基于分形测度的软切换控制仿真研究

在一些工业过程控制中，由于控制对象系统的运行工况不可避免地经常偏离稳定工况，从而提高了对控制系统的要求。首先从实时性要求的角度，定性地分析了提高控制质量的几个重要因素。其次，基于对分形测度的分析，提出了以分形测度为切换指标的软切换控制，建立了基于工况辨识模型控制与过渡区间的PID控制相结合的控制系统，并实现控制的软切换。最后以余热锅炉汽包水位系统为例进行仿真，结果表明，采用分形测度作为切换指标可以及时地跟踪到系统的突变；基于此指标进行软切换控制策略可以在多扰动的工业过程克服过渡区振荡，提高了控制性能。

Simulation Research on Soft-Switch Control Algorithm Based on Fractal Dimension Measurement

For some complex industrial systems,the frequent deviation from the design operation point puts forward demand to improvement of control system.Based on the analyses of on-line fractal dimension measurement(FDM),a new soft-switch multi-model control algorithm(SSMMC) with fractal dimension measurement as switching index was proposed.With online FDM tracking abrupt-changing operation point,SSMMC used PID control to deal with the transition-region difficulty,and an soft-switch skill was introduced in detail.The simulation results show that FDM can track changing operation mode in time so as the real-time control is realizable,and SSMMC algorithm,compared with other algorithm,can decrease the vibration better in transition region so well as to improve the control performance effectively.