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.

scholarly journals Development of a Poppet-Type Pneumatic Servo Valve

2018 ◽  
Vol 8 (11) ◽  
pp. 2094 ◽  
Author(s):  
Takahiro Kanno ◽  
Takashi Hasegawa ◽  
Tetsuro Miyazaki ◽  
Nobuyuki Yamamoto ◽  
Daisuke Haraguchi ◽  
...  
Keyword(s):  
Control Systems ◽  
Flow Rate ◽  
Position Control ◽  
Maximum Flow ◽  
Air Leakage ◽  
Static And Dynamic Characteristics ◽  
Servo Valve ◽  
Precise Control ◽  
Flow Channels ◽  
Spring Force

In pneumatic positioning and force-control systems, spool-type servo valves are widely used for obtaining quick responses and precise control. However, air leakage from these valves results in increased energy consumption. To address this problem, we developed a three-port poppet-type servo valve to reduce air leakage. The developed valve consists of a camshaft, two orifices, two metal balls, and a housing with two flow channels. The metal ball is pushed by fluid, and spring force closes the orifice. The port opens when the cam rotates and pushes the ball. The cam shape and orifice size were designed to provide the desired flow rate. The specifications of the DC motor for rotating the camshaft were determined considering the fluid force on the ball. Static and dynamic characteristics of the valve were measured. We experimentally confirmed that air leakage was 0.1 L/min or less. The ratio of air leakage to maximum flow rate was only 0.37%. Dynamic characteristic measurements showed that the valve had a bandwidth of 30 Hz. The effectiveness of the valve was demonstrated through experiments involving pressure and position control.

Feedforward model-inverse position control of three-stage servo-valve using zero magnitude error tracking control

2018 ◽  
Vol 233 (7) ◽  
pp. 2340-2348 ◽  
Author(s):  
Kyeong Ha Lee ◽  
Seung Guk Baek ◽  
Hyouk Ryeol Choi ◽  
Hyungpil Moon ◽  
Sang-Hoon Ji ◽  
...  
Keyword(s):  
Flow Rate ◽  
Tracking Control ◽  
Closed Loop ◽  
Position Control ◽  
Control Method ◽  
Least Squares Method ◽  
Flow Direction ◽  
Recursive Least Squares ◽  
Servo Valve ◽  
Model Inverse

Three-stage servo-valves are popularly used in hydraulic systems that require large flow rate and high pressure. For a proper control of flow direction and flow rate fed into a hydraulic actuator, securing a proper position control bandwidth is a critical task for the servo-valve. In this paper, a set of popular control methods are systematically studied and a control method is selected. It is proven that the feedforward model-inverse control is the most effective method in terms of the control bandwidth. In the present work, the feedforward closed-loop architecture is adopted and the closed-loop system is estimated in a linear discrete-time transfer function by recursive least squares method. On recognizing a nonminimum phase zero problem, this work implements the zero magnitude error tracking control, an approximate model-inverse technique, in order to overcome the problem. As a result, the effectiveness of the proposed feedforward model-inverse position control strategy is verified.

Analysis and Simulation on Drive Characteristic of High-Strength Water Hydraulic Artificial Muscle

2014 ◽  
Vol 889-890 ◽  
pp. 488-492
Author(s):  
Zeng Meng Zhang ◽  
Jiao Yi Hou ◽  
Zheng Wen Sun ◽  
Yong Jun Gong ◽  
Jian Miao
Keyword(s):  
Flow Rate ◽  
Control Valve ◽  
Artificial Muscle ◽  
High Strength ◽  
Hydraulic Control ◽  
Hydraulic Circuit ◽  
Water Hydraulic ◽  
The Difference ◽  
Hydraulic Valves ◽  
Load Mass

Driving processes and characteristics are different between the water hydraulic artificial muscle and pneumatic artificial muscle due to the difference of work media employed in muscles. An appropriative hydraulic circuit was designed to control the pressure of the water hydraulic artificial muscle and the performance of this system was analyzed. An AMESim model of the control system was built and the dynamic characteristics are analyzed with various parameters of the hydraulic circuit and various loads by simulation. The results show that the performance of the water hydraulic control valve should agree with the dimension of the water hydraulic artificial muscle. The rated flow rate of the water hydraulic valves can be selected increasingly while the load mass is low. Meanwhile, the overshoot is generated and enlarged along with the increases of the flow rate and load mass. These contribute to the improvements of designs and researches on control systems of water hydraulic artificial muscles.

Modeling and Optimal Control of a Variable-Speed Centrifugal Pump With a Pipeline

2016 ◽  
Author(s):  
Cristian F. Jaimes Saavedra ◽  
Sebastian Roa Prada ◽  
Jessica G. Maradey Lázaro
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Flow Control ◽  
Flow Rate ◽  
Power Efficiency ◽  
Control Valve ◽  
Operating Point ◽  
Variable Frequency ◽  
Centrifugal Pumps ◽  
Variable Frequency Drive

