Optimization and Performance Experiments of Teleoperation System for Tractors

In order to improve the working conditions of drivers, a wireless network based teleoperation system for tractors was designed before, and the feasibility of the system was verified through several experiments. The system was optimized in two ways to further enhance the usability of the system. First of all, a multithreading programming, including a data reading thread and a data processing thread was used to replace single threading programming in the first generation teleoperation system under unchanged hardware conditions, because the first system based on single threading programming had relatively slow response, which cannot fully meet the real-time requirements. Then, a new user interface with a steering wheel manipulator was designed to provide operators more realistic driving experiences, because the first user interface used many buttons to manipulate, which made operation inconvenient and misoperation sometimes. Finally, tests were carried out to detect performances of the optimized system. Results showed that control commands were executed with a delay of no more than 60 ms and the maximum absolute error was no more than 105.3 mm when the tractor was driven along a straight line at speed of 3.17 km/h by the optimized system, with maximum RMS error of 60.1 mm. Compared with the first generation teleoperation system, the precision of right angle turn was improved obviously for the optimized system. When the slalom test was carried out on the teleoperated tractor, there was little difference whether the driver operated in the tractor or operated remotely. Overall, the optimized system provided better remote driving experiences for operators. © 2019, Chinese Society of Agricultural Machinery. All right reserved.