A rear wheel steering failure condition test method, system and bench

Abstract

The application discloses a rear wheel steering gear failure condition test method and system and a test bench, and belongs to the technical field of steering gears. The method comprises the following steps: applying maximum working load to the left and right output ends of the rear wheel steering gear; controlling the rear wheel steering gear to perform a steering action; rapidly reducing the load applied to the rear wheel steering gear to zero during the steering action of the rear wheel steering gear, so that the displacement speed of the screw rod of the rear wheel steering gear exceeds a preset safety limit; obtaining a first internal feedback signal of the rear wheel steering gear; and checking whether the behavior of the rear wheel steering gear after displacement overspeed meets a first preset safety requirement according to the first internal feedback signal. The displacement speed of the screw rod of the rear wheel steering gear is made to exceed the safety limit in a load mutation manner, so that a working condition that should be solved by the required function of the rear wheel steering gear is simulated, and whether the behavior of the rear wheel steering gear after displacement overspeed meets the first preset safety requirement is judged according to the first feedback signal, so that the test on the function requirement of the rear wheel steering gear is completed.

Description

Technical Field

[0001] This invention relates to the field of steering gear technology, and in particular to a method, system and test bench for testing the failure conditions of a rear wheel steering gear. Background Technology

[0002] With the rise of intelligent driving technology, the emerging rear-wheel steering technology has the advantages of improving vehicle handling, stability and turning convenience, but at the same time it puts forward higher safety requirements for rear-wheel steering technology.

[0003] However, existing fault condition testing methods for steering systems cannot fully adapt to or meet the functional requirements of rear-wheel steering systems, while vehicle road testing requires significant time and resource costs. Summary of the Invention

[0004] The purpose of this invention is to provide a method, system, and test bench for testing the failure conditions of a rear wheel steering system, so as to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions.

[0005] To address the aforementioned technical problems, the present invention provides a method for testing the fault conditions of a rear wheel steering system. This method is applied to the testing of rear wheel steering systems. The testing method includes testing for overspeed faults in the rear wheel steering system. Testing for overspeed faults in the rear wheel steering system includes: applying a maximum working load to the left and right output ends of the rear wheel steering system; controlling the rear wheel steering system to perform a steering action; rapidly reducing the load applied to the rear wheel steering system to zero during the steering action, causing the displacement speed of the rear wheel steering system's lead screw to exceed a preset safety limit; acquiring a first feedback signal from within the rear wheel steering system; and verifying, based on the first internal feedback signal, whether the behavior of the rear wheel steering system after overspeed meets a first preset safety requirement.

[0006] The technical solution has at least the following beneficial effects: by causing a sudden change in the load at the two output ends of the rear wheel steering gear, the displacement speed of the rear wheel steering gear screw exceeds the safety limit, thereby simulating the working conditions that the required functions of the rear wheel steering gear should be able to handle, and judging whether the behavior of the rear wheel steering gear after the displacement exceeds the speed based on the first feedback signal inside the rear wheel steering gear, whether it meets the first preset safety requirements, thereby completing the test of the functional requirements of the rear wheel steering gear.

[0007] Optionally, the testing method further includes testing for the sticking fault of the rear wheel steering gear. Testing for the sticking fault of the rear wheel steering gear includes: controlling the rear wheel steering gear to perform a steering action; during the steering action of the rear wheel steering gear, applying a maximum working load to the left and right output ends of the rear wheel steering gear to stop the steering action; when the steering action of the rear wheel steering gear stops for more than a first preset time, reducing the load applied to the left and right output ends of the rear wheel steering gear to zero; acquiring a second feedback signal inside the rear wheel steering gear; and verifying, based on the second feedback signal, whether the behavior of the rear wheel steering gear after sticking meets a second preset safety requirement.

[0008] Optionally, the testing method further includes testing for signal loss faults in the rear wheel steering system. Testing for signal loss faults in the rear wheel steering system includes: losing the control signal of the controller in the rear wheel steering system; retransmitting the lost control signal when the loss of the controller signal exceeds a second preset time; acquiring a third feedback signal from inside the rear wheel steering system; and verifying, based on the third feedback signal, whether the state of the rear wheel steering system during and after the fault meets a third preset safety requirement.

[0009] Optionally, the control signal includes one, two, or more of the following: vehicle speed signal, steering enable signal, and target angle request signal.

