Weak current College】 【optimal control strategies for water supply pumping station.

<br> <br> 【Summary】 article Overview of the main method of motion control, and the characteristics of the water supply system, the control of the water supply pumping station the best selection of control strategies. <br> <br> I .. preface <br> <br> With the increasing degree of automation and motion control system can be used to be very difficult to achieve complex algorithms that control performance has been greatly improved. Motion control system controller intelligently, to address those who use traditional methods .to address the complex system of control provides a valid theory and methods. Motion control methods are more mature are: PID control algorithm, neural network, fuzzy control, expert system, intelligent control, etc. <br> <br> Second, the primary .method for motion control <br> <br> 1.PID control. PID control is the earliest developed and applied fields still extensive control methods, it is based on the object model method that applies in particular to establish precise mathematical model of deterministic control systems .. But for non-linear, time-varying systems of uncertainty, it is difficult to use conventional PID controller achieves the ideal control effect. Moreover, in actual production, since the subject parameter tuning methods for complex, General of PID parameters often setting objectionable ., performing well. <br> <br> 2. control of artificial neural networks. Artificial neural network originated in the 1940s, which in some ways reflect the basic characteristics of the human brain, but it is not a true depiction of the human brain ., but only its abstract, simplify, and simulation, network of information processed by neuronal interactions. Neural network control key to select a suitable neural network models, training and learning requirements, until, that is, looking for the best neural network structure and weights .. However, neural network learning, requires some experimental samples of these experimental samples must also be from the known experience and prior to the experiment. At the same time, the neural network training and learning process, sometimes a more complex, the need to run .thousands of times to get the best structure. Sometimes get a partial solution, not the global optimal solutions, because of the limitations of the method, similarly to the object under discussion to achieve effective control. <br> <br> 3. fuzzy control .. Practical engineering, a highly skilled operator, by virtue of their own rich experience, through on-site phenomena in the judgement a satisfactory control effect. If you experience on measures taken into the corresponding control rules, and the development of a controller instead of .these rules, may also be implemented on the control of complex industrial processes. Practice has proved that to fuzzy control theory-based fuzzy controller (FC) to accomplish this task. <br> <br> Fuzzy control is based on fuzzy reasoning and imitate .human thinking method, the mathematical model for difficult to establish the object implementation of a control. It is used in Fuzzy mathematics characterizations of fuzzy sets and fuzzy language the production rules, that is, "If the conditions set up execution" statement in their realization .. Application of fuzzy control technology in the country has achieved remarkable results. <br> <br> 4. expert control. Intelligent control expert control is an important part in the expert system theory and control theory of technology and the theory and methods on the .basis of the combination, in an unknown environment imitating expert intelligence to achieve effective control of the system. Expert control of core is the expert system, it has to deal with a variety of non-structural problems, especially with qualitative, heuristic, or uncertainty .of knowledge and information, through various reasoning process reach system control objectives. <br> <br> 5. intelligent control. HSIC (HSIC) after 20 years of effort, has formed a basic theory of the system and a system design methods and a .lot of success in the actual application. The main content of which is summed up the experience of human control, simulate human thought and behavior of the control to production rule describes its control heuristic and intuitive reasoning. <br> <br> Because of the .fundamental characteristics of the HSIC is to imitate the behavior of the control control experts, so its control algorithm was multi-mode control is in multiple mode control used interchangeably between. The algorithm can be perfectly coordinated control system many contradictory control quality requirements. For example ., robustness and precision, speed and smoothness. <br> <br> 3. water supply pumping station features and control requirements <br> <br> In the city's development process, the smart building has become the pursuit of good living conditions of a .standard water supply pumping station is indispensable to intelligent building group field, select the pump control, not only reduces construction costs, but also can save energy. <br> <br> 1. water supply system characteristics. For a specific object, user water .most prominent feature is random and which users of water, how much water, when water used and so on, are of great uncertainty. From a broad perspective, the water supply system characteristics mainly in the following areas: <br> <br> ( .1) system parameters of unknown nature, time consistency, randomness and dispersion; <br> <br> (2) system lag of unknown and when denatured; <br> <br> (3) non-linear system seriously; <br> .<br> (4) the system variables of relevance; <br> <br> (5) environmental interference of unknown nature, diversity and randomness. <br> <br> 2. problems in the control. The above properties, belonging to .the uncertainty of complex objects (or process) of control issues, traditional control already powerless, the main problems: <br> <br> (1) uncertainty. Water supply systems in many control problem with uncertainty, using a traditional approach to modeling and ., consequently, to achieve effective control. <br> <br> (2) highly nonlinear. In the water supply system, there is a wide range of nonlinear problems exist, the traditional control theory, nonlinear theory is far better than linear theory of .mature, complex and difficult to approach too. <br> <br> (3) a semi-structured and unstructured problem. Traditional control theory cannot resolve the water supply systemSemi-structured and unstructured problem. <br> <br> (4) .water supply system complexity. Complex systems and complex relationships between various subsystems, each main factor of mutual coupling between height, constraints, the external environment is extremely complex, traditional control the lack of effective solutions. <br> <br> (5) reliability .problems. Conventional control based on mathematical model of a problem orientation so interdependent whole, simple system of control reliability issues are not pronounced. While on the water supply system, if you used the above method, (continued on page 18) (continued from page .16) may be due to a change in the condition that the entire control system to crash. <br> <br> Thus, using traditional methods cannot on such systems are effective control, it is necessary to explore more effective control methods. <br .> <br> 3. control requirements. Regardless of what kind of control methods, to meet the water needs (ie a certain pressure), protection of the environment is not affected by noise pollution, in addition to consider energy efficiency. Therefore, the .control requirements can determine to meet user demands for water, to minimize the environmental pollution and save energy. <br> <br> IV. selection of control strategies <br> <br> Control strategy selection and charged object properties is closely related to error .or improper control strategy often results in poor control of, or even cause a system out of control. <br> <br> At present, in the modern water supply pumping stations for energy saving are generally adopts frequency converter, to improve the control quality .to create good conditions. <br> <br> Inverter in general have PID control module, but on the uncertainty of the water complex system, with a PID algorithm is not appropriate. <br> <br> Artificial neural networks, due to the .limitations of methods, are also difficult to object under discussion to achieve effective control. <br> <br> Expert control system (ECS), due to the characteristics of the information collection, the expression of the characteristic information as well as a complete knowledge .base for implementation difficulty, using expert control system also is not necessarily - a good choice. <br> <br> To fuzzy control theory-based fuzzy controller (FC) can be realized on the control of complex industrial processes. The quality and effectiveness .of their control or satisfactory, is an alternative strategy. <br> <br> HSIC, experts using HISC and FC control strategies on uncertainty complex object (or process) for simulation, although both are based on the error and the error rate to calculate .the amount of control, but the system complex and uncertain factors, Association of Chief intense (strong interaction), the field-trial comparison, HISC and FC can implement effective control, the control of the quality and robustness of the former better, HSIC complete .uncertainty water supply system of control, is a sensible choice. <br> <br> 5. concluding remarks <br> <br> Smart control has been widely used in industry, agriculture, military, etc, has solved a lot of traditional control .will not solve the problem of actual control application, showing a strong vitality and development prospects, with basic theoretical research and practical application of intelligent control will implement control a big leap. <br> <br>.