Radar sensor module

• US 9,063,230 B2
• Filed: 11/06/2013
• Issued: 06/23/2015
• Est. Priority Date: 10/08/2008
• Status: Active Grant

• Current Assignee: Aptiv Technologies AG
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Alland, Stephen W., Shi, Shawn
• Primary Examiner(s): Brainard, Timothy A
• Application Number:
  US14/073,489
• Publication Number:
  US 20140118179A1
• Time in Patent Office: 594 Days
• Field of Search: 342/70, 342/22
• US Class Current: 1/1
• CPC Class Codes: G01S 13/867 Combination of radar systems with cameras
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/93276 in the windshield area
• CPC Class Codes: G01S 7/025 involving the transmission of linearly polarised waves
• CPC Class Codes: H01Q 1/1271 for mounting on windscreens
• CPC Class Codes: H01Q 1/3291 mounted in or on other locations inside the vehicle or vehicle body
• CPC Class Codes: H01Q 15/04 comprising wave-guiding channel or channels bounded by effective conductive surfaces substantially perpendicular to the electric vector of the wave, e.g. parallel-plate waveguide lens
• CPC Class Codes: H01Q 21/0075 Stripline fed arrays H01Q21/065 takes precedence
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037
• CPC Class Codes: H01Q 9/0435 using two feed points

Abstract

A sensor module configured to be located behind a window of a vehicle to detect an object through the window and about the vehicle. The module includes a radar unit with an antenna and a controller. The antenna emits and/or receives a radar signal through the window with a selected or preferred polarization. The polarization determines a preferred angle of propagation of the radar signal through the window based on reflection characteristics of the window that vary with impingement angle and transmitted polarization. By varying the transmitted polarization vs. beam direction when a directional antenna is used, the signal propagating through the windshield can be maximized to enhance object detection over a range of signal directions. Also, by varying the transmitted polarization when an omnidirectional type antenna is used, the object can be ‘illuminated’ with variable intensity and detected with variable sensitivity.

Claims

1. A sensor module configured to be located behind a window of a vehicle to detect an object through the window and in an area about the vehicle, said module comprising:

an antenna configured to emit a radar signal through the window and into the area, wherein the radar signal is characterized by a transmitted polarization of the radar signal, wherein the transmitted polarization is influenced by a first transmit signal received at a first port of the antenna and a second transmit signal received at a second port of the antenna; and

a controller configured to output the first transmit signal and the second transmit signal, wherein the first transmit signal is characterized by a first characteristic, and the second transmit signal is characterized by a second characteristic, wherein a relative difference between the first characteristic and the second characteristic is selected based on a preferred angle of propagation of the radar signal through the window.

2. The module in accordance with claim 1, wherein the preferred angle comprises a rake angle of the window and an azimuth angle relative to a boresight of the antenna.

3. The module in accordance with claim 1, wherein the first characteristic includes a first amplitude of the first transmit signal, and the second characteristic includes a second amplitude of the second transmit signal, wherein an amplitude difference between the first amplitude and the second amplitude corresponds to the preferred angle.

4. The module in accordance with claim 1, wherein the first characteristic includes a first amplitude and a first phase of the first transmit signal, and the second characteristic includes a second amplitude and a second phase of the second transmit signal, wherein a characteristic difference between the first characteristic and the second characteristic corresponds to the preferred angle.

5. The module in accordance with claim 1, wherein the antenna is configured to output a first detection signal and a second detection signal in response to a reflected signal from the area that passes through the window.

6. The module in accordance with claim 5, wherein the controller is configured to determine an object direction angle based on the first detection signal, the second detection signal, and the transmitted polarization of the radar signal.

7. The module in accordance with claim 6, wherein the object direction angle is determined based on the transmitted polarization used when the reflected signal exhibits maximum amplitude.

8. The module in accordance with claim 1, wherein the module further comprises

a camera component located in the module and configured to capture an image of the area.

9. The module in accordance with claim 8, wherein the antenna is configured to output a first detection signal and a second detection signal in response to a reflected signal from the area that passes through the window, and the controller is further configured to determine an object location relative to the vehicle based on the first detection signal, the second detection signal, the transmitted polarization of the radar signal, and the image of the area.

10. The module in accordance with claim 1, wherein

the antenna is further configured to output a first detection signal and a second detection signal in response to a reflected signal from the area that passes through the window and impinges on the antenna, wherein the reflected signal is characterized by a received polarization of the reflected signal;

and

the controller is further configured to receive the first detection signal and the second detection signal, wherein the first detection signal is characterized by a first characteristic, and the second detection signal is characterized by a second characteristic, wherein a relative difference between the first characteristic and the second characteristic is selected based on a preferred angle of propagation of the radar signal through the window.

11. The module in accordance with claim 10, wherein the object direction angle is determined based on the reflected polarization used when the reflected signal exhibits maximum amplitude.

12. A sensor module configured to be located behind a window of a vehicle to detect an object through the window and in an area about the vehicle, said module comprising:

an antenna configured to output a first detection signal and a second detection signal in response to a reflected signal from the area that passes through the window and impinges on the antenna, wherein the reflected signal is characterized by a received polarization of the reflected signal; and

a controller configured to receive the first detection signal and the second detection signal, wherein the first detection signal is characterized by a first characteristic, and the second detection signal is characterized by a second characteristic, wherein a relative difference between the first characteristic and the second characteristic is selected based on a preferred angle of propagation of the radar signal through the window.

13. The module in accordance with claim 12, wherein the preferred angle comprises a rake angle of the window and an azimuth angle relative to a boresight of the antenna.

14. The module in accordance with claim 12, wherein the object direction angle is determined based on the reflected polarization used when the reflected signal exhibits maximum amplitude.

15. The module in accordance with claim 12, wherein

the antenna is further configured to emit a radar signal through the window and into the area, wherein the radar signal is characterized by a transmitted polarization of the radar signal, wherein the transmitted polarization is influenced by a first transmit signal received at a first port of the antenna and a second transmit signal received at a second port of the antenna, and

the controller is further configured to output the first transmit signal and the second transmit signal, wherein the first transmit signal is characterized by a first characteristic, and the second transmit signal is characterized by a second characteristic, wherein a relative difference between the first characteristic and the second characteristic is selected based on a preferred angle of propagation of the radar signal through the window.