Brake control system defined by field programmable gate arrey
A brake control system for a wheeled vehicle includes a field programmable gate array configured to perform the algorithm of brake control subsystems in a typical brake control system for a wheeled vehicle. The brake control subsystems typically include anti-skid control, brake temperature monitoring, built-in tests, and, in the case of an aircraft, nose wheel steering. The system also includes wheel speed sensors, brake temperature monitors, brake valves and associated control circuits, and brake valve monitors respecting brake valve current and voltage. The use of field programmable gate arrays to configure a brake control system avoids the obsolescence and shortened life of control systems previously dependent upon microprocessors and the like.
1. A brake control system for a wheeled vehicle, comprising:
a field programmable gate array configured to perform an algorithm of brake control subsystems taken from the group comprising anti-skid control, nosewheel steering, brake temperature monitoring, and built-in tests;
a wheel speed interface interposed between wheel speed transducers of said wheeled vehicle and said field programmable gate array for presenting signals to said field programmable array corresponding to instantaneous wheel speed; and
a brake temperature interface interposed between brakes of said vehicle and said field programmable gate array and providing signals corresponding to brake temperature.
2. The brake control system according to claim 1 , further comprising a comparator interposed between anti-skid brake valves and said field programmable gate array, said comparator providing signals to said field programmable gate array corresponding to anti-skid brake valve current and voltage.
3. The brake control system according to claim 2 , wherein said field programmable gate array provides brake control signals to said anti-skid valves.
4. The brake control system according to claim 2 , wherein said field programmable gate array provides brake control signals to said anti-skid valves.
5. The brake control system according to claim 1 , wherein said anti-skid control subsystem comprises:
a frequency to digital converter receiving wheel speed signals and passing said wheel speed signals through low pass and notch filters, generating filtered wheel speed signals;
first and second interconnected differentiators receiving said filtered wheel speed signals, generating first and second derivatives of wheel speed.
6. The brake control system according to claim 4 , wherein said anti-skid control system further comprises a limiter connected to said first and second interconnected differentiators for limiting the signal corresponding to the second derivative of wheel speed.
7. The brake control system according to claim 5 , wherein said anti-skid control system further comprises a modulator operatively connected to an anti-skid valve driver and providing thereto an instantaneous average wheel speed signal.
8. The brake control system according to claim 6 , wherein said anti-skid control system further comprises a skid detector passing output signals corresponding to instantaneous large changes in wheel speed to said anti-skid brake control valve driver and said modulator.