A Follower-based Control Framework for 6-DOF Surgical Robotic Arm with Real-Time System Validation using Haptic Module

Abstract

Real-time control in surgical robotic systems demands low-latency communication and stable force feedback to ensure precision and safety. Inverse kinematics (IK)-based control approaches often introduce computational overhead and may exhibit instability under dynamic operating conditions, limiting their effectiveness in high-frequency control loops. This work presents a follower-based control framework for a 6-DOF surgical robotic arm that eliminates the need for explicit IK computation by directly mapping master device inputs to joint-level actuation. The proposed system integrates a haptic interface with ROS 2-based middleware and an EtherCAT-driven motor network to enable deterministic, high-rate operation. A lightweight WebSocket bridge facilitates real-time data exchange, while joint-level control loops ensure smooth motion with safety-constrained behavior. Experimental validation demonstrates end-to-end latency of at most 8 ms and consistent force feedback using a Hooke’s law-based virtual wall model. The complete system is validated in a real-time setup, confirming stable and reliable interaction across the control pipeline. The results indicate that the proposed framework provides a computationally efficient and robust alternative to IK-based methods, demonstrating its suitability for precision robotic control applications.