The Application of Sensorless-Based Torque Estimation Technique in Industrial Collaborative Robots

Abstract

Traditional industrial robots often require separate work areas and safety equipment to avoid human collisions, restricting their use in smaller or densely populated environments. Most commercially sold robots use position control, and adding force control requires a force sensor, which can be costly. This research introduces a power-assisted control strategy directly implemented on the controller, eliminating the need for an external force sensor. The mathematical model calculation module estimates the robot's friction, and inertial force, while the collaborative function algorithm refines the robot arm's flexible function. The driver's torque limit mechanism is essential for safe human-robot collaboration. By controlling the joint module's torsion in the mechanical arm, the robot can prevent potential injuries from human contact. If contact occurs, the robot can be easily pushed away, safeguarding personnel. Once any issues are addressed, the robot resumes its original work target, enhancing the overall efficiency of the collaborative process.