Affiliation:
1. School of Engineering, The Open University of China, Beijing, China
2. College of Mechanical Engineering, Qinghai University, Xining, China
3. Beijing Key Laboratory of Optimized Design for Modern Agricultural Equipment, College of Engineering, China Agricultural University, Beijing, China
Abstract
An automatic navigation system aiming at improving the accuracy and efficiency of a large high clearance self-propelled sprayer was developed. First, a navigation hydraulic steering system was designed according to the structural characteristics and operation requirements of the sprayer, and a mathematical model of the system was established to describe the working characteristics of the navigation system. The system includes a navigation control strategy, a pure pursuit path tracking algorithm, and a fuzzy adaptive proportional-integral-derivative control method. To verify the performance of the system, a simulation model was developed using MATLAB/Simulink, and the performance of the control methods were compared. Additionally, an actual vehicle test platform was built based on 3WPG-3000 high clearance self-propelled sprayer independently developed by the research group. The simulation results revealed that under the two-wheel steering mode, the lateral position deviation of the vehicle decreases to 0 m in 11 s, and the heading angle deviation decreases to 0 rad in about 11 s; while under four-wheel steering mode, the lateral position deviation of the vehicle decreases to 0 m in 8 s, and the heading angle deviation decreases to 0 rad in 8 s. The field test results revealed that at the speed of 3 km/h, the sprayer tracked the target path in 5.84 s under the two-wheel steering mode and reached stability, and tracked the target path in 4.08 s under the four-wheel steering mode and reached stability; while at the speed of 5 km/h, the spray tracked the target path in 3.75 s under the four-wheel steering mode and reached stability. Altogether, the results of the simulation and field test verify the stability, accuracy, and practicability of the system.
Funder
National Key R&D Program of China