scholarly journals Static and Dynamic Characterization and Control of a High-Performance Electro-Hydraulic Actuator

Actuators ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 46
Author(s):  
Govind N. Sahu ◽  
Suyash Singh ◽  
Aditya Singh ◽  
Mohit Law
Keyword(s):  
Machine Tool ◽  
High Performance ◽  
Closed Loop ◽  
Dynamic Models ◽  
Static Model ◽  
Dynamical Model ◽  
Model Parameters ◽  
Closed Loop Control ◽  
Hydraulic Actuator ◽  
Loop Control

This paper characterizes the static, dynamic, and controlled behavior of a high-performance electro-hydraulic actuator to assess its suitability for use in evaluating machine tool behavior. The actuator consists of a double-acting piston and cylinder arrangement controlled by a servo valve and a separate rear chamber controlled by a separate valve, designed to work in conjunction to generate static forces of up to 7000 N that can be superposed with dynamic forces of up to ±1500 N. This superposition of periodic forces with a non-zero mean makes the actuator capable of applying realistic loading conditions like those experienced by machines during cutting processes. To characterize the performance of this actuator, linearized static and dynamic models are described. Since experiments with the actuator exhibit nonlinear characteristics, the linearized static model is expanded to include the influence of nonlinearities due to flow, leakages, saturations, and due to friction and hysteresis. Since all major nonlinearities are accounted for in the expanded static model, the dynamical model remains linear. Unknown static and dynamical model parameters are calibrated from experiments, and the updated models are observed to capture experimentally observed behavior very well. Validated models are used to tune the proportional and integral gains for the closed-loop control strategy, and the model-based tuning in turn guides appropriate closed-loop control of the actuator to increase its bandwidth to 200 Hz. The statically and dynamically characterized actuator can aid machine tool structural testing. Moreover, the validated models can instruct the design and development of other higher-performance electro-hydraulic actuators, guide the conversion of the actuator into a damper, and also test other advanced control strategies to further improve actuator performance.

Backlash Compensation on CNC Machine Tool Based on Semi-Closed Loop Control

2011 ◽  
Vol 346 ◽  
pp. 644-649 ◽  
Author(s):  
Bin Feng ◽  
Xue Song Mei ◽  
Liang Guo ◽  
Dong Sheng Zhang ◽  
You Long Cheng
Keyword(s):  
Machine Tool ◽  
Closed Loop ◽  
Closed Loop Control ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Positional Accuracy ◽  
Loop Control ◽  
Open Cnc ◽  
Contouring Error ◽  
Open Cnc System

The positional accuracy and machining precision are mainly affected by backlash for semi-closed loop control CNC machine tool. And compensation for backlash is essential to improving the accuracy of machine tool. A method is developed to reduce contouring error in this paper. A simulated model of backlash and Open CNC system are used to verify compensation algorithm. Computational simulations and experimental results have shown that the contouring error due to backlash can be greatly reduced by using backlash compensation.

Research on Error Compensation by Semi-Closed Loop Control for a 3-UPS Parallel Machine Tool

2012 ◽  
Vol 461 ◽  
pp. 272-276
Author(s):  
Jian Ye Guo ◽  
Jia Shun Shi ◽  
Liang Zhao
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Closed Loop ◽  
Parallel Machine ◽  
Control Mode ◽  
Closed Loop Control ◽  
Kinematics Analysis ◽  
Compensation Strategy ◽  
Loop Control ◽  
Parallel Machine Tool

This paper took a 3-UPS Parallel Machine Tool (PMT) as the object of research; it mainly introduced the process of establishing the compensation strategy for this PMT. Firstly the kinematics equations on driving chain and constraint chain was established on the basis of kinematics analysis. Then according to the structural characteristics and the results of kinematics analysis, the error compensation strategy of feedback correction type with the semi-closed loop control mode was used in the error compensation for this PMT by the method of installing respectively the encoders on the each joint of parallelogram mechanism, namely the compensation way of “parallel driving and series feedback” was adopted. Finally this paper has also deduced the theoretical model of error compensation. The research results in this paper provided a theoretical basis for realizing error compensation of this PMT, and had important practical significance for improving machining precision of PMT

Dynamic Characteristics and Double Closed Loop Control Method of Warping Machine

2012 ◽  
Vol 627 ◽  
pp. 428-434
Author(s):  
Tao Yang ◽  
Lin Yin Liu ◽  
Wei Rong Dai
Keyword(s):  
Control System ◽  
Closed Loop ◽  
Dynamic Models ◽  
Control Method ◽  
Stable State ◽  
The Other ◽  
Closed Loop Control ◽  
Loop Control ◽  
Yarn Tension ◽  
Warp Tension

The warp tension is caused by the speed difference between rewinding shaft and unwinding shaft. The mathematical dynamic models of the system are established based on rewinding shaft and unwinding shaft．Double closed loop are included in the control system. One is winding speed closed loop which could control warping speed according to the requirements; the other is tension closed loop which ensure the yarn tension to be kept constant. The experimental results show the curve of tension enters a stable state after two or three times’ oscillation. The accuracy of the yarn tension has reached ±3%.

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.

scholarly journals Design and Analysis of Closed Loop Control of Multilevel SVPWM Inverter Fed PMSM Drive

2019 ◽  
Vol 8 (6S2) ◽  
pp. 809-816
Keyword(s):  
Permanent Magnet ◽  
Feedback Linearization ◽  
High Performance ◽  
Closed Loop ◽  
Permanent Magnet Synchronous Motor ◽  
Voltage Source ◽  
Closed Loop Control ◽  
Loop Control ◽  
Controlled Switching ◽  
Switching Devices

Permanent magnet synchronous machines have been universally used over induction machines in variable speed drives. For present trends and future developments, power electronics technology gives the extensive research of multilevel inverters that brings high safety voltages with low harmonic content in comparison with two-level inverter strategies. Multi level inverters implementation can be done by raising the number of power semi conductor controlled switching devices per phase to increase the number of inverter output voltage levels. By increasing the levels, power controlled switching devices and other components are increased, which makes the inverter complex and overpriced. From the above aspects, three-phase three-level inverter strategy is used for high performance and high voltage A.C drives. Multilevel inverter using a space vector pulse width modulation (SVPWM) strategy gives great advantages in high performance A.C drive applications. Various types of control strategies have been recommended for voltage source inverter fed A.C drives. In the proposed work, a PI controller is designed for the outer loop and non-linear controller using a state feedback linearization technique is designed for the inner loop. The closed loop control system for three-level inverter fed Permanent magnet synchronous motor drive employing SVPWM is extensively simulated using MATLAB.

Remote Concrete Spraying in Shafts and Tunnels With Closed Loop Control

1996 ◽  
Author(s):  
Liu Hongzhao ◽  
E. Appleton
Keyword(s):  
High Performance ◽  
Closed Loop ◽  
Transformation Method ◽  
Emission Angle ◽  
Impact Angle ◽  
Order System ◽  
Closed Loop Control ◽  
Loop Control ◽  
Loop Control System ◽  
Velocity Measuring

Abstract In this paper, a closed-loop control system for the remote concrete spraying in shafts and tunnels is presented. The design includes a velocity measuring element, a PID controller, and a DC servo-motor drive system which is used to control the relative velocity of the grout, emission velocity, emission angle, and rotation to impact angle. The mathematical model of this system has been established and its transfer function obtained by the Laplace Transformation method. A set of stability conditions for this fourth-order system has been developed by means of the modified Hurwitz criterion. These studies provide the possibility of creating high-performance remote concrete spraying machines that operate in shafts and tunnels and have directional spray capability.

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