Modeling and Control of a Novel High-Pressure Pneumatic Servo Valve Direct-Driven by Voice Coil Motor

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Li Baoren ◽  
Gao Longlong ◽  
Yang Gang
Keyword(s):  
High Pressure ◽  
Pid Controller ◽  
Gas Flow ◽  
Position Control ◽  
Hybrid Control ◽  
Voice Coil Motor ◽  
Direct Drive ◽  
Modeling And Control ◽  
Servo Valve ◽  
Control Scheme

High-pressure pneumatic control valves have been widely investigated during last decades. The published literature includes experimental and analytical studies on both constant value on–off valve and pressure reducing valve, but rarely on servo valve. In this paper, a novel voice coil motor (VCM) direct drive high-pressure pneumatic servo valve (HPPSV) is proposed. The mathematical model of the HPPSV including electromechanical and fluid subsystem is presented. Furthermore, the hybrid control scheme consisting of a proportional integral differential (PID) controller with velocity/acceleration feed-forward and a disturbance observer is proposed to improve the control performance of the HPPSV, taking into account the factors such as compressibility of high-pressure gas, high nonlinearity of gas flow force and friction force. The experimental results show that the spool position control system based on the proposed control scheme has strong robustness and disturbance rejection capability, and the control accuracy of the valve spool position can be enhanced greatly compared with the conventional PID controller. The study has general implications in the development of high-pressure pneumatic servo valves and high-pressure pneumatic precision control field.

Feasibility Study on the Use of a Voice Coil Motor Direct Drive Flow Rate Control Valve

2009 ◽  
Author(s):  
Shuai Wu ◽  
Richard Burton ◽  
Zongxia Jiao ◽  
Juntao Yu ◽  
Rongjie Kang
Keyword(s):  
Neural Network ◽  
Flow Control ◽  
Flow Rate ◽  
Rate Control ◽  
Network Flow ◽  
Voice Coil Motor ◽  
Direct Drive ◽  
Hydraulic Test ◽  
Servo Valve ◽  
Flow Rate Control

This paper considers the feasibility of a new type of voice coil motor direct drive flow control servo valve. The proposed servo valve controls the flow rate using only a direct measurement of the spool position. A neural network is used to estimate the flow rate based on the spool position, velocity and coil current. The estimated flow rate is fed back to a closed loop controller. The feasibility of the concept is established using simulation techniques only at this point. All results are validated by computer co-simulation using AMESim and Simulink. A simulated model of a VCM-DDV (Voice Coil Motor-Direct Drive Valve) and hydraulic test circuit are built in an AMESim environment. A virtual digital controller is developed in a Simulink environment in which the feedback signals are received from the AMESim model; the controller outputs are sent to the VCM-DDV model in AMESim (by interfacing between these two simulation packages). A LQR (Linear Quadratic Regulator) state feedback and nonlinear compensator controller for spool position tracking is considered as this is the first step for flow control. A flow rate control loop is subsequently included via a neural network flow rate estimator. Simulation results show that this method could control the flow rate to an acceptable degree of precision, but only at low frequencies. This kind of valve can find usage in open loop hydraulic velocity control in many industrial applications.

Hybrid Control of the Berkeley Lower Extremity Exoskeleton (BLEEX)

2005 ◽  
Author(s):  
Lihua Huang ◽  
Ryan Ryan Steger ◽  
H. Kazerooni
Keyword(s):  
Position Control ◽  
Hybrid Control ◽  
System Sensitivity ◽  
Walking Gait ◽  
Mixed Control ◽  
Stance Control ◽  
Control Scheme ◽  
Load Carrying ◽  
Human Limb ◽  
Careful Design

The first functional load-carrying and energetically autonomous exoskeleton was demonstrated at U.C. Berkeley, walking at the average speed of 0.9 m/s (2 mph) while carrying a 34 kg (75 lb) payload. The original BLEEX sensitivity amplification controller, based on positive feedback, was designed to increase the closed loop system sensitivity to its wearer’s forces and torques without any direct measurement from the wearer. The controller was successful at allowing natural and unobstructed load support for the pilot. This article presents an improved control scheme we call “mixed” control that adds robustness to changing BLEEX backpack payload. The walking gait cycle is divided into stance control and swing control phases. Position control is used for the BLEEX stance leg (including torso and backpack) and the sensitivity amplification controller is used for the swing leg. The controller is also designed to smoothly transitions between these two schemes as the pilot walks. With mixed control, the controller does not require a good model of the BLEEX torso and payload, which is difficult to obtain and subject to change as payload is added and removed. As a tradeoff, the position control used in this method requires the human to wear seven inclinometers to measure human limb and torso angles. These additional sensors require careful design to securely fasten them to the human and increase the time to don (and doff) BLEEX.

