基于脉宽调制(PWM)技术的控制系统广泛应用于工业和日常生活中,随机脉宽调制(RP-WM)技术也已提出.利用耦合到系统的环境噪声和系统本身的噪声经加工处理后调制控制信号,由噪声信号的自相关函数和功率谱密度函数给出噪声调制脉冲的平均开关频率和平均加热功率的计算方法.利用模拟器件设计了一个简单的基于噪声调制的薄膜电阻加热温度控制系统.实验表明:控制系统能够稳定地运行,在一定范围内能抑制噪声,实现了高精度温度控制.
Control systems based-on PWM are widely used in industry and dally life, with control systems based-on RPWM being occured. A computing method was presented in this paper, in which the control signal was modulated by processed random noise resulting from environment and systems. A computing method of the average switching frequency and the average heating power via the autocorrelation function and the power spectrum density function of the noise was proposed. A simple heating and temperature control system based on noise modulation using analog circuit was designed. The experimental results show that the control system can operate stably and perform high precise temperature control in a certain scope of temperature.