摘要
针对某小型浮式并联光电跟踪平台体积小、负载惯量大的特点，提出了一种以少自由度并联机构为基础的改进型并联机构。推导了平台的系统雅可比矩阵，基于拉格朗日方法得到了平台的动力学模型。针对并联平台的内部耦合、参数不确定和干扰的问题，基于工作空间提出了一种带有干扰观测器的复合滑模控制策略。利用干扰观测器观测系统干扰，减小干扰上界，基于反步法设计了滑模控制器跟踪目标轨迹并进一步抑制未观测出的干扰。仿真和实验结果表明，提出的数学模型和控制策略使平台跟踪误差减小到±0．08°，为PID控制误差的14．5％，特别适用于并联平台等内部耦合及干扰较显著的场合。
In order to meet the optoelectronic tracking requirements for a small size floating stabilized platform with small volume and high load inertia, an improved parallel mechanism based on deficient DOF parallel mechanism has been designed. The Jacobian matrix is derived, and the dynamic model has been established by using Lagrange method. Considering the internal coupling, uncertainties and disturbances of the system, a workspace based composite control with disturbance observer is proposed. The disturbance observer is used to observe the disturbance of the system and reduces the upper bound of the disturbance. Based on backstepping method, the sliding mode controller is designed for tracking and residual disturbance suppression. The simulation and experiment results show that the proposed model and method have made tracking error reduced to ＋ 0.08~ which is 14.5% of PID, and is suitable for parallel mechanism.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2014年第3期293-298,共6页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金资助项目(60908037)
关键词
并联机构
动力学建模
干扰观测器
滑模控制
工作空间
Parallel mechanism Dynamic modeling Disturbance observer Sliding mode controlWorkspace
