Analyses of a Free-Floating Manipulator Control Scheme Based on the Fixed-Base Jacobian with Spacecraft Velocity Feedback

2015 ◽  
pp. 59-69 ◽  
Author(s):  
Tomasz Rybus ◽  
Tomasz Barciński ◽  
Jakub Lisowski ◽  
Karol Seweryn
Keyword(s):  
Velocity Feedback ◽  
Control Scheme ◽  
Fixed Base ◽  
Manipulator Control

Workspace Analysis of Parallel Manipulator for Telemicromanipulation Systems

2001 ◽  
Vol 13 (5) ◽  
pp. 488-496 ◽  
Author(s):  
Noriaki Ando ◽  
◽  
Masahiro Ohta ◽  
Kohei Gonda ◽  
Hideki Hashimoto
Keyword(s):  
Kinematic Analysis ◽  
Parallel Mechanism ◽  
Parallel Manipulator ◽  
Parallel Mechanisms ◽  
Dual Systems ◽  
Position Accuracy ◽  
Control Scheme ◽  
Workspace Analysis ◽  
Manipulator Control ◽  
Vr Simulator

This paper describes the research results on telemicromanipulation systems for microlevel tasks. Because of its better manipulation precision, stiffness and speed characteristics, the parallel mechanism micromanipulator was chosen to compose our systems. First, the kinematic analysis of our original manipulator mechanism is performed. Then, the structure of our parallel manipulator, control scheme, and experimental results are shown. Position accuracy and device control characteristics are analyzed and the feasibility of the use of parallel mechanisms for micromanipulator is then discussed. A parallel manipulator motion is restricted by 3 factors: mechanical limits of the passive joints, collision between links and actuators limitations. Results of the numerical workspace analysis considering the above factors are shown. We are proposing the use of dual manipulators for implementing improved real manipulation systems. The first kinematics and workspace analysis of dual systems using the VR simulator are also shown.

An Adaptive Control Scheme for Mechanical Manipulators—Compensation of Nonlinearity and Decoupling Control

1986 ◽  
Vol 108 (2) ◽  
pp. 127-135 ◽  
Author(s):  
Roberto Horowitz ◽  
Masayoshi Tomizuka
Keyword(s):  
Adaptive Control ◽  
Control System ◽  
Adaptive Controller ◽  
Fundamental Properties ◽  
Integral Action ◽  
Control Scheme ◽  
Mechanical Manipulators ◽  
Nonlinear Compensator ◽  
Manipulator Control ◽  
Adaptive Control Scheme

This paper presents a new adaptive control scheme for mechanical manipulators. Making use of the fundamental properties of the manipulator equations, an adaptive algorithm is developed for compensating a nonlinear term in the dynamic equations and for decoupling the dynamic interaction among the joints. A computer simulation study is conducted to evaluate the performance of a manipulator control system composed of the manipulator, adaptive nonlinear compensator/decoupling controller and state feedback controller with integral action. Simulation results show that the manipulator control system with adaptive controller is insensitive to variations of manipulator configurations and payload.

scholarly journals Repetitive Control Scheme of Robotic Manipulators Based on Improved B-Spline Function

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Xingyu Wang ◽  
Anna Wang ◽  
Dazhi Wang ◽  
Wenhui Wang ◽  
Bingxue Liang ◽  
...  
Keyword(s):  
Spline Interpolation ◽  
Repetitive Control ◽  
Robotic Manipulator ◽  
Experimental Results ◽  
Correction Function ◽  
Tracking Accuracy ◽  
Optimization Scheme ◽  
B Spline ◽  
Control Scheme ◽  
Manipulator Control

In this paper, a repetitive control scheme of a 2-DOF robotic manipulator based on the improved cubic B-spline curve is proposed. Firstly, a repetitive controller for robotic manipulator is designed, which is composed of an iterative controller and disturbance observer. Then, an improved B-spline optimization scheme is introduced to divide the task of the robotic manipulator into three intervals. A correction function is added to each interval of cubic spline interpolation. Finally, a variety of cases are designed and simulated by MATLAB. The experimental results show that, compared with the conventional B-spline, the improved B-spline has better performance in tracking accuracy and smoothness of motion trajectory. By changing the mechanism of the manipulator, the cases of different weights and lengths are designed. The experimental results in these cases show that the proposed scheme can be applied to most of the 2-DOF robotic manipulator control systems.

Energy efficient throttling control of a multi-pressure system using a genetic algorithm and model predictive control

2021 ◽  
pp. 095965182110277
Author(s):  
Mikko Huova ◽  
Matti Linjama
Keyword(s):  
Energy Efficiency ◽  
Energy Savings ◽  
Hydraulic Cylinder ◽  
Pressure System ◽  
Velocity Feedback ◽  
Load Variations ◽  
Control Scheme ◽  
Good Energy ◽  
System Robustness ◽  
Harsh Conditions

The energy efficiency of hydraulic cylinder drives can be increased by replacing the actuator with a multi-chamber cylinder, utilising multiple supply lines with unique pressures or a combination of the concepts. Previous studies have demonstrated significant energy savings using a cascaded control system, which requires velocity feedback to stabilise the system. To avoid the need of position or velocity sensors in harsh conditions of mobile machines, this article presents a throttling control scheme, which achieves good energy efficiency on multi-pressure systems without velocity feedback. A simulation study was performed to determine the efficiency of the system, robustness against load variations and the effect of valve response time on performance.

