The Research And Development Of Constant-pressure Water Supply Controller In High Building Based On ARM

In recent years, with the urbanization of Chinese progress, the demand for urban housing surges in momentum year after year, a continuous expansion and transformation of the residential areas is followed. Going with the building ever-increasing floors, the old water pipe network is difficult to maintain the water pressure to satisfy the residents, so the difficulty of water using for the urban residents becomes more and more prominent. It brings great inconvenience to residents. For that reason, how to invent a safe, reliable and high quality controller is a key issue for the engineers, which can supply constant water pressure to ensure the demand of high-rise buildings. In this paper, the writer incorporates frequency control technology which is reliable and has good energy conservation into the water supply system to develop the controller.In the paper, the writer has investigated the background of constant pressure water supply systems for the high-rise building, also the domestic and international research status of constant pressure water supply system, as well as some popular frequency conversion constant pressure water supply control systems on the market. Then, the overall plan is established by the general frequency converters with PID control. The control circuit is designed as an independent part for the controller in the use of LM3S1138, and it is fixed outside the converter, making it has the function of self-tuning PID parameters. At the same time, the main controller module is designed including the I/O modules, LCD module, keyboard input module, E2PROM module, calendar module, and communication module. Moreover, the key processing and displaying sub-routine are programmed for the system. Then the controller model has been developed successfully. Otherwise, a reliable and anti-interference technology is put forward to improve the system stability effectively.The writer has worked out the fuzzy self-tuning PID subroutine based on ARM in the use of C language. By calling the subroutine, the controller completes the right pressure deviation computation. The water supply system is a complex system with detention. Every part has nonlinearity and time-variability. The variable quantities are cross-coupling. It is difficult to determine the precise mathematical model. A method combining with fuzzy control and PID control is given to supply the constant pressure water, so that both the dynamic response and steady-state response can give complement to each other, and then according to the requirements of water supply system and the objective function. The parameters of the PID controller are adjusted to achieve the best control effect. The author utilizes MATLAB to simulate the improved PID self-tuning PID control algorithm, and the simulation result illustrates the effect of PID self-tuning. Simulation results illustrate that when using the combination of the fuzzy control and PID control. There is no overshoot in system response, the system set-up time is short, and it is a highly robust controller with anti-interference ability. Finally, the function of the controller is improved in advance by testing the controller model in order to satisfy the command of user.