scholarly journals Realization of Fast and Dexterous Tasks by a DD Parallel Robot Using Motor Back-drivability

2001 ◽  
Vol 13 (5) ◽  
pp. 554-560
Author(s):  
Doohyung Kim ◽  
◽  
Masaru Uchiyama
Keyword(s):  
Control System ◽  
High Speed ◽  
Parallel Robot ◽  
Control Algorithms ◽  
Torque Sensor ◽  
Compliance Control ◽  
Control Scheme

This paper presents the execution of very fast, complicated tasks with a high-speed accurate parallel robot we named HEXA. First, unified motion, force and compliance control scheme comprising several control algorithms are given. A key distinguishing feature of our model is control scheme, which does not use any force/torque sensors but uses the actuator backdrivability for this purpose. Hence we can ignore the weight and cost of the force/torque sensor. The motivation for this work is to show the usefulness of the versatile HEXA mechanism for applications in industry. Several experiments for complex, fast tasks, for example, the sequential peg-in-hole task on an inclined table, crank-turning, deburring and composite tasks, have been conducted using this control system to show its effectiveness.

RESPONSE OF A HIGH-SPEED WAVE-PIERCING CATAMARAN TO AN ACTIVE RIDE CONTROL SYSTEM

2021 ◽  
Vol 158 (A4) ◽  
Author(s):  
J AlaviMehr ◽  
M R Davis ◽  
J Lavroff ◽  
D S Holloway ◽  
G A Thomas
Keyword(s):  
Control System ◽  
Control Systems ◽  
High Speed ◽  
Control Surface ◽  
Control Algorithms ◽  
Active Centre ◽  
Ride Control ◽  
Control Step ◽  
Set Up ◽  
Ride Control System

Ride control systems on high-seed vessels are an important design features for improving passenger comfort and reducing motion sickness and dynamic structural loads. To investigate the performance of ride control systems a 2.5m catamaran model based on the 112m INCAT catamaran was tested with an active centre bow mounted T-Foil and two active stern mounted trim tabs. The model was set-up for towing tank tests in calm water to measure the motions response to ride control step inputs. Heave and pitch response were measured when the model was excited by deflections of the T-Foil and the stern tab separately. Appropriate combinations of the control surface deflections were then determined to produce pure heave and pure pitch response. This forms the basis for setting the gains of the ride control system to implement different control algorithms in terms of the heave and pitch motions in encountered waves. A two degree of freedom rigid body analysis was undertaken to theoretically evaluate the experimental results and showed close agreement with the tank test responses. This work gives an insight into the motions control response and forms the basis for future investigations of optimal control algorithms.

A Control Method Research of Parallel Mechanisms

2012 ◽  
Vol 619 ◽  
pp. 51-55
Author(s):  
Heng Chen ◽  
Yan Bing Ni
Keyword(s):  
Control System ◽  
High Speed ◽  
Control Method ◽  
Low Cost ◽  
Parallel Robot ◽  
Joint Space ◽  
Linear Mapping ◽  
Single Step ◽  
Parallel Mechanisms ◽  
Motion Controller

This paper deals with a control method research and trajectory planning of parallel mechanisms. Control system scheme which is based on PC and motion controller has high openness, high degree of modularization and support for non-linear mapping relationship between operating space and joint space of parallel mechanisms with high flexibility and low cost. PC and NI motion controller and LabVIEW constituted hardware core and software platform of control system, respectively. Hardware technology of control system contained hardware selection, control circuit design and interface technology; software technology of control system developed application programs layer, core control layer and drive functions layer to realize core control functions of finding home, single-step or continuous movement and micro adjustment, which was based on hardware principle. Trajectory has been planned for a typical high speed parallel robot.

An Adaptive Control System Incorporating H∞ Concepts for High-Speed Machinery with Independent Drives

1994 ◽  
Vol 208 (1) ◽  
pp. 43-52
Author(s):  
R W Beaven ◽  
L D Wilkes ◽  
M T Wright ◽  
S D Garvey ◽  
M I Friswell
Keyword(s):  
Control System ◽  
High Speed ◽  
Dynamic Models ◽  
Simulated Performance ◽  
Current State ◽  
Control Scheme ◽  
Parameter Variations ◽  
Degree Of Confidence ◽  
Adaptive Decentralized Control ◽  
High Degree

Current state of the art in the design of high-speed machinery for the production or processing of discrete products often involves the use of independent drives synchronized through controllers, rather than via stiff mechanical connections. High-speed machinery for discontinuous processes tends to be characterized by the following attributes: (a) synchronization is highly critical between the axes in certain groups; (b) strong coupling between axes (groups) can be introduced by the work material; (c) the speeds of operation are such that computation is at a premium and just be restricted; (d) individual axes have periodically varying parameters (with additional non-periodic noise); (e) individual axes can become strongly non-linear at high torque (or force) rates; (f) slow and steady trends in the plant parameters are common; and (g) the development of reliable, high-fidelity dynamic models of all machine components for perfect design simulation is impracticable. This paper addresses the issue of how controllers may be specified and designed to provide control solutions for high-speed machinery, which provide the designer with a high degree of confidence that simulated performance may be realized in practice. The form of the solution proposed is an adaptive decentralized control scheme with a recursive identifier to track machine parameter variations. H∞ design methods are used both to specify the form of the control system and to ensure ongoing robust control of the machinery with minimum sacrifice of performance. Three examples are given(two simulation and one experimental) to demonstrate the benefits of using H∞ methods, rather than traditional methods, for this type of machinery, and one of these illustrates the effectiveness of adaption for maximizing performance while maintaining stability.

