This paper proposes abstraction and reproduction methods on bilateral control of real world force sensation, and reconstruction of real world environment as well. In the abstraction mode, a master-slave system is composed, and the action-reaction law is attained through bilateral control. Later, based on acceleration information, the force, position and velocity of both master and slave systems are estimated and obtained. In the reconstruction mode, an environmental model is reconstructed based on the obtained data from real-world. Next, by using reproduction mode on master side, the operator would feel the force sensation from the obtained environmental model. Here, the proposed system is able to store the bilateral real-world force sensation to a sensation database. Finally, the experimental results show the validity of the proposed method.
In this paper, the effect of double support phase in bipedal walking is investigated, and a new design approach for bipedal waking pattern based on the synchronization of the motions in sagittal and lateral planes is developed. The analysis of the motions both in the sagittal and lateral planes reveals that the motions in these two planes are tightly coupled together. The motion parameters such as walking speed, phase motion time, and phase stride can be easily adjusted simply by altering the start and finish points of double support phases in the lateral plane. Consequently, a new bipedal walking pattern for adjusting walking speed by controlling the double support phase is developed. Moreover, it is pointed out that smooth and fast walking can be obtained by shortening the double support phase after a high instantaneous speed is reached at the end of the acceleration phase. Such a walking pattern is very similar to a walker's pattern in the walking race. The procedures of motion planning are also proposed and a numerical example is presented.
The template matching has been used for various industrial image applications. The normalized correlation matching is known as one of general-purposed template matching method. The main advantage of the template matching is an easy operation that requires only registration of a template image. However, a template image has been set by the manual operation. The registered template image by manual operation is not always best for matching. Especially, in the positioning and the alignment of components, the image pattern in a template image and its size influence to the reliability and computational cost. This paper proposes a method to register a template image in a referenced image. An optimal template image area is selected by the genetic algorithm in the proposed method. The experimental results show that the template images selected by the proposed method recorded higher reliability than ones registered by the manual operation.
Programmable Logic Controllers (PLCs) are widely used in industrial world. In PLC-based control systems, low-resolution (especially ON/OFF) sensors are low-cost, and actuators are commonly used since they are compatible with programming languages used in PLCs. PLC switches ON/OFF of the actuators as ON/OFF of the sensors changes. In designing PLC-based systems, the design of parameters of these sensors and actuators (e.g., position of limit switches, torque of motors, and so on.) is important problem since they affect on overall performance of the system. This problem, however, has not been fully discussed yet. In this paper, the systematic design method for this problem is developed. The main idea is to express the model of the system as Mixed Logical Dynamical System (MLDS), and to formulate the problem as mathematical programming problem. The developed idea is applied to line following control of two-wheeled vehicle. The usefulness of the proposed method is demonstrated through simulation and experiment.
A feeding circuit for a superconducting magnetic levitation train system, or the so-called “maglev” consists of feeder cables and armature coils which show characteristics of a distributed-parameter line. Electric power is supplied to the cables and coils by PWM inverters whose output voltage contains a large amount of harmonics. As a result, a harmonic resonance may occur in the feeding circuit. Besides the above characteristics, the connecting point of sections (groups of armature coils) or the feeder cables length changes according to the movement of a maglev train, thus causing changes in the harmonic-resonance characteristics of the feeding circuit. This paper describes analytical results of the harmonic resonance in the feeding circuit for the maglev, with the focus on changes in the connecting point of sections and the feeder cables length.
An algorithm optimizing total energy consumption of a train operation considering DC feeding system is investigated in this paper. Our mathematical formulation consists of kinetic equation of a train and circuit equation of DC feeding system, and includes several characteristics of a train which depend on catenary voltage. It makes us possible to give more detailed consideration to energy-saving operation than that of previous works. Especially, it is remarkable aspect that several discussion about the effect of squeezing control of regenerating current and feeding loss have been possible with our proposed method. The optimizing algorithm is constructed based on the gradient method, which could be useful for the large-scale problem of future works with its light computer load and extensibility. Several numerical examples are demonstrated to verify the reliability and validity of the proposed method.
