Yoshihiro Suda

Self-powered active vibration control using a single electric actuator

Abstract The authors have proposed self-powered active vibration control systems that achieve active vibration control using regenerated vibration energy. Such systems do not require external energy to produce a control force. This paper presents a self-powered system in which a single actuator realizes active control and energy regeneration. The system proposed needs to regenerate more energy than it consumes. To discuss the feasibility of this system, the authors proposed a method to calculate the balance between regenerated and consumed energies, using the dynamical property of the system, the feedback gain of the active controller, the specifications of the actuator, and the power spectral density of disturbance. A trade-off was found between the performance of the active controller and the energy balance. The feedback gain of the active controller is designed to have good suppression performance under conditions where regenerated energy exceeds consumed energy. A practical system to achieve self-powered active vibration control is proposed. In the system, the actuator is connected to the condenser through relay switches, which decide the direction of the electric current, and a variable resistor, which controls the amount of the electric current. Performance of the self-powered active vibration was examined in experiments; the results showed that the proposed system can produce the desired control force with regenerated energy, and that it had a suppression performance similar to that of an active control system using external energy. It was found that self-powered active control is attainable under conditions obtained through energy balance analysis.

A NEW HYBRID SUSPENSION SYSTEM WITH ACTIVE CONTROL AND ENERGY REGENERATION

SUMMARY This paper proposes new control concept of suspension, i.e. a hybrid control system with active control and energy regeneration. In ordinary passive suspension system, damper converts vibration energy into heat energy by its viscosity, so that the vibration energy is dissipated. This dissipated energy is not used practically at all. On the other hand, active suspension system has great performance of vibration isolation but it consumes extra energy. This paper presents a method to solve these problems in active imd passive control systems as follows: In passive suspension an energy regenerative damper system which converts vibration energy into useful energy is proposed. The hybrid system combines this energy regenerative system and active control in order to achieve good performance of vibration reduction with few energy consumption. By numerical simulations and basic experiments it was found that the proposed hybrid control system had satisfactory performance in both vibration reduction and ener...

Absolutely exponential stability of a class of neural networks with unbounded delay

In this paper, the existence and uniqueness of the equilibrium point and absolute stability of a class of neural networks with partially Lipschitz continuous activation functions are investigated. The neural networks contain both variable and unbounded delays. Using the matrix property, a necessary and sufficient condition for the existence and uniqueness of the equilibrium point of the neural networks is obtained. By constructing proper vector Liapunov functions and nonlinear integro-differential inequalities involving both variable delays and unbounded delay, using M-matrix theory, sufficient conditions for absolutely exponential stability are obtained.

COMBINED TYPE SELF-POWERED ACTIVE VIBRATION CONTROL OF TRUCK CABINS

A self-powered active suspension, which produces control force using energy regenerated by dampers, is applied to truck suspensions. Such systems do not require external energy to produce control force. To discuss its feasibility, the balance between the regenerated and the consumed energy is examined and active controllers that can achieve active control with regenerated energy are obtained. Control schemes for the self-powered system are presented, and their performances are examined through numerical simulations. The results show that the system achieves active vibration control without external energy, and has better suppression performance than passive or semi-active control systems. (A)

Hybrid Suspension System with Skyhook Control and Energy Regeneration (Development of Self-Powered Active Suspension)

Abstract This paper presents a method of active vibration control system using regenerated vibration energy,i.e., the hybrid suspension system with active control and energy regeneration. In this system, all the energy for active control is supplied from a damper which regenerates vibration energy. In order to attain this system, less energy consumed control law and a device which can regenerate vibration energy are required. This paper proposes less energy consumed active control law using the concept of skyhook control. A linear DC motor which can convert kinetic energy to electric energy with high efficiency is developed as an actuator and an energy regenerative damper. From experiments and numerical simulations, it is proved that the proposed hybrid suspension system has better isolation performance than passive or semi-active suspension system without any energy consumption.

Electro-mechanical suspension system considering energy consumption and vehicle manoeuvre

In this paper, the performance of the electro-mechanical suspension is discussed on the energy consumption, vibration isolation, and vehicle manoeuvrability. On the basis of the formulation of electro-mechanical suspension, the energy consumption and vibration isolation are discussed through the contour maps with the sprung and unsprung mass velocity feedback gain axes. From the numerical simulation and experimental results, the contour maps for the evaluation of the performance with feedback gain axes are proposed, and on these maps, the abilities of vibration isolation and manoeuvrability are evaluated. On the energy consumption, the regeneration region exists, and the velocity feedback gain of unsprung mass should be considered for regeneration and energy saving. Moreover, Gain settings for improving each vehicle performance are proposed and verified by shaker tests. From simulation and experimental results, it is demonstrated that the proposed active suspension system is able to solve the compatibility between vibration isolation and energy saving.

Study on rail corrugation in sharp curves of commuter line

This paper presents study on short-wave rail corrugation on the sharp curve in commuter lines. It becomes a serious problem because it causes not only large noise, but also violent wheel vibration of that may damage the rail and the track sleeper. It is necessary to renewal of rail and rail re-profiling. These countermeasures need large cost. From these backgrounds, a project started to examine the mechanism of rail corrugation on commuter line. It is important to consider the possible cause from both the viewpoints of vehicle and track. In this project, both the measurements on vehicle and rail were carried out. In this paper, observation results of corrugation and measurement on vehicle running tests were shown. From these facts the mechanism of corrugation and countermeasure are discussed.

Experimental study on mechanism of rail corrugation using corrugation simulator

This paper presents experimental study on corrugation phenomenon growing on the top surface of rail in a tight curve of track. One of the characteristics of the corrugation is to involve a slight slip, i.e. creepage, in rolling contact surfaces between rails and wheels. In order to examine the mechanism of corrugation, the authors reproduced the phenomenon in experiments. In particular they examined it with focusing on the value of steady creepage. From this investigation, the effect of steady creepage on corrugation development has been cleared.

High Speed Stability and Curving Performance of Longitudinally Unsymmetric Trucks with Semi-active Control

SUMMARY The possibility of improving both the dynamic stability and curving performance of railway trucks through the use of semi-active control is discussed. According to the direction of vehicle motion, the truck parameters are switched in a longitudinally asymmetric manner. Using a method of evaluation proposed here, the stability of trucks having the same steering ability was examined using linear models. A truck equipped with independently rotating wheels on the trailing axle and with unsymmetric primary suspension has the best performance. A realistic method of achieving this is proposed: using harder primary longitudinal stiffness on the trailing axle and using a primary yaw damper only on the leading, allows bidirectional operation by changing the damping force.

SELF-POWERED ACTIVE CONTROL APPLIED TO A TRUCK CAB SUSPENSION

Abstract A method of active vibration control using regenerated vibration energy, i.e. self-powered active control, applied to the cab suspension of a heavy duty truck. In the proposed system, an electric generator that is installed in the suspension of the chassis regenerates vibration energy and stores it in the condenser. An actuator in the cab suspension achieves active vibration control using the energy stored in the condenser. Numerical simulations and basic experiments demonstrate better isolation performance of the self-powered active vibration control system than that of a passive and a semi-active control.