Motoyuki Adachi

Dynamical Characteristics of Gyroscopic Weight Measuring Device

This paper describes analytical and experimental studies about an entirely new system for measuring forces using a gyroscope (called Gyroscopic Weight Measuring Device, or simply GWMD throughout this paper) which provides precise direct digital output proportional to the single axis weight applied. In spite of the complexity of the servo-mechanism, the action of the GWMD is inherently linear, hysteresis, and drift free. Topics in this paper are summarized as follows: 1) The principal dynamical characteristics of the GWMD using a two-degree-of-freedom mathematical modelfor a gyroscope are an) alyzed theoretically. 2) The GWMD is designed with suitable parameters and constructed. Some systematic errors caused by various influences are examined. 3) Performance tests are promising for practical applications. The GWMD constructed in this study offers a repeatable accuracy up to 1/15,000 for weight in the range 0 to 150 N.

Analysis of a gyroscopic force measuring system in three-dimensional space

Abstract This paper concerns the development of an entirely new sensor for measuring forces using a gyroscope (called gyroscopic force measuring system, or simply GFMS) for measuring a force vectorially. In a previous paper [S. Kurosu, M. Adachi, K. Kamimura, Dynamical characteristics of gyroscopic weight measuring device, ASME J. Dynamic System Measurement, and Control 119 (1997) 346–350], the dynamics of the GFMS for measuring a vertical force were investigated and the principal characteristics were examined theoretically and experimentally. The results of this work are directly applicable to measurement of a vectorial force in three-dimensional space. The principle and the dynamical characteristics of the GFMS for measuring a force vector are analyzed theoretically. To measure a force vectorially, two auxiliary turntables (driven by servomechanisms) are installed around the gyroscope, in which turntable outputs are required to follow some angles of incidence of a force vector. Some unfavorable errors caused by various factors and disturbances are analyzed. Two types of compensation methods are proposed as a device both for accurate force measurement and disturbance suppression. The feasibility of the proposed GFMS is confirmed by numerical simulations.

Improvement of accuracy for continuous mass measurement in checkweighers with an adaptive notch filter

With increased automation in the manufacturing industry, the demand for a quick and accurate mass measurement system is growing. Currently, the active belt conveyer is demanded by many enterprises. However, three mechanical noises, a peculiar frequency, a frequency of motor, a frequency of Belt pulley, are included in the observation signal from the active belt conveyer. Therefore, we have to remove those noises for the accuracy. In the current mass measurement system, the moving method is applied to remove those noises. However, it is inadequate only in the moving average method for more quick and accurate measurement. Therefore, we propose a frequency analysis method using the complex LMS algorithm. In this method, oscillation elements included in observation signals is converged every analysis frequency. Since time to converge depends on the constant value called the step size parameter, even in case of few obtained signals noises are removed and the accuracy seems to improve. In this study, the utility of the method is experimentally verified.

Frequency analysis method using the adaptive algorithm and application to dynamic measurement of mass and weight

With increased automation in the manufacturing industry, the demand for a quick and accurate mass measurement system is growing. Currently, an active belt conveyer is in demand by many enterprises. However, there is a problem that the active the active belt conveyer causes mechanical noises. The main noises are three kinds, which are the natural oscillation of measurement conveyer, oscillation by rotation of motor and belt pulley. They cause observable signals within the active belt environment. Therefore, we have to remove those noises to acquire a greater accuracy. In the current mass measurement system, the moving method is objected to remove those noises. Unfortunately, it is inadequate only in the current system method for more quick and accurate measurement. In this paper, we propose a frequency analysis method using the LMS algorithm. Moreover, we develop the system which applied this method and moving average method. Finally, we use device actually marketed in order to verify the utility of the system by comparative experiment between current system and proposed system.

Force-measurement using gyroscopic force measuring system

This paper deals with the development of an entirely new force sensor, called the gyroscopic force measuring system (GFMS), for measuring a force vectorially. In this paper, the GFMS is constructed by a gyro-rotor using a miniature rate-gyro for aircraft instrument. The fundamental experiment suggests the possibility to measure a small force range less than 0-3N.