Steering system test bench, steering system test equipment and steering system test method

Abstract

The invention relates to a steering system test bench, a steering system test device and a steering system test method. The steering system test bench comprises a steering gear mounting seat, a first actuator mounting seat, a tubular column mounting seat and a second actuator mounting seat. The steering gear mounting seat is used for mounting a steering gear assembly; the number of the first actuator mounting bases is two, and the two first actuator mounting bases are arranged on the two sides of the steering gear mounting base in the first direction correspondingly. A first actuator is arranged on each first actuator mounting seat, and the first actuators are used for being connected with an outer pull rod of a steering gear assembly mounted on the steering gear mounting seat; the tubular column mounting seat is used for mounting a steering tubular column assembly; a second actuator is arranged on the second actuator mounting seat, and the second actuator is used for being connected with the input end of a steering column assembly mounted on the column mounting seat and used for driving the input end of the steering column assembly to rotate. The steering system test bench can test more items and performance parameters.

Description

Technical Field

[0001] The invention relates to the field of vehicle steering system testing, and in particular to a steering system testing bench, steering system testing equipment and a method. Background Art

[0002] The steering system is an important part of the vehicle. During or after the development of the vehicle steering system, it is necessary to test the specific performance of the steering system. The existing testing devices and equipment for vehicle steering systems can only test and verify limited items, which is difficult to meet the needs of testing the performance of the steering system during vehicle development. Summary of the invention

[0003] One of the purposes of the present invention is to provide a steering system test bench to solve the problem that the prior art cannot support the testing of more test items of the steering system. The second purpose of the present invention is to provide a steering system test device. The third purpose of the present invention is to provide a steering system test method.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] A steering system test bench comprises a steering gear mounting seat, a first actuator mounting seat, a column mounting seat and a second actuator mounting seat; the steering gear mounting seat is used to mount a steering gear assembly; there are two first actuator mounting seats, and the two first actuator mounting seats are respectively arranged on both sides of the steering gear mounting seat in a first direction; each first actuator mounting seat is provided with a first actuator, and the first actuator is used to be connected to an outer tie rod of the steering gear assembly installed on the steering gear mounting seat; the column mounting seat is used to mount a steering column assembly; the second actuator mounting seat is provided with a second actuator, and the second actuator is used to be connected to an input end of the steering column assembly installed on the column mounting seat, and is used to drive the input end of the steering column assembly to rotate.

[0006] According to the above technical scheme, through the steering gear mounting seat, the first actuator mounting seat, the column mounting seat and the second actuator mounting seat, a scene of a steering system similar to that on an actual vehicle can be simulated, and the various parts of the steering system to be tested are respectively installed on the steering gear mounting seat, the first actuator mounting seat, the column mounting seat and the second actuator mounting seat. When the performance test of the steering system to be tested is carried out, the restrictions and constraints it is subject to are relatively small, and more items and performance parameters can be tested. The steering system test bench in the present invention can simulate the layout of the steering system of an actual vehicle, can test the steering system with and without power assistance, can fully cover the parameter testing requirements for the development of the steering performance of the whole vehicle, and can conduct a preliminary test on the performance parameters of the steering system in the early stage of the whole vehicle project development, thereby improving the efficiency of policy steering performance development verification and shortening the whole vehicle development cycle.

[0007] Furthermore, the steering system test bench also includes a base, the steering gear mounting seat, the first actuator mounting seat, and the column mounting seat are movably connected to the base, 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 seat, the first actuator mounting seat, the column mounting seat and the second actuator mounting seat are all arranged on the base, and can form a whole with each other, which is convenient for overall movement, installation, disassembly, etc.; they can better maintain their relative positions with each other during movement, installation and disassembly, without the need to adjust their relative positions with each other after completing the movement, installation and disassembly.

[0009] Furthermore, the steering gear mounting seat includes a first seat body used to be connected to the base and a second seat body used to connect and install the steering gear assembly, the first seat body and the base are slidably connected in the second direction; the second seat body and the first seat body are slidably connected in the vertical direction; the first actuator mounting seat includes a third seat body used to be connected to the base and a fourth seat body used to connect and install the first actuator, the third seat body and the base are slidably connected in the first direction, and the fourth seat body and the third seat body are slidably connected in the second direction; the column mounting seat includes a fifth seat body used to be connected to the base and a sixth seat body used to connect and install the steering column assembly, the fifth seat body and the base are slidably connected in the first direction, and the sixth seat body and the fifth seat body are slidably connected in the second direction; the first direction and the second direction are two directions perpendicular to each other in the horizontal plane.

[0010] According to the above technical solution, by adjusting the positions of the second seat body, the fourth seat body, and the sixth seat body in various dimensions, the relative positions among the steering gear assembly, the first actuator, and the steering column assembly can be changed, thereby making it possible to make the steering gear assembly, the first actuator, and the steering column assembly have diversified and different relative position relationships, thereby meeting the needs of performance testing of various steering systems to be tested.

[0011] Furthermore, a rotating bracket is provided on the steering gear mounting seat, a steering gear mounting fixture is provided on the rotating bracket, and the steering gear assembly is mounted and fixed on the rotating bracket through the steering gear mounting fixture.

[0012] According to the above technical solution, by setting a rotating bracket, when the steering gear assembly is installed on the steering gear mounting seat, the steering gear assembly can also be rotated with the help of the rotating bracket to change the angle of the steering gear assembly, so as to adjust the posture of the steering gear assembly in a more diversified way, so as to better match the state of the steering gear assembly in the actual vehicle. At the same time, a steering gear mounting fixture is also provided, and with the help of the steering gear mounting fixture, the steering gear assembly is installed and fixed on the rotating bracket. In this way, there is an intermediate structure between the steering gear assembly and the rotating bracket, and the intermediate structure is more convenient to replace. Reflected in the actual scenario of testing different steering gear assemblies, it is only necessary to replace the steering gear mounting fixtures of different specifications to install and fix different steering gear assemblies on the rotating bracket, without the need to replace another rotating bracket or other larger components as a whole.

[0013] Furthermore, the column mounting seat includes a column mounting bracket, a column mounting fixture is provided on the column mounting bracket, and the steering column assembly is fixedly connected to the column mounting bracket via the column mounting fixture.

[0014] According to the above technical solution, the steering column assembly is fixedly mounted on the column mounting bracket through the steering gear mounting fixture. Such a setting is consistent with the above steering gear mounting fixture, and an intermediate structure is formed between the steering column assembly and the column mounting bracket, which is more convenient for replacement. In the actual scenario of testing different steering column assemblies, different steering column assemblies can be installed and fixed to the column mounting bracket by only replacing column mounting fixtures of different specifications, without the need to replace another column mounting bracket or other larger components as a whole.

[0015] Furthermore, the pipe column mounting seat also includes a base, a lifting mechanism and a rotating mounting frame; the lifting mechanism is arranged on the base; the rotating mounting frame is arranged on the lifting mechanism, and is used to be driven by the lifting mechanism to perform lifting and lowering movements in the vertical direction, and the rotating mounting frame is rotatable relative to the lifting mechanism, and the pipe 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 installed 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 installed on the steering column bracket can be adjusted by rotating the mounting frame, so that the posture of the steering column assembly can be adjusted in more dimensions, and the specific scenarios of the steering system on more vehicles can be simulated, and the simulation can be more realistic, so as to better meet the diverse and different needs for testing different steering systems.

[0017] A steering system test device comprises the above-mentioned steering system test bench, and also comprises a data detection module and a data receiving and processing module; the data detection module comprises at least one of an angular torque sensor and a displacement sensor; the angular torque sensor is connected between the second actuator and the input end of the steering column assembly, and is used to obtain the angle of the input end of the steering column assembly and the torque at the angle; the displacement sensor is used to detect the displacement of one end of the first actuator connected to the outer tie rod of the steering gear assembly; the data receiving and processing module is used to receive the data information collected by the data detection module, and analyze and process the data information to obtain the test result.

[0018] According to the above technical solution, when the steering gear assembly and the 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 the steering column assembly respectively for testing, the angular torque sensor can detect the angle of the input end of the steering column assembly and the torque at the angle, and the displacement sensor can detect the displacement of the outer tie rod of the steering gear assembly. The data obtained by these tests can be processed at the data receiving and processing module to obtain corresponding processing results, which reflect the analysis, evaluation and judgment of the performance of the steering system, that is, the results of testing the performance of the steering system.

[0019] Furthermore, the displacement sensor is a laser displacement sensor, which is arranged on the first actuator mounting seat; the steering system testing equipment also includes a reflective plate, which is arranged at one end of the first actuator connected to the steering gear 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 toward the reflector and receiving the laser reflected by the reflector. The detection process is convenient and quick.

[0021] Furthermore, the steering system testing device also includes a road spectrum input module, and the road spectrum input module 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, and the first actuator can dynamically adjust the thrust applied to the outer tie rod of the steering gear assembly according to the preset road spectrum information. In this way, the real scene of driving on the road can be simulated, and the results of the performance test of the steering system will be more realistic and accurate.

[0023] A steering system testing method utilizes the above-mentioned steering system testing equipment to test a steering system to be tested.

