Rear wheel steering gear fault condition test method, system and rack

Abstract

The invention discloses a method, a system and a rack for testing fault conditions of a rear wheel steering gear, and belongs to the technical field of steering gears. The method comprises the following steps: applying maximum working load to left and right output ends of a rear wheel steering gear; a rear wheel steering gear is controlled to conduct steering action; in the steering action process 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 a lead screw of the rear wheel steering gear exceeds a preset safety limit; acquiring a first feedback signal in the rear wheel steering gear; and according to the first internal feedback signal, checking whether the behavior after the displacement of the rear wheel steering gear is overspeed meets a first preset safety requirement or not. The displacement speed of a lead screw of the rear wheel steering gear exceeds the safety limit in a load sudden change mode, so that the working condition which can be solved by the required functions 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 or not is judged according to the first feedback signal; therefore, testing of functional requirements of the rear wheel steering gear is completed.

Description

Technical Field

[0001] The present invention relates to the technical field of steering gears, and in particular to a method, system and test bench for testing fault conditions of rear wheel steering gears. Background Art

[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 higher safety requirements on rear-wheel steering technology.

[0003] However, the fault condition test of the existing steering gear cannot fully adapt to or meet the functional requirements of the rear-wheel steering gear, and the whole vehicle road test requires high time and resource costs. Summary of the Invention

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

[0005] In order to solve the above-mentioned technical problems, the technical solution adopted in the first aspect of the present invention provides a rear wheel steering gear fault condition testing method, which is applied to the testing of the rear wheel steering gear. The testing method includes testing the steering overspeed fault of the rear wheel steering gear. The testing of the steering overspeed fault of the rear wheel steering gear includes: applying a 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; during the steering action of the rear wheel steering gear, quickly reducing 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; obtaining a first feedback signal inside the rear wheel steering gear; and verifying whether the behavior of the rear wheel steering gear after the displacement overspeed meets a first preset safety requirement based on the first internal feedback signal.

[0006] This 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 solve, and judging based on the first feedback signal inside the rear-wheel steering gear whether the behavior of the rear-wheel steering gear after the displacement exceeds the speed limit meets the first preset safety requirement, thereby completing the test of the functional requirements of the rear-wheel steering gear.

[0007] Optionally, the test method also includes testing a stuck fault of the rear wheel steering gear, and the testing of the stuck 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 of the rear wheel steering gear; when the steering action of the rear wheel steering gear is stopped 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; obtaining a second feedback signal from the inside of the rear wheel steering gear; and verifying whether the behavior of the rear wheel steering gear after the stuck action meets a second preset safety requirement based on the second feedback signal.

[0008] Optionally, the testing method also includes testing a signal loss fault of the rear-wheel steering gear, and the testing of the signal loss fault of the rear-wheel steering gear includes: losing the control signal of the controller in the rear-wheel steering gear; when the control signal of the controller in the rear-wheel steering gear is lost for more than a second preset time, resending the lost control signal; obtaining a third feedback signal inside the rear-wheel steering gear; and verifying whether the status of the rear-wheel steering gear during the fault and after the fault recovery meets a third preset safety requirement based on the third feedback signal.

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

[0010] Optionally, the testing method also includes testing the voltage fault of the rear-wheel steering gear, and the testing of the voltage fault of the rear-wheel steering gear includes: controlling the power supply voltage of the rear-wheel steering gear to jump from the working voltage to the fault voltage; when the power supply voltage of the rear-wheel steering gear is at the fault voltage for more than a third preset time, restoring the power supply voltage of the rear-wheel steering gear to the working voltage; obtaining a fourth feedback signal inside the rear-wheel steering gear; and verifying whether the status of the rear-wheel steering gear during the fault and after the fault recovery meets the fourth preset safety requirement based on the fourth feedback signal.

[0011] Optionally, the testing 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 in a stationary state and when the rear wheel steering gear is performing a steering action.

[0012] Optionally, the testing method further includes testing the steering overspeed fault, the jamming fault, the signal loss fault and / or the voltage fault of the rear wheel steering gear respectively under conditions of different vehicle speed signals.

