15 accepted papers
Wheeled-legged robots offer significant mobility advantages, yet their control is complicated by the coupled dynamics of the wheel and leg systems. To address this challenge, we propose a whole-body control framework built upon a decoupled architecture. In this structure, a two-wheeled inverted pend
This paper addresses robust landing stabilization in humanoid locomotion on uneven terrain. The core idea is to find a configuration of the robot that results in small impulsive force when an unexpected obstacle is encountered, and to adjust post-contact reference for swing foot with which the pose…
This paper proposes a 6 degree of freedom (DoF) manipulator for haptic application. The proposed haptic device, named GHap, is designed based on the four-bar-linkage mechanism for linear motion with the ring-type gimbal mechanism. To improve the force display ability, the device is designed to compe…
In this paper, we propose the stabilization strategy for a soft landing in a biped walking using impedance control and the optimization-based whole-body control framework. Even though proper contact forces and desired trajectories of the robot are given, the robot can be unstable easily if unexpecte…
This paper addresses reactive generation of step time and location of biped robots for balance recovery against a severe push. Key idea is to reformulate the balance recovery problem into a tracking problem for "hybrid" inverted pendulum model of the biped, where taking a new step implicitly yields…
This paper revisits computed torque method for robot manipulators and aims at developing its new framework based on the L_{1}L_{1} robustness, in which the L_{\infty}L_{\infty} norm together with its induced norm is employed to characterize model uncertainties and a performance measure. More precise…
In a human-robot interaction (HRI) device that performs physical collaboration operations in constant contact with the user, admittance control and impedance control are generally used. Since the two controllers exhibit opposite performances depending on the stiffness condition, controllers capable…
Feedback controller for robotic bipedal walking models can be multi-layered, consisting of low-level continuous-time controller and high-level event-based controller. Stimulated by the success in our preceding study that demonstrates the validity of the l∞-induced norm as an adequate performance mea…
Based on the liner inverted pendulum model (LIPM) for the dynamics of biped humanoid robots, an analytical method for computing stability regions relevant to standing balance of the biped humanoid robots is introduced in this paper. More precisely, two types of the stability regions are discussed in…
This paper presents a novel haptic device, named VirtuaPower, having abilities of 6 degrees of freedom (DOF) position measurement with a high-force display capability and wide workspace. The VirtuaPower is designed as a parallel mechanism with double in-parallel supporting chains. The mechanical des
Despite successful demonstrations of outdoor walking by a few biped robots, performance measure for such robots has not been formally defined yet. The performance measure should be adequately defined by which one can evaluate how well the robot keeps from falling in the presence of disturbance. If s…
In this paper, we propose a novel planar biped model which achieves asymptotically stable walking, based on ankle actuation and the virtual pendulum concept. Simple models for walking have provided useful insights in understanding fundamental principles of human locomotion as well as developing cont…
In this paper, we consider the L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> optimal proportional-derivative (PD) controller synthesis by which the L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xli
When a robotic manipulator is controlled, computing gravity force of the robot is the primary issue. Exact model parameters are not easy to be known in the practical robot system due to the uncertainty of the robot dynamics. Hence, the gravity force is presented by a combination of gravity regressor…