Nobuaki Fujiki

Extended Internal Model Control Scheme for Sensorless Force Control on Uneven Surfaces

In this paper, an extended internal model control (IMC) scheme for a sensorless force control on an uneven surface is proposed to such kind of surface-polishing, deburring and rubbing machines. The IMC controller scheme has disturbance decoupling property, good tracking performance and disturbance estimation property. In order to extend the conventional IMC scheme to force control on uneven surfaces, we propose a novel control scheme based on the IMC scheme, and discuss stability of the closed-loop system. Moreover, effectiveness of the proposed IMC scheme is confirmed by comparative experiments.

State and Disturbance Estimation Based on Internal Model Control Structure and Its Application to Sensorless Grasping Control

A new controller scheme based on the IMC design structure is proposed in this paper. Due to using an inverse system or an approximate inverse system for the IMC structure, the order of the controller leads the high order, meanwhile the high order controller is not practical in implementation. This paper is concerned with the problem of reducing a high order controller to a reduced order one. The disturbance estimation property of the closed loop system is also discussed. The proposed controller scheme is applied to a prototype robotic hand that can hold an object with suitable grasping force without force sensor. The effectiveness of the proposed controller scheme is confirmed by experiments.

Disturbance estimation by generalized internal model control and its application to assistive devices for rehabilitation technology

Control applications to life science are significant for the development interacting with humans. Assistive devices for rehabilitation technology will be used by elderly or disabled people in order to support more life independence. For the interaction with humans, safety and reliability conditions have to be fulfilled, and control design methods for assistive devices have to be robust against parameter perturbations. To improve these situations, disturbance estimation property of the generalized internal model control (GIMC) design is applied. The effectiveness of the GIMC design is confirmed by experimental case studies for assistive devices

Decoupling property of full Information H ∞ control and its application to mechanical systems

In this paper, a limiting property of full information Hinfin control is discussed. Existence of a stabilizing solution to the control problem is shown, and limiting behaviors, i.e., disturbance attenuation property and decoupling property, of the closed-loop system are proposed. Moreover, the relationship with limiting properties of LQ control is also mentioned. To confirm effectiveness of the proposed limiting property of full information H infin control, the paper gives experimental results on decoupling control of a 2-link robot manipulator

Practical assistive device for sit-to-stand tasks

Physically weak people require support for standing up and sitting down. The purpose of this study is to develop an assistive device for sit-to-stand task in daily life. The device can support not only for standing-sitting motion but also for setting some places easy in house. And users can use the device by oneself or with caregivers. The muscle activity has been observed by using surface myoelectric potential sensor for verifying performance of the proposed assistive device.

Force control of assistive devices for feeding gastrostomy

The paper presents an assistive devices for health care workers and nurses. A new controlled assistive device for feeding gastrostomy and its control technique have been developed. The proposed controller scheme based on the internal model control (IMC) is able to generate appropriate pressure for the pressurized bag. Effectiveness of the assistive device has been verified by experiments.

Simplified assistive devices for upper limbs

The purpose of this research is to develop an assistive device for upper limbs. The disturbance estimation property of the internal model control is applied to detect motion intention of users. The experimental prototype of the assistive device for upper limbs is developed to evaluate the proposed control method. Effectiveness of the proposed method is verified by experiments. The experimental results include also that muscular activities occur in several muscles using surface electromyography. The proposed device is expected to maintain residual function of upper limbs.

Control method for assistive devices for upper limbs

The purpose of this research is to propose a control method for assistive devices for upper limbs. The disturbance estimation property of the internal model control is applied to detect motion intention of users. The experimental prototype of the assistive device for upper limbs is developed to evaluate the proposed control method. Effectiveness of the proposed method is verified by experiments. The proposed device is expected to maintain residual function of upper limbs.

Estimation and control of brush pressure by using IMC based controller

In this paper, we propose the control method of a writing robot for reproducing brush pressure and trajectory without force sensors. The main goal of this research is to estimate and save the brush pressure by using the internal model control. In order to evaluate the proposed controllers, the experimental device is developed. The paper shows that the proposed controller is able to reproduce the brush pressure on flat and inclined surface through experiments.

Consideration of Course Improvement Activities and Its Effect on Mechanical Designing and Drawing Project

The Department of Mechanical Engineering at Kanazawa Institute of Technology has offered a creative mechanical designing and drawing subject, entitled “Machine Design Project (MDP)”, to third year students. It is well known that it is difficult to perform a scholastic evaluation for a creative subject. Moreover, the instructors’ loads are large owing to the large quantity of reports from students. In such a background, we have carried out course improvement activities of the MDP from 2005. The improvement activities and its effects and problems are examined, and the considerations based on the questionnaire results are reported in this paper.Copyright