VisionSafeEnhanced VPC: Cautious Predictive Control with Visibility Constraints under Uncertainty for Autonomous Robotic Surgery

Abstract

Autonomous control of the laparoscope in robot-assisted Minimally Invasive Surgery (MIS) has received considerable research interest due to its potential to improve surgical safety. Despite progress in pixel-level Image-Based Visual Servoing (IBVS) control, the requirement of continuous visibility and the existence of complex disturbances, such as parameterization error, measurement noise, and uncertainties of payloads, could degrade the surgeon's visual experience and compromise procedural safety. To address these limitations, this paper proposes VisionSafeEnhanced Visual Predictive Control (VPC), a robust and uncertainty-adaptive framework for autonomous laparoscope control that guarantees Field of View (FoV) safety under uncertainty. Firstly, Gaussian Process Regression (GPR) is utilized to perform hybrid (deterministic + stochastic) quantification of operational uncertainties including residual model uncertainties, stochastic uncertainties, and external disturbances. Based on uncertainty quantification, a novel safety aware trajectory optimization framework with probabilistic guarantees is proposed, where a uncertainty-adaptive safety Control Barrier Function (CBF) condition is given based on uncertainty propagation, and chance constraints are simultaneously formulated based on probabilistic approximation. This uncertainty aware formulation enables adaptive control effort allocation, minimizing unnecessary camera motion while maintaining robustness. The proposed method is validated through comparative simulations and experiments on a commercial surgical robot platform (MicroPort MedBot Toumai) performing a sequential multi-target lymph node dissection. Compared with baseline methods, the framework maintains near-perfect target visibility (>99.9%), reduces tracking e