scholarly journals Development of a Four-legged Underwater Robot with Parallel-link Mechanism

2010 ◽  
Vol 45 (5) ◽  
pp. 731-736
Author(s):  
Takumi Yaginuma ◽  
Takasi Takesima ◽  
Etsurou Shimizu ◽  
Masanori Ito ◽  
Junnichiro Tahara
Keyword(s):  
Underwater Robot ◽  
Link Mechanism ◽  
Parallel Link

Machining Performance Evaluation of Robot Type Machine Tool Based on Forward Kinematics Model

2020 ◽  
Author(s):  
Akio Hayashi ◽  
Masato Ueki ◽  
Keisuke Nagao ◽  
Hiroto Tanaka ◽  
Yoshitaka Morimoto ◽  
...  
Keyword(s):  
Machine Tools ◽  
Geometric Model ◽  
Forward Kinematics ◽  
Machining Accuracy ◽  
Machining Performance ◽  
Kinematics Model ◽  
Link Mechanism ◽  
Conventional Machine ◽  
Type Machine ◽  
Parallel Link

Abstract Robot type machine tools with parallel link mechanism are characterized by the performance to change tool posture and machine wider range than conventional machine tools. It is realized by simultaneous multi-axis control of parallel link mechanism. However, there are some problems, it is difficult to identify and adjust alignment error. In addition, the machining performance is unidentified due to the rigidity is different from conventional machine tools. In this research, a geometric model is described and the forward kinematics model is derived based on the geometric model. Then, the machining tests were carried out to evaluate the machining accuracy by measured machined surface and the simulated motion of tool cutting edge based on proposed forward kinematics model.

Three DOF parallel link mechanism utilizing smooth impact drive mechanism

2002 ◽  
Vol 26 (3) ◽  
pp. 289-295 ◽  
Author(s):  
Takeshi Morita ◽  
Ryuichi Yoshida ◽  
Yasuhiro Okamoto ◽  
Toshiro Higuchi
Keyword(s):  
Drive Mechanism ◽  
Link Mechanism ◽  
Parallel Link

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.

517 Adaptive Hybrid Control for a Parallel Link Mechanism of Plane Type

2001 ◽  
Vol 2001.76 (0) ◽  
pp. _5-33_-_5-34_
Author(s):  
Toshiya NARIHARA ◽  
Atsushi MITANI ◽  
Sadao AKISHITA
Keyword(s):  
Hybrid Control ◽  
Plane Type ◽  
Link Mechanism ◽  
Parallel Link

226 Development of a Walking Assist Machine using a Spatial Parallel Link Mechanism

2007 ◽  
Vol 2007 (0) ◽  
pp. 200-201
Author(s):  
Eiichirou TANAKA ◽  
Tadaaki IKEHARA ◽  
Kazuteru NAGAMURA ◽  
Kiyotaka IKEJO ◽  
Yusuke INOUE ◽  
...  
Keyword(s):  
Link Mechanism ◽  
Parallel Link
Sign in / Sign up

Export Citation Format

Share Document