[0013] A second aspect of the present invention provides a rear-wheel steering gear fault condition test system, which is used for testing rear-wheel steering gears. The test system includes: a control unit, used to: apply a maximum working load to the left and right output ends of the rear-wheel steering gear; control the rear-wheel steering gear to perform a steering action; during the steering action of the rear-wheel steering gear, 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; a data acquisition unit, used to: obtain a first feedback signal inside the rear-wheel steering gear; and verify whether the behavior of the rear-wheel steering gear after the displacement exceeds the speed limit meets the first preset safety requirement based on the first feedback signal.

[0014] A third aspect of the present invention provides a rear-wheel steering gear fault condition test bench, which is used for testing rear-wheel steering gears. 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, and 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 supply voltage for the rear-wheel steering gear. The rear-wheel steering gear fault condition test bench is used for any of the above-mentioned rear-wheel steering gear fault condition testing methods.

[0015] A fourth aspect of the present invention provides a computer-readable storage medium, in which a computer program is stored, wherein the computer program is configured to execute any of the above-mentioned rear wheel steering gear fault condition testing methods when running on a computer or processor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the structure of a rear wheel steering gear fault condition test bench according to an embodiment of the present invention; Figure 2 Flowchart of a method for testing a rear wheel steering gear fault condition according to an embodiment of the present invention; Figure 3 Schematic diagram of a further test flow of a rear wheel steering gear fault condition test method according to an embodiment of the present invention; Figure 4 1. It is a schematic flow chart of a steering overspeed fault test in a rear wheel steering gear fault condition test method according to an embodiment of the present invention; Figure 5 1. It is a flow chart of a stuck fault test in a rear wheel steering gear fault condition test method according to an embodiment of the present invention; Figure 6 1. It is a schematic flow chart of a signal loss fault test in a rear wheel steering gear fault condition test method according to an embodiment of the present invention; Figure 7 1. It is a flow chart of a voltage fault test in a method for testing a rear wheel steering gear fault condition according to an embodiment of the present invention; Figure 8 This is a structural block diagram of a rear wheel steering gear fault condition testing system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0018] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices. It should be noted that the method provided by the embodiment of the present invention is that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system containing at least one set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here. The method embodiment can also be executed in an electronic system / device including a memory and a processor, a similar control system, or 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 above-mentioned electronic system / device may also include a communication device and a display device for communication functions. It will be understood by those skilled in the art that the above-mentioned structural description is only illustrative and does not limit the structure of the above-mentioned electronic system / device. For example, the electronic system / device may also include more or fewer components than the above-mentioned structural description, or have a configuration different from the above-mentioned structural description. like Figure 1As shown, a rear-wheel steering gear fault condition test bench is used for testing the rear-wheel steering gear 910. The test bench includes a fixed frame 920, a programmable power supply 930 and two linear actuators 940. The fixed frame 920 is used to install and fix the rear-wheel steering gear 910 to maintain the position and posture of the rear-wheel steering gear 910 sample under motion or large load conditions. The housings of the two linear actuators 940 are relatively fixed to the fixed frame 920. The two linear actuators 940 are used to simulate the physical quantities such as motion and load of the rear-wheel steering gear 910 during actual driving. The editable power supply 930 is used to provide a power supply voltage for the rear-wheel steering gear 910, including a normal operating voltage, a high voltage exceeding the operating voltage, or a low voltage below the operating voltage.

[0019] During testing, the rear-wheel steering gear 910 assembly is first mounted on the mounting bracket 920 and the mounting bolts are tightened to the specified torque to ensure a stable and secure installation. The left and right output terminals of the rear-wheel steering gear 910 are then connected to the output terminals of the two linear actuators 940 via hinge structures, ensuring that the output force direction of the linear actuators 940 aligns with the direction of motion of the rear-wheel steering gear 910. Once the test bench is installed, the rear-wheel steering gear 910 is connected to the editable power supply 930, providing a testing environment for the fault condition testing method for the rear-wheel steering gear 910.

[0020] like Figure 2-7 As shown, a rear wheel steering gear fault condition test method is applied to the test of the rear wheel steering gear, and the test method includes: Step S100: testing the steering overspeed fault of the rear wheel steering gear.

