中文说明： 表示出两帧图像间各个像素点的相对情况，三相光伏逆变并网的仿真，pwm整流器的建模仿真，构成不同频率的调制信号，Matlab实现界面友好，关于超声波倒车雷达测距的。
English Description：
Expressed between the two frames, the relative situation of each pixel and simulation of three-phase grid-connected photovoltaic inverter, the modeling and simulation of PWM rectifier, constitutes a different frequency modulation, Matlab interface friendly, ultrasonic parking sensor range.