自适应Dahlin数字控制器

• 作 者: 李清泉
• 机 构: 清华大学
• 出 处: 信息与控制
• 发表日期: 1988年02期
• 关键词: 数字控制器 Dahlin 自适应 受控对象 采样周期 离散时间系统 计算机控制 控制器输出 传递函数 不稳定系统

Dahlin 算法是一种设计数字控制器的直接综合方法。对于有纯滞后的一阶和二阶受控对象,采用这种算法比常规PID 数字控制器效果为好,因而获得应用。但是这种方法只能用于已知的定常时滞工业对象,要求事先确知时滞,而且时滞严格等于采样周期的整数倍。如果实际系统的时滞与设计参数不匹配,系统品质会迅速恶化。然而时滞未知或时变的现象在工业对象中十分普遍,进而要使实际对象的时滞精确等于采样周期的整数倍十分困难。这时会出现传输延迟,其对应的离散时间系统往往是逆不稳定的,从而使常规的Dahlin 数字控制器失效,这就大大地限制了它的应用范围。

The Dahlin algorithm is a direct, integrated approach to designing digital controllers. For the first-order and second-order controlled objects with pure hysteresis, this algorithm is better than the conventional PID digital controller, and thus obtained the application. However, this method can only be used for known fixed-delay industrial objects, requiring time-delay to be known in advance, and the time-delay is strictly equal to an integer multiple of the sampling period. If the actual system skew does not match the design parameters, the quality of the system deteriorates rapidly. However, the phenomenon of unknown or time-varying delay is very common in industrial objects and it is very difficult to make the actual object time delay exactly equal to the integral multiple of the sampling period. At this point there will be transmission delays, the corresponding discrete-time system is often inverse instability, so that the conventional Dahlin digital controller failure, which greatly limits its scope of application.