A multi-arm robot for mandible reconstruction assisted surgery is developed. It has three manipulators and eighteen degrees of freedom. In order to prevent the collision of the manipulator caused by the overlap of the motion space of the manipulator during the space positioning of the whole mandible reconstruction operation, a collision avoidance path planning method for manipulator based on C-space is proposed. In order to obtain the space non-interference posture of one manipulator, and the interference posture of the other manipulators is taken as the obstacle mapping in C-space to obtain the free space after removing obstacles. At the same time, combining with the space position of the system manipulator, the C-space mapping mathematical model of feature points and line segments is studied, and the mapping mathematical model of any point and line segments in the plane is obtained. By introducing admissibility proof lemma to weigh the evaluation function, the improved heuristic A* search algorithm is used to search the best path for collision avoidance. The collision avoidance experiment is carried out through simulation and robot platform, and finally the animal experiment is carried out. The experimental results verify the feasibility and validity of the collision avoidance path planning method for the space manipulator.

In the application process of industrial robots, it is necessary to ensure that the home position is correct when the robot changes the end tool, so that the coordinate values of tool can be calculated more accurately and the accuracy of the robot’s trajectory can be satisfied. A comprehensive calibration method of tool coordinates and home position of serial industrial robots based on fixed-point constraints is presented in this paper. Based on Denavit-Hartenberg (D-H) kinematics theory, the error models of tool coordinates and home position errors of 6-DOF serial industrial robots are established. By constraining the tool center point (TCP) of the robot with fixed points, the joint data of calibration points with different postures at the same position are collected, and the error value of the controlled object is identified by the least square algorithm. The calibration experiment results are basically consistent with the factory calibration parameters, which proves the feasibility of the calibration algorithm.

Based on the status of thyroid nodule puncture diagnosis, a 6-DOF puncture surgery robot is studied. The structure of the robot is combined with active and passive to increase the flexibility of the robot. The weight of the arm and the execution end is reduced by remote driving. A new type of fixed-point puncture mechanism was designed, and two driving modes were analyzed. Kinematics models were constructed respectively. A new rope winding method to prevent falling off was proposed. The D-H method is used to analyze the kinematics of the robot and the kinematics model is established. The kinematics model of fixed-point puncture and the workspace of the robot are simulated and analyzed by using MATLAB. The results show that the configuration of the robot and the design of the fixed-point puncture mechanism are reasonable.