Bi-Level Adaptive Computed-Current Impedance Controller for Electrically Driven Robots

Robotica ◽  
2020 ◽  
pp. 1-17
Author(s):  
Mohsen Jalaeian-F. ◽  
Mohammad Mehdi Fateh ◽  
Morteza Rahimiyan
Keyword(s):  
Optimization Problem ◽  
Electromechanical System ◽  
Rehabilitation Robot ◽  
External Disturbances ◽  
Mechanical Parts ◽  
Optimal Tuning ◽  
Guaranteed Stability ◽  
Electrically Driven Robots

SUMMARY This paper presents a bi-level adaptive computed-current impedance controller for electrically driven robots. This study aims to reduce calculation complexities by utilizing the electrical equations of actuators, instead of the entire model of the electromechanical system. Moreover, taking the dynamical effects of mechanical parts into account through the current’s feedback, external disturbances are compensated. In order to handle uncertainties, a bi-level optimization problem is formulated to obtain guaranteed stability besides the estimation convergence. An adaptation rule and its optimal tuning gain are achieved. The proposed method is applied to control of a rehabilitation robot to evaluate its performance.

Fractional order based trajectory tracking control of an ankle rehabilitation robot

2016 ◽  
Vol 40 (2) ◽  
pp. 550-564 ◽  
Author(s):  
Mustafa Sinasi Ayas ◽  
Ismail Hakki Altas ◽  
Erdinc Sahin
Keyword(s):  
Fractional Order ◽  
Trajectory Tracking ◽  
Human Robot Interaction ◽  
Rehabilitation Robot ◽  
Proportional Integral Derivative ◽  
External Disturbances ◽  
Proportional Integral Derivative Controller ◽  
Proportional Integral ◽  
Rehabilitation Robots ◽  
Ankle Rehabilitation

Human–robot interaction is inherently available and used actively in ankle rehabilitation robots. This interaction causes disturbances to be counteracted on the rehabilitation robots in order to reduce the side effects. This paper presents a fractional order proportional–integral–derivative controller to improve the trajectory tracking ability of a developed 2-degree of freedom parallel ankle rehabilitation robot subject to external disturbances. The parameters of the controller are optimally tuned by using both the cuckoo search algorithm and the particle swarm optimization algorithm. A traditional proportional–integral–derivative controller, which is also tuned using both of the algorithms, is designed to test the performance of the fractional order proportional–integral–derivative controller. The experimental results show that the optimally tuned FOPID controller improves the tracking performance of the ankle rehabilitation robot subject to external disturbances significantly and decreases the steady-state tracking errors compared to the optimally tuned PID controller.

SOSPD Controllers Tuning by Means of an Evolutionary Algorithm

2014 ◽  
Vol 4 (2) ◽  
pp. 40-58 ◽  
Author(s):  
Jesús-Antonio Hernández-Riveros ◽  
Jorge-Humberto Urrea-Quintero
Keyword(s):  
Evolutionary Algorithm ◽  
Optimization Problem ◽  
Heuristic Algorithms ◽  
Operating Mode ◽  
Performance Criterion ◽  
Order System ◽  
Optimal Tuning ◽  
Current Trends ◽  
Controlling Processes ◽  
Better Than

The Proportional Integral Derivative (PID) controller is the most widely used industrial device to monitoring and controlling processes. There are numerous methods for estimating the controller parameters, in general, resolving particular cases. Current trends in parameter estimation minimize an integral performance criterion. Therefore, the calculation of the controller parameters is proposed as an optimization problem. Although there are alternatives to the traditional rules of tuning, there is not yet a study showing that the use of heuristic algorithms it is indeed better than using the classic methods of optimal tuning. In this paper, the evolutionary algorithm MAGO is used as a tool to optimize the controller parameters. The procedure is applied to a range of standard plants modeled as a Second Order System plus Time Delay. Better results than traditional methods of optimal tuning, regardless of the operating mode of the controller, are yielded.

