Velocity-Based Admittance-Impedance Control with Contact Compliance Modeling for Robust Dual-Arm Manipulation
Samriddhi Dubey, Yash Kashiv, Shreyas Kumar, Siddhi Jain, Rajesh Kumar, Harish Palanthandalam-Madapusi
AI summary
Problem
Commercial manipulators typically offer only position or velocity control interfaces, making direct force regulation and stable force closure in dual-arm tasks difficult. Relying on noisy force-torque sensors without torque-level actuation often leads to high-frequency oscillations and grasp instability.
Approach
The framework combines contact-level admittance to map force errors into velocity corrections with object-level impedance to regulate net wrench, while explicitly modeling contact padding as a spring-damper system to filter sensor noise and stabilize the closed loop.
Key results
- 100% cooperative lifting success with double foam padding versus 0% with no padding
- Contact compliance modeled as a passive high-pass filter that attenuates high-frequency force sensor noise
- Accurate force regulation and disturbance rejection demonstrated on heterogeneous velocity-controlled manipulators
- Closed-loop error dynamics analysis providing explicit guidance for stiffness and damping parameter selection
Why it matters
Enables safe, compliant, and force-aware dual-arm manipulation on widely available, cost-effective velocity-controlled industrial robots without requiring expensive torque interfaces or perfect sensor data.
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. Experiments with a dual-arm setup with two heterogeneous velocity-controlled manipulators validate the framework and the theoretical pre- dictions. 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.