Automation Test System Establish For Automatic Transmission Control Unit Based On CAN-bus Communication

As an important component of automobile,gearbox plays a very important role in vehicle power train system.With the increasing of digitization.The automatic transmission control software is also undergoing rapid development and update,the order of magnitude for monitoring signal also increases geometrically.The development and testing of gearbox software also face greater challenges.Under the background of market economy,the faster development,debugging and testing process are more and more valued by gearbox manufacturers and vehicle manufacturers.The development of the corresponding tools has also become a top priority.Good hardware has played an important role in the transmission industry and even the entire vehicle industry chain.Automatic transmission control system is constructed precisely and complex,which often presents ambiguity and correlation in case of failure.In terms of fault monitoring diagnosis,fault phenomena or signal changes are the most basic basis for fault cause judgment,and they are only information that can be directly observed or measured.However,these signals are not so direct to fault judgment.It is usually related to the state of operation at that time and the causal relationship between them.In other words,only observation or measurement signals,except for a few exceptions,cannot directly infer the cause of the failure.It is often necessary to refer to other possible faults to infer the most likely cause.The cause of the failure can be known to be used for troubleshooting.Therefore,how to observe or measure signals,fault performance,and fault inference is the most important knowledge connotation in vehicle maintenance diagnosis.However,if there is no connection between the three,how to accurately define,express measurement signals,fault performance,fault causes,and the correlation between the three are the main issues to be discussed in this study.This research is mainly aimed at the maintenance and diagnosis design of the automatic transmission box control system of vehicles.A framework of association definition of automatic transmission control unit automatic test system based on CAN bus and its inference specification are proposed.The system structure and hierarchy of various vehicle systems are consistent so that each part,assembly,or device of the system can be clearly calibrated.On the other hand,using the Microchip PIC18F4520 micro-controller to cooperate with the analog sensor’s feedback signal circuit,a fuzzy inference rule library and data array record the vehicle automatic transmission control unit are constructed.The realization clearly distinguishes the original measurement point information,system state,numerical state,fault characteristics,and fault causes,and clearly specifies the format of each part,to standardize the conversion of the measurement point signal to the system state and the numerical state.Mode,The mutual inference method from the system state and numerical state to the fault and the cause of failure.The experimental results show that the fault characteristics of the automatic transmission are deduced according to the inference rules through the embedded program algorithm,and the possible fault causes are found from the fault characteristics to form a complete and efficient fault diagnosis system for the automatic transmission control unit of the vehicle.And can quickly assist maintenance staff to find the cause of the failure,improve the accuracy of vehicle fault detection and maintenance efficiency.