[0010] Optionally, the testing method further includes testing the voltage fault of the rear wheel steering system. Testing the voltage fault of the rear wheel steering system includes: controlling the power supply voltage of the rear wheel steering system to jump from the operating voltage to the fault voltage; when the power supply voltage of the rear wheel steering system remains at the fault voltage for more than a third preset time, restoring the power supply voltage of the rear wheel steering system to the operating voltage; acquiring a fourth feedback signal from inside the rear wheel steering system; and verifying, based on the fourth feedback signal, whether the state of the rear wheel steering system during and after the fault meets a fourth preset safety requirement.

[0011] Optionally, the test method further includes testing the signal loss fault and / or voltage fault of the rear wheel steering gear when the rear wheel steering gear is stationary and when the rear wheel steering gear is performing a steering action.

[0012] Optionally, the test method further includes testing the rear wheel steering system for overspeed faults, jamming faults, signal loss faults, and / or voltage faults under different vehicle speed signal conditions.

[0013] A second aspect of the present invention provides a rear wheel steering system fault condition testing system for testing rear wheel steering systems. The testing system includes: a control unit, configured to: apply a maximum working load to the left and right output ends of the rear wheel steering system; control the rear wheel steering system to perform steering actions; and during the steering actions of the rear wheel steering system, rapidly reduce the load applied to the rear wheel steering system to zero, so that the displacement speed of the rear wheel steering system lead screw exceeds a preset safety limit; and a data acquisition unit, configured to: acquire a first feedback signal inside the rear wheel steering system; and verify, based on the first feedback signal, whether the behavior of the rear wheel steering system after displacement overspeed meets a first preset safety requirement.

[0014] A third aspect of the present invention provides a test bench for a rear wheel steering system failure condition, applied to the testing of a rear wheel steering system. The test bench includes a fixed frame, a programmable power supply, and two linear actuators fixed relative to the fixed frame. The fixed frame is used to fix the rear wheel steering system. The output ends of the two linear actuators are respectively hinged to the left and right output ends of the rear wheel steering system. The programmable power supply provides power voltage to the rear wheel steering system. The rear wheel steering system failure condition test bench is used in any of the aforementioned rear wheel steering system failure condition testing methods.

[0015] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program, wherein the computer program is configured to execute, when run on a computer or processor, any of the above-described methods for testing the failure conditions of a rear wheel steering system. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the rear wheel steering system failure test bench according to an embodiment of the present invention;

[0017] Figure 2 This is a flowchart of the rear wheel steering system failure condition test method according to an embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram of a further test process for the rear wheel steering system failure condition test method according to an embodiment of the present invention;

[0019] Figure 4 This is a schematic diagram of the steering overspeed fault test in the rear wheel steering system fault condition test method of this invention.

[0020] Figure 5 This is a schematic diagram of the process for testing the jamming fault in the rear wheel steering system fault condition testing method of this invention.

[0021] Figure 6 This is a schematic diagram of the signal loss fault test in the rear wheel steering system fault condition test method of this invention.

[0022] Figure 7 This is a schematic diagram of the voltage fault test process in the rear wheel steering system fault condition test method of this invention.

[0023] Figure 8 This is a structural block diagram of the rear wheel steering system failure condition testing system according to an embodiment of the present invention. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] The method provided in the embodiments of the present invention should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system containing at least one set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0027] This method embodiment can also be executed in an electronic system / device containing a memory and a processor, a similar control system, or in the cloud. Taking an electronic system / device as an example, the electronic system / device may include one or more processors and a memory for storing data. Optionally, the aforementioned electronic system / device may also include communication devices for communication functions and display devices. Those skilled in the art will understand that the above structural description is merely illustrative and does not limit the structure of the aforementioned electronic system / device. For example, the electronic system / device may also include more or fewer components than those described above, or have a different configuration than those described above.

[0028] like Figure 1 As shown, a test bench for rear-wheel steering system failure conditions is used to test a rear-wheel steering system 910. The test bench includes a mounting frame 920, a programmable power supply 930, and two linear actuators 940. The mounting frame 920 is used to mount and fix the rear-wheel steering system 910, maintaining the position and orientation of the rear-wheel steering system 910 sample under motion or high load conditions. The housings of the two linear actuators 940 are relatively fixed to the mounting frame 920, and the two linear actuators 940 are used to simulate the motion, load, and other physical quantities of the rear-wheel steering system 910 during actual driving. The programmable power supply 930 is used to provide power voltage to the rear-wheel steering system 910, including normal operating voltage, high voltage exceeding the operating voltage, or low voltage below the operating voltage.

