Abstract: An engine control method and apparatus for optimizing an operating condition of an engine. A plurality of engine variables are determined and operated upon to direct the control of engine effectors so as to place the engine in an optimum operating condition. In particular, the engine effectors are controlled to minimize the fuel consumption of an engine operating at a steady-state. The system selectively moves a pair of engine effectors so as to determine the sensitivity of the engine variables to changes in effector outputs. Such sensitivities are updated during the system operation. The engine effectors are selectively moved as a function of the engine variable sensitivities in a direction to minimize fuel consumption without violating any predetermined operating limits of the engine variables. Once an optimum operating point is obtained, the system remains at rest and checks for changes in operating conditions that may require a new optimum to be determined.

Abstract: A servo booster mechanism (18) having a piston (48) responsive to movement of a plunger (84) by an input signal for controlling the rate of fluid flow past a seat (82) into a passage (80) for distribution to the surrounding environment. A first restrictor (75) creates a first pressure drop in a supply fluid pressure P.sub.s to present an operational chamber (46) with fluid at a pressure P.sub.x. A second restrictor (openings 74-76) creates a second pressure drop in fluid pressure P.sub.x supplied from the operational chamber (46) to present control chamber (88) with fluid at a pressure P.sub.h. The difference in pressures combine to act on the piston (48) and plunger (84) to provide a constant force at stem (26), which provides a feedback to the input member (12), and provide a linkage (22) with a force to hold a position sensor (24) in a stationary position.

Abstract: A two-stage pneumatic servo valve assembly for controlling an output motor is disclosed. An input device, such as a torque motor, is coupled to the two-stage servo valve assembly. The first stage of the servo valve assembly includes a vane valve movable by the output of the torque motor to selectively provide a fluid path from an input source to one of the first-stage output channels. The first-stage pneumatic servo valve is coupled with a second stage servo valve. The second stage servo valve controls fluid flow from a pneumatic fluid source to an output motor. The second stage servo valve includes a slidable spool valve movable by fluid received from the first-stage servo valve. A feedback control from the second-stage servo valve to the first-stage servo valve is provided. A second feedback control is provided from the output of the output motor to the first stage servo valve.

Abstract: A lever mechanism having an output end and an input end wherein the input end is pivotally mounted to a fixed support and provided with a track portion. The track portion has a spaced apart relationship to the pivot axis of the lever and is provided with a generally V-shaped portion and lateral side portions oppositely extending therefrom. A reference force is applied through a roller member which is positioned along the track by a variable input position signal applied thereto. The apex of the V-shaped portion is on a line through the pivot axis such that with the roller member held in a bottomed position and engaging both sides of the V-shaped portion there is no input moment applied to the lever mechanism and movement of the roller member in either direction from a null position produces a clockwise or counterclockwise motion of the output end of the lever mechanism, depending upon the direction of movement of the output end in response to the roller movement.

Abstract: A fluid servo network having a servo fluid pressure responsive movable output member controlled by a variable area orifice the effective area of which is established by a movable servo valve which is actuated by lever means in response to a variable force input applied thereto. The lever means includes a main input lever responsive to the variable force input and an opposing variable feedback force which varies in response to the reaction of the output member to establish a force balance on the main input lever. The main input lever is attached to a roller loaded by a constant reference force and movable along a secondary lever mounted for pivotal movement about a fixed axis to vary the effective lever arm of the secondary lever which is attached to the servo valve. The input torque tending to close the servo valve is opposed by the torque derived from a characteristic orifice force unbalance acting through the secondary lever.