An Analysis of a Pneumatic Servo System and Its Application to a Computer-Controlled Robot

1988 ◽  
Vol 110 (3) ◽  
pp. 228-235 ◽  
Author(s):  
S. Liu ◽  
J. E. Bobrow
Keyword(s):  
Position Control ◽  
Low Cost ◽  
Flow Characteristics ◽  
Open Loop ◽  
System Response ◽  
Direct Drive ◽  
Control Applications ◽  
Pneumatic Actuators ◽  
Loop Control ◽  
Pneumatic Servo System

Pneumatic actuators are capable of providing high power output levels at a relatively low cost. In addition, they are clean, lightweight, and can be easily serviced. The difficulty of achieving a high-bandwidth, stable, pneumatic control system has limited its use in robotic position control applications. For open-loop control applications, such as many robot grippers, pneumatic actuators are often used. In this paper, direct-drive pneumatic servo-actuators are examined for their potential use in robotic applications. A complete mathematical model of the actuator is derived, and several control algorithms are tested numerically and experimentally. Our analysis shows that pneumatic systems are practical for use in servo-control applications. The main limitation is that of the system response time, which is determined by the valve flow characteristics and supply pressure. Large output forces can be obtained and accurately controlled with the servo-valve and differential pressure transducer used in the experiments.

The Design of Spraying Manipulator Control System in Mines

2014 ◽  
Vol 602-605 ◽  
pp. 1157-1160
Author(s):  
Mei Yu ◽  
Guo Wei Liu ◽  
Bing Kong
Keyword(s):  
Control System ◽  
Position Control ◽  
Low Cost ◽  
Open Loop ◽  
Open Loop Control ◽  
Mining Equipment ◽  
Loop Control ◽  
Precise Position ◽  
Loop Control System ◽  
Manipulator Control

In view of the present mining spraying manipulator operation is not flexible ,spraying effect is poor, susceptible to interference and other issues, this paper studies and realizes a kind of low cost, strong practicability of spraying manipulator control system. Using S7-200PLC and 2MA860H drive to control the 86BYG250A stepper motor open-loop control system, and the precise position control is realized. By controlling of the x-y axis mine spraying manipulator. Validate the system operation is simple, highly efficient and stable, energy conservation and environmental protection, strong anti-jamming capability, it can be widely used in all kinds of mining equipment.

An Integrated Design for a CNC Machine

2014 ◽  
pp. 254-265
Author(s):  
Amro Shafik ◽  
Salah Haridy
Keyword(s):  
Low Cost ◽  
Integrated Design ◽  
Numerical Data ◽  
Open Loop ◽  
Numerical Control ◽  
Future Research ◽  
Cnc Machine ◽  
Loop Control ◽  
Loop Control System ◽  
Stepper Motors

Computer Numerical Control (CNC) is a technology that converts coded instructions and numerical data into sequential actions that describe the motion of machine axes or the behavior of an end effector. Nowadays, CNC technology has been introduced to different stages of production, such as rapid prototyping, machining and finishing processes, testing, packaging, and warehousing. The main objective of this chapter is to introduce a methodology for design and implementation of a simple and low-cost educational CNC prototype. The machine consists of three independent axes driven by stepper motors through an open-loop control system. Output pulses from the parallel port of Personal Computer (PC) are used to drive the stepper motors after processing by an interface card. A flexible, responsive, and real-time Visual C# program is developed to control the motion of the machine axes. The integrated design proposed in this chapter can provide engineers and students in academic institutions with a simple foundation to efficiently build a CNC machine based on the available resources. Moreover, the proposed prototype can be used for educational purposes, demonstrations, and future research.

Development of Low-Cost Wearable Servo Valve Using Buckled Tube Driven by Servo Motor

2013 ◽  
Vol 393 ◽  
pp. 532-537 ◽  
Author(s):  
Abdul Nasir ◽  
Tetsuya Akagi ◽  
Shujiro Dohta ◽  
Ayumu Ono ◽  
Yusuke Masago
Keyword(s):  
Control System ◽  
Flow Rate ◽  
Position Control ◽  
Low Cost ◽  
Control Valve ◽  
Artificial Muscle ◽  
Pneumatic Actuators ◽  
Servo Valve ◽  
Precise Control ◽  
Care Systems

Recently, power assisted nursing care systems have received much attention and those researches have been done actively. In such a control system, an actuator and a control valve are mounted on the human body. Designing the system, the size and weight of the valve become serious concerns. The purpose of our study is to develop a small-sized, lightweight and low-cost servo valve for precise control using wearable pneumatic actuators. In this study, a low-cost wearable servo valve that can control the output flow rate by changing the twisted angle of the buckled tube in the servo valve is proposed and tested. The position control system of McKibben rubber artificial muscle using tested valve and embedded controller is also proposed and tested. As a result, we confirmed that the tested servo valve can control the flow rate in both supply and exhaust in an analog way. In addition, the estimated cost of the proposed valve can be reduced about 100 times cheaper (10 US Dollar) compared with the typical servo valve.

