Hysteresis compensation for piezoelectric laser scanner with open-loop control method

2016 ◽  
Author(s):  
Chen Wei ◽  
Ji Ming ◽  
Zhu Lei ◽  
Jiao Guohua ◽  
Lv Jiancheng
Keyword(s):  
Control Method ◽  
Laser Scanner ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Hysteresis Compensation

Positioning of Pneumatic Actuator Using Open-Loop System

2015 ◽  
Vol 816 ◽  
pp. 160-164
Author(s):  
Ivan Virgala ◽  
Michal Kelemen ◽  
Erik Prada ◽  
Tomáš Lipták
Keyword(s):  
Mathematical Model ◽  
Control Method ◽  
Open Loop ◽  
Pneumatic Actuator ◽  
Open Loop Control ◽  
Open Loop System ◽  
Precise Positioning ◽  
Loop Control ◽  
Experimental Stand ◽  
Loop Control System

In the paper, we experimentally analyze a pneumatic actuator and possibilities of piston positioning. Paper shows mathematical model of pneumatic actuator. Actuator is experimentally tested and therefor experimental stand is assembled for the purposes of positioning of actuator piston. The changing parameters during the experiment are weight of load and pneumatic pressure. The results show how these parameters can have influence on precise positioning of pneumatic actuator. For experiment there is purposely used open loop control system. The aim of the study is not to show control method for positioning but to show influence of mentioned parameters.

Precision open-loop control of piezoelectric actuator

2021 ◽  
pp. 1045389X2110482
Author(s):  
Zhigang Nie ◽  
Yuguo Cui ◽  
Jun Huang ◽  
Yiqiang Wang ◽  
Tehuan Chen
Keyword(s):  
Piezoelectric Actuator ◽  
Open Loop ◽  
Simple Expression ◽  
Creep Model ◽  
Open Loop Control ◽  
Maximum Displacement ◽  
Loop Control ◽  
Hysteresis Compensation ◽  
Rate Dependent ◽  
Partition Method

Due to space constraints, some micro-assemblies and micro-operating systems cannot install sensors, so it is challenging to achieve closed-loop control. For this reason, a precision open-loop control strategy for piezoelectric actuators is proposed. Firstly, based on the PI model and the proposed threshold partition method, the hysteresis model of the piezoelectric actuator with rate-dependent and few operators is established. Then the hysteresis error of the piezoelectric actuator is compensated by the inverse model obtained. Secondly, the creep model of the logarithmic piezoelectric actuator with simple expression and few parameters is established. Then, a creep controller without demand inverse is designed to compensate for the creep error of the piezoelectric actuator. Finally, a ZVD (Zero Vibration Derivative) input shaping method with good robustness is given to eliminate the oscillation generated by the piezoelectric actuator under the action of the step signal. The experimental results show that the displacement error of piezoelectric actuator is reduced from −9.07 to 9.46 μm to −1.22 to 1.78 μm when the maximum displacement is 120 μm after hysteresis compensation; after creeping compensation, within the action time of the 1200 s, the displacement creep of the piezoelectric actuator was reduced from 5.5 μm before compensation to 0.3 μm; after the oscillation control, the displacement overshoot of the piezoelectric actuator is reduced to 0.6% of that before control.

Melnikov-Based Open-Loop Control of Escape for a Class of Nonlinear Systems

1997 ◽  
Vol 119 (3) ◽  
pp. 590-594 ◽  
Author(s):  
Emil Simiu ◽  
Marek Franaszek
Keyword(s):  
Stochastic Systems ◽  
Control Method ◽  
Open Loop ◽  
Heteroclinic Orbits ◽  
Time Interval ◽  
Open Loop Control ◽  
Loop Control ◽  
Random Forcing ◽  
Scale Factors ◽  
System Properties

The performance of certain nonlinear stochastic systems is deemed acceptable if during a specified time interval, the systems have sufficiently low probabilities of escape from a preferred region of phase space. We propose an open-loop control method for reducing these probabilities. The method is applicable to stochastic systems whose dissipation- and excitation-free counterparts have homoclinic or heteroclinic orbits. The Melnikov relative scale factors are system properties containing information on the frequencies of the random forcing spectral components that are most effective in inducing escapes. Numerical simulations show that substantial advantages can be achieved in some cases by designing control systems that take into account the information contained in the Melnikov scale factors.

