温室移栽机电驱移动平台控制系统设计与试验

Design and Experiment of Control System for Electric-driven Mobile Platform of Greenhouse Transplanter

摘要:

针对全自动移栽机在日光温室作业面临的环境复杂、自主行走能力不足及轨迹跟踪精度较低等问题，本文提出一种轮边电机驱动的履带式电驱移动平台架构，构建了多自由度运动学模型，提出了一种结合模糊控制的变时域MPC策略，并设计了相应的TC-MPC控制器，在Matlab/Simulink仿真环境中完成U形轨迹仿真试验并进行了温室试验验证。U形轨迹仿真试验结果表明，电驱移动平台以3种不同速度0.6、0.8、1 m/s进行轨迹跟踪时，TC-MPC控制器横向最大绝对误差分别为2.55、3.12、3.71 cm，MPC控制器横向最大绝对误差分别为2.80、3.73、4.51 cm；温室场景中U形轨迹试验结果表明，TC-MPC控制器在速度0.6、0.8、1 m/s下横向平均绝对误差分别为0.82、1.12、1.28 cm，相较于MPC控制器降低21.15%、17.04%和15.23%，轨迹跟踪效果明显提升，研究结果可为温室移栽机电驱移动平台轨迹跟踪控制提供参考。

Abstract:

Aiming at the problems of complex environment, insufficient autonomous walking ability and low trajectory tracking accuracy faced by fully automatic transplanter in facility greenhouse operation, a tracked electric-driven mobile platform architecture driven by wheel-side motors was proposed, a multi-degree-of-freedom kinematics model was constructed, a variable time-domain MPC strategy combining with fuzzy control was put forward, and the corresponding TC-MPC controller was designed, the U-shaped trajectory simulation test was completed in Matlab/Simulink simulation environment and verified by greenhouse test. The results of the U-shaped trajectory simulation test showed that when the electric drive mobile platform was tracking the trajectory at three different speeds of 0.6 m/s, 0.8 m/s and 1 m/s, the transverse maximum absolute errors of the TC-MPC controller were 2.55 cm, 3.12 cm and 3.71 cm, respectively, and the transverse maximum absolute errors under the MPC controller were 2.80 cm, 3.73 cm and 4.51 cm, respectively. The U-shaped trajectory test in the greenhouse scene showed that the lateral mean absolute errors of the TC-MPC controller at speeds of 0.6 m/s, 0.8 m/s and 1 m/s were 0.82 cm, 1.12 cm and 1.28 cm, respectively, which were reduced by 21.15%, 17.04% and 15.23% compared with that of the MPC controller. The trajectory tracking effect was significantly improved. The research result can provide a reference for the trajectory tracking control research of greenhouse transplanting electric-driven mobile platform.