scholarly journals Design and Experimental Evaluation of a Robust Position Controller for an Electrohydrostatic Actuator Using Adaptive Antiwindup Sliding Mode Scheme

2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Ji Min Lee ◽  
Sung Hwan Park ◽  
Jong Shik Kim
Keyword(s):  
Control Systems ◽  
Pid Controller ◽  
Position Control ◽  
Sliding Mode ◽  
System Modeling ◽  
Modeling Error ◽  
Load Disturbance ◽  
Control Scheme ◽  
Position Controller ◽  
System Uncertainties

A robust control scheme is proposed for the position control of the electrohydrostatic actuator (EHA) when considering hardware saturation, load disturbance, and lumped system uncertainties and nonlinearities. To reduce overshoot due to a saturation of electric motor and to realize robustness against load disturbance and lumped system uncertainties such as varying parameters and modeling error, this paper proposes an adaptive antiwindup PID sliding mode scheme as a robust position controller for the EHA system. An optimal PID controller and an optimal anti-windup PID controller are also designed to compare control performance. An EHA prototype is developed, carrying out system modeling and parameter identification in designing the position controller. The simply identified linear model serves as the basis for the design of the position controllers, while the robustness of the control systems is compared by experiments. The adaptive anti-windup PID sliding mode controller has been found to have the desired performance and become robust against hardware saturation, load disturbance, and lumped system uncertainties and nonlinearities.

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.

scholarly journals A Riemannian-Geometry Approach for Modeling and Control of Dynamics of Object Manipulation under Constraints

2009 ◽  
Vol 2009 ◽  
pp. 1-16 ◽  
Author(s):  
Suguru Arimoto ◽  
Morio Yoshida ◽  
Masahiro Sekimoto ◽  
Kenji Tahara
Keyword(s):  
Riemannian Geometry ◽  
Position Control ◽  
Hybrid Control ◽  
Object Manipulation ◽  
Rolling Contact ◽  
Kernel Space ◽  
Constraint Forces ◽  
Modeling And Control ◽  
Holonomic Constraints ◽  
And Control

A Riemannian-geometry approach for modeling and control of dynamics of object manipulation under holonomic or non-holonomic constraints is presented. First, position/force hybrid control of an endeffector of a multijoint redundant (or nonredundant) robot under a holonomic constraint is reinterpreted in terms of “submersion” in Riemannian geometry. A force control signal constructed in the image space of the constraint gradient is regarded as a lifting (or pressing) in the direction orthogonal to the kernel space. By means of the Riemannian distance on the constraint submanifold, stability of position control under holonomic constraints is discussed. Second, modeling and control of two-dimensional object grasping by a pair of multijoint robot fingers are challenged, when the object is of arbitrary shape. It is shown that rolling contact constraints induce the Euler equation of motion, in which constraint forces appear as wrench vectors affecting the object. The Riemannian metric is introduced on a constraint submanifold characterized with arclength parameters. An explicit form of the quotient dynamics is expressed in the kernel space with accompaniment of a pair of first-order differential equations concerning the arclength parameters. An extension of Dirichlet-Lagrange's stability theorem to redundant systems under constraints is suggested by introducing a Morse-Lyapunov function.

P-CMAC-Based Control Method and its Application in Filament Tension Control

2010 ◽  
Vol 33 ◽  
pp. 101-104
Author(s):  
D.X. Chen ◽  
G. Wang
Keyword(s):  
Neural Network ◽  
Pid Controller ◽  
Fuzzy Inference ◽  
Control Method ◽  
Hybrid Control ◽  
Tracking Error ◽  
Tension Control ◽  
Approximation Accuracy ◽  
Control Scheme ◽  
Hybrid Control Scheme

Cerebella Model Articulation Controller (CMAC) is considered as local association and generalization neural network. Parametric CMAC (P-CMAC) is a modification to the original CMAC. The introduction of continuous activation function applied in the input space can overcome the binary behavior of the original CMAC. Takagi-Sugeno(TS) type fuzzy inference is embedded in the internal mapping to improve the approximation accuracy. Hybrid control scheme, which combines P-CMAC neural network and traditional PID controller, is proposed in the paper. The output of P-CMAC network dominates the overall control signal applied to the plant, while the traditional PID controller serves as compensator for reducing tracking error. The application of hybrid control scheme to filament tension control is illustrated. The experimental results have shown the effectiveness and accuracy improvement of the control scheme.

