输入输出延时对控制性能的影响分析

Impact of Input-Output Delay on Control Performance

为了分析控制任务实施过程中输入输出延时(简称延时)对控制性能的影响规律,建立采样延时控制模型;提出参数延时比用于反映延时大小与采样周期的相对关系;仿真分析了服从不同分布的随机延时及其抖动对控制性能的影响规律;结果表明,延时对不同的性能衡量指标影响规律不同:1)对于超调量,超调量随延时增大而增大;大采样周期控制系统对延时更敏感;抖动的存在增大超调量;2)对于代价指标IAE:各采样周期都存在一个延时的拐点,只有延时大于拐点值时,代价指标才迅速增加;小于拐点值的延时对代价指标的影响非常小,甚至可以忽略;仿真结果为控制任务实施的参数选择及减少延时对控制性能影响的努力方向提供参考。

In order to evaluate the impact of input--output （I/O） delay on control performance, a sampling control model with delay is established and a parameter named delay ratio is employed for describing the proportion of delay to sampling pe riod. Based on the control model, the simulation are carried out and the results demonstrate that： 1 ） For overshoot, the in crease of delay and its jitter gives rise to it, and a system with bigger sampling period is more sensitive to delay; 2） Cost indi ces of a system increase dramatically when delay is more than its inflection point, otherwise cost indices is small and change very little, even is negligible.