Abstract: A power usage control system includes a transmission medium for transmitting power. A management module is coupled to the transmission medium. A control module is coupled to the transmission medium and at least one controlled apparatus. The management module and the control module communicate with each other through the transmission medium. The management module monitors an operation status of the at least one controlled apparatus through the control module. The management module controls the at least one controlled apparatus through the control module.

Abstract: A method for estimating an operational parameter of a motor is to be implemented by an estimating device. In the method, the estimating device is configured to: receive an acoustic signal attributed to operation of the motor; process the acoustic signal to obtain a plurality of sample points in the frequency domain, each of which has a frequency and a corresponding amplitude; compute an estimated peak frequency using a centroid method based upon the frequencies and the amplitudes; from a plurality of peak frequencies and a plurality of known values of the operational parameter corresponding respectively to the peak frequencies, select a part of the peak frequencies approximate to the estimated peak frequency and a corresponding part of the known values of the operational parameter; and compute an estimated value of the operational parameter based upon the peak frequencies and the known values of the operational parameter.