Abstract: A multiple processor system comprising a plurality of microprocessors, a plurality of digital filters for making outputs of the microprocessors smooth, the digital filters corresponding in number to the plurality of microprocessors, a failure judgement unit having a comparator for comparing the smoothed output data and judging the presence of failure of the plurality of microprocessors under majority rule, and a selection and output unit for selecting, on the basis of the result of the judgement of the failure judgement unit and a predetermined priority order, an output of the microprocessor in which there is no failure and whose priority order is higher and for outputting the selected output as an output of the multiple processor system.

Abstract: A flutter control system of an aircraft wing comprising an actuator mounted on the aircraft wing to control a control surface, flight control command unit for outputting an actuation command signal for actuating the actuator, wing-displacement measurement unit for measuring an actual displacement of a predetermined point on the wing and outputting an actual displacement signal corresponding to the measured actual displacement, normal-wing-displacement prediction unit for predicting a normal displacement of the wing during normal flight in which no disturbance occurs, on the basis of the actuation command signal and of an information signal representing information about atmospheric density, flight speed and actuation position of the actuator and for outputting a predicted normal displacement signal representing the predicted displacement during the normal flight, disturbance-component estimation unit for receiving the actual displacement signal and the predicted normal displacement signal and for outputting a

Abstract: An electro-hydraulic servo mechanism comprising: a hydraulic actuator formed with a pair of hydraulic chambers and having an output member which is displaced by a differential pressure between the hydraulic chambers, the output member being connected with an object to be controlled; an electro-hydraulic converter for varying the differential pressure between the hydraulic chambers in response to an electric signal; a first differential transformer for outputting a first induced electromotive force proportional to the displacement of the output member; a control circuit for generating the electric signal in response to the output of the first differential transformer and to an external command signal and for outputting the electric signal to the electro-hydraulic converter; a pressure receiving member that is displaced in response to the differential pressure between the hydraulic chambers; and a second differential transformer for outputting a second induced electromotive force proportional to the displacemen

Abstract: A servo control apparatus comprising: a unit for generating a required position value; an actuator adapted to drive a load and having its maximum displacement in one direction and its minimum displacement in the other direction; a drive unit for driving the actuator; a position detecting unit for detecting a displacement of the actuator; and a control unit for correcting the required position value on basis of the maximum and minimum displacements of the actuator and for computing a deviation between an output of the position detecting unit and the corrected required position value; the load being controlled by the deviation.

Abstract: A four way directional control valve comprises a valve body having a sleeve formed therein, a spool slidable in the sleeve, two output ports, a pump port and two tank ports formed in the valve body so that the output ports can be a pressure side and an exhaust side by operation of the spool. The four way directional valve further comprises a communicating passage formed in the valve body to provide communication of the output ports with each other, a fixed orifice disposed in the communicating passage, a control passage, formed in parallel with the communicating passage, a control spool disposed in the control passage movable in response to a differential pressure between the output ports to block the communicating passage.

Abstract: A four way directional control valve comprises a valve body having a sleeve formed therein, a spool slidable in the sleeve, two output ports, two pump ports and a tank port formed in the valve body so that the output ports can be a pressure side and an exhaust side by operation of the spool. The four way directional valve further comprises a communicating passage formed in the valve body to provide communication of the output ports with each other, a fixed orifice disposed in the communicating passage, a control passage, formed in parallel with the communicating passage, a control spool disposed in the control passage movable in response to a differential pressure between the output ports to block the communicating passage.

Abstract: A control apparatus of a control surface of aircraft comprising a plurality of servomechanisms each including a hydraulic working oil source for supplying working oil under pressure, an actuator for driving the control surface, a servo valve for controlling the control surface, a switch valve interposed between the hydraulic working oil source and the servo valve, a bypass valve interposed between the servo valve and the actuator, a control valve connected to the bypass valve, actuator-displacement detecting means connected to the actuator to detect a drive displacement of the actuator and to output a displacement signal, and a control circuit for outputting actuating signals to the switch valve and servo valve, respectively, to drive the actuator, and for outputting a control signal to the control valve in response to the displacement signal in order to stop the actuator at a predetermined position.

Abstract: A servo circuit with a failure detection mechanism comprising: a servo circuit for servo controlling on the basis of a control signal an actuator which is connected through a hydraulic circuit with a source of oil pressure and is operated by the hydraulic circuit which is changed over by a servo valve; a monitor circuit arranged in parallel relationship with the servo circuit and generating a monitor control signal; and a failure detection circuit in which the control signal of the servo circuit and the monitor control signal of the monitor circuit are inputted and which detects a failure of the servo circuit on the basis of the control signal and the monitor control signal; wherein the hydraulic circuit is provided with pressure detecting means for detecting a pressure thereof; and the monitor circuit includes a correction circuit in which a pressure signal from the pressure detecting means is inputted and which corrects a loop gain of the monitor circuit in correspondence with a value of the pressure signal