[0021] Step S200: Testing the stuck fault of the rear wheel steering gear.

[0022] Step S300: Testing the rear wheel steering gear for a signal loss fault.

[0023] Step S400: testing the voltage fault of the rear wheel steering gear.

[0024] Step S500 : testing the rear wheel steering device for a signal loss fault and / or a voltage fault when the rear wheel steering device is in a stationary state and when the rear wheel steering device is performing a steering action.

[0025] Step S600 , testing the rear wheel steering gear for steering overspeed fault, stuck fault, signal loss fault and / or voltage fault under conditions of different vehicle speed signals.

[0026] In step S100, the test for the steering overspeed fault of the rear wheel steering gear includes the following steps: Step S110: applying a maximum working load to the left and right output ends of the rear wheel steering gear.

[0027] Specifically, two linear actuators were controlled to apply the maximum load the rear-wheel steering gear could withstand to its left and right output terminals, simulating the linear actuator's ultimate load condition. During the steering overspeed fault test, the programmable power supply provided the rear-wheel steering gear with normal operating voltage.

[0028] Step S120: Control the rear wheel steering gear to perform steering action.

[0029] Specifically, a control signal is sent to the rear wheel steering gear to make the rear wheel steering gear perform a steering action under a maximum working load state, so as to simulate the working process of the rear wheel steering gear under an extreme load state.

[0030] Step S130: During the steering action of the rear wheel steering gear, the load applied to the rear wheel steering gear is quickly reduced to zero, so that the displacement speed of the screw rod of the rear wheel steering gear exceeds a preset safety limit.

[0031] Specifically, when the rear-wheel steering gear is steering under maximum load, the two linear actuators are controlled simultaneously or sequentially to rapidly reduce the load applied to the rear-wheel steering gear to zero. At this point, the displacement speed of the rear-wheel steering gear's lead screw exceeds a preset safety limit, simulating a steering overspeed fault. The deceleration rate for load reduction is set based on the maximum deceleration provided by the linear actuators.

[0032] Step S140: obtaining a first feedback signal from the rear wheel steering gear.

[0033] Specifically, the first feedback signal inside the rear wheel steering gear includes a working state signal, an error state signal, a DTC fault code, an angle signal, and the like.

[0034] Step S150: Checking whether the behavior of the rear wheel steering gear after displacement overspeed meets a first preset safety requirement based on the first feedback signal.

[0035] Specifically, the system records whether the transitions between the operating and error status signals meet functional specifications, checks whether the errors reported by the DTC are expected faults, and records the angle curve. Based on this recorded data, the system verifies the behavior of the rear-wheel steering gear after displacement overspeed, determining whether the tested rear-wheel steering gear meets the first preset safety requirement for the rear-wheel steering gear function, thereby completing the rear-wheel steering overspeed fault test.

[0036] Furthermore, in step S500, the rear wheel steering gear may be tested for steering overspeed faults by sending different vehicle speed signals to the rear wheel steering gear. The vehicle speed signal may indicate a current vehicle speed of 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.

[0037] In step S200, the test for the stuck fault of the rear wheel steering gear includes the following steps: Step S210: Control the rear wheel steering gear to perform steering action.

[0038] Specifically, a control signal is sent to the rear wheel steering gear to make it perform a steering action, thereby simulating the normal steering operation of the rear wheel steering gear. During the stuck fault test, the programmable power supply provides a normal operating voltage for the rear wheel steering gear.

[0039] Step S220: During the steering operation of the rear wheel steering gear, a maximum working load is applied to the left and right output ends of the rear wheel steering gear to stop the steering operation of the rear wheel steering gear.

[0040] Specifically, during the rear-wheel steering operation, the two linear actuators are controlled to simultaneously or sequentially apply the maximum operating load of the rear-wheel steering gear to the left and right output terminals of the rear-wheel steering gear, thereby stopping the steering movement of the rear-wheel steering gear. This simulates a situation where the rear-wheel steering gear is stuck during normal steering operation.

[0041] Step S230: When the steering action of the rear wheel steering gear is stopped 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.

