# US 10,768,307 B2 · Systems and methods for estimating vehicle speed based on radar > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,768,307 B2 - Document ID: US10768307B2 - Status: Granted - Kind: B2 - Application number: 16/237,153 - Filed: 2018-12-31 - Published: 2020-07-02 - Granted: 2020-09-08 - Earliest claimed: 2018-12-31 - Assignees: Lyft, Inc. - Applicants: Lyft, Inc. - Inventors: Farzad Cyrus Foroughi Abari - Web page: https://patentgrep.com/patent/US10768307B2 ## CPC - G01S 13/605: {using a pattern, backscattered from the ground, to determine speed or drift by measuring the time required to cover a fixed distance} - B60W 30/146: {Speed limiting} - G01S 13/865: {Combination of radar systems with lidar systems} - G01S 13/931: of land vehicles - G01S 17/931: of land vehicles - G06V 10/764: using classification, e.g. of video objects - 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 - G08G 1/166: {for active traffic, e.g. moving vehicles, pedestrians, bikes} - B60W 2554/00: Input parameters relating to objects - G01S 17/42: Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S17/46) - G01S 2013/9316: {combined with communication equipment with other vehicles or with base stations} - G01S 2013/932: {using own vehicle data, e.g. ground speed, steering wheel direction} - G01S 2013/9322: {using additional data, e.g. driver condition, road state or weather data} - G01S 2013/93271: {in the front of the vehicles} - 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 - 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 - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING - G08G: TRAFFIC CONTROL SYSTEMS (guiding railway traffic, ensuring the safety of railway traffic B61L; arrangement of road signs or traffic signals E01F9/00; radar or analogous systems, sonar systems, lidar systems specially adapted for traffic control G01S13/91, G01S15/88, G01S17/88; {radar or analogous systems, sonar systems, lidar systems specially adapted for anti-collision purposes G01S13/93, G01S15/93, G01S17/93}) ## Abstract Systems, methods, and non-transitory computer-readable media can receive a frame of data generated by a radar system on a vehicle that is associated with an environment at a particular time as detected by the radar system. The frame of data can comprise a plurality of angular positions. Data points included within the frame of data that correspond to the plurality of angular positions can be determined. A fit of a curve having a trigonometric function can be determined to the data points. A speed estimate for the vehicle can be generated based at least in part on the fit of the curve to the data points. ## Claims ### Claim 1 A computer-implemented method performed by a computing system, the computer-implemented method comprising: receiving a frame of data generated by a radar system on a vehicle that is associated with an environment at a particular time as detected by the radar system, the frame of data comprising a plurality of angular positions; determining data points included within the frame of data that correspond to the plurality of angular positions; determining a fit of a curve having a trigonometric function to the data points; and generating a speed estimate for the vehicle based at least in part on the fit of the curve to the data points. ### Claim 2 (depends on 1) The computer-implemented method of claim 1, wherein the data points included within the frame of data further correspond to a plurality of measured velocities, the measured velocities comprising a measured velocity at each angular position of the plurality of angular positions. ### Claim 3 (depends on 2) The computer-implemented method of claim 2, wherein the determining the fit of the curve to the data points comprises fitting a cosine curve to the plurality of angular positions and the plurality of measured velocities. ### Claim 4 (depends on 2) The computer-implemented method of claim 2, further comprising: identifying, before the determining the fit of the curve, one or more data points in the frame of data that are associated with one or more moving objects; removing, before the determining the fit of the curve, the one or more data points associated with the one or more moving objects from the frame of data. ### Claim 5 (depends on 4) The computer-implemented method of claim 4, wherein the removing the one or more data points associated with the one or more moving objects from the frame of data comprises removing all data points associated with the one or more moving objects from the frame of data to generate a filtered frame of data, wherein the fit of the curve is determined to data points in the filtered frame of data. ### Claim 6 (depends on 4) The computer-implemented method of claim 4, wherein an error metric indicative of a quality of the fit is calculated for the fit of the curve. ### Claim 7 (depends on 4) The computer-implemented method of claim 4, wherein the determining the fit of the curve to the data points comprises fitting a cosine curve to the plurality of angular positions and the plurality of measured velocities after the one or more data points associated with the one or more moving objects are removed from the frame of data. ### Claim 8 (depends on 2) The computer-implemented method of claim 2, further comprising: receiving a second frame of data generated by a second radar system on the vehicle, the second frame of data comprising a second plurality of angular positions; determining second data points included within the second frame of