# US 11,442,162 B2 · Millimeter wave radar modeling-based method for object visibility determination

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,442,162 B2
- Document ID: US11442162B2
- Status: Granted
- Kind: B2
- Application number: 16/825,416
- Filed: 2020-03-20
- Published: 2020-10-08
- Granted: 2022-09-13
- Earliest claimed: 2019-04-04
- Assignees: Jilin University
- Applicants: Jilin University
- Inventors: Jun Zhan; Xuecai Dong; Chunguang Duan; Zhangu Wang; Rong Liu; Kai Yang; Huainan Zhu
- Web page: https://patentgrep.com/patent/US11442162B2

## CPC

- G01S 7/4052: {by simulation of echoes}
- G01S 13/931: of land vehicles
- G01S 7/40: Means for monitoring or calibrating
- G01S 13/52: Discriminating between fixed and moving objects or between objects moving at different speeds
- 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

The invention provides a millimeter wave radar modeling-based method for object visibility determination, to solve the problem of object visibility determination based on virtual sensor modeling in intelligent vehicle simulation and testing, and improve the fidelity of sensor modeling while meeting simulation efficiency requirements. It includes the steps of target vehicle information detection to obtain target vehicle information; target vehicle reflection intensity simulation: for each target vehicle performing geometry culling on the target vehicle, discarding completely-invisible target vehicles, and calculating visible section information for each target vehicle that has a visible section, and reflection intensity calculation; target vehicle visibility determination: analyzing visibility of the target vehicle according to the target vehicle reflection intensity, and converting and outputting information of a visible object into an expression form of a real millimeter-wave radar sensing an object.

## Claims

### Claim 1

A millimeter wave radar modeling-based method for object visibility determination, comprising the steps of:
obtaining information of a target vehicle at a variety of positions and a variety of angles within a detection area of a host vehicle, wherein the target vehicle is detected by the host vehicle, and the information comprises a vehicle type, shape, size, material, position, speed, acceleration, moving direction and reflectivity of the target vehicle, according to vehicle types stored in an intelligent vehicle simulation testing model, and calibrated reflectivities of the vehicle types at a variety of positions within 360 degrees within a millimeter wave radar, and building a linked list for storage;
performing geometry culling on each target vehicle, discarding completely invisible target vehicles, and calculating visible section information for each target vehicle that has a visible section, the visible section information including a position of the visible section and a corresponding angle;
categorizing target vehicles into four classes according to their moving directions relative to the host vehicle, including (i) the target vehicle moves in the same direction as the host vehicle; (ii) the target vehicle moves in the opposite direction of the host vehicle; (iii) the target vehicle moves to the left relative to the host vehicle; and (iv) the target vehicle moves to the right relative to the host vehicle; and further dividing each class into a plurality of situations according to a positional relationship between the visible section and the host vehicle, and calculating a target vehicle reflection intensity according to the situation; wherein the target vehicle reflection intensity calculation further comprises finding a reflectivity of the target vehicle at a corresponding area from the calibrated reflectivities according to the position and angle of the current target vehicle, determining a situation in a class according to the position of the visible section, and obtaining an object reflection intensity of the target vehicle by calculating an integral on an angle interval corresponding to the visible section and multiplying by a height of the target vehicle type; and
analyzing visibility of the target vehicle according to the target vehicle reflection intensity, and outputting information of a visible target vehicle in an expression form of a real millimeter-wave radar sensing an object.

### Claim 2 (depends on 1)

The millimeter wave radar modeling-based method for object visibility determination according to claim 1, wherein the class where the target vehicle moves in the same direction as the host vehicle includes three situations & flrcorner feature, frrcorner feature and frearside feature, wherein:
the flrcorner feature indicates that the target vehicle visible section starts from the center of the rear end of the vehicle and runs the contour of the vehicle to the top left corner;
the frrcorner feature indicates that the target vehicle visible section starts from the center of the rear end of the vehicle and runs the contour of the vehicle to the top right corner;
the frearside feature indicates that the target vehicle visible section starts from the left side to the right side of the rear end of the vehicle.

### Claim 3 (depends on 1)

The millimeter wave radar modeling-based method for object visibility determination according to claim 1, wherein the class where the target vehicle moves in the opposite direction of the host includes three situations frfcorner feature, flfcorner feature, and ffrontside feature, wherein:
the frfcorner feature indicates that the target vehicle visible section starts from the center of the front end of the vehicle and runs the contour of the vehicle to the top right corner;
the flfcorner feature indicates that the target vehicle visible section starts from the center of the front end of the vehicle and runs the contour of the vehicle to the top left corner;
the ffrontside feature indicates that the target vehicle visible section starts from the left side to the right side of the front end of the vehicle.

### Claim 4 (depends on 1)

The millimeter wave radar modeling-based method for object visibility determination according to claim 1, wherein the class where the target vehicle moves to the left relative to the host vehicle includes three situations fflcorner feature, frlcorner feature, and fleftside feature, wherein:
the fflcorner feature indicates that the target vehicle visible section starts from the center of the left side of the vehicle and runs the contour of the vehicle to the top corner at the front end;
the frlcorner feature indicates that the target vehicle visible section starts from the center of the left side of the vehicle and runs the contour of the vehicle to the top corner at the rear end;
the fleftside feature indicates that the target vehicle visible section starts from the front to the end of the left side of the vehicle.

### Claim 5 (depends on 1)

The millimeter wave radar modeling-based method for object visibility determination according to claim 1, wherein in the class where the target vehicle moves to the right of the host vehicle includes three situations frrcorner feature, frfcorner feature, and frightside feature, wherein:
the frrcorner feature indicates that the target vehicle visible section starts from the center of the right side of the vehicle and runs the contour of the vehicle to the top corner at the rear end;
the frfcorner feature indicates that the target vehicle visible section starts from the center of the right side of the vehicle and runs the contour of the vehicle to the top corner at the front end;
the frightside feature indicates that the target vehicle visible section starts from the front to the end of the left side of the vehicle.

### Claim 6 (depends on 1)

The millimeter wave radar modeling-based method for object visibility determination according to claim 1, wherein the case where the course angle of the target vehicle changes relative to the host vehicle:
the target vehicle moves in the same direction as the host vehicle when the course angle of the target vehicle ranges from 0 to 45° or 315° to 360° counterclockwise;
the target vehicle moves to the left relative to the host vehicle when the course angle of the target vehicle ranges from 45° to 135° counterclockwise;
the target vehicle moves in the opposite direction of the host vehicle when the course angle of the target vehicle ranges from 135° to 225° counterclockwise;
the target vehicle moves to the right of the host vehicle when the course angel of the target vehicle ranges from 225° to 315° counterclockwise.

### Claim 7 (depends on 1)

The millimeter wave radar modeling-based method for object visibility determination according to claim 1, further comprising the steps of:
calculating a vector projection of the obtained reflection intensity, considering the angle between the target vehicle and the radar which causes refraction loss, and based on calculating a position vector of the current target vehicle relative to the radar, and
obtaining an actual object reflection intensity by calculating the vector projection of the obtained reflection intensity onto the line segment OO1 wherein if the visible section has endpoints A and B, the midpoint of the line AB is O1 and the mounting position of the radar is O.

### Claim 8 (depends on 1)

The millimeter wave radar modeling-based method for object visibility determination according to claim 1, wherein the visibility determination further comprises the steps of:
sequentially extracting relevant data from the target vehicle reflection intensity result list, determining whether a target vehicle reflection intensity result is greater than a target vehicle reflection intensity visibility threshold in the simulated sensor, and if the target vehicle reflection intensity result is greater than the target vehicle reflection visibility intensity threshold, determining the inputted object is visible to the simulated sensor, and converting and outputting the information of the target vehicle such as position, angle, speed and acceleration obtained in the simulation scene according to an output data format required by the current radar model; if the target vehicle reflection intensity result is less than or equal to the target vehicle reflection intensity visibility threshold, determining the inputted object is invisible to the simulated sensor.