Arm-based Portable Pid Parameters Self Tuning,

The PID control is the most common control algorithm.95% above control loop has the PID structure in the commercial run control. The main characteristic of the PID control is the simple structure, the good stability, the reliable work and the convenient adjustment. Therefore, as one kind of widespread control rule, the PID control has not been eliminated in quite long period of time, because of each kind of advanced control algorithm appearance. On the contrary, the PID control still was occupying the dominant position in each kind of control technology.In the practical application, is the PID controller's parameter fit or not, determines the PID controller obtain the good closed-loop control effect or not. Until now, each advanced PID parameter installation method emerges one after another incessantly, has brought the vigor and the turning point for the PID controller parameter installation research.The classic Ziegler-Nichols engineering tuning method is introduced in this chapter. By experiential formula, the method can get PID parameters. In the formula, the characteristic parameters K_c and T_c is obtained by identification of relay feedback. Twoself-tuning methods of PID control are designed based on the SOPDT, which are direct synthesis method and stable abundant method.This article has designed one kind of portable PID parameter self-tuning instrument, based on the installation method above.In the hardware, the master control chip in the instrument is LPC2138. The LPC2138 microcontroller is based on a 132 bit ARM7TDMI-S? CPU which has high performance and low power consumption and cost. It has 512 KB of embedded high speed Flash memory, 32 KB of on-chip static RAM, two 8 channel 10-bit A/D converters, single 10-bit D/A converter, single 3.3V power supply. So it can satisfy the request to the memory, RAM, power cost very well. The instrument expanded 128x64 LCD and 1x4 keyboard to implement...