Abstract: An electric powered vehicle includes a traction motor powered from a source of switched DC power. The motor includes a tachometer for measuring the rotational velocity of the motor and for providing a tachometer signal indicative thereof. A low pass filter low pass filters the tachometer signal and produces a reference tachometer signal. A summing circuit combines the tachometer signal and the reference tachometer signal to produce a deviation signal. The deviation signal is provided to a signal processing circuit which includes a comparator and a reference value generator. The comparator compares the output of the summing circuit to a reference value provided by the reference value generator and produces a binary changing signal as a function of the comparison.

Abstract: A vehicle initialization system for a control system that includes a vehicle, such as a train that is to be initialized, a vehicle track, a first reader, an onboard computer and a tachometer. The vehicle is adapted to coact with the track. At least two spaced apart position identifiers are positioned along the track. The first reader attaches to the vehicle and is adapted to read information from the position identifiers and relay the information to the onboard computer. The tachometer is also interfaced with the onboard computer, so that as the vehicle passes the position identifiers, the tachometer can be calibrated and the vehicle direction of travel and the vehicle orientation can be determined. The system also includes a vehicle identifier adapted to identify the vehicle characteristics. A second reader is positioned along the track and is adapted to read the vehicle identifier as the vehicle travels along the track. A wayside computer interfaces with the second reader.

Abstract: An electric power vehicle includes a propulsion system connected to a direct current (DC) source via a supply line. The propulsion system converts the DC supplied via the supply line to an AC electrical power to operate an AC motor at a desired level. An electromagnetic interference detection system for the vehicle includes an EMI processor connected to a current transducer and the propulsion system. The transducer detects AC signals appearing on the supply line and provides an output to the EMI processor. The EMI processor determines the frequency, amplitude and duration of the detected AC signals and causes the propulsion system to adjust the AC electrical power supplied to the motor as a function thereof.

Abstract: A method and apparatus for communicating over a track circuit which includes an interference signal. The invention includes sampling the interference signal on the track circuit at a predetermined sampling frequency to produce a sampled interference signal, detecting interference at a predetermined first sub-carrier frequency based on a fast Fourier transform of the sampled interference signal, forming a vector signal corresponding to a predetermined second sub-carrier frequency related to the predetermined sampling frequency and different from the predetermined first sub-carrier frequency, performing an inverse fast Fourier transformation on the vector signal to form a series communication signal, coupling the series communication signal to the track circuit, sampling the series communication signal on the track circuit at the predetermined sampling frequency from a sampled communications signal, and recovering the vector signal based on a fast Fourier transform of the sampled communication signal.