T-ASE 2023: A hybrid controller enhancing transient performance for an aerial manipulator extracting a wedged object

Abstract: Autonomous aerial manipulation requires the capability to handle inevitable dynamic changes during physical interaction. Previously, very few studies have addressed the stability and transient performance of the scenarios involving abrupt changes in dynamics. This paper proposes a hybrid controller enhancing transient performance for an aerial manipulator extracting an object wedged in a static structure. This task incurs a significant jump in the interaction force on the end-effect...

ICRA 2023: Stable contact guaranteeing motion/force control for an aerial manipulator on an arbitrarily tilted surface

Abstract: This study aims to design a motion/force controller for an aerial manipulator which guarantees the tracking of time-varying motion/force trajectories as well as the stability during the transition between free and contact motions. To this end, we model the force exerted on the end-effector as the Kelvin-Voigt linear model and estimate its parameters by recursive least-squares estimator. Then, the gains of the disturbance-observer (DOB)-based motion/force controller are calculated ba...

ICCAS 2021: Robust Control of the Aerial Manipulator with a Fixed End-effector Position

Abstract: The necessity for aerial manipulation while grasping a fixed point is on the rise to broaden the range of tasks that can be performed with flying robots such as plug-pulling or drawer knob grasping. In this paper, a robust controller for the aerial manipulator with a fixed end-effector position is designed, and stability analysis is performed with the proposed control law. Using the constrained Euler-Lagrange equation, a dynamic equation for the aerial manipulator which is freely ro...

IROS 2021: Stability and robustness analysis of plug-pulling using an aerial manipulator

Abstract: In this paper, an autonomous aerial manipulation task of pulling a plug out of an electric socket is conducted, where maintaining the stability and robustness is challenging due to sudden disappearance of a large interaction force. The abrupt change in the dynamical model before and after the separation of the plug can cause destabilization or mission failure. To accomplish aerial plug-pulling, we employ the concept of hybrid automata to divide the task into three operative modes, i...

ICCAS 2020: On-line parameteter estimation of a hexacopter equipped with 2-DOF robotic arm against disturbance

Abstract: In this paper, autonomous aerial transportation with an unknown payload is presented. The unknown parameters of an object are estimated by the estimator based on the dynamics of an aerial manipulator. Also, to cope with the external disturbance, estimation law is modified to compensate for the error between control input and actual generalized force. With the estimated mass and the location of COM(center of mass), an adaptive sliding mode controller is designed. Stability and conver...