Path Tracking of an Automatic Ground Vehicle with Different Payloads and Ground Conditions by Hierarchical Improved Fuzzy Dynamic Sliding-Mode Control

• Main Authors: CHANG-JIA YANG, 楊長珈
• Other Authors: Chih-Lyang Hwang
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/x52r4y

碩士 === 國立臺灣科技大學 === 電機工程系 === 104 === Due to the hierarchical architecture of the derived model of the automatic guided vehicle (AGV), i.e., kinematics, mechanical motion subsystem, and electrical dc motor dynamics, the virtual desired input (VDI) (i.e., the desired motor current) is at the outset designed by the 1st Lyapunov function, which is a quadratic function of the first sliding surface, set as the linear dynamic pose error of the AGV. In sequence, the hierarchical path tracking control (HPTC) is designed by the 2nd Lyapunov function, which is made up by the quadratic function of the second sliding surface, i.e., the linear dynamic tracking error of the VDI. Thus, the direct output (i.e., the motor current) either asymptotically or boundedly tracks the VDI. In this situation, the asymptotic or bounded tracking of the indirect outputs (i.e., the pose of AGV) is achieved. Both VDI and HPTC contain equivalent control and improved fuzzy dynamic sliding-mode control (IFDSMC). The nominal dynamic system is tackled by equivalent control; on the other hand, IFDSMC deals with the system uncertainties (e.g., friction force or torque caused by different ground conditions, different payloads). The integration of VDI and HPTC is the proposed hierarchical improved fuzzy dynamic sliding-mode control (HIFDSMC). The stability of the closed-loop system is also verified by Lyapunov stability theory using hierarchical concept. Finally, the application to the assembly line of the AGV with payload for tracking circular path and piecewise straight-line path by the proposed HIFDSMC are compared with the hierarchical fuzzy decentralized path tracking control (HFDPTC).