Eiichi Bamba

Frictional dynamics of the overrunning clutch for pulse-continuously variable speed transmissions: rolling friction

The overrunning clutch for pulse-continuously variable speed transmissions (pulse-CVT) is a roller-type mechanism whose working condition is different from the conventional types of overrunning clutches. This paper studies the rolling friction of this clutch with the dynamic effect of the operation of the pulse-CVT. The contribution of elastic hysteresis and viscous shear to the rolling friction of the clutch is analyzed.

Fuzzy theoretical interactions between consciousness and emotions

Emotional processes in the paper are defined as both synergistic processes of consciousness with stimuli and expressive processes caused for movements of the mind affected with consciousness. Models of the former are organized by system control models and the latter expressed from the introduced psychogenic particles driven by consciousness. It is proved that the probability space formed by psychogenic particles becomes the probability informational resource of expressions. Fuzzy decision problems with emotions are definable on the hypothesis that emotions are fuzzy. Expressions of a hatred by random walking of an autonomous vehicle (AV) are found from the application example of emotion process models with the AV avoiding obstacles.

Evaluative cognition and attention allocation in human interface

This paper investigates evaluative cognition and attention, which are the most important human abilities required in the manmachine system. A mathematical model for the evaluative cognition is proposed, and an effort is made to describe clearly the basic relation between the evaluative cognition based on the importance of several simultaneously presented information data and the attention allocation based on the result of the evaluative cognition. The information cognition space is introduced into the model to represent the state which describes the human information cognition. In the space, the information is compressed into the set of information expectation values, and then the evaluative cognition is performed. The allocation of attention is formulated as the ratio of the object information expectation values to the sum of the presented information expectation values. By the proposed evaluative cognition model, a clearer theoretical basis is provided for the attention allocation model. To verify the validity of the attention allocation model, a psychological experiment was made in which several figures are presented for a short interval (0.5 s). The results of experiment agreed almost completely with theoretical values, indicating the validity of the theory.

Dynamic System Identification using a Step Input

In this paper, we propose a deterministic off-line identification method performed by using input and output data with a constant steady state output response such as a step response that causes noise or vibration from a mechanical system at the moment when it is applied but they are attenuated asymptotically. The method can directly acquire any order of reduced model without knowing the real order of a plant, in such a way that the intermediate parameters are uniquely determined so as to be orthogonal with respect to 0 ∼ N-tuple integral values of output error and irrelevant to the unmodelled dynamics. From the intermediate parameters, the coefficients of a rational transfer function are calculated. In consequence, the method can be executed for any plant without knowing or estimating its order at the beginning. The effectiveness of the method is illustrated by numerical simulations and also by applying it to a 2-mass system.

Anti-Windup Feedforward Controller Design for Reference Input Expressed as a Time Polynomial

In this paper, we propose an anti-windup method for feedforward controller of 2 degree of freedom (2DOF) control by which model matching is done. The proposed method replaces memorized variable of output of reference model in the feedforward controller with controlled variable when input is saturated. It is verified by numerical simulations that satisfactory reference input response is derived by the proposed method even if input is saturated or controlled object has uncertainty.

A Study on a Controller to Suppress Periodic Speed Variation

This paper is concerned with a practical controller to suppress the periodic speed variation of a motor. Speed variation in a pump, a compressor or a wheel of an electric vehicle causes vibration and noise, which shorten the life of the machine. Although repetitive control can suppress the speed variation, there are the following problems: If a reference velocity changes, the period of the speed variation changes and the effect of the suppression is reduced. The tuning parameters are difficult to tune. In the case where a low-resolution angle sensor is used, the output of the controller to suppress the speed variation becomes pulse-shaped and causes harmonic ripples that increase energy consumption. In order to eliminate the harmonic ripples, we propose a controller of which the output is interpolated with a sine wave.

Fractal dependence of texture perception

Humans can easily discriminate not only simple figures but also similar complex textures. At present, a large information processing capability is required for a machine to process such texture image information in a short time on the CRT screen or medical images. It is important to analyze the visual information mechanism for those images. In recent studies of visual search, the texton is considered as a pop-out discrimination element. There remain a number of problems in the recognition of the texture composed of complex patterns such that the texton in not clear. On the other hand, fractal can be a measure for the complexity, and is related closely to the visual system. This paper presents a recognition experiment and an attention allocation model by simultaneous presentation of multiple images, where a set of textures with known fractal dimensions are used as the image information. The relations are examined quantitatively. As a result, it is shown that a relation can be assumed between the fractal dimension (Dp, DH) of the texture and the allocation of attention fi to the texture. For the set (A) of textures, a multiple regression expression f(A) = 97.6 + 20.1 Dp − 55.3 DH can be applied with a high correlation coefficient. Thus, it is verified that the fractal information can be used as the pop-out discrimination element in the recognition of the texture.

State-space model identification using input and output data with steady state values zeroing multiple integrals of output error

This study proposes a new deterministic off-line identification method that obtains a state-space model using input and output data with steady state values. This method comprises two methods: zeroing the 0 » N -tuple integral values of the output error of single-input single-output transfer function model [1] and Ho-Kalman’s method [2]. Herein, we present a new method to derive a matrix similar to the Hankel matrix using multi-input and multi-output data with steady state values. State space matrices A, B, C and D are derived from the matrix by the method shown in reference [2]. This method’s utility is that the derived state-space model is emphasized in the low frequency range under certain conditions. Numerical simulations of multi-input multi-output system identification are illustrated.

Improved State-Space Model Identification Using Input and Output Data with Steady State Values

In this paper, we improve the deterministic off-line identification method (Kosaka et. al., 2002) that obtains a state-space model from input and output data with a constant steady state response. The method is composed of determining the parameters by zeroing the 0 ~ N-tuple integral values of output error between the plant and the model (Kosaka et. al., 2000) and by using Ho-Kalmans method (Zeiger et. al., 1974). The method theoretically has an assumption that plant system matrix A satisfies |A| < 1 because the method utilizes Taylor series expansion. But the method can be applied to plants without the assumption |A| < 1. The feature is that the method is performed by using a step response, which is suitable to a mechnical system where noise and vibration are undesirable, and that the identification result is accurate at low frequency range. Numerical simulations of multi-input multi-output system identification are illustrated.

Anti-Windup Feedfoward Controller Design for Reference Input Expressed as Time Polynomial

Abstract In this paper, we propose an anti-windup method for feedforward controller of 2 degree of freedom (2D0F) control (Araki et. al., 1991) by which model matching is done. The proposed method replaces memorized variable of output of reference model in the feedfoward controller with controlled variable when input is saturated. Furthermore, we propose that model of controlled object used in the method is derived by using identification method (Kosaka et. al., 2000), (Kosaka et. al., 2002) for a reduced model with zeroing 0 ~ N- -tuple integral values of output error. By using the model, tracking error for reference input that consists of 0 ~ N- th power of time becomes zero even if controlled object has uncertainty. The resulting system has neither deterioration in the feedback characteristics nor increase in the tuning man-hour because feedforward controllers do not affect the feedback characteristics and the feedback controller can be designed with accumulated know-how. It is verified by numerical simulations that satisfactory reference input response is derived by proposed method even if input is saturated or controlled object has uncertainty.