Ryuichi Oguro

Torque and rotational speed estimation with parameter identification of Line-start Induction Motor for Motor Operated Valve

This paper presents a torque and rotational speed estimation method for line-start induction motor operated valves. Routine inspections are carried out to those valves, because motor operated valves are used in the serious plant such as power plant. and securing reliability is an extreme important matter for these systems. Movement environments in these plants are high temperature and humidity, so it is difficult to put sensors near motors. In such a case, we must find the trouble of the system without torque sensor or speed sensor. The proposal method can estimate the torque and rotational speed of induction motor by using time-series data of voltages and currents at the switchboard. Furthermore, we propose the parameter identification method of mutual inductance by comparing the inner and outer products between voltages and currents. First, a torque and rotational speed of induction motor are estimated. Next, a mutual inductance parameter is got. Last, the proposed estimation method is verified by results of experiment.

Developing a new carrier system with throwing and catching robot

Control of an object-throwing and catching robot is examined in this paper. We develop a new carrier system which uses two robots, thrower robot and catcher robot. In order to realize this system, we need to know problems which could happen in throwing and catching motion of these robots. Therefore, we have to produce a preliminary experiment system by a linear slider which has two sliders, thrower slider and catcher slider. In this experiment, the thrower slider throws a ball by inertial force, and the catcher slider moves automatically to point of fall of the ball with information about velocity of the thrower side. The experiment has following results. First, points of the thrown ball differ a little from each result in spite of the same condition. Second, we can find it is important to improve the accuracy of throwing a ball to a target position. In this paper, we show the structure of the preliminary system, and the verified problems about this system.

Modeling and position control based on a two-mass system for a machine stand vibration system

This article describes modeling and position control for a linear slider with machine stand vibration. We propose a strict transformation method between a Machine Stand Vibration System (MSVS) model and a Two-Mass System (2MS) model based on the similarity in mathematical models. This shows that the MSVS model is absolutely equivalent to the 2MS model. Consequently, a position control of the MSVS can be realized by one of many proposed control methods for the 2MS. Moreover the effectiveness of the proposed transformation method is demonstrated by simulations. As a result, we confirmed that the position control of the MSVS can be realized by a PD control with a disturbance observer proposed for the 2MS.

The Control Method of A Virtual Contact Feeling System

In this paper, we propose a new system that conveys the virtual contact feeling to people. Virtually, we make the real contact feeling that they touch the tip of their finger to the object. As the friction exits between the tip of their finger and the object, we make the friction, and will be able to consummate the virtual contact feeling. Nowadays, only the visual information of the object is conveyed to the user on the screen on Web. By this technique, not only the visual information of the object but also the real contact feeling will be able to be conveyed to the user in the near future. And, we think that even use as a training system for the medical treatment and use as the braille system which even visual disability people can use the Internet. The real contact feeling of the object needs comparatively high frequency. Then, first of all, we focus the real contact feeling that is made from low frequency. At present, we study to make the real contact feeling without friction

A Control Proposal for Circle Contour Manufacturing in Rotary Coordinate System

Trajectory error always exist in circle contour manufacturing due to the servo system lag of industrial manufacture devices such as x-y ball screw which is used for two-dimensional manufacture, especially in high speed production. Sometimes, high frequency input commands also make the precision of circle contour manufacture even worse because of the weakness of usual controllers that position trailing deterioration of high frequency input. In other words, a common problem in most of control methods for circle contour manufacturing is higher frequency with longer servo lag and bigger trajectory error. In this paper, a control proposal for contour manufacturing which could cope with the high frequency input problem has been presented. At the end of this paper, the comparison of traditional method and proposal will show the effectiveness of the proposal.

Torque and speed estimation for line-start IM using dot-cross Products of current and voltage vectors

The IM has been adopted widely as the driving sources of the industrial machine and the plants. That reason is that IM is robust and easy to drive. A typical line-start drive system is a motor operated valve arranged to the power plants, the chemical plants. These valves are used for application that energy supply is shut down in an emergency. So, the IM which makes valve operate is connected to 3-phase power supply directly and used. Because of this, the drive system heart of an IM has very high reliability. However, mechanical deterioration is problem. Routine inspections are carried out to those valves and reliability is secured.

A method of high efficiency control for IPMSM by disturbance observer

In this paper, we propose the method to realize high efficiency control for IPMSM (Interior Permanent Magnet Synchronous Motor). In this method, we pay attention to the torque equation. We realize high efficiency control by controlling the vector angle of stator current. As for the high efficiency control, we define the optimum angle as the stator current angle which makes the torque biggest against certain stator current value. The optimum angle is shown as the equation about the stator current value. In addition, we propose the methods to find real optimum angle for the real system by changing stator current angle around calculated optimum angle in the low frequency. Furthermore, we show the possibility of more efficiency method to find real optimum angle by using the disturbance observer. Proposed method is realized by uniting between motor drive control region and mechatronics control region. The proposed method is validated by simulation.

A feedback control for a feel regeneration system with linear slider

In this paper, we present the feel regeneration system that uses a linear motor, and propose the feedback control system based on disturbance observer for generating the reaction force from object things. The proposed feel regeneration system consists of the linear slider and the sensing stage that is connected with the base by spring elements. In addition, we can get optical reactive force by controlling the stretch of the spring, which is a cause of producing the reactive force, and we recognize it as a feeling. In particular, the feel that the stage moves without adding the power, i.e., the regeneration of a feeling of the friction-less is the base technology of such a system, and we call this feeling the one like pushing air. The feedback controller realizes this friction-less feeling with the use of disturbance observer, which is proposed in order to estimate and cancel the friction force. The proposed control algorithm and the system are experimentally verified by results of simulation.

A Decoupling Control Method for Two Link Manipulator

In this paper, we propose a new decoupling control method that based on conventional control technique for each axis. This method realizes the decoupling control by not using a complex system but adding a compensation control input to offset interference. Recently, industrial robots that have multiple joints manipulators are required high speed and high precision response. Therefore, the decoupling control is necessary to offset the interference that arises between each joints of the manipulator. At present, when we think about the manipulator with 2-inertial system we must build the complex system to realize generally decoupling control. Because of that, it is said that the decoupling control is difficult. However, we think it is possible for any people to realize decoupling control more easily without thinking about a complex system construction by using our propose method. At present, we confirm the validity of the proposed method by the simulation.

A Method for Improvement of a Position Control with Analog Signal

In this paper, we propose a method for improving a position control using sliding mode. For industrial equipments, a pulse encoder is generally used for measurement of a position, but the position is not stable by quantization errors which fluctuate between a resolution of the pulse encoder. It is known that this problem can be solved by an analog clamp method that uses two analog sinusoidal signals. However, transmission quantity increases if the analog signals are passed on serial transmission. Therefore, we propose an analog clamp controller judging of a control condition on an sliding mode plane. Effectiveness of the proposed method is confirmed by experiments.