User interface actuator for a pilot-by-wire system

Abstract

A user interface actuator for a pilot-by-wire system comprises a rotary electric motor having an output shaft suitable to be connected to a rotating user interface, a first absolute angular sensor for detecting in direct drive the number of revolutions of the shaft and a second absolute angular sensor redundant with respect to the first absolute angular sensor.

What is claimed is: 
     
         1 . A user interface actuator for a pilot-by-wire system comprising:
 a rotary electric motor having an output shaft suitable to be connected to a rotating user interface;   a first angular sensor for detecting in direct drive the number of revolutions of the output shaft; and   a second angular sensor, which is redundant with respect to the first angular sensor,   wherein the first angular sensor and second angular sensor are absolute angular sensors;   by comprising a transmission having a non-unitary gear ratio and connected to the electric motor; in that the first angular sensor and the second angular sensor are connected to each other by the transmission and coupled according to the non-unitary gear ratio, the transmission being suitable to connect the electric motor to the rotating user interface in a rotational manner;   in that the transmission comprises an endless flexible member; and   an electronic control unit programmed to detect a deviation from the non-unitary gear ratio of first and second absolute angular sensor and generate a signal when the deviation is above a threshold.   
     
     
         2 . The actuator according to  claim 1 , wherein the electronic control unit is programmed to combine respective signals from the absolute angular sensors to obtain an absolute angular signal of the rotating user interface over a range of several revolutions, calculated by dividing the least common multiple of “m” teeth of a pinion and “n” teeth of a pulley of the transmission by the “m” teeth of the pinion. 
     
     
         3 . The actuator according to  claim 1 , wherein the electric motor is controllable to apply at least one of a braking and a blocking torque of the transmission in response to a rotation of the rotating user interface. 
     
     
         4 . The actuator according to  claim 1 , wherein the electric motor is controllable to apply a driving torque on the rotating user interface and to bring the rotating user interface back to a given position. 
     
     
         5 . The actuator according to  claim 1 , further comprising a steering column driven by the electric motor. 
     
     
         6 . The actuator according to  claim 1 , further comprising a casing for housing at least the rotary motor and the absolute angular sensors. 
     
     
         7 . The actuator according to  claim 1 , wherein at least one of the absolute angular sensors is integrated in a bearing.