[0024] According to the above technical solution, the above steering system test equipment can be used to test a steering system to be tested in a plurality of test items, thereby better meeting the requirements for 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 comprises:

[0026] Step S11, setting the two first actuators in a zero thrust state, controlling the second actuator to drive the input end of the steering column assembly to reciprocate in a set positive and negative stroke range, and the angular torque sensor records the angle and torque information during the rotation process;

[0027] Step S12, selecting multiple angle positions and obtaining corresponding torque information.

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

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

[0030] The set positive and negative stroke interval is the area between 95% positions of the maximum stroke from the middle position to both ends; and / or

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

[0032] According to the above technical solution, it is helpful to make the test result of the steering system friction test performed on the steering system to be tested more real and accurate.

[0033] Furthermore, the step S12 includes:

[0034] Step S121, establishing an angle-force coordinate diagram according to the angle and torque information recorded by the rotation angle torque sensor, with the angle information as the first coordinate and the torque information as the second coordinate;

[0035] Step S122, selecting a plurality of angle positions in the angle-force coordinate diagram, and searching for torque information corresponding to the plurality of angle 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 angle positions; it is easier and more convenient to find the torque information corresponding to the selected multiple angle positions.

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

[0038] Step S21, setting the two first actuators in a zero thrust state, controlling the second actuator to drive the input end of the steering column assembly to reciprocate between the extreme positions at both ends, and using a displacement sensor to detect the displacement stroke of one end of the first actuator connected to the steering gear assembly;

[0039] Step S22, obtaining the left limit stroke and the right limit stroke according to the detection data of the displacement sensor, and obtaining the rack stroke of the steering gear assembly according to the left limit stroke and the right limit stroke; and, selecting multiple angular positions, obtaining the corresponding displacement stroke information, and determining the transmission ratio of the steering gear assembly at the corresponding point through differential calculation.

[0040] According to the above technical solution, the rack stroke and transmission ratio of the steering gear assembly can be tested for the steering system to be tested.

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

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

[0043] According to the above technical solution, it is helpful to make the test result of the rack stroke of the steering gear assembly, that is, the transmission ratio test, of the steering system to be tested more real and accurate.

[0044] Furthermore, the step S22 includes:

[0045] Step S221, establishing an angle-stroke coordinate diagram according to the angle and displacement stroke recorded by the displacement sensor, with the angle information as the first coordinate and the displacement stroke as the second coordinate;

[0046] Step S222, selecting a plurality of angle positions in the angle-stroke coordinate diagram, and searching for displacement stroke information corresponding to the plurality of angle positions;

[0047] Step S223, determining the transmission ratio of the steering gear assembly at the corresponding point by differential calculation.

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

[0049] Furthermore, the steering system testing method is used to perform a steering system stiffness and clearance test; the steering system testing method comprises:

[0050] Step S31, setting one end of the two first actuators connected to the steering gear assembly in a fixed state, and controlling the second actuator to drive the input end of the steering column assembly to rotate between an angle position corresponding to a set maximum positive torque and an angle position corresponding to a set maximum negative torque;

[0051] Step S32, selecting a torque value, obtaining an angular position when the positive torque reaches the torque value, and an angular position when the negative torque reaches the torque value, and determining a steering system clearance according to the two angular positions; and

[0052] Selecting a starting angle and an ending angle of a center section of a positive moment and a negative moment, obtaining corresponding moment values, and determining a steering stiffness of the center section according to the moment values; and

[0053] The starting angle and the ending angle of the non-center section of the positive moment and the negative moment are selected, the corresponding moment values ​​are obtained, and the steering stiffness of the non-center section is determined according to the moment values.

[0054] According to the above technical solution, the steering system to be tested can be subjected to a steering system stiffness and clearance test.

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

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

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

[0058] According to the above technical solution, it is helpful to make the test results of the steering system stiffness and clearance test performed on the steering system to be tested more real and accurate.

[0059] Further, the step S32 includes:

[0060] Step S321, establishing an angle-force coordinate diagram according to the angle and torque information recorded by the rotation angle torque sensor, with the angle information as the first coordinate and the torque information as the second coordinate;

[0061] Step S322, selecting a torque value in the angle-force coordinate diagram, and searching for a positive angle position and a negative angle position corresponding to the selected torque value; and

[0062] Determine the starting angle and ending angle of the center section of the positive moment and the negative moment in the angle-force coordinate diagram, and find the corresponding moment values; and

[0063] Determine the starting angle and ending angle of the non-central section of the positive moment and the negative moment in the angle-force coordinate diagram, and find the corresponding moment value;

[0064] Step S323, calculating and determining the steering system clearance according to the found positive angular position and negative angular position; and

[0065] According to the moment value of the central section of the positive moment and negative moment found, according to the formula:

[0066]

[0067] Determining the steering stiffness of the center section for positive and negative moments; and

[0068] According to the moment values ​​of the non-central section of the positive moment and negative moment found, according to the formula:

[0069]

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

[0071] Where, G1 is the stiffness of the central section; G2 is the stiffness of the non-central section; T A -T - the torque value of the starting angle of the center section; B-T - torque value of the end angle of the central section; C - the torque value of the starting angle of the non-central segment; T D - the torque value of the end angle of the non-central section; a A - the starting angle of the central section; a B - the end angle of the central section; a C - the starting angle of the non-central segment; a D - The ending angle of the non-center segment.

[0072] According to the above technical solution, the steering stiffness of the central section for positive torque and negative torque, and the steering stiffness of the non-central section for positive torque and negative torque can be obtained.

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

[0074] Step S41, setting one of the first actuators in a zero thrust state, and setting one end of the other first actuator connected to the steering gear assembly in a fixed state; controlling the second actuator to drive the input end of the steering column assembly to rotate from the neutral position in one direction until a set maximum positive torque is reached; and to rotate in the other direction until a set maximum negative torque is reached; and in the process, recording the thrust applied by the first actuator whose end connected to the steering gear assembly is set in a fixed state;

[0075] Step S42, determining the thrust applied by the first actuator when the maximum positive torque and the maximum negative torque are present, and determining the maximum output rack force of the electric power steering system according to the magnitude of the thrust found.

[0076] According to 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 the step S41, the rotation starting point of the input end of the steering column assembly is the middle position 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 during the process of rotating in the same direction.

[0080] According to the above technical solution, it is helpful to make the test result of the maximum output rack force of the electric power steering system of the steering system to be tested more real and accurate.

[0081] Further, the step S42 includes:

[0082] Step S421, establishing a torque-thrust coordinate diagram with the torque information as the first coordinate and the thrust information as the second coordinate according to the torque information recorded by the rotation angle torque sensor and the recorded thrust data information applied by the first actuator;

[0083] Step S422, searching the thrust data corresponding to the positions of the maximum positive torque and the maximum negative torque in the torque-thrust coordinate diagram;

[0084] Step S423, calculating the average value of the thrust data found out 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 corresponding relationship between the torque and thrust at the same position can be clearly and intuitively displayed; thereby, 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 the electric power steering; the steering system testing method comprises:

[0087] Step S51, executing a first simulation working condition, under which 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 in a set positive and negative stroke range at a first rotation speed; and the angular torque sensor records angle and torque information during the rotation process;

[0088] Step S52, comparing the maximum torque recorded by the angular torque sensor with the set torque value. If the maximum torque recorded by the angular 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 angular 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, according to steps S51-S52, respectively execute the subsequent second to nth simulation conditions to determine whether the catch up characteristics under the second to nth simulation conditions meet the requirements; wherein, the first thrust to the nth thrust decreases, and the first rotation speed to the nth rotation speed increases.

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

[0091] Further, in step S51, the electric power steering is set in a power-assisted state when the vehicle speed is 0; and / or

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

[0093] The set positive and negative stroke interval is the area between 90% positions of the maximum stroke from the middle position to both ends; and / or

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

[0095] According to the above technical solution, it is helpful to make the test result of the catch up characteristic of the electric power steering of the steering system to be tested more real and accurate.

[0096] Further, the ratio of the first thrust to the maximum rack force of the steering system in a static state is 95%, and the first rotation speed is 180° / s;

[0097] The ratio of the nth thrust to the maximum rack force of the steering system in a static state is 50%, and the nth rotation speed is 600° / s.

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

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

[0100] Step S61, controlling the second actuator to drive the input end of the steering column assembly to reciprocate between the extreme positions at both ends, and the angular torque sensor records the angle and torque information during the rotation process; and during the rotation process, the first actuator responds to the preset road spectrum information provided by the road spectrum input module and correspondingly adjusts the thrust applied to the steering gear assembly;

[0101] Step S62, selecting an angle position according to the angle and torque information recorded by the angular torque sensor, and searching and determining a torque value corresponding to the selected angle position during the rotation of the input end of the steering column assembly;

[0102] Step S63, comparing the torque value found and determined 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] According to the above technical solution, the overheat protection performance of the electric power steering can be tested on the steering system to be tested.

[0104] Further, in step S61, the second actuator drives the input end of the steering column assembly to rotate for multiple cycles, each of which includes: rotating from the middle position of the input end to the first end direction to the extreme position, and rotating to the second end direction to the extreme position; rotating from the extreme position in the second end direction to the first end direction to the extreme position, and maintaining for a predetermined time; rotating from the extreme position in the first end direction to the second end direction to the extreme position, and maintaining for a predetermined time; rotating from the extreme position in the second end direction to the middle 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 during the process of rotating in the same direction.

