Kenji Nagase

Control of a Sphere Rolling on a Plane with Constrained Rolling Motion

In this paper, we discuss control of contact coordinates for a contact point between a sphere and a plane with pure rolling contact by using iterative closed paths on the sphere with contstrained rolling motion. We first analyze the boundary of the reachable area by the closed path with constrained rolling motion. Utilizing the result, we second propose a method which converge all the contact coordinates to a target point by the iteration of a finite number of the closed paths. A numerical example where the rolling motion is restricted to the area on the semisphere shows the effectiveness of the proposed method.

Wave-based analysis and wave control of damped mass-spring systems

This paper is concerned with the active vibration control of non-uniform damped mass-spring systems by wave control. In particular, this study considers the clarification of a class of damped mass-spring systems that can be analyzed by a wave-based analysis. Because the wave properties are determined by the propagation constants, three conditions for these propagation constants are considered. A necessary and sufficient condition for the physical parameters to hold the three conditions is obtained. Moreover, for this class of damped mass-spring systems, the properties of the propagation constants and the characteristic impedances, which achieve the impedance matching, are studied. Numerical examples are shown to prove the efficiency of the impedance-matching controller.

Simultaneous control of grasp/manipulation and contact points with rolling contact

Abstract In this paper, for simultaneous control of grasp/manipulation and contact points by a two-fingered robot hand with the pure rolling contact, we provide an entire treatment of the system equations including motion and force constraint, which consist of the generalized coordinates and the contact coordinates. In contrast to most previous studies where specified degrees of freedom (DOF) of fingers are consiered we provide a general treatment of the system for any DOF of the fingers. Utilizing the results, a control design method which achieves the simultaneous control is proposed.

Parameter identification method for piezoelectric shunt damping

Piezoelectric shunt damping is a method to reduce structural vibration by shunting a piezoelectric element with an electrical circuit. This paper proposes a method to identify the physical parameters that are required to design piezoelectric shunt damping systems. Employing self-sensing actuator methodology, the proposed method requires no additional sensor or actuator other than a simple bridge circuit. The parameters can be identified from a transfer function simply by linear least squares method. To demonstrate the validity of the proposed method, the shunt damping of the steel plate with the piezoelectric ceramic is performed based on the identified parameters.

A study on the impedance matching controller for uniformly varying damped mass-spring systems

This paper considers the analysis of the impedance matching controller for the uniformly varying damped mass-spring systems. The positive real property of the impedance matching controller is first investigated. The closed loop properties of the damped mass-spring systems controlled by the impedance matching controller is also discussed.

Wave Control of Damped Mass-Spring Systems

Abstract This paper concerns with active vibration control of cascade-connected damped mass-spring systems by the wave control. We first clarify a class of the damped mass-spring systems to hold the three conditions for the propagation constants to be analyzed by the wave-based analysis. For the class of the damped mass-spring system, we next investigate analytical properties of the impedance matching controller and the closed loop system such as the positive real property and the internal stability. A numerical example is shown to prove the efficiency of the wave control for vibration suppression.