Workspace analysis and optimization of 4-links of an 8-DOF haptic master device

• 4-Links of a new haptic master device have been optimized using a new cost function.
• Goal requirements are large workspace, more dexterity & smooth forces transmission.
• Force transmissibility is improved by 66% and manipulability is increased by 62%.
• Effective plan of trajectories is between −20°and 20° of second & third joints.

Efficient minimally invasive surgeries greatly depend on a dexterous workspace in which a surgeon feels great comfort in incorporating his skills. Serial Haptic Master devices with large DOF have the advantages of large workspace and improved dexterity but these also contribute more to the kinematic errors and dynamics effects if not properly designed. Consequently, improper transmission of forces from the surgeon could result in damaging delicate tissues in the surroundings of the surgical site. This paper provides workspace analysis and optimization of the 4 links of an 8-DOF Haptic Master device that minimizes the kinematics errors during its manipulation, and ultimately improves the efficiency of surgical procedures. The complete kinematics of the device is calculated. A cost function is defined that uses a global performance index to provide a uniform dexterous workspace for effective force transmissibility in the surgical environment and then optimization of 4-link lengths is carried out on the basis of the defined cost function. An analysis of efficient trajectories is made on the basis of optimization results.