[0029] During testing, the rear wheel steering unit 910 assembly is first installed onto the mounting bracket 920, and the mounting bolts are tightened to the specified torque to ensure stable and reliable installation of the rear wheel steering unit 910. Then, the left and right output ends of the rear wheel steering unit 910 are connected to the output ends of the two linear actuators 940 via hinge structures, ensuring that the output force direction of the linear actuators 940 is consistent with the movement direction of the rear wheel steering unit 910. After the test bench is installed, the rear wheel steering unit 910 is connected to the programmable power supply 930, thus providing a test environment for the fault condition testing method of the rear wheel steering unit 910.

[0030] like Figure 2-7 As shown, a test method for rear wheel steering system failure conditions is applied to the testing of rear wheel steering systems. The test method includes:

[0031] Step S100: Test for overspeed fault in the rear wheel steering system.

[0032] Step S200: Test for the sticking fault of the rear wheel steering system.

[0033] Step S300: Test for signal loss fault in the rear wheel steering system.

[0034] Step S400: Test for voltage faults in the rear wheel steering system.

[0035] Step S500: Test the signal loss fault and / or voltage fault of the rear wheel steering system when the rear wheel steering system is stationary and when the rear wheel steering system is performing a steering action.

[0036] Step S600: Test the rear wheel steering system for overspeed faults, jamming faults, signal loss faults and / or voltage faults under different vehicle speed signal conditions.

[0037] In step S100, the test for overspeed fault in the rear wheel steering system includes the following steps:

[0038] Step S110: Apply the maximum working load to the left and right output ends of the rear wheel steering system.

[0039] Specifically, by controlling two linear actuators to apply the maximum working load that the rear wheel steering unit can withstand to the left and right output ends of the rear wheel steering unit, the ultimate load state of the linear actuators is simulated. During the steering overspeed fault test, a programmable power supply provides the normal operating voltage to the rear wheel steering unit.

[0040] Step S120: Control the rear wheel steering gear to perform a steering action.

[0041] Specifically, a control signal is sent to the rear wheel steering system to make it perform steering actions under maximum working load conditions, in order to simulate the working process of the rear wheel steering system under extreme load conditions.

[0042] In step S130, during the steering action of the rear wheel steering gear, the load applied to the rear wheel steering gear is rapidly reduced to zero so that the displacement speed of the rear wheel steering gear lead screw exceeds the preset safety limit.

[0043] Specifically, when the rear wheel steering system performs a steering action under maximum working load, the two linear actuators are controlled to simultaneously or sequentially reduce the load applied to the rear wheel steering system to zero rapidly. At this time, the displacement speed of the rear wheel steering system lead screw will exceed the preset safety limit, thus simulating the working condition of steering overspeed fault. The deceleration rate of the load reduction can be set according to the maximum deceleration that the linear actuators can provide.

[0044] Step S140: Obtain the first feedback signal inside the rear wheel steering gear.

[0045] Specifically, the first feedback signals inside the rear wheel steering system include operating status signals, error status signals, DTC fault codes, and angle signals.

[0046] Step S150: Verify whether the behavior of the rear wheel steering gear after displacement overspeed meets the first preset safety requirements based on the first feedback signal.

[0047] Specifically, the system records whether the working status signals and error status signals meet the functional specifications, checks whether the errors in the DTC report are expected faults, and records the angle curves. Based on these recorded data, the behavior of the rear wheel steering gear after displacement overspeed is verified to determine whether the tested rear wheel steering gear meets the first preset safety requirements of the rear wheel steering gear function, thus completing the steering overspeed fault test of the rear wheel steering gear.

[0048] Furthermore, in step S500, the rear wheel steering system can be tested for overspeed faults by sending different vehicle speed signals to the rear wheel steering system. The vehicle speed signal can indicate the current vehicle speed as 0 km / h, 3 km / h, 10 km / h, 20 km / h, 25 km / h, 30 km / h, 50 km / h, 80 km / h, 100 km / h, or 120 km / h.

[0049] In step S200, the test for the sticking fault of the rear wheel steering system includes the following steps:

[0050] Step S210: Control the rear wheel steering gear to perform a steering action.

[0051] Specifically, a control signal is sent to the rear wheel steering system to induce steering action, simulating the normal steering process of the rear wheel steering system. During the jamming fault test, a programmable power supply provides the normal operating voltage to the rear wheel steering system.

