Tread depth variation determining method for car tire, involves selecting subset of ratios representing measurement for tire contact patch, and inferring subset on variation of tread depth from timely variation of ratios

摘要

#CMT# #/CMT# The method involves determining and outputting acceleration-measured values (a) in rotating tires (1) by an acceleration sensor (2) provided in the tires. Ratios representing a measurement for a tire contact patch are determined from the acceleration-measured values. A subset of the ratios is selected from the ratios. A common iterative load condition is associated to the subset. The subset is inferred on variation of a tread depth (4b) from timely variation of the ratios. A detection direction of the sensor is arranged in a radial direction and/or in a tangential direction of the tires. #CMT# : #/CMT# An independent claim is also included for an arrangement for determining a variation of a tread depth of a tire of a vehicle. #CMT#USE : #/CMT# Method for determining a variation of a tread depth of a tire of a vehicle i.e. car (from drawings). #CMT#ADVANTAGE : #/CMT# The subset of the ratios is selected from the ratios, and the common iterative load condition is associated to the subset, thus avoiding the need for constantly updating the determined tire contact patch at the load condition of the vehicle, and detecting the load condition, short-term variation and long-term variation relative to the variation of the tread depth of the tire of the vehicle. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The drawing shows a graph illustrating a measured acceleration depending on time. a : Acceleration-measured values 1 : Tires 2 : Acceleration sensor 3 : Road 4a : Tread surface region 4b : Tread depth 6 : Control unit.