Force display control system for simultaneous 3-axis translational motion in surgical training simulator for chiseling operation

The present study proposes an advanced force display control system for a surgical training simulator with virtual reality. In oral and orthopedic surgeries, a surgeon uses a chisel and mallet for chiseling and cutting hard tissue. To enable the representation of force sensation for the chiseling operation in a virtual training simulator, the force display device has been constructed with the ball-screw mechanism to obtain high stiffness. In addition, two-degrees-of-freedom (2DOF) admittance control has been used to react instantaneously to the impactive force caused by pounding with the mallet. The virtual chiseling operation was realized by the force display device with a single axis in the previous studies. In the current study, we propose the design procedure for the force display control system with the 2DOF admittance control approach to virtual operation in three-dimensional space. Furthermore, we propose the design method for the PD controller with imperfect derivative using frequency characteristics for the 2DOF admittance control system. The efficacy of the proposed control system is verified through the virtual experience from manipulating the chisel using the developed force display device in the current study.