[0052] Step S220: During the steering action of the rear wheel steering gear, apply the maximum working load to the left and right output ends of the rear wheel steering gear to stop the steering action of the rear wheel steering gear.

[0053] Specifically, during the steering action of the rear wheel steering system, by controlling two linear actuators to simultaneously or sequentially apply the maximum working load of the rear wheel steering system to the left and right output ends, the steering action of the rear wheel steering system is stopped. This simulates a situation where the rear wheel steering system encounters a jamming fault during normal steering operation.

[0054] Step S230: When the steering action of the rear wheel steering gear stops for more than a first preset time, the load applied to the left and right output ends of the rear wheel steering gear is reduced to zero.

[0055] Specifically, when the steering action of the rear wheel steering gear is stuck for a first preset time, the two linear actuators are controlled to simultaneously or sequentially reduce the load applied to the rear wheel steering gear to zero, that is, to cancel the stuck resistance, allowing the rear wheel steering gear to resume normal steering operation. The first preset time can be 9 seconds, 10 seconds, or 11 seconds.

[0056] Step S240: Obtain the second feedback signal inside the rear wheel steering gear.

[0057] Specifically, the second feedback signals inside the rear wheel steering system include operating status signals, error status signals, and DTC fault codes.

[0058] Step S250: Verify whether the behavior of the rear wheel steering gear after jamming meets the second preset safety requirements based on the second feedback signal.

[0059] Specifically, the system records whether the working status signals and error status signals meet the functional specifications, and checks whether the errors in the DTC report are expected faults. Based on this recorded data, the behavior of the rear wheel steering system after jamming is verified, and it is determined whether the tested rear wheel steering system meets the second preset safety requirement of the rear wheel steering system function, thus completing the jamming fault test of the rear wheel steering system.

[0060] Furthermore, in step S500, the rear wheel steering system can be tested for sticking faults by sending different vehicle speed signals to the rear wheel steering system. The vehicle speed signal can indicate the current vehicle speed as 0 km / h, 3 km / h, 10 km / h, 20 km / h, 25 km / h, 30 km / h, 50 km / h, 80 km / h, 100 km / h, or 120 km / h.

[0061] In step S300, the test for signal loss fault in the rear wheel steering system includes the following steps:

[0062] Step S310: The control signal of the controller in the rear wheel steering system is lost.

[0063] Specifically, the control signals of the controller in the rear-wheel steering system include vehicle speed signal, steering enable signal, and target angle request signal. One, two, or more of these control signals can be lost by deleting, replacing, or not sending the corresponding signals, thus simulating a signal loss fault condition in the rear-wheel steering system. During the signal loss test, a programmable power supply provides the rear-wheel steering system with its normal operating voltage.

[0064] Step S320: When the control signal of the controller in the rear wheel steering gear is lost for more than a second preset time, the lost control signal is retransmitted.

[0065] Specifically, if the rear wheel steering system remains in a state of lost control signal for more than a second preset time, the corresponding lost control signal in the controller of the rear wheel steering system is restored by means of replacement or transmission, thereby enabling the rear wheel steering system to conditionally resume normal steering operation. The second preset time can be set to 9 seconds, 10 seconds, or 11 seconds.

[0066] Step S330: Obtain the third feedback signal inside the rear wheel steering gear.

[0067] Specifically, the third feedback signals inside the rear wheel steering system include operating status signals, error status signals, and DTC fault codes.

[0068] Step S340: Verify whether the state of the rear wheel steering system during and after the fault meets the third preset safety requirements based on the third feedback signal.

[0069] Specifically, the system records whether the working status signals and error status signal jumps meet the functional specifications, and checks whether the errors in the DTC report are expected faults. Based on these recorded data, the behavior of the rear wheel steering system when and after the control signal is lost is verified to determine whether the tested rear wheel steering system meets the third preset safety requirement of the rear wheel steering system function, thereby completing the signal loss fault test of the rear wheel steering system.

[0070] Furthermore, in step S500, a signal loss fault test can be performed on the rear wheel steering system by sending different vehicle speed signals to it. The vehicle speed signal can indicate the current vehicle speed as 0 km / h, 3 km / h, 10 km / h, 20 km / h, 25 km / h, 30 km / h, 50 km / h, 80 km / h, 100 km / h, or 120 km / h.

