Patent ID: 8864559

Claim:
A multiple outflow valve cabin pressure control system for an aircraft comprising: a first outflow valve unit comprising: a first valve; a first automatically controlled motor configured to selectively open and close said first valve to produce a first flow rate through said first valve; a first manually controlled motor configured to selectively open and close said first valve to produce the first flow rate through said first valve; a first automatic controller having inputs from avionics of said aircraft and being configured to automatically control said first automatically controlled motor without the aid of motor or valve speed feedback; a first manual controller having a pilot interface and being configured to manually control said first manually controlled motor; and a first rotary position sensor configured to sense angular position of said first valve and supply an angular position sensor feedback of the first valve to said first automatic controller; a second outflow valve unit comprising: a second valve; a second automatically controlled motor configured to selectively open and close said second valve to produce a second flow rate through said second valve, said second flow rate having a commanded flow rate ratio relative to the first flow rate; a second manually controlled motor configured to selectively open and close said second valve to produce the second flow rate through said second valve, said second flow rate having the commanded flow rate ratio relative to the first flow rate; a second automatic controller having inputs from avionics of said aircraft and being configured to automatically control said second automatically controlled motor without the aid of motor or valve speed feedback; a second manual controller having a pilot interface and being configured to manually control said second manually controlled motor; and a second rotary position sensor configured to sense angular position of said second valve and supply an angular position sensor feedback of the second valve to said second automatic controller; a cross-com link configured to supply the position of said first valve to said second automatic controller and to supply the position of said second valve to said first automatic controller; an outflow valve biasing control configured to receive a value representative of the angular position of the first valve, a value representative of the angular position of the second valve, and a commanded flow ratio between the first and second valves; and said first and second automatic controllers being configured to receive duty cycle commands from the outflow biasing control and automatically control said first and second valves to bias air flow within said cabin in response to the commanded flow ratio between the first and second valves.