[0042] Specifically, when the steering motion of the rear-wheel steering system 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 system to zero, thereby eliminating the stuck resistance and allowing the rear-wheel steering system to resume normal steering operation. The first preset time can be 9 seconds, 10 seconds, or 11 seconds.

[0043] Step S240: Acquire a second feedback signal from the rear wheel steering gear.

[0044] Specifically, the second feedback signal inside the rear wheel steering gear includes a working state signal, an error state signal, a DTC fault code, etc.

[0045] Step S250: Checking whether the stuck hysteresis of the rear wheel steering device meets a second preset safety requirement based on the second feedback signal.

[0046] Specifically, the system records whether the transitions between the operating and error status signals meet functional specifications, and checks whether the errors reported by the DTCs are expected faults. Based on this recorded data, the system verifies the behavior of the rear steering gear after it becomes stuck, determining whether the tested rear steering gear meets the second preset safety requirement for the rear steering gear function, thereby completing the rear steering gear stuck fault test.

[0047] Furthermore, in step S500, the rear wheel steering gear may be tested for a stuck fault by sending different vehicle speed signals to the rear wheel steering gear. The vehicle speed signal may indicate a current vehicle speed of 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.

[0048] In step S300, testing the rear wheel steering gear signal loss fault includes the following steps: Step S310: The control signal of the controller in the rear wheel steering gear is lost.

[0049] Specifically, the control signals of the rear-wheel steering controller include a vehicle speed signal, a steering enable signal, and a target angle request signal. Loss of one, two, or more of these control signals can be achieved by deleting, replacing, or not sending the corresponding signals, thereby simulating a rear-wheel steering signal loss fault condition. During the signal loss test, the programmable power supply provides normal operating voltage for the rear-wheel steering.

[0050] Step S320: When the control signal of the controller in the rear wheel steering device is lost for more than a second preset time, the lost control signal is resent.

[0051] Specifically, if the rear-wheel steering system maintains a control signal loss state for longer than a second preset time, the corresponding control signal in the controller of the rear-wheel steering system is restored by replacing or sending the lost control signal, thereby conditionally restoring the rear-wheel steering system to a normal steering state. The second preset time can be set to 9 seconds, 10 seconds, or 11 seconds.

[0052] Step S330: Acquire a third feedback signal from the rear wheel steering gear.

[0053] Specifically, the third feedback signal inside the rear wheel steering gear includes a working state signal, an error state signal, a DTC fault code, etc.

[0054] Step S340: Checking whether the states of the rear wheel steering gear during and after the fault is recovered meet a third preset safety requirement based on the third feedback signal.

[0055] Specifically, the system records whether the transitions between the operating and error status signals meet functional specifications, and checks whether the errors reported by the DTC are expected faults. Based on this recorded data, the system verifies the behavior of the rear-wheel steering system during and after a control signal loss. This determines whether the tested rear-wheel steering system meets the third preset safety requirement for the rear-wheel steering system function, thus completing the rear-wheel steering system signal loss fault test.

[0056] Furthermore, in step S500, the rear wheel steering gear may be tested for signal loss faults under conditions where different vehicle speed signals are sent to the rear wheel steering gear. The vehicle speed signal may indicate a current vehicle speed of 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.

[0057] Furthermore, in step S600, the rear wheel steering gear can be controlled to test the signal loss fault of the rear wheel steering gear in a stationary state and when performing a steering action, and the third feedback signal can also include an angle signal and record whether the angle returns to zero.

[0058] It is understood that the rear wheel steering system can be tested for signal loss failure by sending different vehicle speed signals to the rear wheel steering system when the rear wheel steering system is in a stationary state. The rear wheel steering system can also be tested for signal loss failure by sending different vehicle speed signals to the rear wheel steering system when the rear wheel steering system is in a steering state.

[0059] In step S400, the voltage fault test of the rear wheel steering gear includes the following steps: Step S410: Control the power supply voltage of the rear wheel steering gear to jump from the working voltage to the fault voltage.

