Positional control of a parallel kinematics mechatronic manipulator linear drive

2020 ◽  
Vol 49 (9) ◽  
pp. 6-13
Author(s):  
N. S. Slobodzyan
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Cumulative Effect ◽  
Open Loop ◽  
Microprocessor System ◽  
Parallel Kinematics ◽  
Static Displacement ◽  
Dynamic Constraints ◽  
Advantages And Disadvantages ◽  
Positional Control

The research is part of the current work on the design and research of precision actuators with parallel kinematics, designed to guide and orient of various objects. To protect the sensitive load and the supporting platform from undesirable disturbances above the permissible ones, as well as to limit the time of transient processes and the consumed power, a method for planning the trajectory of the linear actuator stem when operating in positional mode is proposed. The article describes an algorithm for calculating the parameters of the trajectory of an object under specified restrictions on speed, acceleration and acceleration derivative, and also proposes an algorithm for implementing control along a planned trajectory for a modern microprocessor system, which implements the dependence of speed on movement. The advantage of the proposed control method is the elimination of the cumulative effect of the static displacement error while observing dynamic constraints, as well as the possibility of using algorithms in both closed-loop and open-loop drives based on various types of electric motors. The article presents the results of computer simulation of an open-loop drive operating according to the proposed algorithm, the advantages and disadvantages of this approach are noted.

ADAPTIVE OPEN-PLUS-CLOSED-LOOP CONTROL METHOD OF MODIFIED FUNCTION PROJECTIVE SYNCHRONIZATION IN COMPLEX NETWORKS

2011 ◽  
Vol 22 (12) ◽  
pp. 1393-1407 ◽  
Author(s):  
HONGYUE DU
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Open Loop ◽  
Projective Synchronization ◽  
Closed Loop Control ◽  
Loop Control ◽  
Function Projective Synchronization ◽  
Advantages And Disadvantages ◽  
Modified Function Projective Synchronization ◽  
Loop Feedback

This paper investigates the modified function projective synchronization (MFPS) in drive-response dynamical networks (DRDNs) with different nodes, which means that systems in nodes are strictly different. An adaptive open-plus-closed-loop (AOPCL) control method is proposed, which is a practically realizable method and can overcome the model mismatched to achieve synchronization. It is well known that each of the close-loop and open-loop control method possesses some advantages and disadvantages. By combining their advantages, the open-plus-closed-loop (OPCL) control method was proposed by Jackson and Grosu. For arbitrary nonlinear dynamic systems, dx/dt = F(x,t), Jackson and Grosu proved that there exists solutions, x(t), in the neighborhood of any arbitrary goal dynamics g(t) that are entrained to g(t), through the use of an additive controlling action, K(g,x,t) = H(dg/dt,g) + C(g,t)(g(t) - x), which is the sum of the open-loop action, H(dg/dt,g), and a suitable linear closed-loop (feedback) action C(g,t). This method is a practically realizable method and robust to limited accuracy of data and effects of noise. The AOPCL control method preserve the merits of OPCL control method and its closed loop control part can be automatically adapted to suitable constants. Considering time-delays are always unavoidably in the practical situations, MFPS in DRDNs with time-varying coupling delayed is further investigated by the proposed method. Corresponding numerical simulations are performed to verify and illustrate the analytical results.

Comparison of Dc-Dc SEPIC, CUK and Flyback Converters Based LED Drivers

2020 ◽  
pp. 99-107
Author(s):  
Erdal Sehirli
Keyword(s):  
Integrated Circuit ◽  
Closed Loop ◽  
Input Voltage ◽  
Open Loop ◽  
Current Sensor ◽  
Switching Frequency ◽  
Led Driver ◽  
Advantages And Disadvantages ◽  
Led Drivers ◽  
Conduction Mode

This paper presents the comparison of LED driver topologies that include SEPIC, CUK and FLYBACK DC-DC converters. Both topologies are designed for 8W power and operated in discontinuous conduction mode (DCM) with 88 kHz switching frequency. Furthermore, inductors of SEPIC and CUK converters are wounded as coupled. Applications are realized by using SG3524 integrated circuit for open loop and PIC16F877 microcontroller for closed loop. Besides, ACS712 current sensor used to limit maximum LED current for closed loop applications. Finally, SEPIC, CUK and FLYBACK DC-DC LED drivers are compared with respect to LED current, LED voltage, input voltage and current. Also, advantages and disadvantages of all topologies are concluded.

