| 摘要 |
A brake control system which limits the operation of the braking forces applied to the tires, to the non-slip portion of the tire brake force and wheel velocity characteristic curve, i.e., the front or positive slope side of the characteristic Mu/slip curve; and thereby, minimizes both tire and brake wear. In particular, two embodiments of the invention are disclosed. All of which contain three aspects: a basic deceleration control circuit; a large deviation control circuit; and an energy balance system. The basic deceleration control circuit produces an average deceleration by summing the decelerations from all of the wheels, through a filtered differentiation of the wheel speed, and dividing it by the number of wheels. The average deceleration is then compared to the pilot selected deceleration rate for Dry, Wet, or Icy conditions and an error signal is generated. This error signal is then applied to a hysteresis circuit which outputs a constant level positive or negative signal. This signal is then integrated and supplied to a valve driver, which will modulate the metered braking pressure applied to the wheel. When the basic deceleration control circuit can no longer maintain braking control, the large deviation control circuit is actuated and generates a second error signal for providing corrective action to recover quickly when the selected deceleration rate is exceeded by a certain predetermined amount. This second error signal is also applied to a time constant circuit from which a controlled duration memory signal is provided that will reduce the brake torque of the wheel to a level consistent with the surface conditions of the runway.
|