[0071] Furthermore, in step S600, the rear wheel steering system can be controlled to test for signal loss faults in both a stationary state and when a steering action is performed. The third feedback signal can also include an angle signal and record whether the angle returns to zero.

[0072] Understandably, signal loss fault tests can be performed on the rear wheel steering system when it is stationary, by sending different vehicle speed signals to it. Similarly, signal loss fault tests can be performed on the rear wheel steering system when it is in a turning state, by sending different vehicle speed signals to it.

[0073] In step S400, the voltage fault test for the rear wheel steering system includes the following steps:

[0074] Step S410: Control the power supply voltage of the rear wheel steering system to switch from the working voltage to the fault voltage.

[0075] Specifically, the programmable power supply first provides the normal operating voltage to the rear wheel steering system, and then switches the supplied voltage to a fault voltage. The rear wheel steering system fault levels are divided into two categories: yellow (recoverable fault, recovery is achieved by eliminating the fault conditions) and red (unrecoverable fault, requiring restart and the transmission of a normal operating signal). Fault voltages include ultra-low voltage (red light fault), low voltage (yellow light fault), high voltage (yellow light fault), and ultra-high voltage (red light fault). For example, ultra-low voltage ranges from 6.5 volts to less than or equal to 6.5 volts, low voltage ranges from 6.5 volts to 10.5 volts, high voltage ranges from 16 volts to 27 volts, and ultra-high voltage ranges from greater than 27 volts. These ranges may vary depending on the specific rear wheel steering system. It is crucial that the maximum voltage does not exceed the breakdown voltage of the rear wheel steering system to avoid permanent damage.

[0076] Step S420: When the power supply voltage of the rear wheel steering system is at the fault voltage for more than a third preset time, the power supply voltage of the rear wheel steering system is restored to the working voltage.

[0077] Specifically, if the power supply voltage of the rear wheel steering system remains at a fault voltage for more than a third preset time, the power supply voltage of the rear wheel steering system will be restored to the normal operating voltage by controlling the programmable power supply, thereby allowing the rear wheel steering system to conditionally return to normal operation. The third preset time can be set to 9 seconds, 10 seconds, or 11 seconds.

[0078] Step S430: Obtain the fourth feedback signal inside the rear wheel steering gear.

[0079] Specifically, the fourth feedback signal inside the rear wheel steering system includes operating status signal, error status signal, DTC fault code, etc.

[0080] Step S440: Verify whether the state of the rear wheel steering system during and after the fault meets the fourth preset safety requirements based on the fourth feedback signal.

[0081] Specifically, the system records whether the working status signals and error status signal jumps meet the functional specifications, and checks whether the errors in the DTC report are expected faults. Based on these recorded data, the behavior of the rear wheel steering system during and after a voltage fault is verified to determine whether the tested rear wheel steering system meets the fourth preset safety requirement of the rear wheel steering system function, thus completing the voltage fault test of the rear wheel steering system.

[0082] Furthermore, in step S500, a voltage fault test can be performed on the rear wheel steering system by sending different vehicle speed signals to it. The vehicle speed signal can indicate the current vehicle speed as 0 km / h, 3 km / h, 10 km / h, 20 km / h, 25 km / h, 30 km / h, 50 km / h, 80 km / h, 100 km / h, or 120 km / h.

[0083] Furthermore, in step S600, the voltage fault of the rear wheel steering gear can be tested when the rear wheel steering gear is stationary and when steering action is performed. The fourth feedback signal can also include an angle signal and record whether the angle returns to zero.

[0084] It is understandable that voltage fault tests can be performed on the rear wheel steering system when it is stationary, by sending different vehicle speed signals to it. Similarly, voltage fault tests can be performed on the rear wheel steering system when it is in a steering state, by sending different vehicle speed signals to it.

[0085] This invention's testing method, combined with a test bench, enables in-loop testing of rear-wheel steering systems. It effectively and accurately simulates various fault conditions, providing comprehensive testing of the rear-wheel steering system. This ensures the system meets and adapts to the functional requirements of rear-wheel steering systems, exhibiting high controllability and repeatability. It guarantees performance and reliability under various fault conditions, thereby improving vehicle safety. Bench testing effectively shortens the testing cycle, reduces the time and resources required for real-vehicle road testing, and avoids the potential risks associated with road testing. Furthermore, this invention's testing method allows for increased stress levels during testing, simulating extreme conditions and enabling the identification of potential problems in early design and production, thus shortening the development cycle.