Orthogonal Eigenstructure Control for Vibration Suppression

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
Mohammad Rastgaar ◽  
Mehdi Ahmadian ◽  
Steve Southward
Keyword(s):  
Closed Loop ◽  
Vibration Suppression ◽  
Control Method ◽  
Null Space ◽  
Output Feedback Control ◽  
Open Loop ◽  
Unique Property ◽  
Gain Matrix ◽  
Coefficient Vector ◽  
Value Decomposition

Orthogonal eigenstructure control is a novel active control method for vibration suppression in multi-input multi-output linear systems. This method is based on finding an output feedback control gain matrix in such a way that the closed-loop eigenvectors are almost orthogonal to the open-loop ones. Singular value decomposition is used to find the matrix, which spans the null space of the closed-loop eigenvectors. This matrix has a unique property that has been used in this new method. This unique property, which has been proved here, can be used to regenerate the open-loop system by finding a coefficient vector, which leads to a zero gain matrix. Also several vectors, which are orthogonal to the open-loop eigenvectors, can be found simultaneously. The proposed method does not need any trial and error procedure and eliminates not only the need to specify any location or area for the closed-loop eigenvalues but also the requirements of defining the desired eigenvectors. This method determines a set of limited number of closed-loop systems. Also, the elimination of the extra constraints on the locations of the closed-loop poles prevents the excessive force in actuators.

DC/AC Converter Based on Buck Regulator

2013 ◽  
Vol 392 ◽  
pp. 435-438
Author(s):  
Rong Chen ◽  
Jia Sheng Zhang
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Open Loop ◽  
Control Effect ◽  
Integral Control ◽  
Line Frequency ◽  
Working Principle ◽  
Simulation Results ◽  
Proportional Integral Control ◽  
Differential Control

The introduction of DC/AC converter based on buck regulator is firstly shown, and the analysis of the converters working principle is taken. The control method applied for DC/AC converter based on buck regulator is studied also. The control effect of the open-loop proportional-differential control and closed-loop proportional-integral control are compared by using PSIM software. The parameters adopted in the realistic simulation, waveforms such as voltage of modulation reference and load were given. The simulation results proved that adopting the DC/AC converter could achieve a good performance and can gain a line frequency as 50Hz and the correctness of theoretical analysis.

Convergence of PD-Type Iterative Learning Control of Nonlinear Discrete Systems and its Robustness

2012 ◽  
Vol 557-559 ◽  
pp. 2049-2053
Author(s):  
Chang Liang Liu ◽  
Wan Gen Jia
Keyword(s):  
Iterative Learning Control ◽  
Closed Loop ◽  
Discrete Systems ◽  
Open Loop ◽  
Iterative Learning ◽  
System Operation ◽  
Advantages And Disadvantages ◽  
Output Error ◽  
The Status ◽  
Nonlinear Discrete Systems

Abstract: For the control problem of nonlinear discrete systems, this paper describes the status of current research and analyzes the advantages and disadvantages of open-loop and closed-loop iterative learning controller. A class of nonlinear discrete systems will be extended to the general nonlinear discrete systems. To the general nonlinear discrete systems, a open-closed-loop PD-type iterative learning controller which based on current and last output error instead of last output error only is proposed. It makes use of information on system operation more fully and accurately. Besides, based on norm of λ and mathematical induction, its sufficient condition for convergence is given. In order to test its robustness, a simulation is done in the case of a persistent interference. Simulation results show that it is efficient.

A New Close-Loop Control Method for an Inspection Robot Equipped with Electropermanent-Magnets

2016 ◽  
Vol 28 (2) ◽  
pp. 185-193 ◽  
Author(s):  
Pakpoom Kriengkomol ◽  
◽  
Kazuto Kamiyama ◽  
Masaru Kojima ◽  
Mitsuhiro Horade ◽  
...  
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Steel Structures ◽  
Open Loop ◽  
Closed Loop Control ◽  
Loop Control ◽  
Inspection Robot ◽  
Industrial Age ◽  
Set Up ◽  
Close Loop Control

[abstFig src='/00280002/09.jpg' width=""300"" text='ASTERISK use our proposed method to walk' ]Since the industrial age began, increasing numbers of manufacturing plants have been set up to serve economic growth demand. More bridges were built simultaneously to connect cities and to make transportation more convenient. As these facilities have aged, regular maintenance has increased. The limb mechanism project we started almost 20 years ago was to deliver new types of inspection and maintenance to industrial fields. Our first prototype, a six-limb robot called Asterisk, included such capabilities as walking on ceilings, climbing and descending stairs and ladders, walking tightropes, and transversing rough terrain. Asterisk's latest version uses electromagnets to work in antigravity environments such as steel structures. Unfortunately, this presented a major danger, requiring that we replace electromagnets with electropermanent magnets (EPMs). Limitations on EPMs, however, required a new control strategy. We propose and compare three control methods -- open-loop control, closed-loop control using torque feedback, and closed-loop control using angle feedback -- in the sections that follow. Our objective is to determine the best control for inspection robots having electropermanent magnets but not using additional sensors.

scholarly journals Multivariable Constrained Adaptive Predictive Control based on Closed-loop Subspace Identification

2020 ◽  
Vol 14 ◽  
Keyword(s):  
Predictive Control ◽  
Closed Loop ◽  
Control Method ◽  
Open Loop ◽  
System Model ◽  
Quadratic Program ◽  
Subspace Identification ◽  
Identification Algorithm ◽  
Prediction Errors ◽  
Adaptive Predictive Control

