Application of model predictive control for reduced torque ripple in orthopaedic drilling using permanent magnet synchronous motor drive

Abstract

A ubiquitous procedure in many fields of medical surgery is drilling of bones. Several consequential factors are identified that affect bone drilling that results in crack initialization, thermal necrosis, burr formation, etc. The dominant reason for these causes is the varying torque produced by the drilling motor, the main unit of the drilling kit. This varying torque produces varying mechanical vibrations that cause irreversible damages to the bones. Additionally, the wear and tear of the universal motors in the drilling unit are highly recorded. This work concentrates on implementing a permanent magnet synchronous machine (PMSM) for the orthopaedic drilling application along with the motor control using model predictive control (MPC) with maximum torque per ampere (MTPA) technique. The work proposes to reduce the torque ripple and flux ripple effectively along with the reduction of the current harmonics. The work is implemented in a simulation environment and in the RT-Lab environment. The performance of the proposed work in the steady state and dynamic state is compared with that of the conventional MPC, and the effectiveness of the proposed work is presented. This paper suggests PMSM as a suitable motor for the orthopaedic drilling application.