Mohamed Fanni

Ahmed Khalifa, Mohamed Fanni, Alaa Khalifa

The research on aerial manipulation systems has been increased rapidly in recent years. These systems are very attractive for a wide range of applications due to their unique features. However, dynamics, control and manipulation tasks of such systems are quite challenging because they are naturally unstable, have very fast dynamics, have strong nonlinearities, are very susceptible to parameters variations due to carrying a payload besides the external disturbances, and have complex inverse kinematics. In addition, the manipulation tasks require estimating (applying) a certain force of (at) the end-effector as well as the accurate positioning of it. Thus, in this article, a robust force estimation and impedance control scheme is proposed to address these issues. The robustness is achieved based on the Disturbance Observer (DOb) technique. Then, a tracking and performance low computational linear controller is used. For teleoperation purpose, the contact force needs to be identified. However, the current developed techniques for force estimation have limitations because they are based on ignoring some dynamics and/or requiring of an indicator of the environment contact. Unlike these techniques, we propose a technique based on linearization capabilities of DOb and a Fast Tracking Recursive Least Squares (FTRLS) algorithm. The complex inverse kinematics problem of such a system is solved by a Jacobin based algorithm. The stability analysis of the proposed scheme is presented. The algorithm is tested to achieve tracking of task space reference trajectories besides the impedance control. The efficiency of the proposed technique is enlightened via numerical simulation.

Ahmed Khalifa, Mohamed Fanni

This paper presents the inverse kinematic analysis and parameters identification of a novel aerial manipulation system. This system consists of 2-link manipulator attached to the bottom of a quadrotor. This new system presents a solution for the limitations found in the current quadrotor manipulation system. By deriving the inverse kinematics, one can design the controller such that the desired end effector position and orientation can be tracked. To study the feasibility of the proposed system, a quadrotor with high enough payload to add the 2-link manipulator is designed and constructed. Experimental setup of the system is introduced with an experiment to estimate the rotors parameters. Its parameters are identified to be used in the simulation and controller design of the proposed system. System dynamics are derived briefly based on Newton Euler Method. The controller of the proposed system is designed based on Robust Internal-loop Compensator (RIC) and compared to Fuzzy Model Reference Learning Control (FMRLC) technique which was previously designed and tested for the proposed system. These controllers are tested for provide system stability and trajectory tracking under the effect of picking as well as placing a payload and under the effect of changing the operating region. Simulation framework is implemented in MATLAB/SIMULINK environment. The simulation results indicate the effectiveness of the inverse kinematic analysis and the proposed control technique.