Velocity-Based Admittance-Impedance Control with Contact Compliance Modeling for Robust Dual-Arm Manipulation

Abstract

Many industrial and commercial manipulators provide only position and velocity control interfaces, making direct regulation of contact forces challenging. In dual-arm manipulation, this limitation prevents stable force closure and consistent control of the object wrench. We present a control framework that combines contact-level admittance and object- level impedance to compute velocity commands for both arms. The contact admittance law maps force errors into velocity corrections, while the object impedance relation regulates the net wrench on the object. Together, these laws generate joint velocities through the stacked Jacobian, ensuring consistent integration of force and motion objectives. Contact compliance is explicitly modeled using linear spring–damper elements. The analysis of closed-loop error dynamics shows how the stiffness and damping parameters of the contact compliance influence the frequency response of the error dynamics and explains the origin of high-frequency oscillations in the presence of sensor noise. Experiments with a dual-arm setup with two heteroge- nous velocity-controlled manipulators validate the framework. Results confirm accurate force regulation, disturbance rejection, and stable cooperative lifting under different contact padding conditions. The proposed approach establishes a velocity-based method for dual-arm force closure with contact compliance.