Simple Trajectory Control Method of Robot Arm Using Flexible Pneumatic Cylinders

2015 ◽  
Vol 27 (6) ◽  
pp. 698-705 ◽  
Author(s):  
Mohd Aliff ◽  
◽  
Shujiro Dohta ◽  
Tetsuya Akagi ◽  

<div class=""abs_img""><img src=""[disp_template_path]/JRM/abst-image/00270006/12.jpg"" width=""300"" /> Flexible robot arm</div>Robots, due to their excellent speed, accuracy and cost-effectiveness in repetitive tasks, now have a tendency to be used in rehabilitation field. A simple trajectory control of robot arm using flexible pneumatic cylinders and embedded controller which can be used as rehabilitation for human wrist is described. The system consists of the flexible robot arm, an accelerometer, an embedded microcomputer, a potentiometer and compact quasi-servo valves. The analytical model for trajectory control is proposed and applied on the flexible pneumatic robot arm. The proposed trajectory control method does not need a linearized model which is commonly used in a robot arm. The flexible structure has the characteristics of high safety such as not to cause harm to user and is suitable for use in therapeutic devices. The trajectory control can help patients recover more quickly by repeating the movements based on the patient's individual condition. Both experiment and simulation show that the trajectory control of robot arm can be realized for several kinds of trajectory by using the proposed control method and the tested robot arm.

2011 ◽  
Vol 5 (4) ◽  
pp. 523-530 ◽  
Author(s):  
Tetsuya Akagi ◽  
◽  
Shujiro Dohta ◽  
Feifei Zhao ◽  
Takahiro Fujikawa

A wearable actuator needs to be flexible so as not to injure the human body. The purpose of our study is to develop a flexible and lightweight actuator which can be safe enough to be attached to the human body, and to apply it to a robot arm and rehabilitation device. New types of flexible pneumatic actuator that can be used even if the actuator is deformed by external force have been developed in our previous studies. In this paper, a robot arm using the flexible pneumatic cylinder that can realize a natural flowing movement with multi-motion such as bending, expanding, and contracting is described. The analytical model of the robot arm is proposed for attitude control. In addition, an inexpensive quasi-servo valve using the on/off control valve is utilized in the master-slave control system to improve the control performance. As a result, the usability of the proposed robot arm and the effectiveness of the attitude control method using the analytical model and the quasi-servo valve are confirmed.


Author(s):  
Keyvan Noury ◽  
Bingen Yang

Abstract Developed in this work, is a simple and innovative control method, by which a nonminimum-phase (NMP) process can be easily stabilized in a closed-loop setting. The method is named as the parallel feed-forward compensation with derivative effort (PFCD). Through use of a high order process, the control system designed by the PFCD method is shown to be less influenced by noise, disturbance, and model mismatch, compared to other methods. Moreover, the necessary data required for implementing the PFCD method are discussed. The proposed control method is illustrated on tip position control in a slewing beam as a flexible robot arm, in which the effectiveness of the PFCD method is demonstrated. In addition, the proposed control method is compared with the existing methods in terms of stability and performance. The paper is concluded with notes about the advantages.


1988 ◽  
Vol 29 (3) ◽  
pp. 459-467 ◽  
Author(s):  
James D. Lee ◽  
Ben-Li Wang

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