[0086] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0087] This embodiment also provides a rear wheel steering system failure condition testing system. The system includes a memory, a processor, and a program stored in the memory and executable on the processor. When executed by the processor, the program implements the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" refers to a combination of software and / or hardware capable of performing a predetermined function. Although the systems described in the following embodiments are preferably implemented in software, hardware implementations, or a combination of software and hardware, are also possible and contemplated.

[0088] like Figure 8 As shown, a rear-wheel steering system fault condition testing system is used to execute the above steps S100, S200, S300, S400, S500 and S600, namely, testing the rear-wheel steering system for steering overspeed faults; testing the rear-wheel steering system for jamming faults; testing the rear-wheel steering system for signal loss faults; testing the rear-wheel steering system for voltage faults; testing the rear-wheel steering system for signal loss faults and / or voltage faults under the conditions of the rear-wheel steering system being stationary and when the rear-wheel steering system is performing steering actions; and testing the rear-wheel steering system for steering overspeed faults, jamming faults, signal loss faults and / or voltage faults under different vehicle speed signal conditions.

[0089] Specifically, the rear wheel steering system failure condition testing system includes:

[0090] The control unit 700 is used to execute the above steps S110, S120 and S130. That is, to apply the maximum working load to the left and right output ends of the rear wheel steering gear; to control the rear wheel steering gear to perform steering action; and to quickly reduce the load applied to the rear wheel steering gear to zero during the steering action of the rear wheel steering gear so that the displacement speed of the rear wheel steering gear screw exceeds the preset safety limit.

[0091] The data acquisition unit 800 is used to execute the above steps S140 and S150. That is, to acquire the first feedback signal inside the rear wheel steering gear; and to verify whether the behavior of the rear wheel steering gear after displacement overspeed meets the first preset safety requirements based on the first feedback signal.

[0092] Optionally, the control unit 700 is also used to execute steps S210, S220, and S230 above. Specifically, it controls the rear wheel steering to perform a steering action; during the steering action of the rear wheel steering, it applies a maximum working load to the left and right output ends of the rear wheel steering to stop the steering action; when the steering action of the rear wheel steering is stopped for more than a first preset time, it reduces the load applied to the left and right output ends of the rear wheel steering to zero. The data acquisition unit 800 is also used to execute steps S240 and S250 above, specifically, it acquires a second feedback signal from inside the rear wheel steering; and verifies whether the behavior of the rear wheel steering after jamming meets a second preset safety requirement based on the second feedback signal.

[0093] Optionally, the control unit 700 is also used to execute steps S310 and S320 above. That is, to retransmit the lost control signal of the controller in the rear wheel steering system when the loss of the control signal exceeds a second preset time. The data acquisition unit 800 is also used to execute steps S330 and S340 above, that is, to acquire the third feedback signal inside the rear wheel steering system; and to verify whether the state of the rear wheel steering system during and after the fault meets the third preset safety requirements based on the third feedback signal.

[0094] Optionally, the control unit 700 is also used to execute steps S410 and S420 above. That is, to control the power supply voltage of the rear wheel steering system to jump from the operating voltage to the fault voltage; when the power supply voltage of the rear wheel steering system is at the fault voltage for more than a third preset time, to restore the power supply voltage of the rear wheel steering system to the operating voltage. The data acquisition unit 800 is also used to execute steps S430 and S440 above, that is, to acquire the fourth feedback signal inside the rear wheel steering system; and to verify whether the state of the rear wheel steering system during and after the fault meets the fourth preset safety requirements based on the fourth feedback signal.

[0095] Optionally, the control unit 700 and the data acquisition unit 800 are also used to collaboratively execute the above steps S500 and S600. The signal loss fault and / or voltage fault of the rear wheel steering system are tested respectively when the rear wheel steering system is stationary and when the rear wheel steering system is performing a steering action; under different vehicle speed signal conditions, the steering overspeed fault, jamming fault, signal loss fault, and / or voltage fault of the rear wheel steering system are tested respectively.

[0096] The control unit 700 is communicatively connected to the rear wheel steering gear, the two linear actuators, and the programmable power supply. It simulates the control signals required for the rear wheel steering gear to operate, such as vehicle speed signals, steering gear enable signals, and target angle request signals, and controls the initiation and termination of fault injection. Furthermore, the control unit 700 coordinates the operation of the two linear actuators and the programmable power supply.

