Method, control device and system for determining a tread depth of a tread of a tire

• US 9,669,664 B2
• Filed: 09/19/2013
• Issued: 06/06/2017
• Est. Priority Date: 10/01/2012
• Status: Active Grant

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Continental Automotive GmbH (Continental AG)
• Inventors: Kretschmann, Matthias
• Primary Examiner(s): Shaawat, Mussa A
• Assistant Examiner(s): ODEH, NADEEM N
• Application Number:
  US14/423,189
• Publication Number:
  US 20150239298A1
• Time in Patent Office: 1,356 Days
• Field of Search: 701 337
• CPC Class Codes: B60C 11/243 Tread wear sensors, e.g. electronic sensors
• CPC Class Codes: B60C 11/246 Tread wear monitoring systems
• CPC Class Codes: G07C 5/006 Indicating maintenance
• CPC Class Codes: G07C 5/0808 Diagnosing performance data testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005

Abstract

A method for determining a tire tread depth during operation of a vehicle includes determining an instantaneous rotational speed of a vehicle wheel having the tire based on data determined by at least one first sensor, then determining a vehicle speed based on data determined by at least one different second sensor, then determining an instantaneous dynamic wheel radius based on the determined instantaneous rotational speed and the determined instantaneous speed. At least one first tire parameter selected from an instantaneous tire temperature, tire pressure and tire load is determined. An instantaneous dynamic inner wheel radius is determined based on the at least one determined first parameter, wherein the inner wheel radius is the distance between the center of the wheel and the tire-side start or seam of the tread. A tire tread depth is determined based on the determined instantaneous dynamic radius and the determined instantaneous dynamic inner radius.

Claims

1. A method for determining a tread depth of a tread of a tire during operation of a vehicle having the tire, the method comprising the following steps:

determining an instantaneous rotational speed of a wheel of the vehicle having the tire, based on data determined by at least one first sensor;

determining an instantaneous speed of the vehicle based on data determined by at least one second sensor, being different from the at least one first sensor;

determining an instantaneous dynamic radius of the wheel having the tire, based on the determined instantaneous rotational speed of the wheel and the determined instantaneous speed of the vehicle;

determining at least one first parameter of the tire selected from the group consisting of an instantaneous tire temperature, an instantaneous tire pressure and an instantaneous tire load;

determining an instantaneous dynamic internal radius of the wheel based on the at least one determined first parameter, the internal radius of the wheel being a distance between a wheel center and a tire-side start of the tread; and

determining the tread depth of the tread of the tire based on the determined instantaneous dynamic radius and the determined instantaneous dynamic internal radius.

2. The method according to claim 1, which further comprises providing the at least one first sensor as a rotational speed sensor.

3. The method according to claim 1, which further comprises selecting the at least one second sensor from the group consisting of a satellite-assisted position-determining sensor, a radar sensor, a lidar sensor, an ultrasonic sensor and an optical camera;

and estimating the instantaneous speed of the vehicle based on the data determined by the at least one second sensor.

4. The method according to claim 1, which further comprises additionally determining the instantaneous dynamic internal radius of the wheel based on the determined instantaneous speed of the vehicle.

5. The method according to claim 1, which further comprises additionally determining the instantaneous dynamic internal radius of the wheel based on at least one of a type of tire or an age of the tire.

6. The method according to claim 1, which further comprises determining the instantaneous dynamic internal radius of the wheel by using at least one characteristic curve stored in a memory device.

7. The method according to claim 1, which further comprises:

additionally determining at least one second parameter selected from the group consisting of an instantaneous acceleration of the vehicle, an instantaneous yaw rate of the vehicle, an instantaneous steering angle, and an instantaneous torque of a drive engine of the vehicle; and

determining that the at least one second parameter does not exceed a predetermined threshold value and that a brake device of the vehicle is not activated before performing the steps of determining the instantaneous dynamic radius of the wheel and determining the instantaneous dynamic internal radius of the wheel.

8. The method according to claim 1, which further comprises additionally issuing a warning message if the determined tread depth of the tread of the tire undershoots a first predetermined threshold value.

9. The method according to claim 1, which further comprises additionally informing a service device if the determined tread depth of the tread of the tire undershoots a second predetermined threshold value.

10. The method according to claim 1, which further comprises transmitting the determined tread depth of the tread of the tire to at least one driver assistance system of the vehicle.

11. A control device for a vehicle for determining a tread depth of a tread of a tire of the vehicle, the control device comprising:

at least one receiver device constructed to receive an instantaneous rotational speed of a wheel of the vehicle having the tire, an instantaneous speed of the vehicle and at least one first parameter of the tire selected from the group consisting of an instantaneous tire temperature, an instantaneous tire pressure and an instantaneous tire load;

a first determining device constructed to determine an instantaneous dynamic radius of the wheel having the tire, based on the received instantaneous rotational speed of the wheel and the received instantaneous speed of the vehicle;

a second determining device constructed to determine an instantaneous dynamic internal radius of the wheel based on the at least one received first parameter, the internal radius of the wheel being a distance between a wheel center and a tire-side start of the tread; and

a third determining device constructed to determine the tread depth of the tread of the tire based on the determined instantaneous dynamic radius and the determined instantaneous dynamic internal radius.

12. A system for a vehicle for determining a tread depth of a tread of a tire of the vehicle, the system comprising:

a control device according to claim 11; and

at least one wheel unit constructed to be disposed in the tire and having at least one sensor selected from the group consisting of a temperature sensor, a pressure sensor and a tire load sensor.