Method and apparatus for generating asymmetric high-voltage waveforms with near-rectangular profiles. The method comprises producing selected low-frequency components of the Fourier series for a rectangular waveform explicitly and adding them to the amplified residual of lower-amplitude near-rectangular waveform upon filtering out certain frequencies.

A device and method for detecting the number of revolutions of a sensorless electric park brake (EPB) motor. The device for detecting the number of revolutions of a sensorless motor includes: an actuator driving motor used to set and release a parking brake of an EPB system; an electronic control module for controlling the motor, a vehicle battery for supplying power to the motor and the electronic control module; and a main processing unit for receiving an output signal of the electronic control module and estimating the number of revolutions of the motor, wherein the electronic control module further includes a ripple measuring unit for receiving an output signal of the motor and measuring a ripple of the motor.

A power metering circuit includes a current input path for receiving an analog current input at a first analog to digital converter; a voltage input path for receiving an analog voltage input at a second analog to digital converter; a multiplier configured to multiply an output of the current input path and the voltage input path; a notch filter configured to receive an output of the multiplier, the notch filter having a stop band based on a line frequency; and a control circuit for setting a sampling frequency of the first analog to digital converter and the second analog to digital converter to a multiple of the line frequency.

A power metering circuit includes a current input path for receiving an analog current input at a first analog to digital converter; a voltage input path for receiving an analog voltage input at a second analog to digital converter; a multiplier configured to multiply an output of the current input path and the voltage input path; a notch filter configured to receive an output of the multiplier, the notch filter having a stop band based on a line frequency; and a control circuit for setting a sampling frequency of the first analog to digital converter and the second analog to digital converter to a multiple of the line frequency.

A distance detection device and a distance detection method thereof are provided. A second time at which a packet amplitude peak of a preset sound signal is received by a sound receiver is estimated according to a time difference between the preset sound signal and a low pass filter signal thereof. A distance between a speaker and the sound receiver is calculated according to the second time.

A distance detection device and a distance detection method thereof are provided. A second time at which a packet amplitude peak of a preset sound signal is received by a sound receiver is estimated according to a time difference between the preset sound signal and a low pass filter signal thereof. A distance between a speaker and the sound receiver is calculated according to the second time.

Methods, devices, and systems for coherent time-gated residual spur characterization and correction in signal analyzers. In some cases, the method includes: displaying a signal on the display of the signal analyzer that is present without an input signal being provided to an input of the signal analyzer; establishing a predetermined amplitude threshold above which energy spikes in the signal being displayed on the display of the signal analyzer are considered spurious; automatically identifying one or more spurious energy spikes in the signal being displayed on the display of the signal analyzer based on the predetermined amplitude threshold; and automatically reducing or removing the one or more spurious energy spikes from the signal being displayed on the display of the signal analyzer. The method can be performed using one or more processors, application specific integrated circuits (ASICs), field-programmable gate array (FPGA), or other circuitry on any suitable signal analyzer.

Methods, devices, and systems for coherent time-gated residual spur characterization and correction in signal analyzers. In some cases, the method includes: displaying a signal on the display of the signal analyzer that is present without an input signal being provided to an input of the signal analyzer; establishing a predetermined amplitude threshold above which energy spikes in the signal being displayed on the display of the signal analyzer are considered spurious; automatically identifying one or more spurious energy spikes in the signal being displayed on the display of the signal analyzer based on the predetermined amplitude threshold; and automatically reducing or removing the one or more spurious energy spikes from the signal being displayed on the display of the signal analyzer. The method can be performed using one or more processors, application specific integrated circuits (ASICs), field-programmable gate array (FPGA), or other circuitry on any suitable signal analyzer.

A method and system for enabling the determination of a position of a receiver within a space includes transmitting a beacon signal from each of a plurality of beacon devices located at different locations within the space. The beacon signal transmitted from each beacon device has a unique information component and may have a unique frequency pattern of multiple frequencies. Each beacon signal can be distinguishable from the beacon signals transmitted from any other of the beacon devices based on the combination of its unique information component and its unique frequency pattern. The beacon signals are received at a receiver. At the receiver, for each beacon signal of a working subset, time-delay information of the received beacon signal is determined and multilateration is applied to determine the position of the receiver based on the location of each beacon device of the working subset.

A method and system for enabling the determination of a position of a receiver within a space includes transmitting a beacon signal from each of a plurality of beacon devices located at different locations within the space. The beacon signal transmitted from each beacon device has a unique information component and may have a unique frequency pattern of multiple frequencies. Each beacon signal can be distinguishable from the beacon signals transmitted from any other of the beacon devices based on the combination of its unique information component and its unique frequency pattern. The beacon signals are received at a receiver. At the receiver, for each beacon signal of a working subset, time-delay information of the received beacon signal is determined and multilateration is applied to determine the position of the receiver based on the location of each beacon device of the working subset.