Vehicular radar system

• US 7,245,359 B1
• Filed: 09/28/2005
• Issued: 07/17/2007
• Est. Priority Date: 10/01/2004
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Hoashi, Yoshiaki
• Primary Examiner(s): Tarcza; Thomas H.
• Assistant Examiner(s): ALSOMIRI, ISAM A
• Application Number:
  US11/237,115
• Publication Number:
  US 20070146684A1
• Time in Patent Office: 657 Days
• Field of Search: 356/4.01, 356/4.07, 356/5.01, 356/5.1, 356/28, 342 70- 72
• US Class Current: 356/5.01
• CPC Class Codes: G01S 17/48 Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 3/783 using amplitude comparison of signals derived from static detectors or detector systems
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating

Abstract

A radar system of a vehicle has a zero-cross comparator, an integrator, and a sensor. The comparator compares a light reception signal output from each one of photoreceptive elements with a predetermined standard signal and outputs a comparison signal indicating two different states corresponding to a result of the comparison. The integrator samples the comparison signal and converts the comparison signal into one-bit digital data. The integrator integrates the digital data for each photoreceptive element. The sensor compares the integrated data of each photoreceptive element with a predetermined integration standard value. The sensor senses a reflection object based on the integrated data equal to or greater than the integration standard value.

Claims

1. A radar system of a vehicle, the radar system having a light emitter for repeatedly emitting laser light so that the laser light is emitted over a predetermined angular range at least along width direction of the vehicle in each light emission, a photoreceptor for outputting light reception signals, which are output from photoreceptive elements in accordance with intensity of reflected laser light reflected by a reflection object, the photoreceptive elements being arranged at least along the width direction of the vehicle, the radar system comprising:

a comparator for comparing the light reception signal output from each photoreceptive element with a predetermined standard signal and for outputting for each photoreceptive element a comparison signal indicating two different states corresponding to a result of the comparison;

an integrator for sampling the comparison signal of each photoreceptive element and for converting the comparison signal into one-bit digital data while a predetermined time passes after the laser light is emitted, wherein the integrator integrates the digital data for each photoreceptive element based on emitting timing of the laser light every time the laser light is emitted, and outputs the integrated data; and

a sensor for comparing the integrated data of each photoreceptive element with a predetermined integration standard value and for sensing the reflection object based on the integrated data equal to or greater than the integration standard value.

2. The radar system as in claim 1, further comprising:

a light shield in the photoreceptor for shielding at least one of the photoreceptive elements from the light; and

an eliminator for eliminating a base noise component superimposed on the light reception signal of the photoreceptive element, which is not shielded by the light shield, based on the light reception signal of the photoreceptive element shielded by the light shield.

3. The radar system as in claim 1, wherein

the sensor senses a distance to the reflection object and an angle of the reflection object along the width direction of the vehicle, the sensor sensing the angle based on a position of the photoreceptive element corresponding to the integration signal equal to or greater than the integration standard value.

4. The radar system as in claim 3, wherein

the number of the photoreceptive elements is set in accordance with necessary angular resolution of the angle along the width direction of the vehicle.

5. A radar system of a vehicle, the radar system having a light emitter for repeatedly emitting laser light so that the laser light is emitted over a predetermined angular range at least along width direction of the vehicle in each light emission, a photoreceptor for outputting light reception signals, which are output from photoreceptive elements in accordance with intensity of reflected laser light reflected by a reflection object, the photoreceptive elements being arranged at least along the width direction of the vehicle, the radar system comprising:

an adder for adding the light reception signals output from a predetermined number of the adjacent photoreceptive elements and for outputting the added signal;

a comparator for comparing the added signal with a predetermined standard signal and for outputting for each predetermined number of the photoreceptive elements a comparison signal indicating two different states corresponding to a result of the comparison;

an integrator for sampling the comparison signal and for converting the comparison signal into one-bit digital data, wherein the integrator integrates the digital data for each predetermined number of the photoreceptive elements based on the emitting timing of the laser light every time the laser light is emitted, and outputs the integrated data; and

a sensor for comparing the integrated data of each predetermined number of the photoreceptive elements with a predetermined integration standard value and for sensing the reflection object based on the integrated data equal to or greater than the integration standard value.

6. The radar system as in claim 5, further comprising:

a light shield in the photoreceptor for shielding at least one of the photoreceptive elements from the light; and

an eliminator for eliminating a base noise component superimposed on the light reception signal of the photoreceptive element, which is not shielded by the light shield, based on the light reception signal of the photoreceptive element shielded by the light shield.

7. The radar system as in claim 5, wherein

the sensor senses a distance to the reflection object and an angle of the reflection object along the width direction of the vehicle, the sensor sensing the angle based on a position of the photoreceptive element corresponding to the integration signal equal to or greater than the integration standard value.

8. The radar system as in claim 7, wherein

the number of the photoreceptive elements is set in accordance with necessary angular resolution of the angle along the width direction of the vehicle.