# US 2019/0318162 A1 · Method for the recognition of a moving pedestrian

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

- Number: US 2019/0318162 A1
- Document ID: US20190318162A1
- Status: Published application
- Kind: A1
- Application number: 16/361,897
- Filed: 2019-03-22
- Published: 2019-10-17
- Earliest claimed: 2018-04-11
- Assignees: Aptiv Technologies AG
- Applicants: Aptiv Technologies Limited
- Inventors: Honghui Yan; Tao Zhang; Wolfgang Doerr; Alexander Ioffe
- Web page: https://patentgrep.com/patent/US20190318162A1

## CPC

- G01S 7/415: {Identification of targets based on measurements of movement associated with the target}
- G06V 40/25: {Recognition of walking or running movements, e.g. gait recognition}
- G01S 13/46: Indirect determination of position data
- G01S 13/58: Velocity or trajectory determination systems; Sense-of-movement determination systems
- G01S 13/589: {measuring the velocity vector}
- G01S 13/931: of land vehicles
- G06V 40/103: {Static body considered as a whole, e.g. static pedestrian or occupant recognition}
- 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
- G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING

## Abstract

A method for the recognition of a moving pedestrian by means of a radar sensor system includes the steps of transmitting a primary radar signal into an observation space and of receiving a secondary radar signal reflected by the moving pedestrian. The secondary radar signal is processed, wherein the processing of the secondary radar signal includes the steps of generating a Micro-Doppler spectro-gram of the secondary radar signal, determining, based on the Micro-Doppler spectrogram, an observed bulk speed of the moving pedestrian, determining, based on the Micro-Doppler spectrogram, at least one gait cycle parameter of the moving pedestrian and determining, based on the determined observed bulk speed and the determined gait cycle parameter, an illumination angle between a moving direction of the moving pedestrian and the line of sight.

## Claims

### Claim 1

A method for the recognition of a moving pedestrian by means of a radar sensor system, wherein
transmitting a primary radar signal into an observation space; and
receiving a secondary radar signal reflected by the moving pedestrian; and
processing the secondary radar signal, wherein processing the secondary radar signal includes the steps:
(i) generating a Micro-Doppler spectrogram of the secondary radar signal;
(ii) determining, based on the Micro-Doppler spectrogram, an observed bulk speed of the moving pedestrian, wherein the observed bulk speed corresponds to a speed component that is related to the pedestrian's torso and is oriented along a line of sight extending from the moving pedestrian to the radar sensor system;
(iii) determining, based on the Micro-Doppler spectrogram, at least one gait cycle parameter of the moving pedestrian; and
(iv) determining, based on the determined observed bulk speed and the determined gait cycle parameter, an illumination angle between a moving direction of the moving pedestrian and the line of sight.

### Claim 2 (depends on 1)

A method in accordance with claim 1, wherein
the speed of the moving pedestrian in the moving direction is determined based on the determined observed bulk speed and the determined illumination angle using the formula v=vob/cos(θ), wherein v is the speed of the moving pedestrian in the moving direction, vob is the observed bulk speed and θ is the illumination angle.

### Claim 3 (depends on 1)

A method in accordance with claim 1, wherein
the Micro-Doppler spectrogram is generated by one of a Short-Time-Fourier-Transform and a Wigner-Ville-Distribution technique.

### Claim 4 (depends on 1)

A method in accordance with claim 1, wherein
the observed bulk speed is determined by means of a percentile-based method or a curve-fitting method.

### Claim 5 (depends on 1)

A method in accordance with claim 1, wherein
the at least one gait cycle parameter is an average duration of the pedestrian's gait cycle, an average gait cycle repetition frequency or a number of time bins related to one gait cycle.

### Claim 6 (depends on 1)

A method in accordance with claim 1, wherein
the at least one gait cycle parameter is determined by means of a Fourier analysis.

### Claim 7 (depends on 6)

A method in accordance with claim 6, wherein
a Fast Fourier Transform is applied to an upper envelope and/or to a lower envelope of the Micro-Doppler spectrogram to estimate the gait cycle repetition frequency.

### Claim 8 (depends on 1)

A method in accordance with claim 1, wherein
step (iv) includes relating the determined gait cycle parameter to the determined observed speed and to an estimated height of the moving pedestrian's thigh.

### Claim 9 (depends on 8)

A method in accordance with claim 8, wherein
a relation is used which is based on a kinematic human model.

### Claim 10 (depends on 8)

A method in accordance with claim 8, wherein
the height of the moving pedestrian's thigh is estimated based on a relationship between the height of the moving pedestrian's thigh and the overall height of the pedestrian, in particular based on the relationship Ht≈0.53·Hped, wherein Ht is the height of the moving pedestrian's thigh and Hped is the overall height of the pedestrian.

### Claim 11 (depends on 10)

A method in accordance with claim 10, wherein
the overall height of the moving pedestrian is estimated based on a statistical average height of pedestrians.

### Claim 12 (depends on 1)

A method in accordance with claim 1, wherein
in step (iv), the illumination angle is estimated by means of a recursive state estimator.

### Claim 13 (depends on 1)

A system for the recognition of a moving pedestrian comprising:
a radar sensor system for transmitting a primary radar signal into an observation space and for receiving a secondary radar signal reflected by the moving pedestrian; and
an electronic processing device for processing the secondary radar signal, wherein
the electronic processing device is configured for carrying out a method in accordance with claim 1.

### Claim 14 (depends on 13)

A system in accordance with claim 13, wherein
the radar sensor system is configured to be mounted at or in a motor vehicle.

### Claim 15 (depends on 1)

A computer program product including executable program code which, when executed, carries out a method in accordance with claim 1.