[0106] According to the above technical solution, it is helpful to make the test result of the overheat protection performance of the electric power steering of the steering system to be tested more real and accurate.

[0107] Further, the step S62 includes:

[0108] Step S621, establishing an angle-force coordinate diagram according to the angle and torque information recorded by the rotation angle torque sensor during the rotation process, with the angle information as the first coordinate and the torque information as the second coordinate;

[0109] Step S622, selecting an angle position in the angle-force coordinate diagram, and searching for torque information corresponding to each rotation to the selected angle position.

[0110] According to the above technical solution, an angle-force coordinate diagram is first established, so that the torque at different angle positions can be clearly and intuitively displayed; it is easier and more convenient to find the torque information corresponding to the selected angle position.

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

[0112] The standard value of the setting is determined to be 10 Nm.

[0113] According to the above technical solution, the standard for testing the overheat protection performance of the electric power steering is more in line with the actual vehicle scenario.

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

[0115] According to the above technical solution, the maximum value of multiple torques is compared with the set standard value, or the torque value corresponding to the last rotation to the selected angle position is regarded as the maximum value and compared with the set standard value. The test result of the overheating protection performance of the electric power steering will be more accurate.

[0116] Beneficial effects of the present invention:

[0117] The steering system test bench, steering system test equipment and method provided by the present invention can simulate a steering system scenario similar to that on an actual vehicle through a steering gear mounting seat, a first actuator mounting seat, a column mounting seat and a second actuator mounting seat, and the various parts of the steering system to be tested are respectively installed on the steering gear mounting seat, the first actuator mounting seat, the column mounting seat and the second actuator mounting seat. When the steering system to be tested is subjected to performance testing, the restrictions and constraints are small, and more items and performance parameters can be tested. Specifically, it can include steering system friction testing, rack travel and transmission ratio testing of steering gear assembly, steering system stiffness and clearance testing, maximum output rack force of electric power steering system, catch up characteristics of electric power steering, overheat protection performance of electric power steering, etc.

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

[0119] In short, the present invention can simulate the layout of the steering system of an actual vehicle, can perform power-assisted and non-power-assisted working condition tests on the steering system, can fully cover the parameter testing requirements for the development of the steering performance of the entire vehicle, and can perform a basic test on the performance parameters of the steering system in the early stage of the development of the entire vehicle project, thereby improving the efficiency of policy steering performance development and verification and shortening the entire vehicle development cycle. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0121] Figure 2 for Figure 1 The structural schematic diagram of the steering system test bench shown in the figure hides the steering mounting seat;

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

[0124] Figure 5 for Figure 1 A schematic diagram of the structure of a column mounting seat, a second actuator mounting seat, a steering column assembly installed thereon, and a second actuator in a steering system test bench;

[0125] Figure 6 A schematic diagram of a steering system testing device according to an embodiment of the present invention;

[0126] Figure 7 for Figure 6 A schematic diagram of the process of performing a steering system friction test on a steering system test device shown;

[0127] Figure 8 for Figure 6 A schematic diagram of the process of the steering system test equipment for performing the rack formation and transmission ratio test of the steering gear assembly;

[0128] Fig. 9 for Figure 6 A schematic diagram of the process of performing a steering system stiffness and clearance test on a steering system test device shown;

[0129] Fig.10 for Fig. 9 Specific flow diagram of step S32;

[0130] Fig.11 for Figure 6 The steering system test equipment shown is a schematic diagram of the process of testing the maximum output rack force of the electric power steering system;

[0131] Fig.12 for Figure 6 A schematic diagram of a process of performing a catch up characteristic test of an electric power steering using a steering system test device shown;

[0132] Fig.13 for Figure 6 The steering system test equipment shown is a schematic diagram of the process of conducting overheat protection performance test of electric power steering.

[0133] in:

[0134] 1- Steering system test bench;

[0135] 10- base;

[0136] 11-steering gear mounting seat; 111-first seat body; 112-second seat body; 113-rotating bracket; 114-steering gear mounting fixture;

[0137] 12-first actuator mounting seat; 121-third seat body; 122-fourth seat body;

[0138] 13- column mounting seat; 131- fifth seat body; 132- sixth seat body; 133- column mounting bracket; 134- column mounting fixture; 135- base; 136- lifting mechanism; 137- rotating mounting frame;

[0139] 14- second actuator mounting seat;

[0140] 2- Steering gear assembly;

[0141] 3-first actuator; 31-connection end;

[0142] 4-steering column assembly; 41-intermediate shaft assembly;

[0143] 5-second actuator; 51-coupling;

[0144] 6- Angular torque sensor;

[0145] 7-displacement sensor; 71-reflection plate;

[0146] 8-channel spectrum input module;

[0147] 9-data receiving and processing module; 91-multi-channel data acquisition device; 92-computer; 93-first power supply. DETAILED DESCRIPTION

[0148] The following will describe the embodiments of the present invention 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 contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways 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, 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 illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0150] In one embodiment of the steering system test bench of the present invention, Figure 1 to Figure 6 As shown, the steering system test bench 1 includes a steering gear mounting seat 11, a first actuator mounting seat 12, a column mounting seat 13 and a second actuator mounting seat 14; the steering gear mounting seat 11 is used to mount the steering gear assembly 2; the number of the first actuator mounting seats 12 is two, and the two first actuator mounting seats 12 are respectively arranged 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 be connected to the outer tie rod of the steering gear assembly 2 installed on the steering gear mounting seat 11; the column mounting seat 13 is used to mount the steering column assembly 4; the second actuator mounting seat 14 is provided with a second actuator 5, and the second actuator 5 is used to be connected to the input end of the steering column assembly 4 installed on the column mounting seat 13, and is used to drive the input end of the steering column assembly 4 to rotate.

[0151] In this embodiment, the steering gear assembly 2 is mounted on the steering gear mounting seat 11, and the first actuators 3 are mounted on the two first actuator mounting seats 12 respectively. The connection end 31 of the first actuator 3 is connected to the outer tie rod of the steering gear assembly 2. The first actuator 3 can apply a force to the outer tie rod of the steering gear assembly 2 through its connection end 31. The force can be expressed as an inward thrust (toward the steering gear assembly 2) or an outward pulling force (away from the steering gear assembly 2). For the convenience of description, it is generally referred to as thrust in the subsequent description. The first actuators 3 on both sides of the steering gear assembly 2 can be used to simulate the wheels connected to the steering gear assembly 2 on an actual vehicle. The force applied to the steering gear assembly 2 is equivalent to the force applied by the wheels on the steering gear assembly 2 in an actual vehicle.

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

[0153] Based on the above description, in this embodiment, through the steering gear mounting seat 11, the first actuator mounting seat 12, the column mounting seat 13 and the second actuator mounting seat 14, a steering system scenario similar to that on an actual vehicle can be simulated, and the various parts of the steering system to be tested are respectively installed 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 the performance test of the steering system to be tested is carried out, the restrictions and constraints it is subject to are relatively small, and more items and performance parameters can be tested. The steering system test bench in this embodiment can simulate the layout of the steering system of the actual vehicle, can test the steering system with and without power assistance, can fully cover the parameter testing requirements for the development of the steering performance of the whole vehicle, and can conduct a preliminary test on the performance parameters of the steering system in the early stage of the whole vehicle project development, thereby improving the efficiency of policy steering performance development verification and shortening the whole vehicle development cycle.

[0154] In one embodiment of the steering system test bench, 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.

[0155] In this embodiment, the steering gear mounting seat 11, the first actuator mounting seat 12, the column mounting seat 13 and the second actuator mounting seat 14 are all arranged on the base 10, and can form a whole with each other, which is convenient for overall movement, installation, disassembly, etc.; they can better maintain their relative positions with each other during movement, installation, and disassembly, without the need to adjust their relative positions with each other after completing the movement, installation, and disassembly.

[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, and the movement can be specifically manifested as sliding, etc. Figure 1 and Figure 2 As shown, a slide groove is provided on the base 10, and slide rails are provided on the steering gear mounting seat 11, the first actuator mounting seat 12, and the column mounting seat 13, respectively, so that they can move along the slide groove relative to the base 10. 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 respectively, thereby facilitating performance testing of different steering systems.

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

[0158] When the second actuator mounting seat 14 is movably connected to the base 10, it is similar to the above-mentioned steering gear mounting seat 11, the first actuator mounting seat 12, and the column mounting seat 13, and will not be described in detail; however, it should be noted that since the second actuator 5 installed on the second actuator mounting seat 14 needs to be connected to the input end of the steering column assembly 4 installed on the column mounting seat 13, in order to meet this requirement, the column mounting seat 13 and the second actuator mounting seat 14 independently arranged on the base 10 must maintain a relatively fixed position relationship. When the relative position relationship between the two is initially established or a deviation occurs 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 position 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 on the base 10 as a whole without changing their relative position relationship. Figure 1 and Figure 5 As shown, in the subsequent description, the second actuator mounting seat 14 is fixed on the column mounting seat 13 as an example for explanation, and the situation that the second actuator mounting seat 14 is independently arranged on the base 10 is not repeated.

[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 ±10 mm. 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, which helps to reduce the radial force when the interaction force is generated between the two.

[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 is subjected to is small.