PDF Subvariable Control and Its Application to Robot Motion Control

1989 ◽  
Vol 111 (3) ◽  
pp. 452-461 ◽  
Author(s):  
M. C. Leu ◽  
D. I. Freed
Keyword(s):  
Feedback Control ◽  
Nonlinear System ◽  
Motion Control ◽  
Response Speed ◽  
Experimental Results ◽  
Robot Motion ◽  
Velocity Feedback ◽  
Control Scheme ◽  
Control Schemes ◽  
Manipulator Arm

A method for determining the feedback coefficients of pseudo-derivative-feedback control is presented, along with applications of this control scheme. Simulations are performed for controlling a linear inertia system with disturbance loads and inertia variations, and for controlling a nonlinear system represented by a manipulator arm. The results show that PDF subvariable control quickly rejects disturbances and is insensitive to inertia variations. Also, the position responses do not exhibit overshoot or oscillation. Comparison with the results for proportional-plus-velocity-feedback control shows that the PDF approach is superior in response speed, robustness, and disturbance-handling ability. Experimental results from implementation of both control schemes to a revolute manipulator support this conclusion.

Grasp-Dependent Slip Prevention for a Dexterous Artificial Hand via Wrist Velocity Feedback

2014 ◽  
Vol 11 (02) ◽  
pp. 1450016 ◽  
Author(s):  
Benjamin A. Kent ◽  
Erik D. Engeberg
Keyword(s):  
Grip Force ◽  
Position Tracking ◽  
Velocity Feedback ◽  
Control Scheme ◽  
Backstepping Controller ◽  
Artificial Hand ◽  
Proportional Controller ◽  
Periodic Inputs ◽  
Grasp Type ◽  
Significant Factors

A proportional controller is compared to a nonlinear backstepping controller with four different grasps for a dexterous anthropomorphic hand. A bioinspired grasp-dependent control scheme which autonomously modulates the grip force using wrist velocity feedback to prevent grasped object slip is also introduced. Four different grasp types are evaluated to illustrate how the wrist velocity feedback architecture must differ depending upon the manner in which objects are grasped. The backstepping controller can successfully increase grip force with wrist velocity in a robustly stable bioinspired fashion. Experimental results show that the developed backstepping controller improves the position tracking abilities for multiple periodic inputs, as well as reduces step input overshoot. The slip prevention capabilities of the backstepping controller are also demonstrated and compared to the proportional control scheme. Results of the slip prevention experiments show that both the grasp type and manipulator orientation with respect to gravity are significant factors in the performance of the controllers. The backstepping control scheme significantly improves slip prevention of grasped objects for multiple grasps and in two different orientations with respect to gravity.

Repeatable Redundant Manipulator Control Using Nullspace Quasivelocities

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Alan Bowling ◽  
Sean Harmeyer
Keyword(s):  
Redundant Manipulators ◽  
Redundant Manipulator ◽  
Kinematic Singularity ◽  
Control Scheme ◽  
Manipulator Control

This paper presents a repeatable control scheme for redundant manipulators. It is developed in terms of physically meaningful variables, a concept closely related to integrability and homogeneity. This approach sheds a different light on some well-known phenomena related to redundant manipulator control. The control is developed by determining enough physically meaningful variables to describe the manipulator’s motions in the task and nullspaces, in a manner that allows them to be controlled independently. These variables are then used to develop physically meaningful controller error signals. As a consequence, all configurations in the workspace are repeatable, except for those at, or very close, to a kinematic singularity. The approach is illustrated on a 6DOF planar manipulator.

Representation of information in SEM by equal signal lines

1978 ◽  
Vol 36 (1) ◽  
pp. 144-145
Author(s):  
E. Rau ◽  
N. Karelin ◽  
V. Dukov ◽  
M. Kolomeytsev ◽  
S. Gavrikov ◽  
...  
Keyword(s):  
Electronic System ◽  
Space Distribution ◽  
Specimen Surface ◽  
Universal Method ◽  
Base Level ◽  
Signal Value ◽  
Information Signal ◽  
Fixed Base ◽  
Scanning Line ◽  
Amplitude Analyzer

There are different methods and devices for the increase of the videosignal information in SEM. For example, with the help of special pure electronic [1] and opto-electronic [2] systems equipotential areas on the specimen surface in SEM were obtained. This report generalizes quantitative universal method for space distribution representation of research specimen parameter by contour equal signal lines. The method is based on principle of comparison of information signal value with the fixed levels.Transformation image system for obtaining equal signal lines maps was developed in two versions:1)In pure electronic system [3] it is necessary to compare signal U (see Fig.1-a), which gives potential distribution on specimen surface along each scanning line with fixed base level signals εifor obtaining quantitative equipotential information on solid state surface. The amplitude analyzer-comparator gives flare sport videopulses at any fixed coordinate and any instant time when initial signal U is equal to one of the base level signals ε.

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