Polynomial-Based Robust Adaptive Impedance Control of Electrically Driven Robots

Robotica ◽  
2020 ◽  
pp. 1-21
Author(s):  
Alireza Izadbakhsh ◽  
Saeed Khorashadizadeh
Keyword(s):  
Approximation Theorem ◽  
Impedance Control ◽  
Successful Implementation ◽  
External Disturbances ◽  
Polynomial Coefficients ◽  
Adaptive Law ◽  
Electrically Driven Robots ◽  
Robust Adaptive ◽  
The Stability ◽  
Two Degree Of Freedom

SUMMARY This paper presents a robust adaptive impedance controller for electrically driven robots using polynomials of degree N as a universal approximator. According to the universal approximation theorem, polynomials of degree N can approximate uncertainties including un-modeled dynamics and external disturbances. This fact is completely discussed and proved in this paper. The polynomial coefficients are estimated based on the adaptive law calculated in the stability analysis. A performance evaluation has been carried out to verify satisfactory performance of the controller. Simulation results on a two degree of freedom manipulator have been presented to guarantee its successful implementation.

Metaheuristic Tuning and Practical Implementation of a PID Controller Employing Genetic Algorithms

2019 ◽  
Author(s):  
Luis Angel ◽  
Jairo Viola ◽  
Mauro Vega
Keyword(s):  
Genetic Algorithm ◽  
Genetic Algorithms ◽  
Multiobjective Optimization ◽  
Pid Controller ◽  
Optimization Problem ◽  
Settling Time ◽  
Practical Implementation ◽  
Multiobjective Optimization Problem ◽  
External Disturbances ◽  
Generator System

Abstract PID controllers tuning is a complex task from the optimization perspective because it is a multiobjective optimization problem, which must ensure the accomplishment of a set of desired operating conditions of the closed-loop system as the overshoot, the settling time, and the steady state error. Employing metaheuristic optimization techniques is possible to find optimal solutions for the PID tuning multiobjective optimization problem with less computational cost. This paper presents the using of genetic algorithms as metaheuristic optimization technique for the tuning of a PID controller employed for the speed control of a motor-generator system. The genetic algorithm is designed to find the PID controller proportional, integral, and derivate terms that ensure the desired overshoot and settling time of the motor-generator system. The practical implementation of the PID controller is performed with a data acquisition card and the Matlab Stateflow toolbox. The proposed controller is contrasted with a PID controller tuned by the Internal Model Control technique. A robustness analysis is performed to evaluate the system response in the presence of the external disturbances. Obtained results shown that the PID controller tuned by genetic algorithm has a better response in the presence of external disturbances.

scholarly journals Robust Estimation of the Unbalance of Rotor Systems Based on Sparsity Control of the Residual Model

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Tingpeng Zang ◽  
Guangrui Wen ◽  
Zhifen Zhang
Keyword(s):  
Optimization Problem ◽  
Signal Reconstruction ◽  
External Disturbance ◽  
Reconstruction Algorithm ◽  
Working Environment ◽  
External Disturbances ◽  
Convex Optimization Problem ◽  
Rotor Systems ◽  
Vibration Data ◽  
The Impact

The vibration signals of rotating machinery are frequently disturbed by background noise and external disturbances because of the equipment’s particular working environment. Thus, robustness has become one of the most important problems in identifying the unbalance of rotor systems. Based on the observation that external disturbance of the unbalance response often displays sparsity compared with measured vibration data, we present a new robust method for identifying the unbalance of rotor systems based on model residual sparsity control. The residual model is composed of two parts: one part takes regular measurements of noise, while the other part evaluates the impact of external disturbances. With the help of the sparsity of external disturbances, the unbalance identification is converted into a convex optimization problem and solved by a sparse signal reconstruction algorithm. Experiment results have shown that the proposed method is robust and effective in identifying the unbalance of rotor systems in a complex environment, improving the precision of unbalance estimation and simplifying the balancing process.

scholarly journals Synthesis of management stabilizing operation modes of thermodynamic system