[0060] Specifically, the programmable power supply is first controlled to provide the rear-wheel steering gear with a normal operating voltage. The programmable power supply is then controlled to switch the power supply voltage to a fault voltage. Rear-wheel steering gear fault levels are categorized into two levels: yellow (recoverable fault, recoverable upon eliminating the fault condition) and red (non-recoverable fault, requiring a restart and 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, the ultra-low voltage range is 6.5 volts or less, the low voltage range is 6.5 volts to 10.5 volts, the high voltage range is 16 volts to 27 volts, and the ultra-high voltage range is greater than 27 volts. These ranges may vary for different rear-wheel steering gear projects. It is important to note that the maximum voltage must not exceed the breakdown voltage of the rear-wheel steering gear to avoid permanent damage.

[0061] Step S420: When the power supply voltage of the rear wheel steering gear is at the fault voltage for more than a third preset time, the power supply voltage of the rear wheel steering gear is restored to the working voltage.

[0062] Specifically, when the power supply voltage of the rear-wheel steering device remains at a fault voltage for longer than a third preset time, the programmable power supply is controlled to restore the power supply voltage of the rear-wheel steering device to a normal operating voltage, thereby conditionally resuming normal operation of the rear-wheel steering device. The third preset time can be set to 9 seconds, 10 seconds, or 11 seconds.

[0063] Step S430: Acquire a fourth feedback signal from the rear wheel steering gear.

[0064] Specifically, the fourth feedback signal inside the rear wheel steering gear includes a working state signal, an error state signal, a DTC fault code, etc.

[0065] Step S440: Verify, based on the fourth feedback signal, whether the states of the rear wheel steering gear during and after the fault is recovered meet a fourth preset safety requirement.

[0066] Specifically, the system records whether the transitions between the operating status signal and the error status signal meet functional specifications, and checks whether the error reported by the DTC is an expected fault. Based on this recorded data, the system verifies the behavior of the rear steering gear during and after a voltage fault occurs, determining whether the tested rear steering gear meets the fourth preset safety requirement for the rear steering gear function, thereby completing the voltage fault test for the rear steering gear.

[0067] Furthermore, in step S500, the rear wheel steering gear may be tested for voltage faults under conditions where different vehicle speed signals are sent to the rear wheel steering gear. The vehicle speed signal may indicate a current vehicle speed of 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.

[0068] Furthermore, in step S600, the rear wheel steering gear may be controlled to test the voltage fault of the rear wheel steering gear when it is stationary and when performing a steering action. The fourth feedback signal may also include an angle signal and record whether the angle returns to zero.

[0069] It is understood that the voltage fault test of the rear wheel steering gear can be performed separately when the rear wheel steering gear is in a stationary state by sending different vehicle speed signals to the rear wheel steering gear. The voltage fault test of the rear wheel steering gear can also be performed separately when the rear wheel steering gear is in a steering state by sending different vehicle speed signals to the rear wheel steering gear.

[0070] The testing method of the present invention, combined with a test bench, can realize in-loop testing of the rear-wheel steering gear, can effectively and accurately simulate a variety of fault operating modes, conduct comprehensive testing of the rear-wheel steering gear, adapt to and meet the functional requirements of the rear-wheel steering gear, have high controllability and repeatability, ensure performance and reliability under various fault conditions, and thus improve vehicle safety. Bench testing can effectively shorten the test cycle, reduce the time and resources required for actual vehicle road testing, and avoid the potential risks faced by road testing. The testing method of the present invention can increase the stress level in the test, simulate extreme operating conditions, discover potential problems in early design and production, and shorten the research and development cycle.

[0071] Through the description of the above embodiments, those skilled in the art will clearly understand that the methods according to the above embodiments can be implemented using software plus the necessary general-purpose hardware platform. Of course, hardware can also be used, but in many cases the former is the more preferred implementation method. Based on this understanding, the technical solution of the present invention, or the portion 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, or optical disk) and includes a number of instructions for enabling a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in various embodiments of the present invention. In this embodiment, a rear-wheel steering gear fault condition test system is also provided, which includes a memory, a processor, and a program stored in the memory and executable on the processor. When the program is executed by the processor, it is used to implement the above-mentioned embodiments and preferred implementation methods. Those that have been explained will not be repeated here. As used below, the term "module" refers to a combination of software and / or hardware that can implement a predetermined function. Although the system described in the following embodiments is preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and conceivable.

