Vehicle Pre-Impact Sensing System Having Signal Modulation

• US 20090299632A1
• Filed: 05/20/2009
• Published: 12/03/2009
• Est. Priority Date: 05/29/2008
• Status: Active Grant

• Current Assignee: Aptiv Technologies AG
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Murphy, Morgan D., Taylor, Ronald M., Hawes, Kevin J.
• Granted Patent: US 8,249,798 B2
• Time in Patent Office: Days
• US Class Current: 701/300
• CPC Class Codes: B60R 2021/0006 Lateral collision
• CPC Class Codes: B60R 2021/01027 Safing sensors
• CPC Class Codes: B60R 2021/01327 Angular velocity or angular acceleration
• CPC Class Codes: B60R 21/0134 responsive to imminent contact with an obstacle , e.g. using radar systems
• CPC Class Codes: G01S 17/87 Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 2013/93274 on the side of the vehicles
• CPC Class Codes: G01S 7/4802 using analysis of echo signal for target characterisation; Target signature; Target cross-section

Abstract

A vehicle pre-impact sensing system is provided that includes an array of energy signal transmitters mounted on a vehicle for transmitting signals within multiple transmit zones spaced from the vehicle and an array of receiver elements mounted on the vehicle for receiving signals reflected from an object located in one or more multiple receive zones indicative of the object being in certain one or more zones. A processor processes the received reflected signals and determines range, location, speed and direction of the object, determines whether the object is expected to impact the vehicle as a function of the determined range, location, speed and direction of the object, and generates an output signal indicative of a pre-impact event. The system may detect one or more features of a target object, such as a front end of a vehicle. Additionally, the system may modulate the transmit beams. Further, the system may perform a terrain normalization to remove stationary items.

Claims

1. A vehicle pre-impact sensing system comprising:

an array of energy signal transmitters mounted on a vehicle for transmitting energy signals within multiple transmit zones spaced from the vehicle;

an array of receiver elements mounted on the vehicle for receiving the signals reflected from an object located in one or more multiple receive zones indicative of the object being in certain one or more receive zones; and

a processor for processing the received reflected signals and determining range, location, speed and direction of the object, wherein the processor modulates the transmit energy signals and determines a difference in sensed signals for each zone with the transmitters turned on and turned off, said processor further determining whether the object is expected to impact the vehicle as a function of the determined range, location, speed and direction of the object, and generates an output indicative of a sensed pre-impact event.

2. The sensing system as defined in claim 1, wherein the transmit energy signals are modulated by turning the transmitters on and off at a modulation frequency.

3. The sensing system as defined in claim 1, wherein the modulation is at a rate of about 300 Hz.

4. The sensing system as defined in claim 1, wherein the difference in sensed signals provides a ripple signal, wherein the ripple signal is compared to a calibration table to detect a feature of the object.

5. The sensing system as defined in claim 1, wherein the array of energy signal transmitters comprises an array of light transmitters.

6. The sensing system as defined in claim 5, wherein the array of light transmitters comprises an array of infrared transmitters configured to emit infrared radiation in designated multiple transmit zones.

7. The sensing system as defined in claim 6, wherein the array of receiver elements comprises an array of photodetectors for receiving reflected infrared radiation, wherein the photodetectors receive light signals including reflected signals from the designated receive zones.

8. The sensing system as defined in claim 1, wherein the system senses an object on a lateral side of the vehicle.

9. The sensing system as defined in claim 1, wherein the processor further determines size of the object, and wherein the processor generates an output signal indicative of a sensed pre-impact event further based on the determined size of the object.

10. The sensing system as defined in claim 1 further comprising an additional signal receiver for receiving energy signals within an additional beam, wherein signals measured with the additional receiver are subtracted from the signals measured with each of the array of receivers to remove noise.

11. The sensing system as defined in claim 1, wherein the transmitter array and receiver array each comprises a plurality of cone-shaped beams.

12. A method of detecting an expected impact of an object with a vehicle, said method comprising the steps of:

transmitting signals with an array of transmitters within multiple transmit zones incrementally spaced from the vehicle, within one or more zones at a time;

receiving signals with an array of receivers reflected from an object located in the one or more multiple receive zones indicative of the object being in certain one or more received zones;

processing the received reflected signals;

determining a location of the object;

determining a range to the object;

determining speed of the object;

determining direction of the object;

modulating the transmit energy signals array;

determining a difference in sensed signals for each zone with the transmitters turned on and off;

determining whether the object is expected to impact the vehicle as a function of the determined range, location, speed and direction of the object; and

generating an output indicative of the sensed pre-impact event.

13. The method as defined in claim 12, wherein the step of modulating the transmit energy signals comprises turning each of the transmitters on and off at a modulation frequency.

14. The method as defined in claim 13 further comprising the step of determining a ripple signal based on the difference and using the ripple signal to detect a feature of the object.

15. The method as defined in claim 14, wherein the detected feature of the object is used to enhance the determination of range to the object.