# US 10,864,916 B2 · Method and device for determining a coefficient of friction of a passable supporting surface with the aid of an ego vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,864,916 B2 - Document ID: US10864916B2 - Status: Granted - Kind: B2 - Application number: 16/089,059 - Filed: 2017-03-16 - Published: 2019-04-25 - Granted: 2020-12-15 - Earliest claimed: 2016-04-01 - Assignees: Robert Bosch GmbH - Applicants: Robert Bosch GmbH - Inventors: Nils Hagenlocher - Web page: https://patentgrep.com/patent/US10864916B2 ## CPC - B60W 40/068: Road friction coefficient - B60W 50/0205: {Diagnosing or detecting failures; Failure detection models} - B60W 2050/0075: {Automatic parameter input, automatic initialising or calibrating means} - B60W 2050/0215: {Sensor drifts or sensor failures} - B60W 2420/403: Image sensing, e.g. optical camera - B60W 2420/408: Radar; Laser, e.g. lidar - B60W 2555/20: Ambient conditions, e.g. wind or rain - B60W 2556/45: External transmission of data to or from the vehicle - B60W 2556/50: of positioning data, e.g. GPS [Global Positioning System] data - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT ## Abstract A method and device for determining a coefficient of friction of a passable supporting surface with the aid of an ego vehicle, including a step of acquiring first data values, which represent a moisture level in the surrounding area of the ego vehicle, a step of checking the plausibility of the acquired, first data values by comparison with at least one second data value, and a step of determining third data values, which represent the coefficient of friction of the passable supporting surface; the determination taking place as a function of the plausibility check of the first data values, using the at least one second data value. ## Claims ### Claim 1 A method for determining a coefficient of friction of a passable supporting surface with the aid of an ego vehicle, the method comprising: acquiring first data values, which represent a moisture level of water in a non-gaseous state in the surrounding area of the ego vehicle; checking a plausibility of the acquired, first data values by comparing at least one second data value; and determining third data values, which represent the coefficient of friction of the passable supporting surface, wherein the determination takes place as a function of the plausibility check of the first data values, using the at least one second data value, wherein the first data values are acquired by measuring the moisture in the form of: (i) a spray, which is generated by at least one vehicle located in the surrounding area of the ego vehicle and/or by the ego vehicle, and/or (ii) in the form of swirled-up snow, which is generated by at least one vehicle located in the surrounding area of the ego vehicle and/or by the ego vehicle. ### Claim 2 (depends on 1) The method of claim 1, wherein the at least one second data value includes a coefficient of friction from a different friction coefficient determination system. ### Claim 3 (depends on 1) The method of claim 1, wherein the at least one second data value includes a value of a water film height. ### Claim 4 (depends on 1) The method of claim 1, wherein the at least one second data value includes at least one of: an intensity of precipitation in the form of rain and/or snow, and/or a temperature of the surrounding area of the ego vehicle, and/or a speed of at least one windshield wiper of the ego vehicle, and/or information from a weather forecast valid in the surrounding area of the ego vehicle. ### Claim 5 (depends on 1) The method of claim 1, wherein the third data values are determined in such a manner, that with the aid of a database, the first data values, which are checked for plausibility, using the at least one second data value, are assigned a coefficient of friction, and the coefficient of friction is outputted in the form of third data values. ### Claim 6 (depends on 1) The method of claim 1, wherein the third data values are determined in such a manner, that the third data values determined are linked to the position of the ego vehicle, and these are transmitted to an external server. ### Claim 7 A device for determining a coefficient of friction of a passable supporting surface with the aid of an ego vehicle, comprising: at least one first device for acquiring first data values, which represent a moisture level of water in a non-gaseous state in the surrounding area of the ego vehicle; at least one second device for checking the plausibility of the acquired, first data values by comparison with at least one second data value; and at least one third device for determining third data values, which represent the coefficient of friction of the passable supporting surface, wherein the determination takes place as a function of the plausibility check of the first data values, using the at least one second data value, wherein the first data values are acquired by measuring the moisture in the form of: (i) a spray, which is generated by at least one vehicle located in the surrounding area of the ego vehicle and/or by the ego vehicle, and/or (ii) in the form of swirled-up snow, which is generated by at least one vehicle located in the surrounding area of the ego vehicle and/or by the ego vehicle. ### Claim 8 A server for determining a coefficient of friction of a passable supporting surface with the aid of an ego vehicle, comprising: a server arrangement configured to receive, store and process third data values; wherein the third data values are determined by performing the following: acquiring first data values, which represent a moisture level of water in a non-gaseous state in the surrounding area of the ego vehicle; checking a plausibility of the acquired, first data values by comparing at least one second data value; and determining the third data values, which represent the coefficient of friction of the passable supporting surface, wherein the determination takes place as a function of the plausibility check of the first data values, using the at least one second data value wherein the first data values are acquired by measuring the moisture in the form of: (i) a spray, which is generated by at least one vehicle located in the surrounding area of the ego vehicle and/or by the ego vehicle, and/or (ii) in the form of swirled-up snow, which is generated by at least one vehicle located in the surrounding area of the ego vehicle and/or by the ego vehicle. ### Claim 9 (depends on 1) The method of claim 1, wherein the at least one second data value includes a coefficient of friction from a different friction coefficient determination system, in particular, from a brake system for the operational stabilization of the ego vehicle. ### Claim 10 (depends on 1) The method of claim 1, wherein the third data values are determined in such a manner, that the third data values determined are linked to the position of the ego vehicle, in particular, to GPS data, and these are transmitted to an external server.