# US 2021/0333397 A1 · Method of road detection for an automotive vehicle fitted with a lidar sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0333397 A1 - Document ID: US20210333397A1 - Status: Published application - Kind: A1 - Application number: 17/274,304 - Filed: 2019-07-08 - Published: 2021-10-28 - Earliest claimed: 2018-09-11 - Assignees: RENAULT s.a.s. - Applicants: Renault s.a.s. - Inventors: Farouk GHALLABI - Web page: https://patentgrep.com/patent/US20210333397A1 ## CPC - G01S 7/4808: {Evaluating distance, position or velocity data} - G01S 17/42: Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S17/46) - G01S 17/89: for mapping or imaging - G01S 17/931: of land vehicles - G05D 1/0236: {in combination with a laser (lasers per se H01S)} - B60W 30/12: Lane keeping - B60W 2552/53: Road markings, e.g. lane marker or crosswalk - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - 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 road detection method for a motor vehicle provided with at least one rotary multilayer LIDAR sensor and at least one data processor includes acquiring LIDAR data of the environment of the vehicle. The data for which the angle of the beam with respect to the plane of the vehicle is greater than or equal to zero are eliminated from the acquired LIDAR data. For each LIDAR datum, theoretical coordinates of a point are determined as a function of the angle of the beam with respect to the plane of the vehicle and of the angle of the beam in the plane of the vehicle. The standard deviation between the theoretical coordinates and the coordinates of the LIDAR datum is determined. Then, it is determined that the LIDAR datum forms part of the road if the standard deviation is lower than a predefined threshold. ## Claims ### Claim at position 1 1-10. (canceled) ### Claim 11 A road detection method for a motor vehicle provided with a rotary multilayer LIDAR sensor and at least one data processing means, comprising: acquiring LIDAR data of the environment of the motor vehicle as polar coordinates with the LIDAR sensor; eliminating the data for which the polar coordinate relating to the angle of the beam with respect to the plane of the vehicle is greater than or equal to zero from the acquired LIDAR data; for each angle of the beam with respect to the plane of the vehicle, and for each LIDAR datum, the following are carried out: determining theoretical coordinates of a point, corresponding to the LIDAR datum, as a function notably of the angle of the beam with respect to the plane of the vehicle and of the angle of the beam in the plane of the vehicle, determining a standard deviation between the theoretical coordinates and the coordinates of the LIDAR datum, and determining that the LIDAR datum forms part of the road when the standard deviation is lower than a predefined threshold. ### Claim 12 (depends on 11) The method as claimed in claim 11, wherein a LIDAR datum is a point of a cloud of points acquired by the LIDAR sensor over one revolution, or a section comprising at least two consecutive points of the cloud of points acquired by the LIDAR sensor that have the same beam angle with respect to the plane of the vehicle. ### Claim 13 (depends on 12) The method as claimed in claim 12, wherein, when the LIDAR datum is a point of the cloud of points, the theoretical coordinates of the point corresponding to the LIDAR datum are determined as those of a point contained within an ideal circle inscribed within the plane of the road centered on the vehicle. ### Claim 14 (depends on 12) The method as claimed in claim 12, wherein, when the LIDAR datum is a section comprising at least two points of the cloud of points, the theoretical coordinates and the coordinates of the sections being defined as Cartesian coordinates and comprising a coordinate in the direction of movement of the vehicle in the plane of the vehicle, a coordinate in a direction at right angles to the direction of movement of the vehicle in the plane of the vehicle and a theoretical coordinate on the normal to the plane of the vehicle, the theoretical coordinate on the normal to the plane of the vehicle is defined as the average of the coordinates on the normal to the plane of the vehicle of the points of the cloud of points acquired by the LIDAR sensor contained within the section, and the other theoretical coordinates are defined as the coordinates of a point on an ideal circle inscribed within the plane of the road centered on the vehicle. ### Claim 15 (depends on 11) The method as claimed in claim 11, wherein at least two sectors are determined in the plane of the vehicle, each associated with a direction of scanning the sector, for each sector, the LIDAR data are scanned in the scanning direction, a determination is made as to whether each LIDAR datum belongs to the road, the scanning of the LIDAR data is interrupted as soon as the method determines that a LIDAR datum does not belong to the road and the method determines that the LIDAR data of the sector that have not been scanned do not belong to the road. ### Claim 16 (depends on 15) The method as claimed in claim 15, wherein, for each sector, a Gaussian filter is applied to the results of the determination of the standard deviation in order to reduce the impact of the irregularities, notably a Gaussian filter with size 3 kernel and of standard deviation 5. ### Claim 17 (depends on 16) The method as claimed in claim 16, wherein the Gaussian filter has a size 3 kernel and a standard deviation of 5. ### Claim 18 (depends on 15) The method as claimed in claim 15, wherein the direction of movement of the vehicle running forward is defined as corresponding to an angle 0 of the angle of the beam in the plane of the vehicle, four sectors are defined in the plane of the vehicle, a first sector comprising the LIDAR data for which the angle in the plane of the vehicle extends from the angle 0 to the angle π/2, and in which the LIDAR data are scanned from the initial angle 0 to the final angle π/2 in the plane of the vehicle, a second sector comprising the LIDAR data for which the angle in the plane of the vehicle extending from the angle π/2 to the angle π, and in which the LIDAR data are scanned from the initial angle π to the final angle π/2 in the plane of the vehicle, a third sector comprising the LIDAR data for which the angle in the plane of the vehicle extends from the angle π to the angle 3π/2 and in which the LIDAR data are scanned from the initial angle π to the final angle 3π/2 in the plane of the vehicle, and a fourth sector comprising the LIDAR data for which the angle in the plane of the vehicle extends from the angle 3π/2 to the angle 0, and in which the LIDAR data are scanned in the plane of the vehicle from the initial angle 0 to the final angle 3π/2 in the plane of the vehicle. ### Claim 19 (depends on 15) The method as claimed claim 15, wherein the steps relating to each sector are performed via a distinct processing means. ### Claim 20 (depends on 11) The method as claimed in claim 11, wherein, for each angle of the beam with respect to the plane of the vehicle, the method determines that a LIDAR datum belonging to the road corresponds to a marking on the ground, when the reflected light intensity perceived by the LIDAR sensor is lower than a predetermined threshold. ### Claim 21 (depends on 11) The method as claimed in claim 11, wherein the motor vehicle is an autonomous vehicle.