Yasumasa Ogino

PWM technique for power MOSFET inverter

A sinusoidal PWM (pulsewidth-modulated) inverter suitable for use with power MOSFETs is described. The output waveforms in the proposed PWM inverter are investigated both theoretically and experimentally. A modulating signal for the three-phase PWM inverter is obtained by adding the harmonic components of integer multiples of three to the three-phase sine waves. By using the proposed modulating signal, the amplitude of the fundamental component is increased about 15% more than that of a conventional sine-wave inverter and the commutation number of the inverter is decreased to two-thirds of a conventional one. >

Force control without force sensor based on mixed sensitivity H/sup infinity / design method

The authors propose the force control of a robot manipulator without a force sensor. The proposed force control system is realized by both the acceleration controller and the force observer. Both systems are designed by the mixed-sensitivity H/sup infinity / design method. The acceleration controller regulates the actuator of the robot manipulator by the acceleration control command. The force observer estimates the reaction force from the target environment. The experimental results showed that the response of the proposed force control system without a force sensor coincided with that of the force control system with a force sensor.<<ETX>>

High performance motion control based on model following acceleration joint control method

A decentralized manipulator joint control is proposed, based on the model-following acceleration control system which is constructed using only the information from a rotary encoder. When each joint of the robot manipulator is regulated by the proposed acceleration control system, it is not affected by its dynamical nonlinearity and is controlled independently. A continuous-path tracking method for fast-motion control is also designed using the acceleration control. Experimental and numerical examples show that the proposed acceleration control method is valid for multi-degree-of-freedom robot manipulators.<<ETX>>

Hybrid Control of Robot Manipulator without Force Sensor

Abstract This paper proposes the new hybrid control of force and position without force sensor. The proposed hybrid control system is designed by both H ∞ acceleration controller and the force estimation system. H ∞ accleration controller realizes a fine and robust motioncontrol. The reaction force estimation system consists of the torque observe and tip inverse dynamics calculation, and its estimated value is fed to the force control system the experimental results in this paper illustrate the fine hybrid control of the tested three-degrees-of-freedom DD robot manipulator without force sensor

PAM-PWM Inverter Using Power MOSFETs For AC Motor Drives.

A new PWM inverter suitable for use of power MOSFETs is described. The output waveforms in the proposed PWM inverter are investigated both theoretically and experimentally. A modulating signal for the three-phase PWM inverter is obtained by superposing a rectangular wave on the specific trapezoidal wave. This modified signal lends itself to a simple three-phase construction. The output PWM waveform for the new modulating signal does not include the fifth harmonic component and an amplitude of fundamental component is increased by about 20 percent more than that of a conventional PWM inverter. As each inverter arm does not operate during two-third period, the heat generated in the devices are reduced. That is, the size of the inverter system is minimized because of the reduction in the heat dissipating equipment.

H/sup infinity / observer based force control without force sensor

The authors propose the force control of a robot manipulator without a force sensor. The proposed force control system is realized by an H/sup infinity / acceleration controller and a H/sup infinity / force observer. The H/sup infinity / acceleration controller regulates the actuator of the robot manipulator by the acceleration control command omega /sup cmd/. The H/sup infinity / force observer estimates the imposed force to the actuator. Both H/sup infinity / systems are designed by the mixed sensitivity H/sup infinity / control design method. The experimental results show the response characteristics of both the force sensor feedback force control and the H/sup infinity / force observer based force control. It is shown that the system regulates force well.<<ETX>>

Novel Pwm Strategy For Power Mosfet Converter

A new PWM converter suitable for use with power MOSFETs is described. A modulating signal for the three-phase PWM converter is obtained by modifying the specific trapezoidal wave. The output PWM waveform for the new modulating signal does not include the fifth and the seventh harmonic components, and other higher-order harmonics can be neglected. The input cur ren t is converted into a sinusoidal waveform and the power factor of the input power can be adjusted to a rb i t ra ry values. A s each of these converter arms do not operate during about half period, the heat generated in the devices is reduced. That is, the size of the converter system can be minimized by the reducing the size of t h e heat dissipating equipment.