Method for detecting a wear-relevant load on a vehicle wheel

A tire pressure monitoring device optimized for low energy consumption comprising a pressure sensor, at least one acceleration sensor and a control unit, wherein the control unit is designed to carry out in operation a method comprising the following steps:

• determining a first rotational frequency of the vehicle wheel for an overall first time interval from a series of measured values of the at least one acceleration sensor at first time intervals;
• determining a centrifugal acceleration value for the overall first time interval;
• determining a proportionality factor from the rotational frequency and centrifugal acceleration value, linking the square of the rotational frequency with the centrifugal acceleration
• measuring a second set of centrifugal acceleration values by the at least one acceleration sensor;
• successively calculating a second rotational frequency of the vehicle wheel from measured values of the centrifugal acceleration, which have been determined at second time intervals that are greater than the first time intervals, and from the proportionality factor;
• calculating a load value from the rotational frequency and the corresponding second time interval;
• and
• successively adding these load values up to an overall load;
• wherein a first energy consumption of the at least one acceleration sensor of the tire pressure monitoring device during the first time intervals is greater than a second energy consumption of the at least one acceleration sensor of the tire pressure monitoring device during the second time intervals when the first and second time intervals are compared over a same elapsed time period.

A tire pressure monitoring system comprising:

• a tire pressure monitoring device and a central vehicle unit in data communication with the tire pressure monitoring unit, said tire pressure monitoring device comprising a pressure sensor, at least one acceleration sensor and a control unit;
• wherein the tire pressure monitoring system is designed to carry out a method comprising the following steps:
• measuring, via the tire pressure monitoring unit, a first set of centrifugal acceleration values by the at least one acceleration sensor;
• determining, via the tire pressure monitoring unit and/or the central unit, a first rotational frequency of the vehicle wheel for an overall first time interval from a series of measured values of the at least one acceleration sensor at first time intervals;
• determining, via the tire pressure monitoring unit and/or the central unit, a centrifugal acceleration value for the overall first time interval;
• determining, via the tire pressure monitoring unit and/or the central unit, a proportionality factor from the rotational frequency and centrifugal acceleration value, linking the square of the rotational frequency with the centrifugal acceleration;
• measuring, via the tire pressure monitoring unit, a second set of centrifugal acceleration values by the at least one acceleration sensor;
• successively calculating, via the tire pressure monitoring unit and/or the central unit, a second rotational frequency of the vehicle wheel from measured values of the centrifugal acceleration, which have been determined at second time intervals that are greater than the first time intervals, and from the proportionality factor;
• calculating, via the tire pressure monitoring unit and/or the central unit, a load value from the rotational frequency and the corresponding second time interval;
• and
• via the tire pressure monitoring unit and/or the central unit, successively adding these load values up to an overall load.