Pumping processes often require different operating conditions for the same pipeline. The conditions downstream in the pipeline can change in such a way that the pressure at the discharge of the pump may vary, which automatically introduces changes in the flow supplied by the pump into the pipeline due to the head vs flow characteristic curve of the pump. Even under varying pipeline pressure conditions, it may be necessary to keep the flow discharge of the pump constant. The two most commonly used control strategies for flow control with centrifugal pumps are by means of a fixed-speed pump and a control valve at the outlet of the pump, or by means of a variable frequency drive which avoids the need for the control valve. It has been demonstrated that the approach with the fixed-speed pump and the control valve provides poor power efficiency results, so a variable frequency drive is normally the solution of choice in industry applications. The use of a variable frequency drive allows reaching the flow required by the system without changing the physical characteristic of the pump or pipeline, i.e., it is not necessary to shut the system down to replace the impeller of the pump. However, affinity laws of centrifugal pumps dictate that a change in the rotational speed of the impeller shifts the characteristic curves of the pump, not only the flow vs head curve, but also the efficiency curves, among others. Besides, searching for a different operating point by changing the speed of the pump does not necessarily guarantees optimal operating power efficiency. This paper proposes an optimization approach where a compromise is made between flow control and power efficiency by minimizing the error in the flow rate while at the same time maximizing the power efficiency. To accomplish this goal, this paper presents the modeling of the pump and pipeline, and the design of a linear quadratic regulator control for the fluid flow passing through a given pipeline. The fluid under consideration is water. The mathematical model of the overall system is derived by considering the model of an AC motor, the pump and the hydraulic circuit. Then, with the help of the software MATLAB, the controller was designed and implemented with the linearized mathematical model. The actuator of the control system is the variable frequency drive that changes the speed of the impeller to adjust the flow rate to the required operating point under different loading conditions. The results show the behavior of the compensated system with the optimal controller. In practice, the control system must take into account the constraints of the control effort, which means, the frequency of the pump must be kept within safe values to achieve proper functioning of the pumping system.

Analysis of an Opto-Pneumatic Control System and Improvement of its Control Performance

1999 ◽  
Vol 11 (4) ◽  
pp. 251-257 ◽  
Author(s):  
Tetsuya Akagi ◽  
◽  
Shujiro Dohta ◽  
Hisashi Matsushita ◽  
Keyword(s):  
Control System ◽  
Position Control ◽  
Sliding Mode ◽  
Pneumatic Cylinder ◽  
Control Performance ◽  
Pneumatic Control ◽  
Servo Valve ◽  
Proposed Model ◽  
Control Scheme

This paper describes an analysis of an opto-pneumatic control system and an improvement of control performance of the system. The opto-pneumatic system consists of an optical servo valve, a pneumatic cylinder and a cart. First, we built an analytical model of the system considering a nonlinear friction where exists in sliding parts. And we confirmed the validity of the proposed model by comparing theoretical results with experimental results of the characteristics of optical servo valve and cart position control. Then, we applied a sliding mode control scheme compensating a steady-state disturbance to multi- position control and follow-up control of a cart. By computer simulation, we confirmed that the control performance of opto-pneumatic control system was improved by using this control scheme.

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.

Development of Miniaturized Rubber Muscle Actuator Driven by Gas-Liquid Phase Change

2016 ◽  
Author(s):  
Tomonori Kato ◽  
Kazuki Sakuragi ◽  
Mingzhao Cheng ◽  
Ryo Kakiyama ◽  
Yuta Matsunaga ◽  
...  
Keyword(s):  
Control System ◽  
Liquid Phase ◽  
Frequency Response ◽  
Artificial Muscle ◽  
Phase Changes ◽  
Corner Frequency ◽  
Pi Control ◽  
Pneumatic Actuators ◽  
Frequency Responses ◽  
Soft Actuators

The goal of this study is to develop a miniaturized artificial muscle in which a tiny compressor can be installed. Pneumatic actuators, such as pneumatic artificial rubber muscles (PARMs), have been widely used in many industrial and robotic research applications because they are compact and lightweight. However, the compressors driving such actuators are relatively large. To solve this problem, the authors have been researching soft actuators driven by gas-liquid phase changes (GLPCs). In this study, a fixed chamber containing a constantan heater and fluorocarbon was used to generate pressure instead of a compressor. The pressure generation caused by the GLPC was confirmed, and a PARM contraction experiment was then conducted. Additionally, a PI control system was built to test the step and frequency responses of the actuator. A frequency response of up to 4.0 Hz was determined, and the corner frequency was found to be approximately 1.5 Hz. The size of the actuator was reduced by removing the chamber and installing the heater in the rubber muscle. A PARM driving experiment was conducted, and the performance of the PARM was evaluated. The miniaturized actuator consumes less power than the original actuator.

The Pneumatic Position Control System Based on Fuzzy-PID

2014 ◽  
Vol 488-489 ◽  
pp. 1142-1145
Author(s):  
Sheng Zhong Li ◽  
Jian Xin Liu ◽  
Yi Fei Xia
Keyword(s):  
Control System ◽  
Position Control ◽  
Control Valve ◽  
Pneumatic Cylinder ◽  
Fuzzy Pid ◽  
Fuzzy Pid Control ◽  
Positioning Control ◽  
Development Platform ◽  
Directional Control ◽  
Self Tuning

Put forward a kind of control system to achieve precise positioning of the pneumatic cylinder, coring to PC upper monitor and using Visual C++ as the development platform. Establish an experimental platform of pneumatic cylinder positioning control system: selecting the parameter self-tuning Fuzzy-PID control algorithm, using the proportional directional control valve, standard cylinder, displacement sensordata acquisition card and other components. the use of MATLAB to simulate and optimize, carry out the actual experiment on the basis of simulation. The experimental results proved the effectiveness and correctness of Fuzzy PID in pneumatic control system.

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