Rib displacement amount determination method, rib displacement amount determination device, and rib displacement amount determination program

Abstract

This technology provides a way to reduce the computational load in area variation analysis used to reduce tire noise. [Solution] In the rib displacement amount determination method, the variable setting step sets the values ​​of multiple variables corresponding to the displacement amounts of multiple ribs within a predetermined range based on a genetic algorithm. The area variation calculation step calculates the variation in the contact area of ​​the tread portion for the variables set in the variable setting step. The objective function calculation step calculates the value of the objective function based on the area variation calculated in the area variation calculation step. The rib displacement amount determination step instructs the repetition of the processing by the variable setting step, the area variation calculation step, and the objective function calculation step, and determines the combination of variable values ​​based on the value of the objective function.

Claims

1. Multiple ribs are formed in a direction intersecting the main grooves, and multiple sub-grooves are formed in the circumferentially extending main grooves formed in the tread portion of the tire. In a method for determining the amount of displacement between ribs, A variable setting step involves setting the values ​​of multiple variables corresponding to the displacement amounts of multiple ribs within a predetermined range based on a genetic algorithm, An area variation calculation step which calculates the change in the contact area of ​​the tread portion with respect to the variables set in the variable setting step, A step to calculate the value of the objective function based on the area variation calculated in the area variation calculation step, A rib displacement determination step instructs the repetition of the process described in the variable setting step, the area variation calculation step, and the objective function calculation step, and determines a combination of the variable values ​​based on the value of the objective function, A method for determining the amount of rib displacement, comprising the following features.

2. The method for determining rib displacement according to claim 1, wherein the variable setting step defines the variable in accordance with the displacement amount of each of the other ribs relative to a specific rib.

3. The method for determining the amount of rib displacement according to claim 1, wherein the variable setting step involves setting discrete values ​​within the predetermined range to the variables.

4. The method for determining the amount of rib displacement according to claim 1, wherein the variable setting step limits the number of generations to be performed in the genetic algorithm.

5. The objective function is the combined power spectrum of area variation in a predetermined bandwidth. The rib displacement amount determination step, according to claim 1, determines the combination of variable values ​​that minimizes the value of the objective function calculated by multiple iterations.

6. The number of ribs is an odd number of three or more. The aforementioned ribs are formed under the condition that the sub-grooves of the ribs on both sides of the central rib in the tire width direction are symmetrical with respect to the central rib. The method for determining the amount of rib displacement according to claim 1, wherein the variable setting step defines the variable in accordance with the amount of displacement of one rib in the tire width direction relative to the central rib.

7. Multiple ribs are formed in a direction intersecting the main grooves, and multiple sub-grooves are formed in the circumferentially extending main grooves formed in the tread portion of the tire. In a rib displacement amount determination device that determines the amount of displacement between ribs, A variable setting unit sets a combination of multiple variables corresponding to the displacement amounts of multiple ribs within a predetermined range based on a genetic algorithm, An area variation calculation unit calculates the change in the contact area of ​​the tread portion with respect to the variable set by the variable setting unit, An objective function calculation unit calculates the value of the objective function based on the area variation calculated by the area variation calculation unit, A rib displacement amount determination unit commands the repetition of processing by the variable setting unit, the area variation calculation unit, and the objective function calculation unit, and determines a combination of the variable values ​​based on the value of the objective function, A rib displacement amount determination device equipped with the following features.

8. Multiple ribs are formed in the tread portion of the tire, each demarcated by a circumferentially extending main groove, and multiple sub-grooves intersecting the main groove are formed in the rib slip amount determination program, which determines the amount of slip between the ribs. A variable setting step involves setting the values ​​of multiple variables corresponding to the displacement amounts of multiple ribs within a predetermined range based on a genetic algorithm, An area variation calculation step which calculates the change in the contact area of ​​the tread portion with respect to the variables set in the variable setting step, A step to calculate the value of the objective function based on the area variation calculated in the area variation calculation step, A rib displacement determination step instructs the repetition of the process described in the variable setting step, the area variation calculation step, and the objective function calculation step, and determines a combination of the variable values ​​based on the objective function, A program that uses a computer to determine the amount of rib displacement.

Images