Kinematic Analysis And Design Of A Surgical Robot With A Remote Center Of Motion

Compared with traditional open surgery,minimally invasive surgery has many advantages,such as small wound,rapid patient recovery and less postoperative complications,and has gradually become one of the development trends of surgery.However,minimally invasive surgery,due to its operational principles and characteristics,will cause a series of problems during the operation,such as high difficulty in operating surgical instruments,low hand-eye coordination,difficulty for doctors to fully observe the tissues and organs in patients.The minimally invasive surgery assisted by a robot can not only solve the above problems,but also have the advantages of safety and efficiency.Based on the advantages of the minimally invasive surgery robot mentioned above and the requirement of freedom of minimally invasive surgery mechanism,this paper proposes a 2-dof telecardial parallel operation robot.The main content of the article can be divided into the following parts:Given the length of the bar and the geometric relations between the members of the mechanism,the analytical expressions of the positive and negative solutions of the mechanism can be obtained.In SolidWorks drawing software,the 3d model of the surgical robot is established,the motion simulation is carried out,and the position analysis of the mechanism is verified.The jacobian matrix is derived and the velocity formula is obtained.The most widely used Jacobi matrix analysis method is adopted to analyze the singularity of the mechanism and list all singular configuration,and to analyze the degree of freedom of the mechanism under different singular configuration.To avoid singular configuration in the target workspace by limiting the rotation Angle range of the drive pair and given the length range of the bar,the end points of the mechanism executor can reach the set of all space points through Matlab,and the accessible working space of the mechanism is obtained,and the working space is visualized in the three-dimensional coordinate system.By using the dexterity performance index based on jacobian matrix and the motion/force transfer performance index based on screw theory,the performance of the mechanism is analyzed,and the performance of the mechanism under the single configuration and the global configuration is evaluated.The scale synthesis takes the performance index as the evaluation standard,carries on the optimized design to the size parameter of the mechanism.In this paper,the spatial model method is used to integrate the scale of the mechanism,and the dexterity and motion/force transfer performance are used to evaluate the mechanism at the same time,and the optimized optimal region is selected as the optimal scale region.After a series of improvements to the mechanism,the prototype design of the bizheng surgical mechanism was carried out according to the optimized size parameters.The work content included part selection,structural design and the overall assembly layout of the mechanism.A series of studies on the mechanism in this paper provide theoretical support for the subsequent dynamic analysis and motion control,laying a solid foundation for the practical application in the future clinical field.