Design and experimental validation of a master manipulator with position and posture decoupling for laparoscopic surgical robot

Background The master manipulator with position and posture decoupling and force feedback can improve the immersion of the operation, and the gravity balance can reduce the fatigue of surgeons. Methods A seven degree of freedom master manipulator is developed. The parallelogram structure and the angle conversion method contribute to the realization of decoupling position and posture. The calculating method based on the virtual work principle is adopted to achieve the passive gravity balance. The relationship between the master manipulator's joint torque and output force is established to achieve force feedback. Results A prototype of the master manipulator was built and its performance was experimentally evaluated. The maximum value of the positioning mean absolute error is 1.2 mm. The maximum absolute error of the force‐feedback is 0.32 N. Conclusion With the functions of positioning, gravity balance, and force feedback, our manipulator shows the potential for single port laparoscopic surgery.