用CAD变量几何法精确求解六自由度并联机器人的位姿、线速度/线加速度、欧拉角速度/角加速度。以有限差分理论为基础,利用计算机辅助几何约束和尺寸驱动技术,构造含有欧拉角的并联模拟机构,得到其位姿解。在此基础上进一步构造线速度/线加速度模拟机构和欧拉角速度/角加速度模拟机构,得到其线速度/线加速度以及欧拉角速度/角加速度解。当改变6个驱动杆长度时,模拟机构也随之相应变化,自动求得各项运动学参数。结果表明CAD变量几何法不仅快速直观,而且准确可靠。
A CAD variation geometry approach was proposed for accurately solving the position-- orientation, linear velocity/acceleration, and Euler angular velocity/angular acceleration of the parallel robot with six degrees of freedom. Based on the finite--difference method as the foundations, using the computer aided geometry constraints and dimension driving technique, a simulation mechanism of the parallel robot with Euler angles was created, and the position--orientation could be obtained. Then the linear velocity/acceleration simulation mechanisms and Euler angular velocity/ angular acceleration ones were created. When modifying the driving dimension of the six driving limbs, the configurations of the simulation mechanisms were varied correspondingly, and all of the kinematical parameters were solved automatically. The results show that the CAD variation geometry is fairly quick and straightforward, and is also advantageous from viewpoint of accuracy and repeatability.