[0097] The data acquisition unit 800 is responsible for collecting and storing data and control signals from the rear wheel steering sensor and two linear actuator sensors, and processing the data or transmitting it to a separate data processing system for processing. The entire fault condition test system can simulate vehicle signals, real-time voltage, displacement and load of the steering screw when a fault occurs, according to test requirements.

[0098] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, which will not be repeated here. The system embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0099] Embodiments of the present invention also provide a computer-readable storage medium storing a computer program, wherein the computer program is configured to execute, when run on a computer or processor, a method for testing the failure condition of a rear wheel steering system as described in any of the above embodiments.

[0100] Optionally, in this embodiment, the computer program described above may be configured to store a computer program for performing the control method steps in the foregoing embodiments:

[0101] Step S100: Test for overspeed fault in the rear wheel steering system.

[0102] Step S110: Apply the maximum working load to the left and right output ends of the rear wheel steering system.

[0103] Step S120: Control the rear wheel steering gear to perform a steering action.

[0104] In step S130, during the steering action of the rear wheel steering gear, the load applied to the rear wheel steering gear is rapidly reduced to zero so that the displacement speed of the rear wheel steering gear lead screw exceeds the preset safety limit.

[0105] Step S140: Obtain the first feedback signal inside the rear wheel steering gear.

[0106] Step S150: Verify whether the behavior of the rear wheel steering gear after displacement overspeed meets the first preset safety requirements based on the first feedback signal.

[0107] Step S200: Test for the sticking fault of the rear wheel steering system.

[0108] Step S210: Control the rear wheel steering gear to perform a steering action.

[0109] Step S220: During the steering action of the rear wheel steering gear, apply the maximum working load to the left and right output ends of the rear wheel steering gear to stop the steering action of the rear wheel steering gear.

[0110] Step S230: When the steering action of the rear wheel steering gear stops for more than a first preset time, the load applied to the left and right output ends of the rear wheel steering gear is reduced to zero.

[0111] Step S240: Obtain the second feedback signal inside the rear wheel steering gear.

[0112] Step S250: Verify whether the behavior of the rear wheel steering gear after jamming meets the second preset safety requirements based on the second feedback signal.

[0113] Step S300: Test for signal loss fault in the rear wheel steering system.

[0114] Step S310: The control signal of the controller in the rear wheel steering system is lost.

[0115] Step S320: When the control signal of the controller in the rear wheel steering gear is lost for more than a second preset time, the lost control signal is retransmitted.

[0116] Step S330: Obtain the third feedback signal inside the rear wheel steering gear.

[0117] Step S340: Verify whether the state of the rear wheel steering system during and after the fault meets the third preset safety requirements based on the third feedback signal.

[0118] Step S400: Test for voltage faults in the rear wheel steering system.

[0119] Step S410: Control the power supply voltage of the rear wheel steering system to switch from the working voltage to the fault voltage.

[0120] Step S420: When the power supply voltage of the rear wheel steering system is at the fault voltage for more than a third preset time, the power supply voltage of the rear wheel steering system is restored to the working voltage.

[0121] Step S430: Obtain the fourth feedback signal inside the rear wheel steering gear.

[0122] Step S440: Verify whether the state of the rear wheel steering system during and after the fault meets the fourth preset safety requirements based on the fourth feedback signal.

[0123] Step S500: Test the signal loss fault and / or voltage fault of the rear wheel steering system when the rear wheel steering system is stationary and when the rear wheel steering system is performing a steering action.

[0124] Step S600: Test the rear wheel steering system for overspeed faults, jamming faults, signal loss faults and / or voltage faults under different vehicle speed signal conditions.

[0125] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated here.

[0126] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0127] In some embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The system embodiments described above are merely illustrative; for example, the division of modules can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between modules may be electrical or other forms.

[0128] It will be understood by those skilled in the art that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically include computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0129] The embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

Claims

1. A method for testing fault conditions in a rear-wheel steering system, applied to the testing of rear-wheel steering systems, characterized in that, The testing method includes testing for steering overspeed faults in the rear wheel steering system, wherein testing for steering overspeed faults in the rear wheel steering system includes: Control the two linear actuators to apply the maximum working load to the left and right output ends of the rear wheel steering system respectively; Control the rear wheel steering system to perform steering actions; During the steering action of the rear wheel steering gear, the linear actuator is controlled to quickly reduce the load applied to the rear wheel steering gear to zero, so that the displacement speed of the rear wheel steering gear lead screw exceeds the preset safety limit; Obtain the first feedback signal from inside the rear wheel steering gear; The behavior of the rear wheel steering gear after displacement overspeed is verified based on the first feedback signal to see if it meets the first preset safety requirements.

