Actuator monitoring circuit, controller, and actuator unit

1. An actuator unit mounted in an airplane comprising:

a controller that is attached to an actuator having an output portion and that controls a position of the output portion of the actuator, wherein the controller comprises:

a monitoring unit that determines whether abnormality has occurred in an operation of the actuator; and

an actuator monitoring circuit that monitors the actuator,

wherein, when the monitoring unit determines that no abnormality has occurred in the operation of the actuator, the actuator monitoring circuit monitors the actuator, and wherein, when the monitoring unit determines that abnormality has occurred in the operation of the actuator, the actuator monitoring circuit monitors the actuator,

wherein, when a total moving distance of the output portion up to the present time after a replacement of the actuator exceeds a predetermined first threshold, the actuator monitoring circuit outputs a progression notification signal to notify excess over the first threshold, and when the total moving distance of the output portion exceeds a predetermined second threshold, the actuator monitoring circuit outputs an approaching notification signal to notify excess over the second threshold,

wherein the first threshold is a replacement mileage of the actuator,

wherein the second threshold is smaller than the first threshold and is set at a predetermined mileage,

wherein the actuator monitoring circuit comprises:

a distance adder configured to calculate an added distance, which is the sum of moving distances of the output portion from the activation of power at a stage of flight start to the present time;

a total moving distance calculator configured to calculate the total moving distance up to the present time by adding the added distance input from the distance adder to a total moving distance until flight, which is a total moving distance of the output portion from the replacement of the actuator to the flight start;

a first notification signal transmitter configured to, when the total moving distance up to the present time input from the total moving distance calculator exceeds the predetermined first threshold, output the progression notification signal; and

a second notification signal transmitter configured to, when the total moving distance up to the present time input from the total moving distance calculator exceeds the predetermined second threshold, output the approaching notification signal,

wherein the total moving distance calculator is configured to output the total moving distance up to the present time to a Primary Flight Computer for monitoring an operation of the actuator,

wherein the total moving distance calculator includes a non-volatile memory that stores the total moving distance until flight, and

wherein, after the flight, the non-volatile memory stores the total moving distance up to the present time as a new total moving distance until flight.

2. The actuator unit according to claim 1 , wherein information regarding the actuator is stored in the controller.

3. The actuator unit according to claim 1 , wherein:

a plurality of the actuators is provided;

the controller causes an actuator in which abnormality has occurred in the operation according to the monitoring unit to be driven by another actuator in which no abnormality has occurred in the operation according to the monitoring unit; and

the actuator monitoring circuit monitors the operation of the driven actuator.

4. The actuator unit according to claim 1 , wherein:

a plurality of actuators are provided;

the controller includes:

a normal-mode control unit that controls an actuator in which no abnormality has occurred in the operation according to the monitoring unit; and

a backup control unit that is provided to be independent from the normal-mode control unit and controls an actuator in which abnormality has occurred in the operation according to the monitoring unit; and

the actuator monitoring circuit monitors the operation of the actuator that is controlled by the backup control unit.

5. The actuator unit according to claim 1 , wherein the progression notification signal and the approaching notification signal are output to an instrument in a cockpit of the airplane.

6. The actuator unit according to claim 1 , wherein the progression notification signal and the approaching notification signal are directly transmitted to an airline or maintenance facility on the ground.

7. The actuator unit of claim 1 , wherein:

the actuator monitoring circuit is attached to the actuator, and

the actuator monitoring circuit and the actuator form a single unit.