| The research mainly intends to develop a surgical robotic system,which is used for thoracic cancer under computerized tomography(CT)scanning.This system belongs to an interdisciplinary between medicine and mechanical engineering,whose contents consist of design,analysis,optimization and experiment of puncture robotic system.The main research work and achievements are as follow:In the first place,design of robot was accomplished,including four aspects: robot structure,tendon-sheath transmission device,control system and appearance.According to clinical demand,an innovative 7 degrees of freedom(DOF)series robot was designed,which can meet the requirements of robot position and angle adjustment.Tendon-sheath transmission was chosen as the drive mode.The motion error model of the axial and radial wire winding were established and analyzed respectively.The result shows that the error caused by the axial winding is less than that in the radial direction.The hardware design of the control system was completed.Multi axis motion controller and single chip microcomputer was chosen as two kinds of controllers of robotic system.Besides,the shell of the robot was designed,which is practical and beautiful.In the second place,the content is robot kinematics analysis and structure optimization.The forward and inverse kinematics of the robot was carried out through D-H method,and reachable workspace of the robot was obtained,which prove the structure can meet the requirements of the workspace.Jacobian matrix was solved,and the lengths of the main parts were optimized based on the condition number of Jacobian matrix.In addition,the optimization of the arc plate size was completed through the mechanical modeling of the arc plate.At last,related experiments were conducted.Compatibility experiment was conducted in the CT lab,and the scanning image demonstrates that the robot has good CT compatibility.The experiment of positioning error correction was made to compensate localization error to improve the positioning accuracy of robot.The measurement experiment of robot puncture accuracy was completed and error is 0.93 mm,which shows that the system meets the requirement of the operation precision.Besides,“rapid wave crest puncture” method was innovatively proposed to solve the puncture error caused by real-time motion of tumor,and puncture experiments was carry out based on respiratory motion simulation device.It is proved that this method will lead to an increase of the puncture accuracy by 2.2 times. |
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