摘要
高速并联机器人驱动关节等效惯性参数随位形变化且支链间耦合效应明显,高速运行时惯性参数的改变显著影响系统控制品质.以一种新型四自由度高速并联机器人CrossⅣ为例,在分析其动力学模型基础上,首先建立惯性矩阵,并证明其在全工作空间内具有严格对角占优的特性;其次构造对角占优特性指标,并借此提出一种充分考虑各支链间耦合作用的驱动关节等效惯性参数计算方法;然后具体分析了在全工作空间内,对角占优特性指标的分布特点和等效惯性参数随位形的变化规律;最后通过仿真和试验分析发现,该方法能够显著改善系统阶跃响应特性,超调量和调整时间分别减少了30.7%,和44.3%,.所提方法有效计入了关节之间的耦合作用,可为高速并联机器人的电机选型和高精度控制提供正确的系统参数.
The inertial parameter of the high-speed parallel robot changes in real time with the robot＇s configurations,and the coupling effects from other chains are fairly intense.The variation of inertial parameter has remarkable effects on the control quality of the system when the robot runs at high speed.By taking a 4-DOF highspeed parallel robot CrossⅣ as an example,based on the dynamic analyses of the robot,the inertia matrix is established firstly and the characteristic of diagonal dominance throughout the workspace is demonstrated.Secondly,a novel diagonally dominant index is created and a corresponding method of calculating the equivalent inertia parameter in joint-space is put forward.Then the distribution characteristics of the diagonally dominant index and the variation regularities of the inertial parameter along with the robot＇s configurations throughout the workspace are displayed.Finally,by applying the approximated parameters to both simulation and experiment,the dynamic characteristics are improved evidently：the overshoot and the settling time of step response are reduced by up to 30.7%, and 44.3%,,respectively.The proposed approach gives full consideration to the inter-chain coupling effects and provides proper system parameters for motor selection and high precision control of the high-speed parallel robot.
出处
《天津大学学报（自然科学与工程技术版）》
EI
CSCD
北大核心
2017年第8期868-876,共9页
Journal of Tianjin University：Science and Technology
基金
国家自然科学基金资助项目(51305293
51541501
51135008)~~