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

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

[0163] In this embodiment, by adjusting the positions of the second seat body 112, the fourth seat body 122, and the sixth seat body 132 in various dimensions, the relative positions among the steering gear assembly 2, the first actuator 3, and the steering column assembly 4 can be changed, so that the steering gear assembly 2, the first actuator 3, and the steering column assembly 4 can have diverse and different relative position relationships, thereby meeting the needs of performance testing of various steering systems to be tested.

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

[0165] In this embodiment, by providing a rotating bracket 113, when the steering gear assembly 2 is installed on the steering gear mounting seat 11, the steering gear assembly 2 can also be rotated with the help of the rotating bracket 113 to change the angle of the steering gear assembly 2, thereby adjusting the posture of the steering gear assembly 2 in a more diverse manner so as to better match the state of the steering gear assembly 2 in the actual vehicle.

[0166] In this embodiment, a steering gear installation fixture 114 is also provided, and the steering gear installation fixture 114 is used to realize the installation and fixation of the steering gear assembly 2 on the rotating bracket 113. In this way, there is an intermediate structure between the steering gear assembly 2 and the rotating bracket 113, and the intermediate structure is more convenient for replacement. In the actual scenario of testing different steering gear assemblies 2, it is only necessary to replace the steering gear installation fixtures 114 of different specifications to install and fix different steering gear assemblies 2 on the rotating bracket 113, without having to replace another rotating bracket 113 or other larger components as a whole.

[0167] In one embodiment of the steering system test bench, the column mounting seat 13 includes a column mounting bracket 133, and a column mounting fixture 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 fixture 134.

[0168] In this embodiment, the steering column assembly 4 is fixedly mounted on the column mounting bracket 133 through the steering gear mounting fixture 114. Such a setting is consistent with the above-mentioned steering gear mounting fixture 114, and an intermediate structure is formed between the steering column assembly 4 and the column mounting bracket 133, which is more convenient for replacement. In the actual scenario of testing different steering column assemblies 4, different steering column assemblies 4 can be installed and fixed on the column mounting bracket 133 by simply replacing column mounting fixtures 134 of different specifications, without having to replace another column mounting bracket 133 or other larger components as a whole.

[0169] In one embodiment of the steering system test bench, the column mounting seat 13 also includes a base 135, a lifting mechanism 136 and a rotating mounting frame 137; the lifting mechanism 136 is arranged on the base 135; the rotating mounting frame 137 is arranged on the lifting mechanism 136, and is used to be driven by the lifting mechanism 136 to perform lifting and lowering movements in the vertical direction, 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 installed 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 installed on the steering column bracket 133 can be adjusted by the rotating mounting bracket 137, so that the posture of the steering column assembly 4 can be adjusted in more dimensions, and more specific scenarios of the steering system on more vehicles can be simulated, and the simulation can be more realistic, so as to better meet the diverse and different needs for testing different steering systems.

[0171] In one embodiment of the steering system testing device of the present invention, Figure 6 As shown, the steering system test equipment includes the steering system test bench described in the above embodiment, and also includes a data detection module and a data receiving and processing module. The data detection module includes at least one of an angular torque sensor 6 and a displacement sensor 7. The angular torque sensor 6 is connected between the second actuator 5 and the input end of the steering column assembly 4, and is used to obtain the angle of the input end of the steering column assembly 4 and the torque at this angle. The displacement sensor 7 is used to detect the displacement of one 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, and analyze and process the data information to obtain the test results.

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

[0173] In this embodiment, the data receiving and processing module 9 may specifically include a multi-channel data collector 91 and a computer 92 . In addition, it may also include other devices such as a first power supply 93 for powering 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 angular torque sensor 6 can detect the angle of the input end of the steering column assembly 4 and the torque at the angle, and the displacement sensor 7 can detect the displacement of the outer tie rod of the steering gear assembly 2. The data obtained by these tests can be collected through the multi-channel data acquisition device 91 and obtained by the computer 92. The computer 92 is installed with corresponding processing software. With the help of the installed processing software, the computer 92 can process the received data and obtain corresponding processing results. These processing results reflect the analysis, evaluation and judgment of the performance of the steering system, that is, the results of testing the performance of the steering system.

[0175] In one embodiment of the steering system testing equipment, the displacement sensor 7 is a laser displacement sensor, and the laser displacement sensor is arranged on the first actuator mounting seat 12; the steering system testing equipment also includes a reflective plate 71, and the reflective plate 71 is arranged at one end of the first actuator 3 connected to the steering gear assembly 2, that is, arranged on the connecting end 31.

[0176] In this embodiment, the laser displacement sensor can detect the distance between the reflective plate 71 and the laser displacement sensor by emitting laser toward the reflective plate 71 and receiving the laser reflected by the reflective plate 71 , and the detection process is convenient and quick.

[0177] Since the connection end 31 of the first actuator 3 is always connected to the outer tie rod of the steering gear assembly 2, the reflection plate 71 provided on the connection end 31 and the outer tie rod of the steering gear assembly are consistent in spatial motion, therefore, the displacement between the reflection plate 71 and the laser displacement sensor is equivalent to the displacement of the outer tie rod of the steering gear assembly 2. The displacement of the reflection plate 71 detected by the laser displacement sensor is the displacement of the outer tie rod of the steering gear assembly 2.

[0178] In one embodiment of the steering system testing device, the steering system testing device further includes a road spectrum input module 8 , and the road spectrum input module 8 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 gear assembly 2 according to the preset road spectrum information. In this way, the real scene of driving on the road can be simulated, 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 utilizes the steering system testing equipment described in the above embodiment 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 performances of the steering system, such as steering system friction test, rack stroke and transmission ratio test of the steering gear assembly, steering system stiffness and clearance test, maximum output rack force test of the electric power steering system, catch up characteristic test of the electric power steering, overheat protection performance test of the electric power steering, etc.

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

[0183] Step S11, setting the two first actuators 3 in a zero thrust state, controlling the second actuator 5 to drive the input end of the steering column assembly 4 to reciprocate in a set positive and negative stroke range, and the angular torque sensor 6 records the angle and torque information during the rotation process.

[0184] In step S11, the first actuator 3 is set in a zero-thrust state, which means that the first actuator 3 does not apply any thrust to the outer tie rod of the steering gear assembly 2. The outer tie rod of the steering gear assembly 2 can remain stationary or can autonomously displace in the first direction without being subjected to the thrust applied by the first actuator 3 during the displacement.

[0185] In step S11, when the second actuator 5 drives the input end of the steering column assembly 4 to rotate, the rotation starting point 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 stroke intervals may specifically be the area between 95% positions of the maximum stroke from the middle position to both ends. For example, if the maximum stroke from the middle 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 to 475° from the middle position to the left, and then stops at this 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 during the process of 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, in the process of the second actuator 5 controlling the rotation of the input end of the steering column assembly 4, when it rotates to the stop points on the left and right sides (i.e., the end points of the positive and negative travel intervals), it is necessary to stop, turn, etc. At this time, the input end of the steering column assembly 4 will of course have a process of decelerating to zero and accelerating in the reverse direction, but the deceleration and acceleration process is short-lived. In the main rotation process after accelerating in the reverse direction to the target speed, and in the main rotation process before deceleration, the speed of the steering column assembly 4 does not change, but is maintained at the target speed for uniform rotation. Therefore, in this step S11, the rotation of the input end of the steering column assembly 4 is limited to uniform rotation, which means that the input end of the steering column assembly 4 maintains a uniform speed during the main rotation process.

[0189] Based on the above definition, in step S11, the specific process of the second actuator 5 driving the input end of the steering column assembly 4 to rotate may be:

[0190] First, the initial position of the input end of the steering column assembly 4 is adjusted to the middle position.

[0191] Afterwards, the second actuator 5 drives the input end of the steering column assembly 4 to move to the right (the stroke from the middle position to the right is the positive stroke, and correspondingly, the stroke from the middle position to the left is the negative stroke). In this process, the input end of the steering column assembly 4 will first undergo a short acceleration process to accelerate to a rotation speed of 45° / s; then maintain the speed unchanged and rotate at a constant speed until it rotates to the end point of the positive stroke interval, that is, 95% of the extreme position of rotation to the right; before reaching the end point of the positive stroke interval, the input end of the steering column assembly 4 undergoes a short deceleration process, the speed is reduced to 0, and stops at the end point of the positive stroke interval.

[0192] Afterwards, the second actuator 5 drives the input end of the steering column assembly 4 to move to the left. During the movement, the input end of the steering column assembly 4 undergoes a short acceleration process, accelerating to a rotation speed of 45° / s; then keeps the rotation speed constant and rotates at a constant speed, passes through the middle position and continues to rotate until it rotates to the end point of the negative travel interval, that is, 95% of the limit position of rotation to the left; before reaching the end point of the negative travel interval, the input end of the steering column assembly 4 undergoes a short deceleration process, the rotation speed is reduced to 0, and stops at the end point of the negative travel interval.

[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 short acceleration process to accelerate to a rotation speed of 45° / s; then maintain the rotation speed and rotate at a constant speed until it rotates to the middle position; before reaching the middle position, the input end of the steering column assembly 4 will undergo a short deceleration process, the rotation speed will be reduced to 0, and it will stop at the middle position.

