[0020] In the following, the method for diagnosing the position fault of the switch handle provided by the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments. According to the following description and claims, the advantages and features of the present invention will be clearer. It should be noted that the drawings are in a very simplified form and all use imprecise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.
[0021] Please refer to figure 1 , Which is the flow chart of the position fault diagnosis method of the switch handle of the present invention, such as figure 1 As shown, the position fault diagnosis method of the switch handle, the switch handle has a handle position sensor, and the position fault diagnosis method of the switch handle specifically includes the following steps:
[0022] First, perform step S1 to collect the logic signal of each pin of the handle position sensor, where the logic signal is a valid signal or an invalid signal; where the logic signal is 0 or 1, the valid signal is set to 1, and the invalid signal is Set to 0. Further, the logic signal fed back by each pin corresponds to a position signal of the switch handle. When the logic signal is a valid signal, the position signal of the switch handle is the valid signal.
[0023] Next, perform step S2 to count the number of valid signals in the logic signals of each pin;
[0024] Then, step S3 is executed to judge and determine the position failure of the switch handle based on the number of valid signals currently counted and the position of the previous valid handle. Wherein, the effective handle position refers to the gear position of the switch handle when the number of effective signals is one; the position fault of the switch handle includes three types: maximum failure, minimum failure and misalignment failure. Specifically, the position fault of the switch handle is diagnosed according to the number of effective handle signals and the arrangement sequence of the handle position. When the diagnosis result is any of the above three kinds of faults, the corresponding fault handling operation is performed.
[0025] Specifically, the specific implementation process of step S3 includes the following steps:
[0026] S30: When the number of effective signals is 1, record the current gear position of the switch handle, and query the gear position of the switch handle recorded when the number of the previous effective signal is one; according to the position arrangement of the switch handle, the switch The position arrangement of the handle is the handle arrangement, that is, the arrangement position relationship of each gear, it is judged whether the current gear is adjacent to the gear of the switch handle recorded when the number of the previous valid signal is one; if so, then It is judged that there is no fault in the position of the switch handle, and the vehicle can run normally without maintenance; otherwise, it is judged that the position of the switch handle is faulty as a misalignment fault;
[0027] Currently, different switch handle positions are arranged on vehicles. For the same type of handle, the gear position relationship of each handle is fixed. Take the linear arrangement of the handle positions as an example, such as figure 2 As shown, the positions of several switch handles are arranged as: P-R-N-D, P-R-N-D-S, P-R-N-D-L, P-R-N-D-3-2-L. Among them, P gear corresponds to TCU (Automatic Transmission Control Unit) to control vehicle parking, R gear corresponds to TCU to control the vehicle to reverse, N gear corresponds to TCU to control the vehicle to cut off power, D gear corresponds to TCU to control the vehicle to move forward, S gear corresponds to TCU control The vehicle advances in the sport mode, and the 3/2/L gears respectively correspond to the 3/2/1 gears that the TCU executes in the manual mode. Taking the position arrangement as PRND as an example, if the switch handle is in the N gear, then the N gear is the current gear. Because the position arrangement of the switch handle determines the order and direction of the toggle handle, therefore, the position adjacent to the N gear The gear is D gear or R gear. Next, determine whether the switch handle recorded when the number of the previous valid signal is 1 is D gear or R gear. If it is not, it means that the position fault of the switch handle is misaligned. malfunction.
[0028] S31: When the number of valid signals is 0 (that is, the position signals of all switch handles are all invalid, the cause of this result may be an abnormal invalid fault in the current gear of the switch handle), at this time, it is judged that the position fault of the switch handle is the smallest malfunction;
[0029] S32: When the number of valid signals is greater than or equal to 2 (that is, the position signals of two or more switch handles are all valid, the cause of this result may be abnormally valid gears other than the current gear of the switch handle Fault), judge the position fault of the switch handle as the biggest fault.
[0030] In order to facilitate the discovery of the position failure of the switch handle, after confirming the position failure of the switch handle, the fault code corresponding to the fault is reported, the fault light is lit to notify the driver to drive to the maintenance station, and the fault code is reported for the maintenance personnel to quickly repair.
[0031] The position fault diagnosis method of the switch handle disclosed in the present invention can be applied to various gearboxes that use switch-type handle position sensors; the handle fault diagnosis strategy disclosed in the present invention includes but is not limited to figure 2 The position arrangement of several switch handles listed.
[0032] The beneficial effects of the position fault diagnosis method of the switch handle of the present invention are as follows:
[0033] 1) It can effectively diagnose that the signal at the position of the switch handle is abnormally invalid;
[0034] 2) It can effectively detect that one or more switch-type handle position signals have abnormally effective faults;
[0035] 3) It can detect the fault that the position signal of the switch handle is misplaced, and diagnose the fault that the pins of the switch-type handle position sensor have double failure.
[0036] In summary, in the position fault diagnosis method of the switch handle provided by the present invention, the position fault diagnosis method of the switch handle includes collecting the logic signal of each pin of the handle position sensor, and the logic signal is valid or invalid. Signal; count the number of valid signals in the logic signal of each pin; judge and determine the position fault of the switch handle according to the number of statistically valid signals and the position of the previous valid handle. The position fault diagnosis method of the switch handle based on the present invention can accurately, quickly, reasonably and effectively diagnose the position fault of the switch handle, thereby improving the accuracy of the shift control of the automatic transmission control unit.
[0037] The foregoing description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by persons of ordinary skill in the field of the present invention based on the foregoing disclosure fall within the protection scope of the claims.