The authors propose a new apparatus with functions of propulsion and non-contact power collection for a future vehicle which can run like an electric vehicle supplied from the onboard battery source in most of the root except near stations. The batteries or power-capacitors are non-contact charged from the winding connected with commercial power on ground in the stations etc. The apparatus has both functions of linear motor and transformer, and the basic configuration is a wound-secondary type linear induction motor (LIM). In the paper, the wound type LIM with the concentrated single-phase winding for the primary member on the ground is dealt from the viewpoint of low cost arrangement. The secondary winding is changed to the single-phase connection for zero thrust in the transformer operation, and the two-phase connection for the linear motor respectively. The change of connection is done by the special converter for charge and linear drive on board. The characteristics are studied analytically.
This study proposes a method of sensorless oscillation control of a suspended load. To suppress oscillation of a suspended load, we use flywheels as a control device. Reaction torque of flywheels is applied for the oscillation control. An angular velocity value of a suspended load must be acquired for the oscillation control. Therefore, a method to estimate the angular velocity value is indispensable. By conventional methods, the estimation and the oscillation control cannot be realized simultaneously in case of one flywheel. Hence, inertia torque observer is proposed. Inertia torque appears as a disturbance torque on flywheels when a suspended load is oscillating. The angular velocity value is calculated based on this inertia toque. By using inertia torque observer, estimation of the angular velocity value and oscillation control of a suspended load are achieved at the same time.
This paper presents electrical and magnetic characteristics of a permanent-magnet induction generator (PMIG) under unbalanced grid voltages. The method of symmetrical components and two-dimensional finite element analysis (2D-FEA) are used to calculate these characteristics and the results are confirmed through experiments. Even if the voltage of power grids is unbalanced, the PMIG can operate at high efficiency over a wide range of slip and the built-in permanent-magnet (PM) rotor is little affected by the negative-sequence rotating field.
The three dimensional vibration of the rotor in a HTSC-permanent magnet bearing system is studied. We have developed the magnetic bearing system which can revolve up to 12,000rpm, and three dimensional vibration of the rotor is measured with laser displacement sensors. To consider the rotor vibration under the mechanical resonance state, static lateral and vertical pinning force of the magnetic bearing is measured. From the results, resonance frequency is given. There are two factors of mechanical resonance caused by the magnetic bearing. One is lateral equivalent spring and the other is vertical one. Influence of the resonance caused by the lateral spring is large, and that by the vertical one is small. Three dimensional vibration of the rotor position around the mechanical resonance frequency is measured. Because revolution of the rotor increases lateral force to the center, resonance frequency given from the free revolution experiment becomes larger than that from pinning force measurement.
In this paper we study the condition that the cogging torque occurs, that is caused by manufacturing errors in the stator of PM motors. Manufacturing errors can be classified into the distortion of the magnetic core, the degradation of magnetic properties etc. They are expressed as the asymmetric spatial distribution of permeance, that is, the component of the spatial distribution function whose number of spatial pulsations is not equal to the multiple of the stator slot number. The overviews of this paper are as follows. (1) We derive the relational expression between the spatial pulsation number of the asymmetric component of the permeance distribution function and the pulsation number of cogging torque per revolution. (2) Examples are shown for seven typical motor specifications, each of which has different pole/slot ratio. (3) We conduct finite element analysis for the seven typical motors. The stator cores were distorted and the spatial order of distortion was set to the parameter. The analyzed pulsation number of cogging torque agreed well with the theoretical solutions.
This paper presents the coupled analysis method for a new structured linear actuator that can convert the rotation into linear actuation by the attractive and repulsive force of permanent magnets. In this method, the 3-D finite element mesh modification method for multi-motion analysis is taken into consideration. The effectiveness of this method is verified through the comparison with the measured results.
This paper proposes a new structured linear oscillatory actuator that can convert the rotation into linear actuation by the attractive and repulsive forces of two multi-poles permanent magnets, one is connected to the linear motion armature and the other is to a DC motor, respectively. The basic construction and the operating principle of this actuator are described. The effectiveness of this actuator is verified by the measurement.