[0072] like Figure 8 As shown, a rear wheel steering gear fault operating condition test system is used to execute the above steps S100, S200, S300, S400, S500 and S600, namely, testing the steering overspeed fault of the rear wheel steering gear; testing the jamming fault of the rear wheel steering gear; testing the signal loss fault of the rear wheel steering gear; testing the voltage fault of the rear wheel steering gear; 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; and testing the steering overspeed fault, jamming fault, signal loss fault and / or voltage fault of the rear wheel steering gear under conditions of different vehicle speed signals.

[0073] Specifically, the rear wheel steering gear fault condition test system includes: The control unit 700 is configured to execute steps S110, S120, and S130. Specifically, the control unit 700 applies a maximum operating load to the left and right output terminals of the rear-wheel steering gear; controls the rear-wheel steering gear to perform a steering action; and during the steering action, rapidly reduces 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 800 is configured to execute the above steps S140 and S150, i.e., to obtain a first feedback signal from the rear wheel steering gear; and to 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.

[0074] Optionally, the control unit 700 is further configured to execute steps S210, S220, and S230. Specifically, the control unit 700 controls the rear-wheel steering gear to perform a steering action; during the steering action, a maximum operating load is applied to the left and right output terminals of the rear-wheel steering gear to stop the steering action of the rear-wheel steering gear; and when the steering action of the rear-wheel steering gear stops for a period exceeding a first preset time, the load applied to the left and right output terminals of the rear-wheel steering gear is reduced to zero. The data acquisition unit 800 is further configured to execute steps S240 and S250, namely, to obtain a second feedback signal from within the rear-wheel steering gear; and to verify, based on the second feedback signal, whether the stuck behavior of the rear-wheel steering gear meets a second preset safety requirement.

[0075] Optionally, the control unit 700 is further configured to execute steps S310 and S320 above. Specifically, the control signal from the controller in the rear-wheel steering system is lost; when the control signal from the controller in the rear-wheel steering system is lost for a second predetermined period of time, the lost control signal is resent. The data acquisition unit 800 is further configured to execute steps S330 and S340 above, specifically, to obtain a third feedback signal from within the rear-wheel steering system; and to verify, based on the third feedback signal, whether the state of the rear-wheel steering system during and after the fault condition meets a third predetermined safety requirement.

[0076] Optionally, the control unit 700 is further configured to execute steps S410 and S420 above. Specifically, the control unit 700 controls the power supply voltage of the rear-wheel steering gear to jump from the operating voltage to the fault voltage; and when the power supply voltage of the rear-wheel steering gear remains at the fault voltage for longer than a third preset time, the power supply voltage of the rear-wheel steering gear is restored to the operating voltage. The data acquisition unit 800 is further configured to execute steps S430 and S440 above, namely, to obtain a fourth feedback signal from within the rear-wheel steering gear; and to verify, based on the fourth feedback signal, whether the states of the rear-wheel steering gear during and after fault recovery meet fourth preset safety requirements.

[0077] Optionally, the control unit 700 and the data acquisition unit 800 are further configured to collaboratively execute the above steps S500 and S600. The rear wheel steering device is tested for signal loss faults and / or voltage faults when the rear wheel steering device is stationary and when the rear wheel steering device is performing a steering action; and the rear wheel steering device is tested for steering overspeed faults, stuck faults, signal loss faults, and / or voltage faults under conditions of different vehicle speed signals.

[0078] The control unit 700 communicates with the rear-wheel steering gear, two linear actuators, and a programmable power supply. It simulates the control signals required for the rear-wheel steering gear, such as vehicle speed, steering enable signal, and target angle request signal, and controls the start and stop of fault injection. Furthermore, the control unit 700 coordinates the operation of the two linear actuators and the programmable power supply.

[0079] Among them, 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 separately established data processing system for processing. The entire fault condition test system can simulate the vehicle signal, real-time voltage, displacement and load of the steering screw when a fault occurs according to test requirements.

[0080] Alternatively, specific examples in this embodiment may refer to the examples described in the above embodiments and optional implementations, and this embodiment will not be described in detail here. The system embodiment described above is merely illustrative, and 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 may be selected according to actual needs to achieve the purpose of this embodiment.

