A Self-Adapted PID System Based on Intrinsic Evolvable Hardware
Wei Zhan, Yuanxiang Li · 2008
Abstract—Based on intrinsic analog evolvable hardware (EHW) technology, a self-adapted control strategy for hydro-turbine governing system (HGS) is proposed to improve the overall performance and adjust adaptively the parameters as the operating conditions change. Considering the complex dynamic characteristic and uncertainty of HGS, the controller implemented is evolved on ANEHP-Alpha, an analog intrinsic EHW platform based on AN231E04 field programmable analog array (FPAA) device, which is one of the latest models of the dpAsp series based on switched capacitor technology from Anadigm Corporation. A fast pre-evaluation and bad individual elimination method was employed which highly increased the speed of evolution and ensured the devices against damage induced by illegal individuals. Hereboy algorithm (HBA) is employed as the main evolutionary mechanism of this system. In the experiments, comparing with the conventional PID, the evolved controller performs well on inhibiting the effects caused by the external disturbance with higher self-adjusting speed, smaller overshoot and lower sensitivity to the parameters, which indicates that this strategy can effectively improve the robustness, stability and dynamic performance of the hydro-turbine governing systems. Index Terms—Evolvable hardware, Evolutionary algorithm, FPAA, Pre-evaluation