Henrik H Straub

40689034, Jan 17, 1978

Dec 8, 1976

5/748579

Henrik H. Straub - Mercer Island WA

The United States of America as represented by the Secretary of the Air
Force - Washington DC

B60T 8093

303 99

A skid detector apparatus utilizing a threshold modulator unit to provide an antiskid valve command signal which is inversely proportional to braking pressure to eliminate wheel lockup in accordance with the existing state of a runway. The threshold level modulator utilizes a feedback control signal to vary the threshold level within the skid detector. The skid detector provides a control signal to the valve driver which in turn varies the brake pressure to the braking device.

39853985, Oct 12, 1976

Apr 8, 1975

5/566158

Henrik H. Straub - Mercer Island WA

The United States of America as represented by the Secretary of the Air
Force - Washington DC

B60T 804

303 21CG

A pneumatic wheel speed sensor provides pulse frequency signal proportional to wheel speed, the signal is converted to DC signal and differentiated and compared to commanded deceleration, error which causes modulation of brake pressure. Excessive deceleration causes a digital amplifier to switch into the system an integrator resulting in rapid brake pressure signal decrease. A second order lead protects against undesirable landing gear oscillation in aircraft applications.