In order to deal with nonlinear, time-varying, and multivariable constrained characteristics in closed-loop industrial processes, a multivariable constrained adaptive predictive control (CAPC) method based on closed-loop subspace identification is proposed. The state-space model is obtained through the closed-loop subspace identification algorithm, which is regarded as the system model. The algorithm is implemented online to update the R matrix with a receding window. By comparing the prediction errors before and after updating, it considers whether or not to update the system model. The model is then used to design the model predictive controller, which involves the solution of a quadratic program solving multivariable constraints. This paper presents a comparison between the performance of the proposed control method when applied to a 2-CSTR system, and that of an open-loop subspace CAPC method. The superiority of the proposed method is illustrated by the simulation results.

scholarly journals A Wiener Model Based Closed Loop FES for Positional Control During Wrist Flexion

2021 ◽  
Vol 15 ◽  
pp. 829-835
Author(s):  
S. J., Mahendra ◽  
Vishwanath Talasila ◽  
Abhilash G. Dutt
Keyword(s):  
Healthy Volunteers ◽  
Closed Loop ◽  
Angular Position ◽  
Open Loop ◽  
Wiener Model ◽  
Wrist Flexion ◽  
Pulse Width Modulated ◽  
Nonlinear Pid Controller ◽  
Functional Movements ◽  
Positional Control

Functional electrical stimulation is an assistive technique used to produce functional movements in patients suffering from neurological impairments. However, existing open-loop clinical FES systems are not adequately equipped to compensate for the nonlinear, time-varying behaviour of the muscles. On the other hand, closed-loop FES systems can compensate for the aforementioned effects by regulating the stimulation to induce desired contractions. Therefore, this work aims to present an approach to implement a closed-loop FES system to enable angular positional control during wrist flexion. First, a Wiener model describing the response of the wrist flexor to pulse width modulated stimulation was identified for two healthy volunteers. Second, a nonlinear PID controller (subject-specific) was designed based on the identified models to enable angular positional control during wrist flexion. Subsequently, the controller was implemented in real-time and was tested against two reference angles on healthy volunteers. This study shows promise that the presented closed-loop FES approach can be implemented to control the angular position during wrist flexion or a novelty of the work when compared with the existing work.

Vibration Cancellation in a Plate Using Orthogonal Eigenstructure Control

2010 ◽  
Vol 77 (6) ◽  
Author(s):  
M. A. Rastgaar ◽  
M. Ahmadian ◽  
S. C. Southward
Keyword(s):  
Degrees Of Freedom ◽  
Closed Loop ◽  
Vibration Suppression ◽  
Control Method ◽  
Null Space ◽  
Flexible Structures ◽  
Element Model ◽  
Open Loop ◽  
Gain Matrix ◽  
Control Gain

Orthogonal eigenstructure control is a novel control method that can be used for vibration suppression in flexible structures. The method described in this study does not need defining the desired locations of the closed-loop poles or predetermining the closed-loop eigenvectors. The method, which is applicable to linear multi-input multi-output systems, determines an output feedback control gain matrix such that some of the closed-loop eigenvectors are orthogonal to the open-loop eigenvectors. Using this, the open-loop system’s eigenvectors as well as a group of orthogonal vectors are regenerated based on a matrix that spans the null space of the closed-loop eigenvectors. The gain matrix can be generated automatically; therefore, the method is neither a trial and error process nor an optimization of an index function. A finite element model of a plate is used to study the applicability of the method to systems with relatively large degrees of freedom. The example is also used to discuss the effect of operating eigenvalues on the process of orthogonal eigenstructure control. The importance of the operating eigenvalues and the criteria for selecting them for finding the closed-loop system are also investigated. It is shown that choosing the operating eigenvalues from the open-loop eigenvalues that are farthest from the origin results in convergence of the gain matrix for the admissible closed-loop systems. It is shown that the converged control gain matrix has diagonal elements that are two orders of magnitude larger than the off-diagonal elements, which implies a nearly decoupled control.

Control System Modeling for Automotive Brake Test-Bench Based on Discrete Closed-Loop and Phase-Locked Loop

2012 ◽  
Vol 433-440 ◽  
pp. 2184-2188
Author(s):  
Jia Xi Du ◽  
Hong Shen ◽  
Su Fang Fu ◽  
Xin Ning
Keyword(s):  
Control System ◽  
Closed Loop ◽  
Control Method ◽  
System Modeling ◽  
Phase Locked Loop ◽  
Current Time ◽  
Loop Control ◽  
Advantages And Disadvantages ◽  
Braking Torque ◽  
Instantaneous Speed

According to the law of rigid body around fixed axis rotation, established the mathematical model of motor drive current and instantaneous rotational speed. From the ideal situation of the simulation, according to the same discrete interval of time equal to the same increment of spindle angular velocity conditions, established the discrete closed-loop control system model. In allusion to the disadvantage of calculating corresponding braking current by the instantaneous speed and the instantaneous braking torque measured during the last interval, proposed the control method of calculating braking current by the instantaneous speed and the instantaneous braking torque measured all discrete intervals before current time. Discussed emphatically the computer controlled method based on the discrete closed-loop and phase-locked loop theory which can be used to design the braking current. Evaluated the advantages and disadvantages of the model, and proposed the improved direction.

Sign in / Sign up

Export Citation Format

Share Document