基于Dahlin算法的变风量空调自校正PID控制

Introduction of Self-Tuning PID Control Based on Dahlin Algorithm in VAV Air Conditioner

变风量空调具有时变、延时、非线性等特点,应用传统的PID控制算法难以取得最佳的控制效果;基于广义预测自校正的控制算法,控制精度高,具有较强的跟踪性能,但是以增大的计算量和频繁的调节系统参数为代价的。提出了一种基于改进的Dahlin参数整定方法的自校正PID控制器,该算法在理论建模的基础上,采用在线的带遗忘因子最小二乘法,实现传递函数的参数估计,建立了系统PID参数之间的关系式,实现变风量空调系统的末端控制。算法仿真运算及实验表明,与传统PID及广义预测自校正控制方法相比,该方法控制精高于传统PID,同时计算复杂度低于通常广义预测自校正控制。

Variable air volume air conditioner has the characteristics of time-changing, time delay and non-liner. It is difficult to achieve best control performances with adoption of traditional PID control algorithm. Control algorithm based on the generalized predictive control （GPC） algorithm owns high control accuracy and strong monitoring performance, along with increased calculation workload and frequent adjustment system as the investment. A self- tuning PID controller based on Dahlin criterion is presented. Based on the theoretical mode construction, the algorithm realizes the parameter estimation of transfer function, and constructs the relationship among the parameters for PID system, and realizes the end control of VAV air conditioning system with applying on-line least-squares method with forgetting factor. Compared to traditional PID and generalized predictive self-tuning control method, the simulation and test results prove that the control accuracy with new algorithm is better than that with traditional PID self-tuning control. Meanwhile the calculation complexity is less than that with generalized predictive self-tuning control.