Abnormality warning system and warning level setting method

1. An abnormality warning system for a plurality of motor systems, the motor systems being configured to respectively drive a plurality of motors corresponding to a plurality of rotors in an electric aircraft, the abnormality warning system comprising a processor programmed to:

determine a motor system, which is abnormal, among the motor systems; and

set a plurality of warning levels to warn of abnormality in the determined motor system based on at least one of

installation position information of a rotor, which corresponds to the motor system determined to be abnormal, among the rotors in the electric aircraft and

a function of the corresponding rotor, wherein

the plurality of warning levels include

a warning level to warn of an abnormality in the determined abnormal motor system that enables flight of the electric aircraft to continue as is, and

a warning level to warn of an abnormality in the determined abnormal motor system that requires an emergency landing of the electric aircraft.

2. The abnormality warning system according to claim 1 , wherein the processor is further programmed to:

compute an output ratio, which is a ratio of a total motor output from the motor systems to a required motor output required for flight of the electric aircraft; and

set the plurality of warning levels based on the output ratio.

3. The abnormality warning system according to claim 1 , wherein

the electric aircraft includes, as the rotors, two types of rotors including

a lifting rotor to provide a lift function to the electric aircraft, and

a thrust rotor to provide a thrust function to the electric aircraft.

4. The abnormality warning system according to claim 3 , wherein the processor is further programmed to:

identify, when the motor system is determined to be abnormal, whether each of the lift function and the thrust function is impaired; and

when none of the thrust function and the lift function is impaired, set the plurality of warning levels to be the same as or lower than the plurality of warning levels when at least one of the thrust function or the lift function is impaired.

5. The abnormality warning system according to claim 4 , wherein

the processor is programmed to, when the lift function is impaired, set the plurality of warning levels to be higher than the plurality of warning levels when the thrust function is impaired.

6. The abnormality warning system according to claim 5 , wherein

the plurality of rotors includes a plurality of lifting rotors, and

the processor is further programmed to set the plurality of warning levels for the motor system corresponding to a lifting rotor, which among the lifting rotors is located far from an airframe gravity center of the electric aircraft, to be higher than the plurality of warning levels for the motor system corresponding to a lifting rotor, which among the lifting rotors is located near the airframe gravity center of the electric aircraft.

7. The abnormality warning system according to claim 1 , wherein the processor is further programmed to:

on determination that one of the motor systems is abnormal continuously for a predetermined threshold count, determine that the one of the motor systems is abnormal;

set the plurality of warning levels by settling the threshold count based on at least one of the installation position information or the function;

set the plurality of warning levels to be higher as the threshold count becomes smaller; and

set the plurality of warning levels to be lower as the threshold count becomes greater.

8. The abnormality warning system according to claim 1 , wherein the processor is further programmed to:

vary the plurality of warning levels according to a period in which a same motor system of the plurality of motor systems is determined to be abnormal; and

when the period is long, set the plurality of warning levels to be higher than the plurality of warning levels when the period is short.

9. The abnormality warning system according to claim 1 , wherein

the plurality of warning levels further include a warning level to warn of an abnormality that requires shortening a flight plan of the electric aircraft.

10. A warning level setting method for a plurality of motor systems, the motor systems being configured to respectively drive a plurality of motors corresponding to a plurality of rotors in an electric aircraft, the warning level setting method comprising:

determining a motor system to be abnormal among the motor systems; and

setting a plurality of warning levels based on at least one of

installation position information of a rotor, which corresponds to the motor system determined to be abnormal, among the rotors in the electric aircraft and

a function of the corresponding rotor, wherein

the plurality of warning levels include

a warning level to warn of an abnormality in the determined abnormal motor system that enables flight of the electric aircraft to continue as is, and

a warning level to warn of an abnormality in the determined abnormal motor system that requires an emergency landing of the electric aircraft.

11. The warning level setting method according to claim 10 , wherein

the plurality of warning levels further include a warning level to warn of an abnormality that requires shortening a flight plan of the electric aircraft.

12. A non-transitory computer-readable medium storing instructions for causing a processor of an abnormality warning system to:

determine an abnormal motor system among a plurality of motor systems, the motor systems being configured to respectively drive a plurality of motors corresponding to a plurality of rotors in an electric aircraft;

set a plurality of warning levels based on at least one of

installation position information of a rotor, which corresponds to the abnormal motor system, among the rotors and

a function of the corresponding rotor; and

cause to be provided an abnormality warning based on the plurality of warning levels, wherein

the plurality of warning levels include

a warning level to warn of an abnormality in the determined abnormal motor system that enables flight of the electric aircraft to continue as is, and

a warning level to warn of an abnormality in the determined abnormal motor system that requires an emergency landing of the electric aircraft.

13. The non-transitory computer-readable medium according to claim 12 , wherein

the plurality of warning levels further include a warning level to warn of an abnormality that requires shortening a flight plan of the electric aircraft.