首先对头盔伺服系统的执行机构——6URHS并联机构进行了运动学分析,建立了丝杠运动状态、螺母运动状态与动平台运动状态间的关系式;其次,采用牛顿-欧拉法对驱动分支及其构件进行了动力学分析,建立了驱动分支整体和包括螺母在内的部分构件的牛顿与欧拉方程,考虑了螺旋副摩擦力的影响,推导完成了封闭式的6URHS并联机构动力学方程;最后,采用MATLAB分别建立了6URHS并联机构的动力学模型和Simulink虚拟样机,对两者进行了动力学响应对比实验。实验结果表明:对于同一组驱动力矩输入,动力学模型与虚拟样机的动力学响应基本一致,动力学模型同虚拟样机的准确度相仿。另外,还进行了动力学仿真程序的轨迹跟踪实验,对驱动力矩进行了计算与分析。
Firstly,kinematic analysis for a manipulator of helmet mounted display with 6--DOF parallel manipulator was developed, and the kinematic relationship among lead screw, nut and plat- form was derived. Secondly, dynamics analysis of leg was carried out using Newton--Euler method, and the Newton--Euler equations of whole leg and corresponding parts including nut were built re- spectively considering friction at helix joint, and then a closed--form dynamics equation of 6URHS parallel manipulator was established. Finally, prototype, dynamics models of 6URHS were built re- spectively by Simulink, and some comparison tests about dynamic response were developed. The re- sults of comparison tests show that the veracity of the dynamics models of 6URHS is as the same as the prototype. Additionally, trajectory tracking simulation was also implemented, and computation and analysis of driving torque were developed.