并联机器人治疗人体下肢畸形矫正控制研究

Control Studieson the Correction of Human Lower Limb Deformity with Parallel Robot

将并联机器人应用于治疗人体下肢畸形,医生需要确定每根驱动杆的调节量并做出相应调整,而杆长的计算基于大量的数学运算,医生主观上无法完成;并且由于肢体内部结构可视化的局限性,医生无法获得治疗过程中骨畸形的状态信息。因此,依据并联机器人的结构特点,建立数学模型,并进行运动学分析,提出采用预估—校正法求解上下平台的位姿,进而由位姿求得杆长。同时,运用VRML技术构建并联机器人及畸形骨的三维模型,根据所求得的位姿参数进行三维仿真,医生可预先观察畸形矫正完成时的骨段复位情况。通过树脂骨模型实验和临床实验,结果表明并联机器人能够精准高效完成人体下肢多维畸形的同期矫正,并取得满意疗效。验证了并联机器人控制研究理论的正确性和并联机构的可用性。

The parallel robot is applied to human lower limb deformity correction. Doctors need to know the elongation of each strut and adjust accordingly. However,the calculation of the length of each strut is based on a large number of mathematical operations,and the doctor cannot complete it subjectively. Because of the limitations of internal structure visualization of limb,the doctor is unable to obtain the status of deformed fragments during the deformity correction process. Therefore,a mathematical model was established according to the structure characteristics of parallel manipulator. The kinematic analysis of parallel robot was carried out,and the algorithm of estimation-correction was used to solve the position relationship between the upper and lower platforms. Then the elongations of the struts were obtained by the position relationship. At the same time,a three-dimensional simulation of the parallel robot and deformed fragment was made using virtual reality modeling language technology based on the position parameters. The doctor can pre-observe the reduction of deformity correction. The results show that the parallel robot can accurately and efficiently complete the correction of the lower limb deformity through resin bone model experiment and clinical experiment. And satisfactory results were achieved with this technique. It verifies the correctness of the control theory and the availability of parallel manipulator.