The Tractor Automatic Steering Control System Research And Optimization

Tractor automatic steering control system is the key technology of automatic transmission, is the only way to realize precision agriculture, it not only improves the production efficiency, but aslo improves the quality of the work. As the key technology of automatic navigation, its performance directly influences the automatic navigation of frontal precision, in this study after fully understand the research status and development trend at home and abroad, with TN654 type tractor as the research platform, in view of the existing two sets of steering system research and optimization, design a set of the stepper motor to drive the execution of the full hydraulic steering gear system. The research content is as follows:(1) Through the research of domestic and foreign research situation of the automatic steering control system and the existing mature products, combined with the geographical environment in xinjiang, to determine the steering control system optimization goal and overall scheme.(2) The overall scheme is optimized for tractor automatic steering system design, design the program flow chart, the full hydraulic steering gear actuators and proportional directional valve actuator, this paper analyzes the work principle and choose model function, analyzed the steering controller, steering mechanism, the influence factors of vehicle position sensor for navigation,steering controller for the selection of design, the LM3S5749 steering controller is determined.(3) For steering actuator is analyzed, the hydraulic steering gear actuators and electromagnetic directional valve actuator were compared to experimental research, respectively measured 7fixed Angle value, to be picked for optimized data processing, and the test results are analyzed,and through experiment it can be seen that the feasibility and reliability of the two sets of steering executive system, considering the advantages and disadvantages of two kinds of actuators, eventually determine a set of parallel hydraulic steering actuator, and through improving the mounting bracket to optimize actuators.(4) Research on automatic steering controller are analyzed, and put forward the optimization analysis of each module, has carried on the design of CAN communication, implementation and PC communications test, analyses the angular displacement sensor is introduced, the selection of the installation, collection procedures for the median filtering processing, the design method of the angular displacement sensor to automatically, design the parameter self-tuning fuzzy PID automatic steering control algorithm, and studied the Simulink modeling, and the experiment results are analyzed.(5) By machine automatic pilot test was carried out on the tractor, the 1.88 km/h and 4.29km/h speed of the path of beeline track, curve track and field linear track test, verify the feasibility of path tracking, and the reliability of the steering control system, through the experiment shows that the reliability of the steering system, can drive along a predefined path, but there is a certainerror, in general, to meet the requirements of automatic navigation.