Mechanism and Control of Parallel-Wire Driven System

2015 ◽  
Vol 27 (6) ◽  
pp. 599-607 ◽  
Author(s):  
Hitoshi Kino ◽  
◽  
Sadao Kawamura ◽  
Keyword(s):  
Robot Manipulators ◽  
Parallel Mechanisms ◽  
Serial Link ◽  
Parallel Wire ◽  
Link Mechanism ◽  
Human Arm ◽  
Driven System ◽  
Parallel Link ◽  
And Control ◽  
Controlled Object

<div class=""abs_img""><img src=""[disp_template_path]/JRM/abst-image/00270006/01.jpg"" width=""300"" /> A parallel-wire driven system</div>Many of the conventional robot manipulators have a serial-link mechanism to imitate a human arm. In recent years, however, industries have been aggressive in putting parallel-link mechanisms into practical use to cope with various problems that no conventional serial-link mechanisms have ever been able to solve. Under the circumstances, this paper describes a parallel-wire driven system, one of the parallel mechanisms. It is a system to drive a controlled object with flexible and light wires instead of rigid links. It has many advantages over conventional serial-link mechanisms or other ordinary parallel-link mechanisms. This paper first overviews previous studies on parallel-wire driven robots, and then details the mechanism and control of these systems, as well as examples of their application.

Force, Stiffness and Viscous Damping Control of a Stewart-Platform-Type Ankle-Foot Rehabilitation Assist Device with Pneumatic Actuator

2013 ◽  
Vol 25 (6) ◽  
pp. 897-905 ◽  
Author(s):  
Takayuki Onodera ◽  
◽  
Eiji Suzuki ◽  
Ming Ding ◽  
Hiroshi Takemura ◽  
...  
Keyword(s):  
Ankle Joint ◽  
Force Control ◽  
Physical Therapists ◽  
Viscous Damping ◽  
Mean Square ◽  
Assist Device ◽  
Link Mechanism ◽  
Parallel Link ◽  
And Control ◽  
Ankle And Foot

The number of physically disabled people in need of rehabilitation is increasing. Unfortunately, there is a shortage of physical therapists specializing in such rehabilitation. This has increased the demand for rehabilitation assist devices that can lessen the burden of physical therapists. In this study, the authors develop a device that can assist in the rehabilitation of the ankle joint by employing a Stewart-platform (SP)-type parallel-link mechanism. With the SP-type parallel-link mechanism, it is possible to measure and control six degrees-of-freedom (DOFs) of ankle-foot movement during rehabilitation. Because the device enables the measurements of the ankle and foot, it is possible to calculate the instantaneous center of the ankle joint. In previous studies, the authors proposed methods to calculate and control the posture of the ankle and foot by an SP-type parallel-link mechanism and verified their accuracy. In this paper, the authors propose a method for force control using the device and also verify its accuracy. Using this device, the force acting on the ankle-foot can be controlled by six air cylinders. The force produced by a single air cylinder is determined by controlling the pressures in the extension and retraction directions. The accuracy of the force control method is verified for a single air cylinder and for the assist device when all six air cylinders are engaged. Results show that the accuracy of the single air cylinder has a mean square error of 0.24 N or less, while those for force control of the entire device are 4.2 N or less for parallel translation and 3.2 Nm or less for rotation. This demonstrates a satisfactory accuracy. To incorporate rehabilitation assistance by means of stiffness or viscous damping in the future, the authors also propose methods to control the coefficients of stiffness and viscous damping of the air cylinder and verify their accuracy. The mean square errors for the accuracies in controlling the coefficients of stiffness and viscous damping are 3.4 N/m and 1.4 Ns/m, respectively, thus verifying the validity of the proposed methods.