[0081] An embodiment of the present invention also provides a computer-readable storage medium, in which a computer program is stored, wherein the computer program is configured to execute a rear wheel steering gear fault condition testing method described in any of the above embodiments when running on a computer or processor.

[0082] Optionally, in this embodiment, the computer program may be configured to store a computer program for executing the steps of the control method in the aforementioned embodiment: Step S100: testing the steering overspeed fault of the rear wheel steering gear.

[0083] Step S110: applying a maximum working load to the left and right output ends of the rear wheel steering gear.

[0084] Step S120: Control the rear wheel steering gear to perform steering action.

[0085] Step S130: During the steering action of the rear wheel steering gear, the load applied to the rear wheel steering gear is quickly reduced to zero, so that the displacement speed of the screw rod of the rear wheel steering gear exceeds a preset safety limit.

[0086] Step S140: obtaining a first feedback signal from the rear wheel steering gear.

[0087] Step S150: Checking whether the behavior of the rear wheel steering gear after displacement overspeed meets a first preset safety requirement based on the first feedback signal.

[0088] Step S200: Testing the stuck fault of the rear wheel steering gear.

[0089] Step S210: Control the rear wheel steering gear to perform steering action.

[0090] Step S220: During the steering operation of the rear wheel steering gear, a maximum working load is applied to the left and right output ends of the rear wheel steering gear to stop the steering operation of the rear wheel steering gear.

[0091] Step S230: When the steering action of the rear wheel steering gear is stopped 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.

[0092] Step S240: Acquire a second feedback signal from the rear wheel steering gear.

[0093] Step S250: Checking whether the stuck hysteresis of the rear wheel steering device meets a second preset safety requirement based on the second feedback signal.

[0094] Step S300: Testing the rear wheel steering gear for a signal loss fault.

[0095] Step S310: The control signal of the controller in the rear wheel steering gear is lost.

[0096] Step S320: When the control signal of the controller in the rear wheel steering device is lost for more than a second preset time, the lost control signal is resent.

[0097] Step S330: Acquire a third feedback signal from the rear wheel steering gear.

[0098] Step S340: Checking whether the states of the rear wheel steering gear during and after the fault is recovered meet a third preset safety requirement based on the third feedback signal.

[0099] Step S400: testing the voltage fault of the rear wheel steering gear.

[0100] Step S410: Control the power supply voltage of the rear wheel steering gear to jump from the working voltage to the fault voltage.

[0101] Step S420: When the power supply voltage of the rear wheel steering gear is at the fault voltage for more than a third preset time, the power supply voltage of the rear wheel steering gear is restored to the working voltage.

[0102] Step S430: Acquire a fourth feedback signal from the rear wheel steering gear.

[0103] Step S440: Verify, based on the fourth feedback signal, whether the states of the rear wheel steering gear during and after the fault is recovered meet a fourth preset safety requirement.

[0104] Step S500 : testing the rear wheel steering device for a signal loss fault and / or a voltage fault when the rear wheel steering device is in a stationary state and when the rear wheel steering device is performing a steering action.

[0105] Step S600 , testing the rear wheel steering gear for steering overspeed fault, stuck fault, signal loss fault and / or voltage fault under conditions of different vehicle speed signals.

[0106] Optionally, specific examples in this embodiment may refer to the examples described in the above embodiments and optional implementation modes, and this embodiment will not be described in detail here. In the above embodiments of the present invention, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments. In some embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the system embodiments described above are only exemplary. For example, the division of the modules can be a logical function division. In actual implementation, there may be other division methods, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, modules or indirect coupling or communication connection of modules, which can be electrical or other forms.