[0194] During the above rotation process, the angular torque sensor 6 continuously records each position to which the input end of the steering column assembly 4 is rotated, and the torque applied by the second actuator 5 to the input end of the steering column assembly 4 when the input end of the steering column assembly 4 is rotated to each position.

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

[0196] Step S12, selecting multiple angle positions and obtaining corresponding torque information.

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

[0198] When analyzing and evaluating the steering system friction test, the evaluation results are given with reference to the torques at the multiple angle positions selected above.

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

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

[0201] Step S121, establishing an angle-force coordinate diagram according to the angle and torque information recorded by the angular torque sensor, with the angle information as the first coordinate and the torque information as the second coordinate.

[0202] Step S122, selecting a plurality of angle positions in the angle-force coordinate diagram, and searching for torque information corresponding to the plurality of angle positions.

[0203] In this specific embodiment, an angle-force coordinate diagram is first established, so that the torque at different angle positions can be clearly and intuitively displayed; it is easier and more convenient to find the torque information corresponding to the selected multiple angle positions.

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

[0205] Step S21, setting the two first actuators 3 in a zero thrust state, controlling 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 using the displacement sensor 7 to detect the displacement stroke of one end of the first actuator 3 connected to the steering gear assembly 2.

[0206] In step S21, the second actuator 5 drives the input end of the steering column assembly 4 to rotate, and the rotation starting point 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.

[0207] In step S21, the second actuator 5 controls the input end of the steering column assembly 4 to maintain a constant speed during the process of 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 consistent with the meaning of step S11, that is, the input end of the steering column assembly 4 maintains a uniform speed during the main rotation process.

[0209] Based on the above definition, in step S21, the specific process of the second actuator 5 driving the input end of the steering column assembly 4 to rotate may be:

[0210] First, the initial position of the input end of the steering column assembly 4 is adjusted to the middle position.

[0211] Afterwards, the second actuator 5 drives the input end of the steering column assembly 4 to move to the right (the stroke from the middle position to the right is the positive stroke, and correspondingly, the stroke from the middle position to the left is the negative stroke). In this process, the input end of the steering column assembly 4 will first undergo a short acceleration process to accelerate to a rotation speed of 45° / s; then maintain the rotation speed unchanged and rotate at a constant speed until it rotates to the extreme position in the right direction; before reaching the extreme position in the right direction, the input end of the steering column assembly 4 can undergo a short deceleration process, the rotation speed is reduced to 0, and stops at the extreme position in the right direction.

[0212] Afterwards, the second actuator 5 drives the input end of the steering column assembly 4 to move to the left. During the movement, the input end of the steering column assembly 4 undergoes a short acceleration process, accelerating to a rotation speed of 45° / s; then keeps the rotation speed constant and rotates at a constant speed, passes through the middle position and continues to rotate until it rotates to the extreme position in the left direction; before reaching the extreme position in the left direction, the input end of the steering column assembly 4 can undergo a short deceleration process, the rotation speed is reduced to 0, and stops 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 short acceleration process to accelerate to a rotation speed of 45° / s; then maintain the rotation speed and rotate at a constant speed until it rotates to the middle position; before reaching the middle position, the input end of the steering column assembly 4 will undergo a short deceleration process, the rotation speed will be reduced to 0, and it will stop at the middle position.

[0214] During the above rotation process, the rotation angle torque sensor 6 continuously records each position to which the input end of the steering column assembly 4 rotates, and the torque applied by the second actuator 5 to the input end of the steering column assembly 4 when the input end rotates to each position. The displacement sensor 7 continuously records the displacement of the outer tie rod of the steering gear assembly 2.

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

[0216] Step S22, obtaining the left limit stroke and the right limit stroke according to the detection data of the displacement sensor 7, and obtaining the rack stroke of the steering gear assembly 2 according to the left limit stroke and the right limit stroke; and, selecting multiple angular positions, obtaining the corresponding displacement stroke information, and determining the transmission ratio of the steering gear assembly 2 at the corresponding point through differential calculation.

[0217] In step S22, when the input end of the steering column assembly 4 rotates to the right and left to the limit position, the outer tie rod of the steering gear assembly 2 will be displaced to the right and left, and the displacement is the maximum, which is the right limit stroke and the left limit stroke. The rack stroke of the steering gear assembly 2 can be calculated according to the following formula:

[0218] y=y max -y min

[0219] It is obtained by performing mathematical operations on the right limit stroke and the left limit stroke.

[0220] Among them, y is the rack travel of the steering gear assembly 2, y max is the right limit travel, y min It is the left limit stroke.

[0221] In step S22, the angle position selected when determining the transmission ratio of the steering gear assembly 2 may be, for example, 20°, -20°, 90°, -90°, 180°, -180°, 360°, -360°, etc. When determining the transmission ratio of each angle position, the following formula may be used:

[0222]

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

[0224] Among them, ratio is the transmission ratio of the steering gear assembly 2, a is the angular position; y is the rack stroke of the steering gear assembly 2.

[0225] In a 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 , according to the angle and displacement stroke recorded by the displacement sensor 7 , an angle-stroke coordinate diagram is established with the angle information as the first coordinate and the displacement stroke as the second coordinate.

[0227] Step S222, selecting a plurality of angular positions in the angle-stroke coordinate diagram, and searching for displacement stroke information corresponding to the plurality of angular positions.

[0228] Step S223, determining the transmission ratio of the steering gear assembly 2 at the corresponding point by differential calculation.

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

[0230] When the steering system testing method of the present invention performs a steering system stiffness and clearance test, the steering system testing method includes the following steps S31-S32: Fig. 9 shown.

[0231] Step S31, setting one end of the two first actuators 3 connected to the steering gear assembly 2 in a fixed state, and controlling the second actuator 5 to drive the input end of the steering column assembly 4 to rotate between the angular position corresponding to the set maximum positive torque and the angular position corresponding to the set maximum negative torque.

[0232] In step S31, one end of the first actuator 3 connected to the steering gear assembly 2, i.e., the connecting end 31, is set in a fixed state, which means that the first actuator 3 applies a thrust to the outer tie rod of the steering gear assembly 2, and the applied thrust is not used to cause the outer tie rod of the steering gear assembly 2 to be displaced, but when the outer tie rod of the steering gear assembly 2 tends to be displaced autonomously, it overcomes the force that causes the outer tie rod of the steering gear assembly 2 to be displaced, so that the connecting end 31 of the first actuator 3 and the outer tie rod of the steering gear assembly 2 connected to the connecting end 31 do not displace during the entire test process.

[0233] In step S31, the maximum positive torque is 30Nm, and the maximum negative torque is -30Nm. After the values ​​of the maximum positive torque and the maximum negative torque are determined, the torque value at the current angle position can be monitored in real time during the process of the second actuator 5 driving the input end of the steering column assembly 4 to rotate. During the process of the input end of the steering column assembly 4 rotating to the right (with the positive torque interval from the middle position to the right), when the angular torque sensor 6 detects that the torque reaches the maximum positive torque, the second actuator 5 controls the input end of the steering column assembly 4 to stop at the angle position and no longer rotates to the right. Similarly, during the process of the input end of the steering column assembly 4 rotating to the left, when the angular torque sensor 6 detects that the torque reaches the maximum negative torque, the second actuator 5 controls the input end of the steering column assembly 4 to stop at the angle position and no longer rotates 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 rotation starting point 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 during the process of rotating in the same direction. Specifically, the speed of rotation of the input end of the steering column assembly 4 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 consistent with the meaning of step S11, that is, the input end of the steering column assembly 4 maintains a uniform speed during the main rotation process.

[0237] Based on the above definition, in step S31, the specific process of the second actuator 5 driving the input end of the steering column assembly 4 to rotate may be:

[0238] First, the initial position of the input end of the steering column assembly 4 is adjusted to the middle position.

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

[0240] After that, the second actuator 5 drives the input end of the steering column assembly 4 to move to the left. During the movement, the input end of the steering column assembly 4 will undergo a short acceleration process, accelerating to a rotation speed of 0.5° / s; then, the rotation speed is maintained constant and rotates at a constant speed, passing through the middle position and continuing to rotate until the angular torque sensor 6 detects that the torque reaches -30Nm, that is, the maximum negative torque is reached, and the second actuator 5 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 will first undergo a short acceleration process to accelerate to a rotation speed of 0.5° / s; then maintain the rotation speed and rotate at a constant speed until it rotates to the middle position; before reaching the middle position, the input end of the steering column assembly 4 will undergo a short deceleration process, the rotation speed will be reduced to 0, and it will stop at the middle position.

[0242] It should be noted that the above process is only an exemplary description and is not required to be completely in accordance with the above process in actual implementation.

[0243] Step S32, selecting a torque value, obtaining an angular position when the positive torque reaches the torque value, and an angular position when the negative torque reaches the torque value, and determining a steering system clearance according to the two angular positions; and

[0244] Selecting a starting angle and an ending angle of a center section of a positive moment and a negative moment, obtaining corresponding moment values, and determining a steering stiffness of the center section according to the moment values; and

[0245] The starting angle and the ending angle of the non-center section of the positive moment and the negative moment are selected, the corresponding moment values ​​are obtained, and the steering stiffness of the non-center section is determined according to the moment values.

