Degradation estimation device, degradation estimation method, and non-transitory storage medium

A degradation estimation method that is applied to a vehicle equipped with an automatic transmission including either or both of a clutch and a brake as an engagement element to estimate a degree of degradation of a seal member attached to the engagement element of the automatic transmission, the method comprising causing a degradation estimation device to calculate a value of an output variable by inputting a thermal history variable and a load history variable as an input variable to the degradation estimation device, wherein the thermal history variable is a variable indicating a period during which the seal member has been exposed to a temperature within a predetermined temperature range, the load history variable is a variable indicating the number of times a load has acted on the seal member, the degradation estimation device stores mapping data, and the mapping data defines a map that outputs the output variable indicating the degree of degradation of the seal member when the input variable is input.

A non-transitory storage medium that serves as a degradation estimation device applied to a vehicle equipped with an automatic transmission including either or both of a clutch and a brake as an engagement element and configured to estimate a degree of degradation of a seal member attached to the engagement element of the automatic transmission, that includes mapping data defining a map that outputs an output variable indicating the degree of degradation of the seal member when an input variable is input, and that stores instructions that are executable by one or more processors and that cause the one or more processors to perform functions comprising:

• acquiring the input variable, the input variable including at least either a thermal history variable or a load history variable, the thermal history variable being a variable indicating a period during which the seal member has been exposed to a temperature within a predetermined temperature range, and the load history variable being a variable indicating the number of times a load has acted on the seal member;
• and
• calculating a value of the output variable by inputting the acquired input variable to the map.