# US 2022/0284615 A1 · Road constraint determining method and apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0284615 A1 - Document ID: US20220284615A1 - Status: Published application - Kind: A1 - Application number: 17/746,706 - Filed: 2022-05-17 - Published: 2022-09-08 - Earliest claimed: 2019-11-18 - Applicants: Huawei Technologies Co., Ltd. - Inventors: Guangnan WAN; Jianguo WANG; Jingxiong GUO - Web page: https://patentgrep.com/patent/US20220284615A1 ## CPC - G06T 7/60: Analysis of geometric attributes - G06T 7/246: using feature-based methods, e.g. the tracking of corners or segments - G06V 10/62: relating to a temporal dimension, e.g. time-based feature extraction; Pattern tracking - G06V 10/806: {of extracted features} - G06V 20/54: of traffic, e.g. cars on the road, trains or boats - G06V 20/58: Recognition of moving objects or obstacles, e.g. vehicles or pedestrians; Recognition of traffic objects, e.g. traffic signs, traffic lights or roads - G06V 20/588: {Recognition of the road, e.g. of lane markings; Recognition of the vehicle driving pattern in relation to the road} - G06T 2207/10024: Color image - G06T 2207/10028: Range image; Depth image; 3D point clouds - G06T 2207/10044: Radar image - G06T 2207/30256: Lane; Road marking - G06V 2201/07: Target detection - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING ## Abstract This application discloses a road constraint determining method and apparatus, applied to the intelligent driving field, and in particular, to a sensor in an advanced driver assistance system ADAS or an autonomous driving system, for example, radar and/or a photographing apparatus. In this method, a moving state of a target is determined based on detection information of the target; at least one road geometry of a road on which the target is located is determined based on the detection information of the target; and a road constraint of the target is determined based on the at least one road geometry and the moving state of the target. The road constraint includes at least one of a road direction constraint and a road width constraint. According to the solutions in this application, road constraint determining accuracy can be improved, and target tracking accuracy can be further improved. ## Claims ### Claim 1 A road constraint determining method, comprising: determining a moving state of a target based on detection information of the target; determining, based on the detection information of the target, at least one road geometry of a road on which the target is located, wherein each of the at least one road geometry is represented by using at least one piece of information; and determining a road constraint of the target based on the at least one road geometry and the moving state of the target, wherein the road constraint comprises at least one of a road direction constraint or a road width constraint. ### Claim 2 (depends on 1) The method according to claim 1, wherein the method further comprises: determining at least one target road geometry in the at least one road geometry; and the determining a road constraint of the target based on the at least one road geometry and the moving state of the target comprises: determining the road constraint of the target based on the at least one target road geometry and the moving state of the target. ### Claim 3 (depends on 2) The method according to claim 2, wherein the determining at least one target road geometry in the at least one road geometry comprises: performing the following steps for each of the at least one road geometry: determining a tangent direction angle of the road geometry at a first location, wherein the tangent direction angle is an included angle between a tangent line of the road geometry at the first location and a radial direction; obtaining a tangent direction angle at a target location of the target based on a lateral velocity and a radial velocity at the target location of the target, wherein a distance between the target location of the target and the first location falls within a first distance range; and determining the road geometry as the target road geometry if an absolute value of a difference between the tangent direction angle at the first location and the tangent direction angle at the target location is less than a first threshold. ### Claim 4 (depends on 2) The method according to claim 2, wherein the determining at least one target road geometry in the at least one road geometry comprises: performing the following steps for each of the at least one road geometry: determining the road geometry as the target road geometry if a distance between the target and the road geometry falls within a second distance range. ### Claim 5 (depends on 2) The method according to claim 2, wherein the determining at least one target road geometry in the at least one road geometry comprises: performing the following steps for each of the at least one road geometry: obtaining a distance between the target and the road geometry; and determining, based on a quantity of the at least one road geometry, that Num road geometries at a smallest distance is the at least one target road geometry, wherein Num is a positive integer not less than 1. ### Claim 6 (depends on 2) The method according to claim 2, wherein the determining the road constraint of the target based on the at least one target road geometry and the moving state of the target comprises: determining at least one second location respectively located in the at least one target road geometry, wherein the at least one second location is a location closest to the target in at least one first target road geometry, and the first target road geometry is a target road geometry in which the second location is located; and determining the road direction constraint of the target based on a confidence level of the at least one target road geometry and a tangent direction angle of the at least one target road geometry at the at least one second location. ### Claim 7 (depends on 6) The method according to claim 6, wherein the confidence level of the target road geometry is a confidence level of a road parameter of the target road geometry; or the confidence level of the target road geometry is a confidence level of the tangent direction angle of the target road geometry at the second location. ### Claim 8 (depends on 7) The method according to claim 7, wherein when the confidence level of the target road geometry is the confidence level of the road parameter of the target road geometry, the method further comprises: determining the confidence level of the road parameter of the target road geometry based on a variance or a standard deviation of the road parameter of the target road geometry, wherein the road parameter is at least one piece of information used to represent the target road geometry; or when the confidence level of the target road geometry is the confidence level of the tangent direction angle of the target road geometry at the second location, the method further comprises: determining the