Paper 16: A Preliminary Investigation into the Effects of Applying a Locking Device to a Position-Controlled Externally Powered Prosthesis

1968 ◽  
Vol 183 (10) ◽  
pp. 93-97
Author(s):  
J. M. Pottinger ◽  
N. D. Ring
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Preliminary Investigation ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Time Control ◽  
Dynamic Phase ◽  
Static Phase ◽  
Powered Prosthesis

The application of position control to externally powered prosthetic arms leads to increased function and versatility when compared to a prosthetic system with open-loop control. However, various compromises are necessary owing to the limited number of available control sites. An investigation is being conducted into the possibility of combining the advantages of position control during the dynamic phase of movement with the locking facility of velocity–time control during the static phase, which leads to a larger number of available control sites and thus a greater number of degrees of freedom.

Research and Design of Control System for a 3-DOF Hybrid Robot

2010 ◽  
Vol 43 ◽  
pp. 207-210 ◽  
Author(s):  
Ju Li ◽  
Hui Ping Shen ◽  
Y.X. Jiang ◽  
Jia Ming Deng ◽  
Shan Shu Liu ◽  
...  
Keyword(s):  
Control System ◽  
Low Cost ◽  
Hybrid Structure ◽  
Open Loop ◽  
The Body ◽  
Step Motor ◽  
Parallel Structure ◽  
Loop Control ◽  
Loop Control System ◽  
Research And Design

This paper studied a novel 3-DOF hybrid robot, and invented a new hybrid structure which was composed of 2-DOF parallel structure and 1-DOF serial structure. The structure of this mechanism was simple, stiffness and positioning accuracy was high. The control system based on ARM micro-controller was a step motor open-loop control system, which features compact and low cost while the control accuracy can be guaranteed. In this paper, the body composition of the robot was described, and its inverse kinematics were derived and further simplified. Hardware and software of the motion control system was designed in detail and experimented through prototype.

Progress of liquid crystal adaptive optics for applications in ground-based telescopes

2020 ◽  
Vol 494 (3) ◽  
pp. 3536-3540
Author(s):  
Xingyun Zhang ◽  
Zhaoliang Cao ◽  
Quanquan Mu ◽  
Dayu Li ◽  
Zenghui Peng ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Liquid Crystal ◽  
Adaptive Optics ◽  
Low Cost ◽  
Response Speed ◽  
Open Loop ◽  
Loop Control ◽  
Compact Size ◽  
Control Scheme ◽  
Resolution Imaging

ABSTRACT Liquid crystal (LC) adaptive optics systems (AOS) can potentially be used in ground-based large aperture telescopes, because of their high spatial resolution, low cost and compact size. However, their disadvantages, such as low energy efficiency and slow response speed, still hinder their application. In this paper, we demonstrate solutions to these problems. With newly synthesized fast nematic LC material and using an overdriving technique, the response time of a LC wavefront corrector was reduced to 0.75 ms. Under an open-loop control scheme, a novel optical system was designed to improve the energy efficiency of LC AOS. With those problems resolved, a LC AOS was built for a 1.23-m telescope. This system has a disturbance rejection bandwidth of 80 Hz, and could fully use the energy of 400–900 nm wavebands. Observation results showed that the diffraction limit resolution imaging of the telescope could be obtained after correction, which indicates that the LC AOS is ready to be used in ground-based telescopes for visible waveband imaging.

