Abstract
Optimizing surgical assistant manipulators is essential for maximizing precision and structural safety in clinical environments. This paper develops a comprehensive, optimized trajectory planning framework for the ROSA (Robotic Surgical Assistant), a 6-DOF manipulator fabricated via hybrid additive manufacturing using PLA+ and PETG materials. To address structural flexibility and dynamic vibrations inherent in rapid-prototyped links, a systematic optimization methodology is implemented. First, the spatial forward kinematics are derived utilizing standard Denavit-Hartenberg parameters, mapped alongside individual joint boundary limits. Second, a rigid-body dynamic plant is constructed via Simscape Multibody, integrating physical mass properties and inertia tensors extracted from computer-aided design parameters. Third, a customized multi-objective Whale Optimization Algorithm (WOA) framework is executed to compute optimal joint paths by minimizing both absolute reachability time and cumulative joint jerk. Simulation assessments confirm that the developed optimizer substantially outperforms conventional genetic algorithm and traditional cubic polynomial approaches, providing a 42.3% reduction in execution cycles alongside streamlined continuity in acceleration transitions. Quantitatively, the optimized path restricts the cumulative structural jerk to 8.4 rad/s³ and limits peak motor torque requirements to 5.2 N·m. The physical feasibility of the planned profiles was validated on the hardware prototype, supporting point-to-point instrument hand-off operations with an average tracking precision of 0.18 mm. Consequently, this methodology bridges the gap between low-cost rapid-prototyped medical apparatus and continuous, vibration-free intelligent robotic control architectures.