ABS Reference speed determination
AssigneesGeneral Motors Corporation, Delco Electronics Corporation
InventorsAlan J. Lee, Philip M. Headley
Life of this patent
Estimating the term…
Abstract
A method for determining an accurate vehicle speed, based upon the wheel speed data, for vehicle antilock systems in which the integrity of each individual wheel speed value is verified before including that wheel speed value in the reference speed calculation. Reference speed is then computed as a function of only those wheel speed values which have been successfully accepted into the calculation.
Claims8
A system for determining a vehicle reference speed value for the purposes of wheel lock control for a vehicle having a plurality of wheels, the system comprising in combination:
- means for measuring a value of speed for each of the vehicle wheels;
- means for (a) comparing predetermined parameters of each wheel with predetermined limits and (b) selecting the wheel speed values of the wheels whose parameters are within the predetermined limits;
- and
- means for determining an average of the selected wheel speed values, the average of the selected wheel speed values comprising the vehicle reference speed.
A method for determining a vehicle reference speed during antilock controlled braking of a vehicle having a plurality of braked wheels, the method comprising, in combination, the steps of:
- establishing a calculation interval;
- measuring a speed value for each wheel during the calculation interval;
- comparing predetermined parameters of each wheel with predetermined limits and selecting the speed values of those wheels whose parameters are within the predetermined limits;
- determining a minimum reference speed value which reflects a maximum allowable decrease in the vehicle reference speed value during a calculation interval;
- determining a bounded selected speed value for each of the speed values selected during each calculation interval in accordance with the expression .omega..sub.bound =max[.omega., V.sub.min ] wherein .omega. is the speed value selected, V.sub.min is the determined minimum reference speed and max[.omega., V.sub.min ] indicates that the greater of these two values be used;
- and
- determining the average of the bounded selected speed values during each calculation interval, the average of the bounded selected speed values comprising the vehicle reference speed.
Dependencies are inferred from the claim text.