Physiological Motion Compensation in Robotized Surgery using Force Feedback Control

This paper presents a force feedback control scheme for the compensation of periodic motions of organs induced by respiration or heartbeat in minimally invasive robotized surgery. It applies surgical tasks involving a contact between an instrument and a moving organ. It is well known that conventional force control allows for compensating the motion of the environment thanks to its natural disturbance rejection capabilities. However, as experimentally evidenced in the first part of this paper, bandwidth limitations do not allow for exact disturbance rejection. Therefore, in addition to a conventional inner force feedback control loop, an outer control loop based on iterative learning control (ILC) is implemented. It is aimed at compensating the physiological motions, based on the hypothesis that the disturbance is periodic. The transient performances of this ILC controller are improved thanks to a wavelet transform-based approach and conclusive experiments are finally presented, evidencing that the tracking performance under cyclic disturbances is significantly improved.