Sensorless contact force estimation and robust impedance control for a quadrotor manipulation system

Area of Science:

• Robotics
• Control Systems Engineering
• Aerospace Engineering

Background:

• Aerial manipulation systems are increasingly researched due to their unique capabilities but face significant challenges.
• These challenges include inherent instability, fast dynamics, strong nonlinearities, parameter variations, external disturbances, and complex inverse kinematics.
• Accurate end-effector positioning and force estimation are critical for manipulation tasks.

Purpose of the Study:

• To propose a robust force estimation and impedance control scheme for aerial manipulation systems.
• To address limitations of existing force estimation techniques by developing a novel approach.
• To solve the complex inverse kinematics problem and ensure system stability.

Main Methods:

• Utilizing a Disturbance Observer (DOb) technique for robustness.
• Implementing a low-computational linear controller for tracking and performance.
• Employing a Fast Tracking Recursive Least Squares (FTRLS) algorithm combined with DOb linearization for force estimation.
• Solving inverse kinematics using a Jacobian-based algorithm.

Main Results:

• The proposed scheme demonstrates robustness through the Disturbance Observer (DOb).
• A novel force estimation technique using DOb linearization and Fast Tracking Recursive Least Squares (FTRLS) overcomes limitations of prior methods.
• The system successfully achieves task space trajectory tracking and impedance control.
• Numerical simulations confirm the efficiency and stability of the proposed algorithms.

Conclusions:

• The developed robust force estimation and impedance control scheme effectively addresses key challenges in aerial manipulation.
• The integration of DOb and FTRLS offers a significant advancement in force identification for teleoperation.
• The proposed methods provide a stable and computationally efficient solution for complex aerial manipulation tasks.