基于测量的人体前列腺会阴部操作空间和手术过程量化分析,研究了一种3-PCR并联式前列腺癌粒子植入机器人。对于这种对称少自由度并联机构作为位置调整机构,其运动学特性需要深入研究。采用封闭矢量法和Beout消元法建立3-PCR并联机构运动学正、逆运动学方程,通过数值计算验证了正、反解模型的正确性。利用MATLAB进行p点为空间旋量曲线时的运动学仿真,仿真结果表明机构具有较好的运动稳定性,便于实时控制。通过极限边界搜索法求解了该机构姿态为α=β=γ=0°下的工作空间,x=0时的YOZ工作空间截面为15 674 mm2能满足临床手术的要求。
We developed a 3-PCR parallel-chain type of seed implantation robot for prostate tumors,based on measurement workspace in the perineum of prostate and quantitative analysis of the surgery procedure. For this kind of symmetry less degrees of freedom of parallel-chain mechanisms as position adjustment device,the kinematics characteristics need further research. The forward and reverse kinematics equations of3-PCR parallel-chain mechanisms were established by the closed vector method and Bezout elimination,and forward and reverse model was verified by numerical calculation to be correct. The kinematics simulation was performed under the helical cure in space with point p by MATLAB software,and simulation results provide evidence that this parallel-chain mechanism has better movement stability and is convenient for real-time control. The limit boundary searching method was used to solve the workspace of this mechanism under the posture with α = β = γ = 0°,and workspace with YOZ section was 15 674 mm2 under x = 0,which also meets the requirements of clinical surgery.