11 accepted papers
This paper provides a new repetitive control framework for robot manipulators with periodic reference and disturbance signals. We first take the inverse dynamics (ID) approach to a robot manipulator to transform its nonlinear input/output behavior into an equivalent linear time-invariant (LTI) syste…
This paper establishes a new framework for repetitive control of uncertain robot manipulators via operator-theoretic robust stabilization. After applying the inverse dynamics approach to robot manipulators, by which the relevant nonlinear input/output behavior is converted to a linear time-invariant
This paper develops a controller synthesis method for ensuring an admissible bound of external forces on biped robots in a desired level. We first introduce the authors’ preceding results on the norm-based stability criterion for a biped walking constructed on its linear inverted pendulum model (LIP…
This paper proposes a new framework for the computed torque method (CTM) of robot manipulators without velocity measurements. We first introduce the Luenberger-observer-based CTM with only position measurements. We then clarify that the external disturbance affects not only the tracking performances…
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…
Actuator modules of humanoid robots have relatively higher joint elasticity than those of industrial robots. Such joint elasticity could lead to negative effects on both the tracking performance and stability for walking. Especially, unstable contact between the foot and ground caused by joint elast…
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…
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…
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