[0246] In step S32, when selecting the torque value, for example, 2Nm and -2Nm torque can be selected. According to the information of the angular position and torque recorded by the angular torque sensor 6, the angular position corresponding to 2Nm and -2Nm is found out, and the following formula is used:

[0247] a=a1+a2

[0248] The steering system clearance can be determined.

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

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

[0251]

[0252] Results are obtained for the steering stiffness of the center section for positive and negative moments.

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

[0254]

[0255] Results for the steering stiffness of the non-center segment for positive and negative moments are obtained.

[0256] In the above formula, G1-central section stiffness; G2-non-central section stiffness; T A -T - the torque value of the starting angle of the center section; B -T - torque value of the end angle of the central section; C - the torque value of the starting angle of the non-central segment; T D - the torque value of the end angle of the non-central section; a A - the starting angle of the central section; a B - the end angle of the central section; a C - the starting angle of the non-central segment; a D - The ending angle of the non-center segment.

[0257] In a specific embodiment, step S32 may include the following steps S321-S323: Fig.10 shown.

[0258] Step S321, according to the angle and torque information recorded by the rotation angle torque sensor 6, an angle-force coordinate diagram is established with the angle information as the first coordinate and the torque information as the second coordinate.

[0259] Step S322, selecting a torque value in the angle-force coordinate diagram, and searching for a positive angle position and a negative angle position corresponding to the selected torque value; and

[0260] Determine the starting angle and ending angle of the center section of the positive moment and the negative moment in the angle-force coordinate diagram, and find the corresponding moment values; and

[0261] Determine the starting and ending angles of the non-central segments of the positive and negative moments in the angle-force coordinate diagram and find the corresponding moment values.

[0262] Step S323, calculating and determining the steering system clearance according to the found positive angular position and negative angular position; and

[0263] According to the moment value of the central section of the positive moment and negative moment found, according to the formula:

[0264]

[0265] Determining the steering stiffness of the center section for positive and negative moments; and

[0266] According to the moment values ​​of the non-central section of the positive moment and negative moment found, according to the formula:

[0267]

[0268] Determine the steering stiffness of the non-center segment for positive and negative moments.

[0269] In this specific embodiment, by establishing an angle-force coordinate diagram, the torque at different angle positions can be clearly and intuitively displayed; it is easier and more convenient to find multiple angle positions corresponding to the selected torque value. At the same time, the process of determining the stiffness and clearance of the steering system according to the above formula is simple, direct and convenient.

[0270] When the steering system testing method of the present invention tests the maximum output rack force of the electric power steering system, the steering system testing method includes the following steps S41-S42: Fig.11 shown.

[0271] Step S41, setting one of the first actuators 3 in a zero thrust state, and setting the other end of the first actuator 3 connected to the steering gear assembly 2 in a fixed state; controlling the second actuator 5 to drive the input end of the steering column assembly 4 to rotate from the neutral position in one direction until a set maximum positive torque is reached; and to rotate in the other direction until a set maximum negative torque is reached; and in the process, recording the thrust applied by the first actuator 3 whose end connected to the steering gear assembly 2 is set in a fixed state.

[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. The CAN communication module is used to input signals to the electric power steering system to set the power assist state of the electric power steering system to the 0 vehicle speed power assist state (i.e., the power assist state corresponding to the actual vehicle speed of 0).

[0273] In step S41, when the second actuator 5 drives the input end of the steering column assembly 4 to rotate, the rotation starting point 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 10Nm, and the maximum negative torque is -10Nm. After the values ​​of the maximum positive torque and the maximum negative torque are determined, the torque value at the current angle position can be monitored in real time during the process of the second actuator 5 driving the input end of the steering column assembly 4 to rotate. During the process of the input end of the steering column assembly 4 rotating to the right (with the positive torque interval from the middle position to the right), when the angular torque sensor 6 detects that the torque reaches the maximum positive torque, the second actuator 5 controls the input end of the steering column assembly 4 to stop at this angle position and no longer rotates to the right. Similarly, during the process of the input end of the steering column assembly 4 rotating to the left, when the angular torque sensor 6 detects that the torque reaches the maximum negative torque, the second actuator 5 controls the input end of the steering column assembly 4 to stop at this angle position and no longer rotates 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 during the process of rotating in the same direction. Specifically, the speed of rotation of the input end of the steering column assembly 4 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 consistent with the meaning of step S11, that is, the input end of the steering column assembly 4 maintains a uniform speed during the main rotation process.

[0277] Based on the above definition, in step S41, the specific process of the second actuator 5 driving the input end of the steering column assembly 4 to rotate may be:

[0278] First, the initial position of the input end of the steering column assembly 4 is adjusted to the middle position.

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

[0280] After that, the second actuator 5 drives the input end of the steering column assembly 4 to move to the left. During the movement, the input end of the steering column assembly 4 will undergo a short acceleration process, accelerating to a rotation speed of 0.5° / s; then, the rotation speed is maintained constant and rotates at a constant speed, passing through the middle position and continuing to rotate until the angular torque sensor 6 detects that the torque reaches -10Nm, that is, the maximum negative torque is reached, and the second actuator 5 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 will first undergo a short acceleration process to accelerate to a rotation speed of 0.5° / s; then maintain the rotation speed and rotate at a constant speed until it rotates to the middle position; before reaching the middle position, the input end of the steering column assembly 4 will undergo a short deceleration process, the rotation speed will be reduced to 0, and it will stop at the middle position.

[0282] It should be noted that the above process is only an exemplary description and is not required to be completely in accordance with the above process in actual implementation.

[0283] Step S42, determining the thrust applied by the first actuator 3 when the maximum positive torque and the maximum negative torque are applied, and determining the maximum output rack force of the electric power steering system according to the magnitude of the thrust found.

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

[0285] Step S421, based on the torque information recorded by the rotation angle torque sensor 6 and the recorded 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, searching the torque-thrust coordinate diagram for thrust data corresponding to the positions of the maximum positive torque and the maximum negative torque.

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

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

[0289] The maximum positive moment to be found is P max , the maximum negative moment to be found is P min , according to the following formula:

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

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

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

[0293] When the steering system testing method of the present invention tests the catch up (an indicator for evaluating whether the power assist of the electric power steering is sufficient) characteristic of the electric power steering, the steering system testing method includes the following steps S51 to S53: Fig.12 shown.

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

[0295] In this step S51, the first simulation working condition and the subsequent second simulation working condition, the nth simulation working condition, etc. are pre-set, 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 rotation speed at which the second actuator 5 drives the input end of the steering column assembly 4 to rotate.

[0296] For example, the pre-set first simulation working condition can specifically be: the first thrust applied by the first actuator 3 to the steering gear assembly 2 is equivalent to 95% of the maximum output rack force in a static state (static refers to the state where the actual vehicle speed is 0, and the maximum output rack force can be obtained by testing in the above steps S41 to S42, or by CAE simulation), and the first rotation speed at which the second actuator 5 drives the input end of the steering column assembly 4 to rotate is 180° / s.

[0297] In step S51, the electric power steering is set in a power-assisting state when the vehicle speed is 0. The rotation starting point of the input end of the steering column assembly 4 is the middle position of the input end, and the input end of the steering column assembly 4 returns to the middle position of the input end after rotating to the end point of the positive travel interval and the end point of the negative travel interval.

[0298] In step S51, the set positive and negative stroke interval may be specifically the area between 90% positions of the maximum stroke from the middle position to both ends. For example, the maximum stroke from the middle 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 to 450° from the middle position to the left, and then stops at this 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 the process of rotating in the same direction, that is, to maintain the input end at the first rotation speed during the main rotation process.

[0300] Based on the above definition, in step S51, the specific process of the second actuator 5 driving the input end of the steering column assembly 4 to rotate may be:

[0301] First, the initial position of the input end of the steering column assembly 4 is adjusted to the middle position.

[0302] Afterwards, the second actuator 5 drives the input end of the steering column assembly 4 to move to the right (the stroke from the middle position to the right is the positive stroke, and correspondingly, the stroke from the middle position to the left is the negative stroke). In this process, the input end of the steering column assembly 4 will first undergo a short acceleration process to accelerate to a rotation speed of 180° / s; then maintain the speed unchanged and rotate at a constant speed until it rotates to the end point of the positive stroke interval, that is, 90% of the extreme position of rotation to the right; before reaching the end point of the positive stroke interval, the input end of the steering column assembly 4 undergoes a short deceleration process, the speed is reduced to 0, and stops at the end point of the positive stroke interval.

[0303] Afterwards, the second actuator 5 drives the input end of the steering column assembly 4 to move to the left. During the movement, the input end of the steering column assembly 4 undergoes a short acceleration process, accelerating to a rotation speed of 180° / s; then, the rotation speed is maintained constant and rotates at a constant speed, passes through the middle position and continues to rotate until it rotates to the end point of the negative travel interval, that is, 90% of the limit position of rotation to the left; before reaching the end point of the negative travel interval, the input end of the steering column assembly 4 undergoes a short deceleration process, the rotation speed is reduced to 0, and stops at the end point of the negative travel interval.

[0304] Finally, the second actuator 5 drives the input end of the steering column assembly 4 to move to the right. In this process, the input end of the steering column assembly 4 will first undergo a short acceleration process to accelerate to a rotation speed of 180° / s; then maintain the rotation speed and rotate at a constant speed until it rotates to the middle position; before reaching the middle position, the input end of the steering column assembly 4 will undergo a short deceleration process, the rotation speed will be reduced to 0, and it will stop at the middle position.