Force-Controlled Assembly of two Objects with a Two-arm Robot

Robotica ◽  
1991 ◽  
Vol 9 (3) ◽  
pp. 299-306 ◽  
Author(s):  
Pierre Dauchez ◽  
Xavier Delebarre
Keyword(s):  
Position Control ◽  
Hybrid Control ◽  
Contact Forces ◽  
Rigid Object ◽  
Assembly Task ◽  
Control Scheme ◽  
The One ◽  
Theoretical Results ◽  
Hybrid Control Scheme ◽  
Approach Phase

SUMMARYThe use of a two-arm robot for assembling two objects, with each being held by one arm, is presented. The assembly task is decomposed into an approach phase and an assembly phase. For each phase, we propose a solution for describing the task. For the approach phase, we suggest to describe the task with respect to a mobile reference frame, attached to the end effector of one of the arms. This allows us to take advantage of the redundancy of the system. For the assembly phase, we propose two solutions, both involving some kind of force control. The first one is based upon a position control similar to the one used for the approach phase, with an updating of the reference position through a measurement of the contact forces. The second scheme is derived from a symmetrical hybrid control scheme initially proposed by Uchiyama and Dauchez to control a two-arm robot handling a single rigid object. The main results of this scheme are summarized, and the way of using it for an assembly task is presented. Finally, the experimental setup we have installed to validate our theoretical results is described.

Comparison of Adaptive and Robust Controllers for Fully-Constrained and Redundant Planar Cable Robots

2014 ◽  
Author(s):  
Sergio J. Torres-Mendez ◽  
Gokhan Gungor ◽  
Baris Fidan ◽  
Amir Khajepour
Keyword(s):  
Pid Controller ◽  
Position Control ◽  
Sliding Mode ◽  
Uncertain Parameters ◽  
Input Output ◽  
Adaptive Controllers ◽  
Control Scheme ◽  
Control Schemes ◽  
Novel Method ◽  
Simulation Results

This work deals with the design and comparison of two adaptive position control schemes with a classical PID controller for fully constrained and redundant planar robots. First, a novel method based on inclusion of virtual cables facilitates the linear separation of the uncertain parameters from the input-output signals. Then, two Lyapunov based adaptive controllers based on the sliding mode and PD schemes are designed to compensate for the structure matrix uncertainties, which result from errors in the anchor point locations. Finally, the adaptive controllers are evaluated and compared with a classical PID controller through simulations for a desired 2D singularity-free pose of the mobile platform. The simulation results have shown that the adaptive PD control scheme has the best performance for both fully constrained and redundant cases.

Modeling and Control of Ultra Precision Positioning System for a Grating Ruling Machine

2011 ◽  
Vol 110-116 ◽  
pp. 2647-2654
Author(s):  
Yuan Shen ◽  
Dong Cai Liu ◽  
Guo Fu Lian ◽  
Jie Guo ◽  
Chan Gan Zhu
Keyword(s):  
Hybrid Control ◽  
System Modeling ◽  
Positioning System ◽  
Precision Positioning ◽  
Positional Accuracy ◽  
Modeling And Control ◽  
Control Scheme ◽  
Positioning Stage ◽  
Ultra Precision ◽  
Long Stroke

This paper presents a system modeling based control scheme of an ultra precision positioning system for a grating ruling machine. Since the positioning system having a long stroke with ultra precision, the positioning system consists of a coarse positioning stage driven by a servo motor and a fine positioning stage driven by a piezoelectric ceramic. In order to improve positional accuracy and remove the noise components of motion, a hybrid control scheme based on the system modeling is implemented. Considering position-dependent and time-dependent behaviors of the stages, a model based LQ controller is utilized to the coarse stage and a PID feedback controller based on neural network is utilized to the fine stage. Experiment results reveal the efficient and robust of the control scheme and show that the positional accuracy has been readily achieved within 8.6 nm.

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