[0107] Those skilled in the art will appreciate that all or some of the steps and systems disclosed above can be implemented as software, firmware, hardware, or any suitable combination thereof. Some or all of the physical components may 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 may be distributed on computer-readable media, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is well 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 disks (DVDs) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. Furthermore, as is well known to those skilled in the art, communication media typically includes computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0108] The embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, i.e., they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

Claims

1. A rear wheel steering gear fault condition testing method, applied to the testing of rear wheel steering gear, characterized in that: The testing method includes testing a steering overspeed fault of the rear wheel steering gear, and the testing of the steering overspeed fault of the rear wheel steering gear includes: Applying a maximum working load to the left and right output ends of the rear wheel steering gear; Controlling the rear wheel steering gear to perform steering action; During the steering action of the rear wheel steering gear, the load applied to the rear wheel steering gear is quickly reduced to zero, so that the displacement speed of the screw rod of the rear wheel steering gear exceeds a preset safety limit; Obtaining a first feedback signal from the rear wheel steering device; 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.

2. A rear wheel steering gear fault condition testing method according to claim 1, characterized in that: The testing method further includes testing the stuck fault of the rear wheel steering gear, wherein the testing the stuck fault of the rear wheel steering gear includes: Controlling the rear wheel steering gear to perform 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 of the rear wheel steering gear; When the steering action of the rear wheel steering gear is stopped 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; Obtaining a second feedback signal from the rear wheel steering device; The second feedback signal is used to check whether the behavior of the rear wheel steering device after it is stuck meets a second preset safety requirement.

3. A rear wheel steering gear fault condition testing method according to claim 2, characterized in that: The testing method further includes testing a signal loss fault of the rear wheel steering gear, wherein the testing of the signal loss fault of the rear wheel steering gear includes: Loss of control signal from the controller in the rear wheel steering gear; When the control signal of the controller in the rear wheel steering device is lost for more than a second preset time, resending the lost control signal; Obtaining a third feedback signal from the rear wheel steering device; The third feedback signal is used to verify whether the states of the rear wheel steering gear during and after the fault is recovered meet a third preset safety requirement.

4. A rear wheel steering gear fault condition testing method according to claim 3, characterized in that: The control signal includes one, two or more of a vehicle speed signal, a steering enable signal and a target angle request signal.

5. A rear wheel steering gear fault condition testing method according to claim 3, characterized in that: The testing method further includes testing a voltage fault of the rear wheel steering gear, wherein the testing of the voltage fault of the rear wheel steering gear includes: Controlling the power supply voltage of the rear wheel steering gear to jump from the working voltage to the fault voltage; When the power supply voltage of the rear wheel steering gear is at a fault voltage for more than a third preset time, restoring the power supply voltage of the rear wheel steering gear to an operating voltage; obtaining a fourth feedback signal from the rear wheel steering device; The fourth feedback signal is used to verify whether the states of the rear wheel steering gear during and after the fault is recovered meet a fourth preset safety requirement.

6. A rear wheel steering gear fault condition testing method according to claim 5, characterized in that: The testing method further includes testing the rear wheel steering device for a signal loss fault and / or a voltage fault when the rear wheel steering device is in a stationary state and when the rear wheel steering device is performing a steering action.

7. A rear wheel steering gear fault condition testing method according to claim 5, characterized in that: The testing method further includes testing the rear wheel steering device for a steering overspeed fault, a stuck fault, a signal loss fault and / or a voltage fault under conditions of different vehicle speed signals.

8. A rear wheel steering gear fault condition test system, used for testing rear wheel steering gear, characterized in that: The test system comprises: a control unit configured to: apply a maximum working load to the left and right output ends of the rear wheel steering gear; control the rear wheel steering gear to perform a steering action; and during the steering action of the rear wheel steering gear, 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: obtain a first feedback signal from the rear wheel steering gear; and verify, based on the first feedback signal, whether the behavior of the rear wheel steering gear after displacement exceeding the speed limit meets a first preset safety requirement.

9. A rear wheel steering gear fault condition test bench, used for testing rear wheel steering gear, characterized by: 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, and the programmable power supply provides power supply voltage for the rear wheel steering gear, wherein the rear wheel steering gear fault condition test bench is used for a rear wheel steering gear fault condition test method as described in any one of claims 1 to 7 above.

10. A computer-readable storage medium, characterized in that The storage medium stores a computer program, wherein the computer program is configured to execute the rear wheel steering gear fault condition testing method according to any one of claims 1 to 7 when running on a computer or a processor.

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