[0305] During the above rotation process, the angular torque sensor 6 continuously records each position to which the input end of the steering column assembly 4 is rotated, and the torque applied by the second actuator 5 to the input end of the steering column assembly 4 when the input end of the steering column assembly 4 is rotated to each position.

[0306] It should be noted that the above process is only an exemplary description and is not required to be completely in accordance with the above process in actual implementation.

[0307] Step S52, compare the maximum torque recorded by the angular torque sensor 6 with the set torque value. If the maximum torque recorded by the angular torque sensor 6 exceeds the set torque value, it indicates that the catch up characteristics under the first simulated working condition do not meet the requirements. If the maximum torque recorded by the angular torque sensor 6 does not exceed the set torque value, it indicates that the catch up characteristics under the first simulated working condition meet the requirements.

[0308] In step S52, according to the torque information recorded by the angular torque sensor 6, the maximum value of the torque is searched therein. If the maximum value exceeds the set torque value, it means that at the angle position corresponding to the maximum value of the torque, 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 large, which can indicate that the power assistance provided by the electric power steering is insufficient at this time, which means that the catch up characteristic of the electric power steering does not meet the requirements. On the contrary, if the maximum value of the torque searched does not exceed the set torque value, it means that the catch up characteristic of the electric power steering meets the requirements.

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

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

[0311] In step S53 and the aforementioned step S51, when setting the first simulation working condition to the nth module working condition, the following principle is followed: the thrust applied by the first actuator 3 to the steering gear assembly 2 is negatively correlated with the rotation speed of the input end of the steering column assembly 4 driven by the second actuator 5. That is, in any two pre-set simulation working conditions, if the thrust of one simulation working condition is greater than that of the other simulation working condition, the rotation speed thereof is smaller than that of the other simulation working condition.

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

[0313] When the steering system test method of the present invention is used to test the overheat protection performance of the electric power steering, it is necessary to perform the test based on the embodiment of the steering system test device with the road spectrum input module. At this time, the steering system test method includes the following steps S61 to S63: Fig.13 shown.

[0314] Step S61, controls 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 responds to the preset road spectrum information provided by the road spectrum input module 8 and correspondingly adjusts the thrust applied to the steering gear assembly 2.

[0315] In this step S61, the electric power steering is set to the zero vehicle speed power assist state.

[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, when the second actuator 5 drives the input end of the steering column assembly 4 to rotate, the thrust applied by the first actuator 3 to the steering gear 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 the 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 during the process of 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 consistent with the meaning of step S11, that is, the input end of the steering column assembly 4 maintains a uniform speed during the main rotation process.

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

[0320] First, the input end is rotated from the middle position toward the first end to the extreme position, and then rotated toward the second end to the extreme position. The first end direction can be, for example, the right side, and the second direction is correspondingly the left side, or vice versa.

[0321] Thereafter, the device rotates from the extreme position in the second end direction to the extreme position in the first end direction and is maintained for a predetermined time, which may be specifically set to 5 seconds.

[0322] Then, the device rotates from the extreme position in the first end direction to the extreme position in the second end direction and maintains the position for a predetermined time, which can also be set to 5 seconds.

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

[0324] Step S62, selecting an angle position according to the angle and torque information recorded by the angular torque sensor 6, and searching and determining 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 angle position may be specifically the 95% position of the extreme position of rotation to both sides. According to the angle and torque information recorded by the rotation angle torque sensor 6, the torque value at each rotation to the angle position may be found.

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

[0327] Step S621, according to the angle and torque information recorded by the angular 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, selecting an angle position in the angle-force coordinate diagram, and searching for torque information corresponding to each rotation to the selected angle position.

[0329] In this specific embodiment, an angle-force coordinate diagram is first established, so that the torque at different angle positions can be clearly and intuitively displayed; it is easier and more convenient to find the torque information corresponding to the selected angle position.

[0330] Step S63, comparing the torque value found and determined 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, specifically, the maximum value among the multiple torque values ​​corresponding to the selected angular position determined by searching can be compared with the set standard value, or the torque value corresponding to the last rotation to the selected angular position (generally, when the input end of the steering column assembly 4 continues to rotate, 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 the angular position will usually be the largest) can be compared with the set standard value; based on the comparison result, 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 means that at the angle position corresponding to the maximum value of the torque, 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 large, which can explain that the power assist provided by the electric power steering is insufficient at this time, which means that the electric power steering enters the overheat protection state after a long period of time or high-intensity work, and the power assist provided in the overheat protection state is significantly reduced, which does not meet the requirements. On the contrary, if the maximum value of the torque found does not exceed the set torque value, it means that after a long period of time or high-intensity work, the power assist provided by the electric power steering is still sufficient and meets the requirements.

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

[0334] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or change made by a person skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. A steering system test bench, characterized in that: The steering system test bench (1) comprises a steering gear mounting seat (11), a first actuator mounting seat (12), a column mounting seat (13) and a second actuator mounting seat (14); The steering gear mounting seat (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 arranged 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 be connected to an outer tie rod of the steering gear assembly (2) installed on the steering gear mounting seat (11); The column mounting seat (13) is used to mount the steering column assembly (4); A second actuator (5) is provided on the second actuator mounting seat (14), and the second actuator (5) is used to be connected to the input end of the steering column assembly (4) mounted on the column mounting seat (13), and is used to drive the input end of the steering column assembly (4) to rotate.

2. The steering system test bench according to claim 1, characterized in that: 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).

3. The steering system test bench according to claim 2, characterized in that: The steering gear mounting seat (11) comprises a first seat body (111) for connecting with the base (10) and a second seat body (112) for connecting and mounting the steering gear assembly (2); the first seat body (111) and the base (10) are slidably connected in a second direction; the second seat body (112) and the first seat body (111) are slidably connected in a vertical direction; The first actuator mounting seat (12) comprises a third seat body (121) for connecting with the base (10) and a fourth seat body (122) for connecting and mounting the first actuator (3), the third seat body (121) and the base (10) are slidably connected in a first direction, and the fourth seat body (122) and the third seat body (121) are slidably connected in a second direction; The column mounting seat (13) comprises a fifth seat body (131) for connecting with 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 directions perpendicular to each other in a horizontal plane.

4. The steering system test bench according to claim 1, characterized in that: The steering gear mounting seat (11) is provided with a rotating bracket (113), the rotating bracket (113) is provided with a steering gear mounting fixture (114), and the steering gear assembly (2) is mounted and fixed on the rotating bracket (113) via the steering gear mounting fixture (114).

5. The steering system test bench according to claim 1, characterized in that: The column mounting seat (13) comprises a column mounting bracket (133), a column mounting fixture (134) is provided on the column mounting bracket (133), and the steering column assembly (4) is fixedly connected to the column mounting bracket (133) via the column mounting fixture (134).

6. The steering system test bench according to claim 5, characterized in that: The pipe column mounting seat (13) also includes a base (135), a lifting mechanism (136) and a rotating mounting frame (137); The lifting mechanism (136) is arranged on the base (135); the rotating mounting frame (137) is arranged on the lifting mechanism (136) and is used to be driven by the lifting mechanism (136) to perform lifting movement in the vertical direction, 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).

7. A steering system testing device, characterized in that: The steering system test equipment comprises the steering system test bench (1) according to any one of claims 1 to 6, and further comprises a data detection module and a data receiving and processing module (9); The data detection module comprises at least one of a rotation angle torque sensor (6) and a displacement sensor (7); The angular torque sensor (6) is connected between the second actuator (5) and the input end of the steering column assembly (4), and is used to obtain the angle of the input end of the steering column assembly (4) and the torque at the angle; The displacement sensor (7) is used to detect the displacement of one 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, and analyze and process the data information to obtain the test results.

8. The steering system testing device according to claim 7, characterized in that: The displacement sensor (7) is a laser displacement sensor, and the laser displacement sensor is arranged on the first actuator mounting seat (12); The steering system testing device further comprises a reflection plate (71), wherein the reflection plate (71) is arranged at one end of the first actuator (3) connected to the steering gear assembly (2).

9. The steering system testing device according to claim 7, characterized in that: The steering system testing device further comprises a road spectrum input module (8), and the road spectrum input module (8) is used to input preset road spectrum information to the first actuator (3).

10. A steering system testing method, characterized in that: The steering system testing method utilizes the steering system testing device described in any one of claims 7 to 9 to test the steering system to be tested.

11. The steering system testing method according to claim 10, characterized in that: The steering system testing method is used to perform a steering system friction test; The steering system testing method comprises: Step S11, setting the two first actuators (3) in a zero thrust state, controlling the second actuator (5) to drive the input end of the steering column assembly to reciprocate in a set positive and negative stroke range, and the angular torque sensor (6) records the angle and torque information during the rotation process; Step S12, selecting multiple angle positions and obtaining corresponding torque information.

12. The steering system testing method according to claim 11, characterized in that: In step S11, the rotation starting point of the input end of the steering column assembly (4) is the middle position of the input end; and / or The set positive and negative stroke interval is the area between 95% positions of the maximum stroke from the middle position to both ends; and / or The second actuator (5) controls the input end of the steering column assembly (4) to maintain a constant speed during the process of rotating in the same direction.

