Vision based 3-D position control for a robot arm

This article presents a novel design of a continuum arm, which has the ability to extend and bend efficiently. Numerous designs and experiments have been done to different dimensions on both types of McKibben pneumatic muscle actuators (PMA) in order to study their performances. The contraction and extension behaviour have been illustrated with single contractor actuators and single extensor actuators, respectively. The tensile force for the contractor actuator and the compressive force for the extensor PMA are thoroughly explained and compared. Furthermore, the bending behaviour has been explained for a single extensor PMA, multi extensor actuators and multi contractor actuators. A two-section continuum arm has been implemented from both types of actuators to achieve multiple operations. Then, a novel construction is proposed to achieve efficient bending behaviour of a single contraction PMA. This novel design of a bending-actuator has been used to modify the presented continuum arm. Two different position control strategies are presented, arising from the results of the modified soft robot arm experiment. A cascaded position control is applied to control the position of the end effector of the soft arm at no load by efficiently controlling the pressure of all the actuators in the continuum arm. A new algorithm is then proposed by distributing the x, y and z-axis to the actuators and applying an effective closed-loop position control to the proposed arm at different load conditions.

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A reduced-order dynamic model for end-effector position control of a flexible robot arm

Mathematics and Computers in Simulation ◽

10.1016/0378-4754(95)00099-2 ◽

1996 ◽

Vol 41 (5-6) ◽

pp. 539-558 ◽

Cited By ~ 6

Author(s):

C.W. Jen ◽

D.A. Johnson ◽

R. Gorez

Keyword(s):

Dynamic Model ◽

Position Control ◽

Robot Arm ◽

Flexible Robot ◽

End Effector ◽

Reduced Order

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EEG-Induced Adaptation of Controller Parameter for Closed-Loop Position Control of the End-Effecter in a Robot Arm

2019 10th International Conference on Computing, Communication and Networking Technologies (ICCCNT) ◽

10.1109/icccnt45670.2019.8944909 ◽

2019 ◽

Cited By ~ 1

Author(s):

Lidia Ghosh ◽

Amit Konar

Keyword(s):

Closed Loop ◽

Position Control ◽

Robot Arm ◽

Controller Parameter

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Robotic Instrumented Complaint Wrist

Journal of Engineering for Industry ◽

10.1115/1.2899749 ◽

1992 ◽

Vol 114 (1) ◽

pp. 120-123 ◽

Cited By ~ 2

Author(s):

Yangsheng Xu ◽

R. P. Paul

Keyword(s):

Force Control ◽

Position Control ◽

Contact Forces ◽

Displacement Sensor ◽

Robot Arm ◽

Sensing Mechanism ◽

Manufacturing Operations ◽

Positioning Errors ◽

Control Scheme ◽

Passive Compliance

A robotic complaint wrist which combines a passive compliance device and a displacement sensor has been developed and tested. The device provides the necessary flexibility to accommodate transitions between the position control and force control modes, and avoid large impact forces as a robot makes contact with parts, as well as correct positioning errors and allow the relaxation of tolerances in assembly and manufacturing operations. The device installed between a robot arm and end-effector is composed of two parts: a passive compliance device and a sensing mechanism. The passive compliance is provided by a rubber structure; its configuration can be arranged to yield the desired stiffness ratio along and about each axis. The sensing mechanism consists of a six-joint serial linkage with a transducer at each point. The measured deflection is used to actively control the contact forces and compensate for the positioning error during motion and contact. In this paper, the design features of two prototypes of the device are described. A systematic hybrid position/force control scheme incorporating the device is presented.

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Dynamic Finite Element Analysis of the Position Control System of a Two-Link Horizontal Flexible Robot

Journal of Robotics and Mechatronics ◽

10.20965/jrm.1990.p0083 ◽

1990 ◽

Vol 2 (2) ◽

pp. 83-90

Author(s):

Hiroyuki Kojima ◽

Keyword(s):

Finite Element ◽

Control System ◽

Position Control ◽

Velocity Curve ◽

Element Formulation ◽

Robot Arm ◽

Flexible Robot ◽

Element Analysis ◽

Flexible Arm ◽

Position Control System

In this paper, a finite element formulation method for a horizontal flexible robot arm with two links is first presented. In the analysis, the kinetic energy of the flexible arm is represented in brief compared with previous methods, and the matrix equation of motion in consideration of the nonlinear forces, such as the Coriolis force, is derived by the finite element method and the variational theorem. Then, the state equation of the mechatronics system consisting of the flexible arm and the position control system is obtained. Secondly, numerical simulations in the case of applying path control based on the trapezoidal velocity curve are carried out by use of the Wilson-<I>θ</I> method, and the effects of the bending rigidity and the shape of the trapezoidal velocity curve on the dynamic characteristics of the mechatronics system are demonstrated.

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