以模糊推論實現輪型機器人軌跡追蹤之控制

Implementation of Trajectory Tracking Control for Wheeled Mobile Robots Based on Fuzzy Controller

蔡樸生(Pu-Sheng Tsai) ； 林盈灝(Ying-Hao Lin) ； 蔡宗福(Chung-Fu Tsai)

《中華技術學院學報》 41期 (2009/12) Pp. 45-65

https://doi.org/10.7095/JCIT.200912.0045

摘要

非完整約束(Nonholonomic Constraints)是指約束方程式具有不可積分之性質，這類系統的運動約束包含廣義座標的微分式，其中輪型機械人是非完整約束系統的經典案例。這類系統的運動模型(Kinematics)是由非完整約束矩陣推導而來，其中蘊含了系統的廣義座標(Generalized Coordinates)與控制輸入（或特權速度Privileged Velocities）之間關係。動力模型(Dynamics)的推導則屬於解析力學的範疇，可以真實地描述輸入力矩與系統變數的關係。本文藉由機械系統的幾何約束以及非完整約束的本質特性，提出一套推導系統模型的結構化方法。進而針對三輪式輪型機器人的剛體結構，建立一組適當的運動模型(Kinematics)以及光學編碼器(Encoder)的量測方程式。本文引入專家的知識與經驗，採用模糊推論引擎來實現小型機械人B-spline軌跡追蹤之控制。由實驗結果顯示，將駕駛車輛的經驗法則建構成If-Then規則庫，植入輪型機器人內建之嵌入式微控器－ATMega162內，確實可以獲得令人滿意的軌跡追蹤效果。

關鍵字

非完整約束 ； 輪型機械人 ； 運動模型 ； 光學編碼器 ； B-spline 軌跡 ； 模糊推論 ； 嵌入式微控器

並列摘要

A constraint is said to be nonholonomic which the non-integrable constraints are imposed on the motions. Nonholonomic systems are characterized by constraint equations involving the time derivatives of the generalized coordinates. Among them, the wheeled mobile robots can be treated as the classical examples. The kinematic equation of such system may be derived from the nonholonomic constraints, and involved the relationship between the generalized coordinates and control inputs (or privileged velocities) of system. Dynamics belong to the scope of fundamental principle in mechanics, which is more realistic to describe the relationship between applied torques and state variables of the system. Using geometric constraints as well as non-holonomic constraints, a systematic and structural procedure is proposed to obtain the kinematics of mechanical system in this paper. Furthermore, a set of kinematics for control and the measurement equation for encoder are established for a tri-wheeled mobile robot. Fuzzy inference system formulates expert knowledge and experience using a set of IF-THEN rules, embedded on the Microcontroller ATMega162, which provides human-like reasoning and decision-making to realize the B-spline trajectory tracking control. Experiment results show that the proposed methodology is applicable, and gives good results.

並列關鍵字

Nonholonomic Constraints ； Wheeled Mobile Robot ； Kinematics ； Encoder ； B-spline Trajectory ； Fuzzy Inference System ； Embedded Microcontroller