An optimal control of Reverse Osmosis (RO) plant is studied in this paper utilizing the auto tuning concept in conjunction with PID controller. A control scheme composing an auto tuning stochastic technique based on an improved Genetic Algorithm (GA) is proposed. For better evaluation of the process in GA, objective function defined newly in sense of root mean square error has been used. Also in order to achieve better performance of GA, more pureness and longer period of random number generation in operation are sought. The main improvement is made by replacing the uniform distribution random number generator in conventional GA technique to newly designed hybrid random generator composed of Cauchy distribution and linear congruential generator, which provides independent and different random numbers at each individual steps in Genetic operation. The performance of newly proposed GA tuned controller is compared with those of conventional ones via simulation. Keywords—Genetic Algorithm, Auto tuning, Hybrid random number generator, Reverse Osmosis, PID controller.

Auto Tuning PID Controller based on Improved Genetic Algorithm for Reverse Osmosis Plant

This paper presents an efficient and fast tuning method based on a modified genetic algorithm (MGA) structure to find the optimal parameters of the proportional-integralderivative (PID) controller so that the desired system specifications are satisfied. To achieve more effective search, the optimization algorithm is based on the integration of classical genetic algorithm structure and a systematic neighbourhood structure. To demonstrate the effectiveness of presented method, the step responses of closed loop system were compared with that of the existing methods in the literature. Simulation results indicate that the performance of the PID controlled system can be significantly improved by the MGA-based method.

Determination of the PID Controller Parameters by Modified Genetic Algorithm for Improved Performance

In this paper, an optimization method of tuning decentralized PI/PID controllers based on genetic algorithms is presented. First, the existence of decentralized PI controllers with integrity is examined. Then, stable regions of each PI/PID controller parameters are calculated as the feasible area to be exploited, and the optimal PI/PID controllers are obtained by using a real-coded genetic algorithm with elitist strategy, to meet the design specifications for the whole control system. The proposed method is applied to six examples from literature. Simulation results demonstrate that the proposed decentralized PI control is compatible to the referenced method while the decentralized PID control is better than the referenced method, and the proposed method is feasible for more complicated control systems optimizations.

Optimization of decentralized pi/pid controllers based on genetic algorithm

The smart house under consideration is a service-integrated complex system to assist older persons and/or people with disabilities. The primary goal of the system is to achieve independent living by various robotic devices and systems. Such a system is treated as a human-in-the loop system in which humanrobot interaction takes place intensely and frequently. Ba sed on our experiences of having designed and implemented a smart house environment, called Intelligent Sweet Home (ISH), we present a framework of realizing human-friendly HRI (human-robot interaction) module with various effective techniques of computational intelligence. More specifically, we partiti on the robotic tasks of HRI module into three groups in consideration of the level of specificity, fuzzine ss or uncertainty of the context of the system, and present effective interaction method for each case. We fi rst show a task planning algorithm and its architecture to deal with well-structured tasks autonomously by a simplified set of commands of the user instead of inconvenient manual operations. To provide with capability of interacting in a human-friendly way in a fuzzy context, it is proposed that the robot should make use of human bio-signals as input of the HRI module as shown in a hand gesture recognition system, called a soft remote control system. Finally we discuss a probabilistic fuzzy rule-based life-l ong learning system, equipped with intention reading capability by learning human behavioral patterns, which is introduced as a solution in uncertain and time-varying situations.

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Intelligent Interaction For Human-Friendly Service Robot in Smart House Environment

Genetic fuzzy modelling and control of bispectral index (BIS) for general intravenous anaesthesia

In this paper, a simple genetic algorithm (GA) method has been applied in a real-time experiment on a liquid-level control system for online autotuning proportional-integral-derivative (PID) parameters. Our proposed method can automatically choose the best PID parameters for each generation. Then, using the reproduction, crossover and mutation to create the new population for other PID parameters, it can continuously control the liquid-level system until the preset iteration number is reached. Finally, the best PID parameters can be obtained. Furthermore, two selection methods, roulette wheel and tournament, have been compared in real-time experiments. Real-time experimental results are given to demonstrate the effectiveness and usefulness for online tuning PID parameters via this evolution process.

T. K. Teng

Papers

Genetic algorithms applied in online autotuning PID parameters of a liquid-level control system: