# US 2021/0333382 A1 · Detection System and Method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0333382 A1 - Document ID: US20210333382A1 - Status: Published application - Kind: A1 - Application number: 17/371,902 - Filed: 2021-07-09 - Published: 2021-10-28 - Earliest claimed: 2018-10-08 - Assignees: Aptiv Technologies AG - Applicants: Aptiv Technologies Limited - Inventors: Yu Wang; Liang Ma - Web page: https://patentgrep.com/patent/US20210333382A1 ## CPC - G01S 13/08: Systems for measuring distance only (indirect measurement G01S13/46) - G01S 13/872: {Combinations of primary radar and secondary radar} - G01S 13/04: Systems determining presence of a target (based on relative movement of target G01S13/56) - G01S 13/723: {by using numerical data} - G01S 13/931: of land vehicles - G01S 2013/9315: {Monitoring blind spots} - G01S 2013/93272: {in the back 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 ## Abstract A detection system includes a radar-unit and a controller-circuit. The radar-unit is configured to detect objects proximate a host-vehicle. The controller-circuit is in communication with the radar-unit and is configured to determine a detection-distribution based on the radar-unit. The detection-distribution is characterized by a longitudinal-distribution of zero-range-rate detections associated with a trailer towed by the host-vehicle. The controller-circuit is further configured to determine a trailer-classification based on a comparison of the detection-distribution and longitudinal-distribution-models stored in the controller-circuit. The trailer-classification is indicative of a dimension of the trailer. The controller-circuit determines a trailer-length of the trailer based on the detection-distribution and the trailer-classification. ## Claims ### Claim 1 A method comprising: determining, by at least one processor of a vehicle and from one or more radar units, a distribution of zero-range-rate detections from behind the vehicle; determining, by the at least one processor, based on the distribution of zero-range-rate detections, a length of a trailer being towed behind the vehicle; and adjusting, by the at least one processor, based on the length of the trailer, an estimated dimension of a blind zone associated with the trailer. ### Claim 2 (depends on 1) The method of claim 1, wherein determining the distribution of zero-range-rate detections comprises determining the distribution of zero-range-rate detections during a finite time period. ### Claim 3 (depends on 1) The method of claim 1, wherein determining the length of the trailer comprises: inputting the distribution of zero-range-rate detections into a model configured to predict a trailer classification; and determining, based in part on the trailer classification, the length of the trailer. ### Claim 4 (depends on 3) The method of claim 3, further comprising: further adjusting, based on the trailer classification predicted by the model from the distribution of zero-range-rate detections input to the model, the estimated dimension of the blind zone associated with the trailer. ### Claim 5 (depends on 3) The method of claim 3, further comprising: receiving, from the model, the trailer classification as one classification from a plurality of different classifications. ### Claim 6 (depends on 5) The method of claim 5, wherein the plurality of different classifications comprise: a first class of trailers that are less than a first length, a second class of trailers that are between the first length and a second length, and a third class of trailers that are greater than the second length. ### Claim 7 (depends on 5) The method of claim 5, wherein the plurality of different classifications comprise: a first class of trailers comprising an open-trailer with an exposed cargo bay, a second class of trailers comprising an enclosed-trailer with exterior paneling for an enclosed cargo bay, and a third class of trailers comprises a boat trailer, and a fourth class of trailers comprises a travel-trailer. ### Claim 8 (depends on 5) The method of claim 5, wherein the model comprises one or more regression models. ### Claim 9 (depends on 8) The method of claim 8, wherein each of the one or more regression models is associated with a different classification from the plurality of different classifications. ### Claim 10 (depends on 1) The method of claim 1, wherein the distribution of zero-range-rate detections includes groups of zero-range-rate targets detected at sequential intervals of potential trailer lengths that extend behind the vehicle. ### Claim 11 (depends on 10) The method of claim 10, wherein the intervals of potential trailer lengths are each less than or equal to about 0.2-meters. ### Claim 12 (depends on 1) The method of claim 1, further comprising: using, by the at least one processor, the estimated dimension of the blind zone associated with the trailer to control the vehicle when the vehicle is towing the trailer. ### Claim 13 A computer-readable storage medium comprising instructions that, when executed, cause at least one processor to: determine, with one or more radar units of a vehicle, a distribution of zero-range-rate detections from behind the vehicle; determine, based on the distribution of zero-range-rate detections, a length of a trailer being towed behind the vehicle; and adjust, based on the length of the trailer, an estimated dimension of a blind zone associated with the trailer. ### Claim 14 (depends on 13) The computer-readable storage medium of claim 13, wherein the instructions, when executed, further cause the at least one processor to: use the estimated dimension of the blind zone associated with the trailer to control the vehicle when the vehicle is towing the trailer. ### Claim 15 (depends on 13) The computer-readable storage medium of claim 13, wherein, when executed, the instructions cause the at least one processor to determine the distribution of zero-range-rate detections by determining the distribution of zero-range-rate detections during a finite time period. ### Claim 16 (depends on 13) The computer-readable storage medium of claim 13, wherein, when executed, the instructions cause the at least one processor to determine the length of the trailer by: execute a model configured to predict a trailer classification; input the distribution of zero-range-rate detections into the model to obtain the trailer classification predicted by the model; and determine, based in part on the trailer classification, the length of the trailer. ### Claim 17 (depends on 16) The computer-readable storage medium of claim 16, wherein, when executed, the instructions cause the at least one processor to receive, from the model, the trailer classification as one classification from a plurality of different classifications. ### Claim 18 (depends on 17) The computer-readable storage medium of claim 17, wherein the plurality of different classifications comprise: a first class of trailers that are less than a first length, a second class of trailers that are between the first length and a second length, and a third class of trailers that are greater than the second length. ### Claim 19 (depends on 17) The computer-readable storage medium of claim 17, wherein the plurality of different classifications comprise: a first class of trailers comprising an open-trailer with an exposed cargo bay, a second class of trailers comprising an enclosed-trailer with exterior paneling for an enclosed cargo bay, and a third class of trailers comprises a boat trailer, and a fourth class of trailers comprises a travel-trailer. ### Claim 20 (depends on 17) The computer-readable storage medium of claim 17, wherein the model comprises one or more regression models, each of the one or more regression models is associated with a different classification from the plurality of different classifications.