System and method for determining true ground speed in a locomotive

摘要

A processor system and method for accurately determining true ground speed in a vehicle having wheel-axles propelled by traction motors is provided. The vehicle is equipped with a radar unit for providing a radar signal indicative of vehicle speed relative to the ground. The radar signal is accurate when averaged over a sufficiently long period of time but may be susceptible to undesirable short term variations. The vehicle is further equipped with speed sensors coupled to the wheel-axles to supply respective wheel-axle speed signals. The respective wheel-axle speed signals may be accurate over a sufficiently short period of time but may also be susceptible to undesirable long term variations. The processor system is made up of a first subprocessor coupled to process the respective wheel-axle speed signals to supply a wheel-axle speed signal limited to a rate within a range that varies based on predetermined operational parameters of the vehicle, and a second subprocessor coupled to process the radar signal and the rate-limited wheel-axle speed signal from the first subprocessor to supply the true ground speed of the vehicle. The second subprocessor includes a filter coupled to supply an estimated creep signal substantially free of any undesirable short-term variation due to the radar signal. The second subprocessor further includes a first processor module coupled to process the estimated creep signal from the filter to substantially reduce any undesirable long term variations in the wheel-axle speed signals.