颞骨手术虚拟触感装置设计及其运动学分析

Design and kinematic analysis of virtual haptic device for temporal bone surgery

针对现有颞骨手术术前培训手段存在的问题,设计了一种具有结构简单、位姿解耦、自重平衡特点的5自由度力反馈触感装置。其采用水平放置的平行四边形结构,使得前后和左右两个位置自由度均满足重力平衡;对于后3个姿态自由度,采用驱动电机补偿的方式实现了完全重力补偿,进而实现了整个触感装置完全重力平衡;在触感装置结构设计的基础上对触感装置开展了工作空间分析,针对触感装置的运动学模型问题,基于旋量法建立了触感装置的正逆运动学模型;利用该模型,通过推导其末端雅可比矩阵,建立了速度模型;最后,通过Matlab对机构的条件数进行了分析计算,对机构灵活性进行了评价。研究结果表明:所设计的机构满足工作空间需求,其灵活性较好、精度较高,验证了触感装置机构设计的合理性。

Aiming at the problem of insufficient pre-operative training methods for temporal bone surgery, a 5-DOF force feedback haptic device was designed, which has the advantages of simple structure, position-posture decoupling and self-weight balance. The gravity balance of the degrees of freedom of front and rear, right and left position could be accomplished by using a horizontally parallelogram structure. For three posture degrees of freedom, the full gravity compensation could be achieved by means of motor compensation. Thus, the complete gravity balance of the haptic device could be achieved. Based on the structural design, workspace analysis of the haptic device was performed. For the kinematic model problem of the haptic device, the forward and inverse kinematic models of the haptic device were established based on screw theory. The velocity model was established by Jacobian matrix of the haptic device, which could be obtained based on the forward kinematic model. Finally, the flexibility of the haptic device was evaluated by using Matlab to analyze and calculate the condition number. The results indicate that the haptic device can meet the needs of the workspace, which has better flexibility and higher precision. The mechanism rationality of the haptic device is verified.