confidence level of the tangent direction angle of the target road geometry at the second location based on a variance or a standard deviation of the tangent direction angle of the target road geometry at the second location. ### Claim 9 (depends on 6) The method according to claim 6, wherein the determining the road direction constraint of the target based on a confidence level of the at least one target road geometry and a tangent direction angle of the at least one target road geometry at the at least one second location comprises: determining, based on the confidence level of the target road geometry, a weight value that is of the tangent direction angle of the at least one target road geometry at the at least one second location and that exists during fusion; and determining, based on the weight value, that a fusion result obtained after fusion is performed on the tangent direction angle is the road direction constraint of the target. ### Claim 10 (depends on 6) The method according to claim 6, wherein the determining the road direction constraint of the target based on a confidence level of the at least one target road geometry and a tangent direction angle of the at least one target road geometry at the at least one second location comprises: determining that the tangent direction angle at the second location is the road direction constraint of the target, wherein the second location is a location closest to the target in a second target road geometry, and the second target road geometry is a target road geometry with a highest confidence level in the at least one target road geometry. ### Claim 11 A road constraint determining apparatus, comprising: at least one processor and a memory, wherein the memory is configured to store program instructions; and the at least one processor is configured to invoke and execute the program instructions stored in the memory, to enable the apparatus to perform the method of: determining a moving state of a target based on detection information of the target; and determining, based on the detection information of the target, at least one road geometry of a road on which the target is located, wherein each of the at least one road geometry is represented by using at least one piece of information; and determining a road constraint of the target based on the at least one road geometry and the moving state of the target, wherein the road constraint comprises at least one of a road direction constraint and a road width constraint. ### Claim 12 (depends on 11) The apparatus according to claim 11, wherein the method further comprising: determining at least one target road geometry in the at least one road geometry; and determining the road constraint of the target based on the at least one target road geometry and the moving state of the target. ### Claim 13 (depends on 12) The apparatus according to claim 12, wherein the method further comprising: determining a tangent direction angle of the road geometry at a first location, wherein the tangent direction angle is an included angle between a tangent line of the road geometry at the first location and a radial direction; obtaining a tangent direction angle at a target location of the target based on a lateral velocity and a radial velocity at the target location of the target, wherein a distance between the target location of the target and the first location falls within a first distance range; and determining the road geometry as the target road geometry if an absolute value of a difference between the tangent direction angle at the first location and the tangent direction angle at the target location is less than a first threshold. ### Claim 14 (depends on 12) The apparatus according to claim 12, wherein the method further comprising: determining the road geometry as the target road geometry if a distance between the target and the road geometry falls within a second distance range. ### Claim 15 (depends on 12) The apparatus according to claim 12, wherein the method further comprising: obtaining a distance between the target and the road geometry; and determining, based on a quantity of the at least one road geometry, that Num road geometries at a smallest distance is the at least one target road geometry, wherein Num is a positive integer not less than 1. ### Claim 16 (depends on 12) The apparatus according to claim 12, wherein the method further comprising: determining at least one second location respectively located in the at least one target road geometry, wherein the at least one second location is a location closest to the target in at least one first target road geometry, and the first target road geometry is a target road geometry in which the second location is located; and determining the road direction constraint of the target based on a confidence level of the at least one target road geometry and a tangent direction angle of the at least one target road geometry at the at least one second location. ### Claim 17 (depends on 16) The apparatus according to claim 16, wherein the confidence level of the target road geometry is a confidence level of a road parameter of the target road geometry; or the confidence level of the target road geometry is a confidence level of the tangent direction angle of the target road geometry at the second location. ### Claim 18 (depends on 16) The apparatus according to claim 16, wherein the method further comprising: determining, based on the confidence level of the target road geometry, a weight value that is of the tangent direction angle of the at least one target road geometry at the at least one second location and that exists during fusion; and determining, based on the weight value, that a fusion result obtained after fusion is performed on the tangent direction angle is the road direction constraint of the target. ### Claim 19 (depends on 16) The apparatus according to claim 16, wherein the method further comprising: determining that the tangent direction angle at the second location is the road direction constraint of the target, the second location is a location closest to the target in a second target road geometry, and the second target road geometry is a target road geometry with a highest confidence level in the at least one target road geometry. ### Claim 20 A computer-readable storage medium, wherein the computer-readable storage medium stores instructions; and when the instructions are run on a computer, the computer is enabled to perform the method of: determining a moving state of a target based on detection information of the target; determining, based on the detection information of the target, at least one road geometry of a road on which the target is located, wherein each of the at least one road geometry is represented by using at least one piece of information; and determining a road constraint of the target based on the at least one road geometry and the moving state of the target, wherein the road constraint comprises at least one of a road direction constraint or a road width constraint.