Suppression of Residual Vibration in Nonlinear Systems with Temporal Variation and Uncertainty in Parameters by Elimination of the Natural Frequency Component

2021 ◽  
Author(s):  
Hiroki Mori ◽  
Kai Kurihara ◽  
Nobuyuki Sowa ◽  
Takahiro Kondou
Keyword(s):  
Temporal Variation ◽  
Natural Frequency ◽  
Low Cost ◽  
Frequency Component ◽  
Open Loop ◽  
Complete Suppression ◽  
Control Input ◽  
Modeling Error ◽  
Residual Vibration ◽  
Loop Control

Abstract A systematic approach is developed for determining a control input for the point-to-point control of an overhead crane that exhibits temporal variation of rope length in addition to damping and nonlinearity, without inducing residual vibration. Complete suppression of the residual vibration is achieved by eliminating the natural frequency component of the cargo from the apparent external force, which is defined to include the effects of damping, nonlinearity, and parameter variation. Furthermore, an effective technique previously proposed by the authors for improving robustness to the modeling error of the natural frequency is extended. Numerical simulation results show that, even when cargo is hoisted up or down during operation, the proposed method realizes accurate positioning of the cargo without inducing residual vibration and sufficiently improves robustness. To the best of the authors' knowledge, this is the first frequency-domain robust open-loop control strategy that ensures a theoretical zero amplitude for residual vibration in the absence of modeling error in nonlinear crane hoisting operation. The developed method is not only a contribution to the realization of low-cost and efficient crane hoisting operation, but is also applicable to the control of other nonlinear damped systems that include time-varying parameters.

Experiments on Point-to-Point Control of a Flexible Beam Using Laplace Transform Technique: Part II—Closed-Loop

1991 ◽  
Vol 113 (3) ◽  
pp. 438-443 ◽  
Author(s):  
S. P. Bhat ◽  
D. K. Miu
Keyword(s):  
Closed Loop ◽  
Position Control ◽  
Open Loop ◽  
Flexible Beam ◽  
Laplace Domain ◽  
Loop Control ◽  
Feed Forward Control ◽  
Laplace Transform Technique ◽  
Point Control ◽  
Point To Point

Using the Laplace domain synthesis technique documented in earlier publications, experiments on the closed-loop point-to-point position control of a flexible beam are presented. Two different approaches are described, a feed-forward control and an iterative open-loop control. Solution to the robustness problems encountered during actual implementation is also demonstrated.

New Electromagnetic Design of Miniature AF VCM Actuator with Low Cost

2015 ◽  
Vol 32 (4) ◽  
pp. 421-426 ◽  
Author(s):  
C.-S. Liu ◽  
L. Kuo ◽  
B.-J. Tsai
Keyword(s):  
High Performance ◽  
Closed Loop ◽  
Cell Phones ◽  
Low Cost ◽  
Voice Coil Motor ◽  
Open Loop ◽  
Closed Loop Control ◽  
Electromagnetic Design ◽  
Loop Control ◽  
Auto Focusing

AbstractRecently, compact and high-resolution camera modules with auto-focusing (AF) function have been integrated into cell phones in order to capture sharp photographs. Consumer demands AF camera modules in cell phones to have high performance with low cost. Accordingly, the present study proposes a new electromagnetic design of miniature AF voice coil motor (VCM) actuator with closed-loop control for cell phone camera modules to satisfy the requirements. The structure of the proposed AF VCM actuators was designed by using simulation methods. The performance of the proposed AF VCM actuators was demonstrated by a laboratory-built prototype. The experimental results have shown that the proposed AF VCM actuator has excellent performance with lower power consumption, higher positioning repeatability, and lower cost, when compared to previous AF VCM actuators with open-loop control or closed-loop control.

Design and Modelling of a Novel Servovalve Actuated by a Piezoelectric Ring Bender

2015 ◽  
Author(s):  
L. Johan Persson ◽  
Andrew R. Plummer ◽  
Christopher R. Bowen ◽  
Ian Brooks
Keyword(s):  
Mathematical Model ◽  
Closed Loop ◽  
Position Control ◽  
Open Loop ◽  
Closed Loop Control ◽  
Hydraulic Fluid ◽  
Loop Control ◽  
Frequency Responses ◽  
Spool Valve ◽  
The Mathematical Model

This paper describes the design, simulation and testing of a piezoelectric spool valve. An actuator has been connected to the valve and tested under closed loop control. A mathematical model of the valve was produced and a prototype of the valve was tested. The mathematical model is validated against the experimental data. Step and frequency responses for both the valve and actuator are presented. It was found that displacement of the hydraulic fluid by the ring bender had an impact on the valve performance. To reduce the effect of the piezoelectric hysteresis, closed loop spool position control was evaluated. A noticeable difference can be observed between open loop and closed loop performance.

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