2. The method for testing the fault conditions of a rear wheel steering system according to claim 1, characterized in that, The testing method further includes testing for the sticking fault of the rear wheel steering system, wherein the testing for the sticking fault of the rear wheel steering system includes: Control the rear wheel steering system to perform steering actions; During the steering action of the rear wheel steering gear, the maximum working load is applied to the left and right output ends of the rear wheel steering gear to stop the steering action of the rear wheel steering gear; When the steering action of the rear wheel steering device is stopped for more than a first preset time, the load applied to the left and right output ends of the rear wheel steering device will be reduced to zero. Obtain the second feedback signal inside the rear wheel steering gear; The second feedback signal is used to verify whether the behavior of the rear wheel steering system after jamming meets the second preset safety requirements.

3. The method for testing the fault conditions of a rear wheel steering system according to claim 2, characterized in that, The testing method further includes testing for signal loss faults in the rear wheel steering system, wherein testing for signal loss faults in the rear wheel steering system includes: The control signal of the controller in the rear wheel steering system is lost; If the control signal of the controller in the rear wheel steering system is lost for more than a second preset time, the lost control signal is retransmitted. Obtain the third feedback signal inside the rear wheel steering gear; The third feedback signal is used to verify whether the state of the rear wheel steering system during and after a fault meets the third preset safety requirements.

4. The method for testing the fault conditions of a rear wheel steering system according to claim 3, characterized in that, The control signals include one, two, or more of the following: vehicle speed signal, steering enable signal, and target angle request signal.

5. The method for testing the fault conditions of a rear wheel steering system according to claim 3, characterized in that, The testing method further includes testing for voltage faults in the rear wheel steering system, wherein testing for voltage faults in the rear wheel steering system includes: The power supply voltage of the rear wheel steering system is switched from the operating voltage to the fault voltage. When the power supply voltage of the rear wheel steering system is at a fault voltage for more than a third preset time, the power supply voltage of the rear wheel steering system will be restored to the working voltage. Obtain the fourth feedback signal inside the rear wheel steering gear; The fourth feedback signal is used to verify whether the state of the rear wheel steering system during and after a fault meets the fourth preset safety requirements.

6. The method for testing the fault conditions of a rear wheel steering system according to claim 5, characterized in that, The test method also includes testing the signal loss fault and / or voltage fault of the rear wheel steering unit when the rear wheel steering unit is stationary and when the rear wheel steering unit is performing a steering action.

7. The method for testing the fault conditions of a rear wheel steering system according to claim 5, characterized in that, The testing method also includes testing the rear wheel steering system for overspeed faults, jamming faults, signal loss faults, and / or voltage faults under different vehicle speed signal conditions.

8. A rear-wheel steering system fault condition testing system, applied to the testing of rear-wheel steering systems, characterized in that, The testing system includes: Two linear actuators, the output ends of which are respectively hinged to the left and right output ends of the rear wheel steering gear; The control unit is configured to: control the two linear actuators to apply maximum working loads to the left and right output ends of the rear wheel steering gear respectively; control the rear wheel steering gear to perform steering actions; and during the steering actions of the rear wheel steering gear, control the linear actuators to quickly reduce the load applied to the rear wheel steering gear to zero, so that the displacement speed of the rear wheel steering gear screw exceeds a preset safety limit. The data acquisition unit is used to: acquire a first feedback signal inside the rear wheel steering gear; and verify, based on the first feedback signal, whether the behavior of the rear wheel steering gear after displacement overspeed meets a first preset safety requirement.

9. A test bench for fault conditions of a rear wheel steering system, used for testing rear wheel steering systems, characterized in that, The test bench includes a fixed frame, a programmable power supply, and two linear actuators fixed relative to the fixed frame. The fixed frame is used to fix the rear wheel steering gear. The output ends of the two linear actuators are respectively hinged to the left and right output ends of the rear wheel steering gear. The programmable power supply provides power voltage to the rear wheel steering gear. The rear wheel steering gear fault condition test bench is used for the rear wheel steering gear fault condition test method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, wherein the computer program is configured to execute, when run on a computer or processor, a method for testing the failure condition of a rear wheel steering system as described in any one of claims 1 to 7.

Images