∑-Δ调制器的高阶滑模设计

Higher order sliding mode design for Sigma-Delta modulator

由于高阶滑模与传统滑模(一阶滑模)相比有更高的控制精度,把高阶滑模控制引入到∑-Δ调制器设计中来。在设计中,把高阶∑-Δ调制器看成一个带反馈的非线性动态系统,并把系统分成被控对象和控制器,然后应用高阶滑模进行控制设计。作为示例,用二阶滑模对三阶∑-Δ调制器进行了设计,仿真结果表明,基于高阶滑模控制设计的调制器信噪比高、量化误差小。

A high order sliding mode approach to design high order Sigma-Delta modulator is introduced because of the high order sliding mode has higher accuracy than the traditional one （one order sliding mode）. Under design, the higher order Sigma-Delta modulator is regarded as a nonlinear dynamic system with feedback control, and is further divided into an object controlled and controller. Then the controller is designed by using the higher order sliding mode method. As an example, a three-order Sigma-Delta demodulator with 2-sliding mode is designed, and the result demonstrates that the modulator design based on the high order sliding mode has the higher rate of signal-to-noise and smaller quantized noise.