Study on High Precision Control Scheme of Ceramic Ferrule Concentricity Grinder

2014 ◽  
Vol 635-637 ◽  
pp. 1266-1270 ◽  
Author(s):  
Yan Jin ◽  
Hui Lin
Keyword(s):  
Control System ◽  
Real Time ◽  
High Speed ◽  
Closed Loop ◽  
Servo Control ◽  
Precision Machining ◽  
Precision Control ◽  
Servo Control System ◽  
Electric Control ◽  
Control Scheme

The paper analyzes the precision coaxial processing requirements and the characteristics of high automatic online compensation, and builds the electric control system based on Delta series products. The system uses a bus controller and absolute encoders servo constitute nearly closed-loop servo control system, combined with torque limiting grading feeding, dressing real-time compensation, stable and high-speed precision machining ceramic ferrule.

Low-Cost PLC-Based Control of a 2-DoF Purely Translational Parallel Robot

2011 ◽  
Vol 383-390 ◽  
pp. 1542-1548
Author(s):  
Zhi Bin Li
Keyword(s):  
Control System ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Low Cost ◽  
Parallel Robot ◽  
Conveyor Belt ◽  
Workspace Analysis ◽  
Translation Motion ◽  
Control System Architecture ◽  
Pick And Place Operation

This paper describes the design and implementation of a low-cost robot control system based on a Programmable Logic Controller (PLC). The robot is a 2-DoF (Degrees of Freedom) purely translational mechanism, which has potential application in food and electronics industry for high speed pick-and-place operation. Combined with a conveyor belt, it can make 3-DoF purely translation motion. In this paper, the inverse kinematics, forward kinematics, singularity, and workspace analysis are presented. The control system architecture and software design is also introduced. The prototype is exhibited at last.

scholarly journals A Control Design Technique for Grinding Systems with Feedforward Undercompensation and Feedback Control

2017 ◽  
Vol 0 (0) ◽  
Author(s):  
C. R. Costea ◽  
E. Gergely ◽  
G. Husi ◽  
Laura Coroiu ◽  
Helga Silaghi ◽  
...  
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Controller Design ◽  
Control Design ◽  
Industrial Processes ◽  
Control Algorithms ◽  
Design Technique ◽  
Best Value ◽  
Control Scheme ◽  
Systems Control

Abstract Feedforward and feedback control are new control algorithms used in industrial processes control and very suitable for grinding systems control. The purpose of this paper is to provide a design technique for a control system of a grinding circuit using the feedforward and feedback control. The control scheme is based on the undercompensation of the milling feed flow. The best value of the undercompensation is chosen after analyzing several scenarios. The controller design based on this value proves to provide improved productivity.

Pulse Width Modulation of Water Jet Propulsion Systems Using High-Speed Coanda-Effect Valves

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Anirban Mazumdar ◽  
H. Harry Asada
Keyword(s):  
Pulse Width ◽  
High Speed ◽  
Pulse Width Modulation ◽  
Pulse Height ◽  
Underwater Vehicles ◽  
Water Jet ◽  
Control Algorithms ◽  
Control Scheme ◽  
Pump Output ◽  
Valve Switching

An integrated high-speed valve switching and pump output control scheme are developed for precision maneuvering of underwater vehicles. High-speed Coanda-effect valves combined with a centrifugal pump allow for precise control of thrust force using a unique pulse width modulation (PWM) control scheme, where both pulse width and pulse height are controlled in a coordinated manner. Dead zones and other complex nonlinear dynamics of traditional propeller thrusters and water jet pumps are avoided with use of the integrated pump-valve control. Three control algorithms for coordinating valve switching and pump output are presented. A simplified nonlinear hydrodynamic model of underwater vehicles is constructed, and design trade-offs between PWM frequency and pulse height, with regard to steady state oscillations, are addressed. The control algorithms are implemented on a prototype underwater vehicle and the theoretical results are verified through experiments.

Extension Adaptive Control of a High-Speed and High-Precision Three-Axis Parallel Robot

2013 ◽  
Vol 694-697 ◽  
pp. 1625-1628 ◽  
Author(s):  
Dong Min Wu ◽  
Ming Shen ◽  
Min Zhi Ma ◽  
Ye Yang
Keyword(s):  
Control System ◽  
High Precision ◽  
High Speed ◽  
Robot Control ◽  
Adaptive Controller ◽  
Parallel Robot ◽  
Time Varying ◽  
Axis Parallel ◽  
New Type ◽  
Simulation Results

In the paper a high-speed and high-precision three-axis parallel robot was studied as the research object and a kind of extension controller used for the control system was established. Seeing properties that the adaptive controller is good at dealing with the same and slowly time-varying problem and extension controller is good at dealing with time-varying and mutation problem. The advantages of the two kinds of controllers were combined and a new type of extension adaptive controller was developed. The simulation results show that the extension adaptive controller can greatly improve end implementation tracking precision of the parallel robot and satisfy the robot control requirements. The methods have broad prospect in application of the parallel robot control.

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