data that correspond to the second plurality of angular positions; determining a second fit of a second curve having a trigonometric function to the second data points; generating a first vehicle speed estimate based at least in part on the fit of the curve to the data points; and generating a second vehicle speed estimate based at least in part on the second fit of the second curve to the second data points, wherein the generating the speed estimate for the vehicle based at least in part on the fit of the curve comprises generating the speed estimate for the vehicle based at least in part on the first vehicle speed estimate and the second vehicle speed estimate. ### Claim 9 (depends on 8) The computer-implemented method of claim 8, wherein the first vehicle speed estimate is associated with a first weight, the second vehicle speed estimate is associated with a second weight, and the generating the speed estimate for the vehicle based at least in part on the fit of the curve comprises generating the speed estimate for the vehicle based at least in part on the first vehicle speed estimate, the second vehicle speed estimate, the first weight, and the second weight. ### Claim 10 (depends on 1) The computer-implemented method of claim 1, further comprising: comparing the speed estimate with a wheel-rotation-based speed estimate for the vehicle generated by a wheel-rotation-based speedometer on the vehicle, and determining that the wheel-rotation-based speedometer requires maintenance based on the comparing the speed estimate with the wheel-rotation-based speed estimate. ### Claim 11 A system comprising: at least one processor; and a memory storing instructions that, when executed by the at least one processor, cause the system to perform: receiving a frame of data generated by a radar system on a vehicle that is associated with an environment at a particular time as detected by the radar system, the frame of data comprising a plurality of angular positions; determining data points included within the frame of data that correspond to the plurality of angular positions; determining a fit of a curve having a trigonometric function to the data points; and generating a speed estimate for the vehicle based at least in part on the fit of the curve to the data points. ### Claim 12 (depends on 11) The system of claim 11, wherein the data points included within the frame of data further correspond to a plurality of measured velocities, the measured velocities comprising a measured velocity at each angular position of the plurality of angular positions. ### Claim 13 (depends on 12) The system of claim 12, wherein the determining the fit of the curve to the data points comprises fitting a cosine curve to the plurality of angular positions and the plurality of measured velocities. ### Claim 14 (depends on 12) The system of claim 12, wherein the instructions, when executed by the at least one processor, further cause the system to perform: identifying, before the determining the fit of the curve, one or more data points in the frame of data that are associated with one or more moving objects; removing, before the determining the fit of the curve, one or more the one or more data points associated with the one or more moving objects from the frame of data. ### Claim 15 (depends on 14) The system of claim 14, wherein the one or more an error metric indicative of a quality of the fit is calculated for the fit of the curve. ### Claim 16 A non-transitory computer-readable storage medium including instructions that, when executed by at least one processor of a computing system, cause the computing system to perform a method comprising: receiving a frame of data generated by a radar system on a vehicle that is associated with an environment at a particular time as detected by the radar system, the frame of data comprising a plurality of angular positions; determining data points included within the frame of data that correspond to the plurality of angular positions; determining a fit of a curve having a trigonometric function to the data points; and generating a speed estimate for the vehicle based at least in part on the fit of the curve to the data points. ### Claim 17 (depends on 16) The non-transitory computer-readable storage medium of claim 16, wherein the data points included within the frame of data further correspond to a plurality of measured velocities, the measured velocities comprising a measured velocity at each angular position of the plurality of angular positions. ### Claim 18 (depends on 17) The non-transitory computer-readable storage medium of claim 17, wherein the determining the fit of the curve to the data points comprises fitting a cosine curve to the plurality of angular positions and the plurality of measured velocities. ### Claim 19 (depends on 17) The non-transitory computer-readable storage medium of claim 17, wherein the instructions, when executed by the at least one processor of a computing system, further cause the computing system to perform: identifying, before the determining the fit of the curve, one or more data points in the frame of data that are associated with one or more moving objects; removing, before the determining the fit of the curve, the one or more measured velocities associated with the one or more moving objects from the frame of data. ### Claim 20 (depends on 19) The non-transitory computer-readable storage medium of claim 19, wherein an error metric indicative of a quality of the fit is calculated for the fit of the curve.