Life determining device and life determining method
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsShogo Tanaka, Ryo Kanda, Seiji Kanda, Ryoko Tanaka, Takuma Endo
Life of this patent
Estimating the term…
Abstract
ECU is configured to determine a life of a brush motor that is a power source of the oil pump. ECU estimates the motor current of the brush motor based on the oil temperature and the hydraulic pressure. ECU measures the operation time of the brush motor at the estimated motor current. ECU determines the life of the brush motor based on the estimated motor current and the measured operation times.
Claims6
A life determining device configured to determine an end of life of a brush motor that is a power source of a supply device that supplies a fluid to a hydraulic cylinder of a vehicle, the vehicle including a temperature sensor configured to detect a temperature of the fluid and a pressure sensor configured to detect a pressure of the fluid, the life determining device comprising
- an electronic control unit (ECU) including a processor and a memory storing (i) a map for deriving a motor current value of the brush motor using the temperature and the pressure as parameters, and (ii) operation history information in which an operation time of the brush motor at each motor current value of the map is accumulated, wherein
- the processor is configured to:
- control the brush motor to start the brush motor;
- acquire the temperature from the temperature sensor and acquire the pressure from the pressure sensor in response to the brush motor being started;
- estimate the motor current value based on the temperature and the pressure using the map;
- measure the operation time of the brush motor at the estimated motor current value;
- and
- control the brush motor to stop the brush motor;
- accumulate the operation time at the estimated motor current value measured prior to stopping the brush motor in the operation history information, in response to the brush motor being stopped;
- calculate a current squared time product by using the operation time at each motor current value accumulated in the operation history information, the current squared time product including a product of (i) a square of the motor current value and (ii) the operation time;
- determine whether a value of the current squared time product exceeds a threshold value;
- and
- control the vehicle to notify a user of the vehicle that the brush motor has reached the end of life to prompt replacement of the brush motor in a case where a determination is made that the value of the current squared time product exceeds the threshold value.
Dependencies are inferred from the claim text.