An Efficient Computational Algorithm of Adaptive Control for Closed-Loop Robots and Experiments

1998 ◽  
Vol 10 (2) ◽  
pp. 147-153
Author(s):  
Yasuhito Oooka ◽  
◽  
Haruhisa Kawasaki ◽  
Nobuhito Takemura
Keyword(s):  
Adaptive Control ◽  
Closed Loop ◽  
Computational Algorithm ◽  
Trajectory Control ◽  
Experimental Results ◽  
Serial Link ◽  
Model Based ◽  
Link Mechanism ◽  
Parallel Link

This paper presents an efficient computational algorithm of model-based adaptive control for closed-loop robots. The algorithm is an extension of the computational algorithm for serial-link robots, which was derived by Kawasaki and Bito. The proposed algorithm is implemented to a 6 DOF robot with a parallel-link mechanism using a 32-bit DSP. Experimental results of trajectory control are also shown.

scholarly journals Control Method for Realistic Motion in a Construction Tele-robotic System with a 3-DOF Parallel Mechanism

2003 ◽  
Vol 15 (4) ◽  
pp. 361-368 ◽  
Author(s):  
Dingxuan Zhao ◽  
◽  
Yupeng Xia ◽  
Hironao Yamada ◽  
Takayoshi Muto
Keyword(s):  
Parallel Mechanism ◽  
Control Method ◽  
Robotic System ◽  
Degree Of Freedom ◽  
Experimental Result ◽  
Parallel Mechanisms ◽  
High Quality ◽  
Link Mechanism ◽  
Acceleration Sensors ◽  
Parallel Link

In this study, we developed a construction tele-robotic system, which can be widely used, for example, for restoration works in damaged areas. The system consists of a servo-controlled construction robot, two joysticks for operations of the robot from a remote place and a 3-degree-of-freedom (DOF) parallel mechanism. An important problem to be solved in such a system is how to convey adequate presence of working area in a high quality to the operator. In this paper, we propose a control method of a 3-DOF parallel link mechanism to simulate the motion of the construction robot by using three acceleration sensors. The validity of this method has been confirmed experimentally. According to the experimental result, each motion of roll, pitch and heave of the construction robot can be simulated accurately by the 3-DOF parallel mechanisms.

Study and Implement on Key Technologies of Ship-Welding Mobile Robot

2010 ◽  
Vol 44-47 ◽  
pp. 321-325
Author(s):  
Liang Hua ◽  
Lin Lin Lv ◽  
Ju Ping Gu ◽  
Yu Jian Qiang
Keyword(s):  
Mobile Robot ◽  
Control Method ◽  
Structure Design ◽  
Seam Tracking ◽  
Precision Positioning ◽  
Positioning Control ◽  
Controlling System ◽  
Welding Torch ◽  
Driven System ◽  
And Control

The key technilogies of ship-welding mobile robot applied to ship-building in plane block production line were researched and realized. The mechanical structure design of the robot was completed. The motion-controlling system of of two-wheel differential driving mobile robot was developed. A novel precision positioning control method of welding torch using ultrasonic motors was putforward. The mechanism and control-driven system of precision positioning system for welding torch were completed. The platform of obstacle avoidance navigation system was designed and the strategies of seam tracking, trajectory and posture adjustment were preliminary studied. The methods and results put forward in the paper could act as the base of deep research on the theories and technologies of ship-welding mobile robot.

Pose Accuracy Analysis of Robot Manipulators Based on Kinematics

2011 ◽  
Vol 201-203 ◽  
pp. 1867-1872 ◽  
Author(s):  
Jian Ye Zhang ◽  
Chen Zhao ◽  
Da Wei Zhang
Keyword(s):  
Matrix Theory ◽  
Robot Manipulators ◽  
Error Model ◽  
Robot Kinematics ◽  
Accuracy Analysis ◽  
Serial Link ◽  
End Effector ◽  
Surface Graph ◽  
Position And Orientation ◽  
Kinematics Parameters

The pose accuracy of robot manipulators has long become a major issue to be considered in its advanced application. An efficient methodology to generate the end-effector position and orientation error model of robotic manipulator has been proposed based on the differential transformation matrix theory. According to this methodology, a linear error model that described the end-effector position and orientation errors due to robot kinematics parameters errors has been presented. A computer program to generate the error model and perform the accuracy analysis on any serial link manipulator has been developed in MATLAB. This methodology and software are applied to the accuracy analysis of a Phantom Desktop manipulator. The positioning error of the manipulator in its workspace cross section (XOZ) has been plotted as 3D surface graph and discussed.

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