Asymptotic Solution and Trajectory Planning for Open-Loop Control of Mobile Robots

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Alan Whitman ◽  
Garrett Clayton ◽  
Alexander Poultney ◽  
Hashem Ashrafiuon
Keyword(s):  
Mobile Robots ◽  
Trajectory Planning ◽  
Control Method ◽  
Open Loop ◽  
Order Correction ◽  
Reference Trajectory ◽  
Open Loop Control ◽  
Loop Control ◽  
First Order ◽  
First Order Correction

A novel open-loop control method is presented for mobile robots based on an asymptotic inverse dynamic solution and trajectory planning. The method is based on quantification of sliding by a small nondimensional parameter. Asymptotic expansion of the equations yields the dominant nonslip solution along with a first-order correction for sliding. A trajectory planning is then introduced based on transitional circles between the robot initial states and target reference trajectory. The transitional trajectory ensures smooth convergence of the robot states to the target reference trajectory, which is essential for open-loop control. Experimental results with a differential drive mobile robot demonstrate the significant improvement of the controller performance when the first-order correction is included.

scholarly journals Research on system modeling and motion control simulation of automatic power trowel

2021 ◽  
Vol 2125 (1) ◽  
pp. 012031
Author(s):  
Hao Xu ◽  
Yutian Zhu ◽  
Mo Chen ◽  
Zhao Liu
Keyword(s):  
Control Algorithm ◽  
Control Method ◽  
System Modeling ◽  
Open Loop ◽  
State Feedback Control ◽  
Open Loop Control ◽  
Loop Control ◽  
Point Motion ◽  
Point To Point ◽  
The Relationship

Abstract Aiming at the problems that the existing control researches on the power trowel are limited to the analysis of the motion principle and the open-loop control of some mechanisms, taking a hydraulically-driven ride-on power trowel as the research object, the closed-loop control method of the point-to-point motion of the power trowel is studied. After analyzing the motion principle of the power trowel, based on the assumption of elastic deformation of concrete, the dynamic model of a single trowel is established, and the relationship between the driving force, driving moment and hydraulic moment, velocity, and angular velocity of the trowel is obtained. The whole machine motion equation of the power trowel is deduced, the point-to-point state feedback control algorithm of the power trowel is studied, and a simulation model is built to verify the accuracy of the system model of the power trowel and the effectiveness of the control algorithm. This research can provide reference for the control method design of other complex motions of the power trowel.

Enhancement of dynamic performance of wave energy converter by introducing a flow control

2022 ◽  
pp. 014233122110699
Author(s):  
Dazhou Geng ◽  
Qijuan Chen ◽  
Yang Zheng ◽  
Xuhui Yue ◽  
Donglin Yan
Keyword(s):  
Flow Control ◽  
Transient Process ◽  
Closed Loop ◽  
Control Method ◽  
Control Valve ◽  
Open Loop ◽  
Closed Loop Control ◽  
Flow Control Valve ◽  
Open Loop Control ◽  
Loop Control

The stabilization of power take-off (PTO) is imperative especially under circumstances of fluctuating input wave energy. In this paper, a flow control valve is introduced to optimize the transient process of the hydraulic PTO, which can contribute to a quicker adjustment and a stronger stability. Under variations of input power and load torque in transient process, an open-loop control method and a closed-loop control method are proposed as the opening law of the above valve, and the hydraulic motor speed, the pressure at the accumulator inlet and the generated power are chosen as indicators to examine the regulation performance. Then, the synergic effect of the flow control valve and the accumulator in the transient process is discussed. The effectiveness of the two presented control methods on the fluctuation suppression is respectively tested and compared in both regular wave and irregular wave situations via simulation. To validate the practical effectiveness of the proposed methods, field experiments are conducted. The results demonstrate that the open-loop control can only improve the damping ability of the hydraulic PTO in the speed raising stage, while the closed-loop control can improve the stability both in the speed raising stage and in the load increasing stage.

Optimum Pulse Control of Flexible Structures

1981 ◽  
Vol 48 (3) ◽  
pp. 619-626 ◽  
Author(s):  
S. F. Masri ◽  
G. A. Bekey ◽  
T. K. Caughey
Keyword(s):  
Control Method ◽  
Flexible Structures ◽  
Open Loop ◽  
Response Threshold ◽  
Distributed Parameter ◽  
Open Loop Control ◽  
Pulse Control ◽  
Loop Control ◽  
Pulse Characteristics ◽  
Active Control Method

A simple yet efficient active control method is presented for reducing the oscillations of distributed parameter systems subjected to arbitrary dynamic environments. Following determination that some specified response threshold has been exceeded, an open-loop control pulse is applied. The optimum pulse characteristics are determined analytically so as to minimize a non-negative cost function related to the structure energy. The proposed control method is shown to be reliable in consistently mitigating the response of realistic multidegree-of-freedom systems, whether linear or nonlinear, subject to arbitrary stochastic or deterministic excitation.

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