| In this paper,combine harvester automatic navigation software and hardware system was designed to improve the intelligence of the combine harvester,and a navigation controller of combine harvester based on single-neuron PID was designed for the problem of no leakage of straight line tracking operation in the field environment of combine harvester under the condition of maintaining high cutting width.The controller used RTK technology to build a high-precision Bei Dou positioning system to obtain the lateral deviation and heading deviation of the harvester as the input of the navigation controller.The single-neuron PID controller and the conventional PID controller were simulated and compared in the field and road.The specific research work was as follows:1)The hardware and software system of combine harvester navigation control based on RTK-BDS was constructed.The hardware system were composed of GE-70 Lovol combine harvester,controller,sensor,drive system and steering actuator.The sensors consists of angle sensor(DWQCB-9-CH)and high-precision Bei Dou positioning system(Sinan M300).The electric control steering of the steering wheel was realized by installing the electric control hydraulic valve group in parallel on the basis of the original hydraulic steering oil circuit of the harvester.The driving system mainly provides power supply for the whole hardware system,so that the sensor can work normally and the steering mechanism acts.The software system was developed based on C++/MFC framework with visual studio 2015 under Windows 10 operating system.The whole system could realize rear wheel steering control,path tracking,human-computer interaction and other functions.2)A navigation controller of combine harvester based on single-neuron PID was designed.Commonly used PID control was adopted,in order to make up for the shortcoming that traditional PID controller cannot adjust parameters online,single-neuron was introduced to adjust parameters online.Combining it with traditional PID controllers could achieve online parameter adjustment and optimization of PID parameters.Matlab simulation experiments were performed on the designed conventional PID controller and single-neuron PID controller.The simulation results showed that the single-neuron PID control had the characteristics of fast response,small overshoot and fast steady state.3)PD steering controller for rear wheel steering was designed.The PD steering controller calculates the steering control voltage signal according to the target steering angle command,the current actual steering angle and the median angle.The steering voltage signal was converted into the current signal by the proportional amplifier to control the opening of the proportional valve to control the flow so as to realize the closed-loop control of the rear wheel steering of the combine harvester.The PD steering controller was tested with ±25° square wave tracking.The rise time of square wave tracking test was 3.34 s,the delay time of steering wheel was 80 ms,and the following error was 0.5°.The followup test shows that the designed steering controller can track the control signal stably and meet the requirements of automatic navigation and steering control of harvester.4)The road test and field test of the navigation controller were carried out.The road and field comparison tests were performed on the conventional PID controller and the single-neuron PID controller.The road test shows that the average absolute deviation of navigation and tracking in the road at 0.7 m/s was 1.21 cm,the maximum tracking deviation was 6.10 cm.The field test shows that the average absolute deviation of navigation and tracking in the field at 0.7 m/s was 3.20 cm,the maximum tracking deviation was 8.14 cm,the standard deviation is 2.82 cm.The experiments show that the designed single-neuron PID navigation controller was superior to the conventional PID control,and could achieve a certain control accuracy and meet the requirements of combine harvester field operations. |
PDF Full Text Request