2019 ◽  
Vol 2019 (3) ◽  
pp. 43-48
Author(s):  
Виктор Лапшин ◽  
Viktor Lapshin ◽  
Илья Туркин ◽  
Ilya Turkin ◽  
Алексей Закалюжный ◽  
...  
Keyword(s):  
Control System ◽  
Thermodynamic System ◽  
Electromechanical System ◽  
Operating Speed ◽  
External Disturbances ◽  
Operating Modes ◽  
Peltier Module ◽  
System Optimal ◽  
Special Case ◽  
Principle Of Maximum

A special case of synthesis of en electromechanical control system by a method of maximum is considered. As a basis there is chosen a problem of synthesis of the electromechanical system optimal in an operating speed to stabilize operating modes of the thermodynamic system on the basis of Peltier module as a thermo-converter. It is shown that the synthesis of the control system on the basis of the principle of maximum allows optimizing a reaction of the thermodynamic system to external disturbances.

scholarly journals Sliding Mode Control with Minimization of the Regulation Time in the Presence of Control Signal and Velocity Constraints

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2887
Author(s):  
Mateusz Pietrala ◽  
Piotr Leśniewski ◽  
Andrzej Bartoszewicz
Keyword(s):  
Sliding Mode ◽  
Control Signal ◽  
Representative Point ◽  
Time Varying ◽  
Signal System ◽  
External Disturbances ◽  
Mechanical Parts ◽  
Switching Curve ◽  
Wide Range ◽  
Velocity Constraints

In this paper, the design of the terminal continuous-time sliding mode controller is presented. The influence of the external disturbances is considered. The robustness for the whole regulation process is obtained by adapting the time-varying sliding line. The representative point converges to the demand state in finite time due to the selected shape of the nonlinear switching curve. Absolute values of control signal, system velocity and both of these quantities are bounded from above and considered as system constraints. In order to evaluate the dynamical performance of the system, the settling time is selected as a quality index and it is minimized. The approach presented in this paper is particularly suited for systems in which one state (or a set of states) is the derivative of the other state (or a set of states). This makes it applicable to a wide range of electromechanical systems, in which the states are the position and velocity of the mechanical parts.

Exergy and sensibility analysis of each individual effect in a kraft multiple effect evaporator

TAPPI Journal ◽  
2019 ◽  
Vol 18 (10) ◽  
pp. 607-618
Author(s):  
JÉSSICA MOREIRA ◽  
BRUNO LACERDA DE OLIVEIRA CAMPOS ◽  
ESLY FERREIRA DA COSTA JUNIOR ◽  
ANDRÉA OLIVEIRA SOUZA DA COSTA
Keyword(s):  
Optimization Problem ◽  
Real Data ◽  
Kraft Pulping ◽  
Steam Temperature ◽  
Input Flow ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Multiple Effect ◽  
Sensibility Analysis ◽  
Exergetic Analysis

The multiple effect evaporator (MEE) is an energy intensive step in the kraft pulping process. The exergetic analysis can be useful for locating irreversibilities in the process and pointing out which equipment is less efficient, and it could also be the object of optimization studies. In the present work, each evaporator of a real kraft system has been individually described using mass balance and thermodynamics principles (the first and the second laws). Real data from a kraft MEE were collected from a Brazilian plant and were used for the estimation of heat transfer coefficients in a nonlinear optimization problem, as well as for the validation of the model. An exergetic analysis was made for each effect individually, which resulted in effects 1A and 1B being the least efficient, and therefore having the greatest potential for improvement. A sensibility analysis was also performed, showing that steam temperature and liquor input flow rate are sensible parameters.

EDUCATIONAL HARDWARE AND SOFTWARE LAYOUT FOR TWO-MASS ELECTROMECHANICAL SYSTEM RESEARCH

2015 ◽  
Vol 20 (96) ◽  
pp. 15-21
Author(s):  
Victor V. Busher ◽  
◽  
Elena V. Naydenko ◽  
Keyword(s):  
Electromechanical System ◽  
System Research
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