotating to the endpoints of the positive and negative travel ranges, the input end of the steering column assembly (4) returns to the midpoint of the input end; and / or The defined positive and negative travel intervals are the areas between 90% of the maximum travel from the midpoint to both ends; and / or The second actuator (5) controls the input end of the steering column assembly (4) to maintain a constant speed while rotating in the same direction.

23. The steering system testing method according to claim 21, characterized in that, The ratio of the first thrust to the maximum rack force of the steering system under static conditions is 95%, and the first rotational speed is 180° / s; The ratio of the nth thrust to the maximum rack force of the steering system under static conditions is 50%, and the nth rotational speed is 600° / s.

24. The steering system testing method according to claim 8, characterized in that, The steering system testing method is used to test the overheat protection performance of electric power steering; and the steering system testing method is based on the steering system testing equipment described in claim 7; The steering system testing method includes: Step S61: Control the second actuator (5) to drive the input end of the steering column assembly (4) to reciprocate between the extreme positions at both ends, and the angle torque sensor (6) records the angle and torque information during the rotation process; and during the rotation process, the first actuator (3) adjusts the thrust applied to the steering assembly (2) in response to the preset road spectrum information provided by the road spectrum input module (8); Step S62: Based on the angle and torque information recorded by the steering torque sensor (6), select an angle position and find the torque value corresponding to the selected angle position during the rotation of the input end of the steering column assembly (4). Step S63: Compare the determined torque value with the set standard value. If it exceeds the set standard value, it indicates that the overheat protection performance of the electric power steering does not meet the requirements. If it does not exceed the set standard value, it indicates that the overheat protection performance of the electric power steering meets the requirements.

25. The steering system testing method according to claim 24, characterized in that, In step S61, the second actuator (5) drives the input end of the steering column assembly (4) to rotate multiple cycles, each cycle including: rotating from the middle position of the input end toward the first end direction to the limit position, and rotating toward the second end direction to the limit position; rotating from the limit position in the second end direction toward the first end direction to the limit position and holding for a predetermined time; rotating from the limit position in the first end direction toward the second end direction to the limit position and holding for a predetermined time; rotating from the limit position in the second end direction to the middle position of the input end; and / or The second actuator (5) controls the input end of the steering column assembly (4) to maintain a constant speed while rotating in the same direction.

26. The steering system testing method according to claim 24, characterized in that, Step S62 includes: Step S621: Based on the angle and torque information recorded by the angle torque sensor (6) during the rotation process, establish an angle-force coordinate diagram with the angle information as the first coordinate and the torque information as the second coordinate. Step S622: Select an angle position in the angle-force coordinate diagram and find the torque information corresponding to each rotation to the selected angle position.

27. The steering system testing method according to claim 24, characterized in that, In step S62, the selected angular position is 95% of the extreme positions of the first end direction and the second end direction; and / or The set standard value is determined to be 10 Nm.

28. The steering system testing method according to claim 24, characterized in that, In step S63, the maximum value among the multiple torque values ​​corresponding to the selected angular position is compared with a set standard value, or the torque value corresponding to the last rotation to the selected angular position is compared with a set standard value. Based on the comparison results, it was determined whether the overheat protection performance of the electric power steering met the requirements.

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