Design Of Active Disturbance Rejection Controller Based On Microcontroller AVR

Currently, the core control algorithm of control instruments for industrial mostly uses the PID algorithm. PID controller is simple and suitable for the deterministic system which can establish precise mathematical model. However, the real industrial plant often has nonlinear and uncertainties and other characteristics, so it is difficult to establish its precisely mathematical model.At this time still using the PID controller is difficult to meet the control requirements. Active Disturbance Rejection Controller (ADRC) is proposed by Han Jinqing researcher who devoted to improve the PID controller. It inherits the essence of the traditional PID controller idea (based on error to eliminate the error), and weakens the contradiction between system response speed and overshoot, no integral part of achieving a static error can be achieved. For years rapid development of ADRC increase its wide range of applications.In this paper, a control instruments based on the ADRC is designed. It uses the ATmega128 of AVR microcontroller family as the main control chip, and 8-bit LED displays the measurement and setpoint values. At the same time, it can collect and outputs 4～20mA,0～10V analog signals and so on. The keys on the controller used to set and modify parameters of the algorithm. The experiment on FESTO level object is using the controller to control water level.And the controller is stable, and show good control quality.Paper first introduces the topic of the research background, significance and contents. Secondly, this paper introduces the whole process of hardware design and software design in detaile, and gives the specific hardware circuit of each function of the controller module. In software design, the paper briefly describes the program design process, and details of the disturbance rejection control algorithm subroutine. Finally, hardware and software reliability measures used in the controller were expounded.Through software and hardware debugging and the actual operation of the system verify the stable operation of the controller and achieve ideal water level control by the object of FESTO.