13. The steering system testing method according to claim 11, characterized in that: The step S12 comprises: Step S121, establishing an angle-force coordinate diagram according to the angle and torque information recorded by the rotation angle torque sensor (6), using the angle information as a first coordinate and the torque information as a second coordinate; Step S122, selecting a plurality of angle positions in the angle-force coordinate diagram, and searching for torque information corresponding to the plurality of angle positions.

14. The steering system testing method according to claim 10, characterized in that: The steering system testing method is used to test the rack travel and transmission ratio of the steering gear assembly (2); The steering system testing method comprises: Step S21, setting the two first actuators (3) in a zero thrust state, controlling 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 using a displacement sensor (7) to detect the displacement stroke of one end of the first actuator (3) connected to the steering gear assembly (2); Step S22, obtaining the left limit stroke and the right limit stroke according to the detection data of the displacement sensor (7), and obtaining the rack stroke of the steering gear assembly (2) according to the left limit stroke and the right limit stroke; and selecting multiple angular positions, obtaining the corresponding displacement stroke information, and determining 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 14, characterized in that: In step S21, the rotation starting point of the input end of the steering column assembly (4) is 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 during the process of rotating in the same direction.

16. The steering system testing method according to claim 14, characterized in that: The step S22 comprises: Step S221, establishing an angle-stroke coordinate diagram according to the angle and displacement stroke recorded by the displacement sensor (7), using the angle information as a first coordinate and the displacement stroke as a second coordinate; Step S222, selecting a plurality of angle positions in the angle-stroke coordinate diagram, and searching for displacement stroke information corresponding to the plurality of angle positions; Step S223, determining the transmission ratio of the steering gear assembly (2) at the corresponding point by differential calculation.

17. The steering system testing method according to claim 10, characterized in that: The steering system test method is used to perform a steering system stiffness and clearance test; The steering system testing method comprises: Step S31, setting one end of the two first actuators (3) connected to the steering gear assembly (2) in a fixed state, and controlling the second actuator (3) to drive the input end of the steering column assembly (4) to rotate between an angle position corresponding to a set maximum positive torque and an angle position corresponding to a set maximum negative torque; Step S32, selecting a torque value, obtaining an angular position when the positive torque reaches the torque value, and an angular position when the negative torque reaches the torque value, and determining a steering system clearance according to the two angular positions; and Selecting a starting angle and an ending angle of a center section of a positive moment and a negative moment, obtaining corresponding moment values, and determining a steering stiffness of the center section according to the moment values; and The starting angle and the ending angle of the non-center section of the positive moment and the negative moment are selected, the corresponding moment values ​​are obtained, and the steering stiffness of the non-center section is determined according to the moment values.

18. The steering system testing method according to claim 17, characterized in that: In the step S31, the maximum positive torque is 30 Nm, and the maximum negative torque is -30 Nm; and / or In step S31, the rotation starting point of the input end of the steering column assembly (4) is 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 during the process of rotating in the same direction.

19. The steering system testing method according to claim 17, characterized in that: The step S32 comprises: Step S321, establishing an angle-force coordinate diagram according to the angle and torque information recorded by the rotation angle torque sensor (6), using the angle information as a first coordinate and the torque information as a second coordinate; Step S322, selecting a torque value in the angle-force coordinate diagram, and searching for a positive angle position and a negative angle position corresponding to the selected torque value; and Determine the starting angle and ending angle of the center section of the positive moment and the negative moment in the angle-force coordinate diagram, and find the corresponding moment values; and Determine the starting angle and ending angle of the non-central section of the positive moment and the negative moment in the angle-force coordinate diagram, and find the corresponding moment value; Step S323, calculating and determining the steering system clearance according to the found positive angular position and negative angular position; and According to the moment value of the central section of the positive moment and negative moment found, according to the formula: Determining the steering stiffness of the center section for positive and negative moments; and According to the moment values ​​of the non-central section of the positive moment and negative moment found, according to the formula: Determine the steering stiffness of the non-center section for positive and negative moments; Where, G1 is the stiffness of the central section; G2 is the stiffness of the non-central section; T A -T - the torque value of the starting angle of the center section; B -T - torque value of the end angle of the central section; C - the torque value of the starting angle of the non-central segment; T D - the torque value of the end angle of the non-central section; a A - the starting angle of the central section; a B - the end angle of the central section; a C - the starting angle of the non-central segment; a D - The ending angle of the non-center segment.

20. The steering system testing method according to claim 10, 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 comprises: Step S41, setting one of the first actuators (3) in a zero thrust state, and setting the other first actuator (3) whose end connected to the steering gear assembly (2) is in a fixed state; controlling the second actuator (5) to drive the input end of the steering column assembly (4) to rotate from the neutral position in one direction until a set maximum positive torque is reached; and to rotate in the other direction until a set maximum negative torque is reached; and in the process, recording the thrust applied by the first actuator (3) whose end connected to the steering gear assembly (2) is in a fixed state; Step S42, determining the thrust applied by the first actuator (3) when the maximum positive torque and the maximum negative torque are achieved, and determining the maximum output rack force of the electric power steering system according to the magnitude of the thrust found.

21. The steering system testing method according to claim 20, characterized in that: In step S41, the rotation starting point of the input end of the steering column assembly (4) is the middle position 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 during the process of rotating in the same direction.

22. The steering system testing method according to claim 11, characterized in that: The step S42 comprises: Step S421, based on the torque information recorded by the rotation angle torque sensor (6) and the recorded 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, searching the thrust data corresponding to the positions of the maximum positive torque and the maximum negative torque in the torque-thrust coordinate diagram; Step S423, calculating the average value of the thrust data found out as the maximum output rack force of the electric power steering system.

23. The steering system testing method according to claim 10, characterized in that: The steering system testing method is used to test the catch up characteristics of the electric power steering; The steering system testing method comprises: Step S51, executing a first simulation working condition, under which the two first actuators (3) jointly apply a first thrust to the steering gear assembly (2), and the second actuator drives the input end of the steering column assembly (2) to rotate at a first rotation speed within a set positive and negative stroke range; and the angular torque sensor records angle and torque information during the rotation process; Step S52, comparing the maximum torque recorded by the angular torque sensor (6) with the set torque value; if the maximum torque recorded by the angular 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 angular 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, according to steps S51-S52, respectively execute the subsequent second to nth simulation conditions to determine whether the catch up characteristics under the second to nth simulation conditions meet the requirements; wherein, the first thrust to the nth thrust decreases, and the first rotation speed to the nth rotation speed increases.

24. The steering system testing method according to claim 23, characterized in that: In step S51, the electric power steering is set in a power-assisted state when the vehicle speed is 0; and / or In step S51, the rotation starting point of the input end of the steering column assembly (4) is the middle position of the input end, and after the input end of the steering column assembly (4) rotates to the end point of the positive travel interval and the end point of the negative travel interval, it returns to the middle position of the input end; and / or The set positive and negative stroke interval is the area between 90% positions of the maximum stroke from the middle position to both ends; and / or The second actuator (5) controls the input end of the steering column assembly (4) to maintain a constant speed during the process of rotating in the same direction.

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

26. The steering system testing method according to claim 10, characterized in that: The steering system testing method is used to test the overheat protection performance of the electric power steering; and the steering system testing method is based on the steering system testing device according to claim 9; The steering system testing method comprises: Step S61, controlling 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 angular torque sensor (6) records the angle and torque information during the rotation process; and during the rotation process, the first actuator (3) responds to the preset road spectrum information provided by the road spectrum input module (8) and correspondingly adjusts the thrust applied to the steering gear assembly (2); Step S62, selecting an angle position according to the angle and torque information recorded by the angular torque sensor (6), and searching and determining the torque value corresponding to the selected angle position during the rotation process of the input end of the steering column assembly (4); Step S63, comparing the torque value found and determined 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.

27. The steering system testing method according to claim 26, characterized in that: In step S61, the second actuator (5) drives the input end of the steering column assembly (4) to rotate for multiple cycles, each of which includes: rotating from the middle position of the input end to the first end direction to the extreme position, and rotating to the second end direction to the extreme position; rotating from the extreme position in the second end direction to the first end direction to the extreme position, and maintaining it for a predetermined time; rotating from the extreme position in the first end direction to the second end direction to the extreme position, and maintaining it for a predetermined time; rotating from the extreme 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 during the process of rotating in the same direction.

28. The steering system testing method according to claim 26, characterized in that: The step S62 comprises: Step S621, establishing an angle-force coordinate diagram according to the angle and torque information recorded by the rotation angle torque sensor (6) during the rotation process, using the angle information as a first coordinate and the torque information as a second coordinate; Step S622, selecting an angle position in the angle-force coordinate diagram, and searching for torque information corresponding to each rotation to the selected angle position.

29. The steering system testing method according to claim 26, characterized in that: In the step S62, the selected angle position is 95% of the limit positions in the first end direction and the second end direction; and / or The standard value of the setting is determined to be 10 Nm.

30. The steering system testing method according to claim 26, characterized in that: In step S63, the maximum value among the multiple torque values ​​corresponding to the selected angle position is compared with the set standard value, or the torque value corresponding to the last rotation to the selected angle position is compared with the set standard value; Based on the comparison result, determine whether the overheat protection performance of the electric power steering meets the requirements.

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