Showing papers in "Journal of the Society of Instrument and Control Engineers in 1985"

Dynamic Manipulability of Robot Manipulators

Abstract: The concept of dynamic manipulability measure of robot arms is proposed as a quantitative measure of their manipulating ability in positioning and orienting the end-effectors, which takes the arm dynamics into consideration. This measure is defined on the basis of the relation between the joint driving force and the acceleration of the end-effector. Some properties of the measure are established. A two-joint link mechanism is analyzed and its best posture is obtained under certain condition from the viewpoint of this measure. A numerical example is also given to illustrate the utilization of this concept for the design of robot manipulators.

Model-Reference Adaptive Control for Distributed Parameter Systems of Parabolic Type

Abstract: During the last several years there have been presented a number of results in the field of model-reference adaptive control. In the most of the results, the process is assumed to be a lumped parameter system, which is described by ordinary differential equations. But real physical systems occupy a certain spatial domain and are not concentrated at a single spatial point. Such systems are called distributed parameter systems, which are modeled by partial differential equations. The principal contribution of this paper is to present a procedure for the design of model-reference adaptive control for an unknown distributed parameter system of parabolic type. We assume the spatial average of the states over some effective sensing region to be the output of the process, and adaptively synthesize the input so that the tracking error between the output of the process and the output of a prescribed reference model, which is a lumped parameter system, is regulated to zero asymptotically.

System Theoretic Study on Learning Control Method

Abstract: High speed motion and accurate positioning of robots can not be obtained simply by applying the desired trajectory to each servo system, because of the dynamic interfernces. To overcome this difficulty we apply a kind of learning control which uses the iteration of motion. In this control scheme, a refernce trajectory is corrected by considering the error in every trial so that the system response can accurately coincide with desired trajectory. This type of learning control system was first investigated by Uchiyama (1978)1. It dealt with a single-input and single-output system, and theoretic properties of learning control are not made clear. In this paper, the stability of learning control for multiinput and multi-output systems is discussed and it is shown that the following three conditions are equivalent each other: (1) stability of learning control (2) bounded real property (3) sensitivity reduction (optimal regulator) From this relation among conditions, it is shown that an optimal regulator system is stable in the sense of learning control and the feedback gains which satisfy the stability of learning control can easily be determined by solving the Riccati matrix equation. Moreover, it is proved that the learning control is considered to be a process of constructing an inverse system. According to some computer simulations, it is shown that a choice of some system parameters (e. g. feedback gains and cost function) extremely changes the performance of learning control.

Mass Flow Measurement of Gravity Flow for High Temperature Dense Phase Solid Gas Two Phase Flow

Abstract: Moved bed gravity flow of solid is required for coal gasifier, metal ore direct reduction furnace, gas phase coal liquifier, etc. as energy conservation. Such a process is high pressure and or high temperature process and required for multi loop injection feeder. The authors developed a new noise flow meter for the process based on the authors' test and the prediction. The measuring method is an noninstrusive method using the simple lean noise sensors and sensing technique without sensing hole on the gravity flow pipe. The conclusion of the authors' test is that noise pressure level on 8kHz by C characteristics is suitable for the mass flow control without back ground noise calibration. Space filtering of the signal or cross correlation method of signal is more suitable for sensing technique. The sensor and senting technique is suitable for solid particle velocity meter of two phase transport pipe.

New Parameter Adjustment Algorithms for Adaptive Systems

Abstract: This paper presents new parameter-adjustment algorithms for adaptive systems and analyzes their properties. Most of the conventional methods for designing adaptive systems require ideal, in other words, unrealistic design conditions that restrict the applications of the methods. Some of these conditions are due to the parameteradjustment algorithms implemented in the systems, i. e., the present popular algorithms perform satisfactorily only under certain restrictive circumstances that cause the ideal design conditions. In order to apply the adaptive methods to a variety of existing plants, it is necessary to develop new parameter-adjustment algorithms that can perform satisfactorily under more realistic circumstances where the conventional ones cannot. This paper presents such three algorithms and analytically clarifies their attractive properties.

A Method for Displaying a Two Dimensional Distributed Pressure Using Pressure Conductive Rubber and Liquid Crystal

Abstract: In this paper the sensor which has a simple structure, flexibility and also has the function of displaying the pressure distribution is proposed, and measured results are shown. The sensor consists of four layers. First and third layers are patterned electrodes. Second layer is the pressure conductive rubber whose resistance varies with pressure. Last layer is the liquid crystal whose color varies with temperature. The theory of measurement is as follows: the distributed pressure(p) on the sensor

Analytical Study on Three-Dimensional Model of Femoropatellar Joint

Abstract: This paper describes simulated analytical results on the femoropatella joint disease and operation in the knee, using the previously reported three-dimensional kinematic model. The primary cause of the cartilage degeneration on the retropatella surface is predominantly considered as abnormal joint contact stress. However, in spite of many experiments, not only its aetiology but also the exact stress pattern have not been clarified yet. In the present study, by the altemation of the physiological parameters in the normal knee, the following three clinical cases were simulated, and the trajectry pattern of contact points and the load bearing capacity in each case were quantitatively obtained. The parameters for simulation-experiment were selected by clinical and pathological significance, as following; 1) Q-angle (a position of the quadriceps muscle's origin) 2) A length of patellar ligament 3) A position of the tibial tuberosity Besides, by connecting the articular surface geometry and the Hertzian elastic contact theory, the contact stress between the normal and the tibial tubercle elevating knees were compared and examined. The simulation results indicated that variations in Q-angle have little effect on the joint contact force, a patella alta case is injurious to the cartilage showing an undulating pattern of contact force, and the elevating of the tibial tuberosity reduces the contact stress by 20-30%. Furthermore, the sliding pattern on the mediolateral contact points, which is closely related to cartilage wear, was examined.