Kanya Tanaka

Experimental analysis of handing over

This paper examines the motions of handing an object over on the plane are investigated experimentally. Hander and receiver generate smooth motions of handing over by adjusting his/her kinematic features to the other. This adjustment is important and needs to be analyzed. The relative movement of both hands is also interesting and are analyzed from the view point of applying the results in robot motions. Moreover, the effect of direction, of the movement, which changes the trajectory of the motions is analyzed finally. Experimental results show that the hand path of the hander is straight and the velocity pattern of the hand is bell-shaped whose velocity peak is located in a little before the middle of the duration, which is similar to the positioning motion of humans. The two representative patterns of trajectory are observed on the motion of the receiver from the view point of the velocity pattern.

Mechanical impedance characteristics of robots for coexistence with humans

This paper examines the appropriate virtual impedance values of robots coexisting with humans from the view point of human emotions. The values are investigated experimentally using the rating scale method which is generally used for evaluating various stimulus subjectively. In the experiments, 11 subjects add force or impact to the robot and evaluate its reaction by the rating scale method. The evaluations are done on 48 combinations of virtual mass, viscous coefficient, stiffness. As a result, the emotions being flexible, pleasant, and human-like are explained by a linear regression model of the impedance values and the emotion being reassuring are classified into 4 groups from the view point of contact force and response speed.

Multi-rate adaptive pole-placement control for pneumatic servo system with additive external forces

In the existent pneumatic servo system with additive external forces, the plant is subjected to the constant disturbances caused by additive external forces. In that case, it is difficult to accomplish good control performance by using the conventional design scheme of an adaptive pole-placement control. In this paper, we propose an improved design scheme of the adaptive pole-placement control for the pneumatic servo system with additive external forces. In this design scheme, difference process of the signals in the identification mechanism and the compensator in the controller are introduced to eliminate the influence of the constant disturbances caused by the additive external forces. Furthermore, a multirate type adaptive law is adopted to improve the control performance. The effectiveness of the proposed design scheme is confirmed by experiments using the existent pneumatic servo system.

Improved design scheme of MRAC for electro-pneumatic servo system with additive external forces

This paper presents an improved design scheme of MRAC for the electropneumatic servo system with additive external forces. In this design scheme, a difference process of the identification signals is adopted in the identification mechanism to eliminate the influence of the constant disturbances caused by the additive external forces. Furthermore, the controller of this design scheme is constructed with a compensator to overcome the influence of the disturbances. As a result, it can be possible to accomplish the satisfactory control performance.

Improved Scheme of Adaptive Pole-Assignment Control for Pneumatic Servo System

Abstract This paper presents an improved design scheme of the adaptive pole-assignment control for the pneumatic servo system with additive external forces. Using the conventional design scheme in the presence of the constant disturbances caused by the additive external forces, it is impossible to identify accurate parameters of the plant. Therefore, in this design scheme, the difference process of the identification signals is introduced to overcome the above mentioned problem. Furthermore, the controller of this design scheme is constructed with a compensator to eliminate the influence of the constant disturbances.

Multi-rate MRAC using delta-operator for electro-pneumatic servo system

This paper presents an approximate design scheme using delta-operator of multirate model reference adaptive control (MRAC) for an electropneumatic servo system. Since the discrete-time plant of the electropneumatic servo system often becomes nonminimum phase, it is impossible to construct the conventional design scheme of MRAC for such a plant. Adopting a delta-operator and neglecting the small coefficients of the plant, the approximate design scheme of MRAC is constructed to overcome the above problem. In this design scheme, the update-time of the controller parameters is chosen to be integral times the sampling-time to supply the lack of the update-time. Effectiveness of this design scheme is confirmed by experiments using the existent electropneumatic servo system.

Approximate Design Scheme of MRAC Using Multi-Rate Identification for Pneumatic Servo System with Additive External Forces

Abstract This paper presents an approximate design scheme of MRAC for a pneumatic servo system with additive external forces. In this design scheme, the accurate time-delay of the pneumatic servo system is decided by the preparatory experiment. Then, the approximate design scheme of MRAC is constructed using the delta-operator. The multi-rate method of identification for parameteres of the plant is also adopted. Furthermore, the difference process of the identification signals is adopted in the identification mechanism of this design scheme to eliminate the influence of the constant disturbances caused by the additive external forces. The controller of this design scheme is also constructed with a compensator to overcome the influence of the constant disturbances.

Switching-type Adaptive Control for Pneumatic Servo System with Additive External Forces

Abstract In this paper, we propose a design scheme of a switching-type adaptive control for a pneumatic servo system with additive external forces. In this design scheme, the unknown parameters are identified at first and the plant model is decided whether to be minimumphase or not. Because the discrete-time plant model of the pneumatic servo system becomes to be a minimum phase or a non-minimum phase by the difference in the sampling period and the load mass [1]. Then, a model reference adaptive control system (MRACS) is adopted in the case of minimum-phase and an adaptive pole-assignment control system (APACS) is used in the other case. Furthermore, in this design scheme, deference process of the signals in the identification mechanism and the compensator in the controller are introduced to eliminate the influence of the constant disturbances caused by the additive external forces. The effectiveness of the proposed design scheme is confirmed by experiments using the existent pneumatic servo system with additive external forces.

Multi-variable virtual impedance control of a robot considering human emotions

When robots conduct several tasks transmitting forces to humans, robots must be controlled taking human emotions into consideration. In this paper, a multivariable impedance control of a robot considering human emotions especially when a human contacts with or lean on the robot is proposed. First, human characteristics of changing his/her softness in decreasing the movement of an object which contacts with human hand with certain force are analyzed experimentally. It is expected that the human characteristics can be expressed by the multivariable impedance models. Second, we try to realize a multivariable impedance control of a robot favorable for human emotions based on the approximated human characteristics using rating-scale method.

Favorable reaction of robots coexisting with humans

This paper examines the relations between human emotions and the virtual impedance values of the robot experimentally using the rating scale method. In the experiments, 11 subjects added force or impact to the robot and evaluated its reaction by the rating scale method. The evaluations were done on 48 combinations of virtual mass, viscous coefficient, and stiffness. As the results, the emotions being flexible, pleasant, and human-like were explained by a linear regression model of the impedance values and classified into 4 groups from the view point of the contact force and response speed.