High performance vehicle radar system

• US 6,232,910 B1
• Filed: 02/19/1998
• Issued: 05/15/2001
• Est. Priority Date: 02/20/1998
• Status: Expired due to Fees

• Current Assignee: Gentherm Incorporated
• Original Assignee: Gentherm Incorporated
• Inventors: Bell, David Allen, Taur, Roger Rong, Delacueva, Jess
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US09/253,468
• Time in Patent Office: 1,181 Days
• Field of Search: 342/70-72, 342/104-110, 342/118, 342/134-147, 342/175, 342/189, 342/195, 342/202, 342/20, 342/21, 342/22, 342/27, 342/28
• US Class Current: 342/70
• CPC Class Codes: B60Q 1/0023 the element being a sensor, e.g. distance sensor, camera
• CPC Class Codes: B60W 2050/143 Alarm means
• CPC Class Codes: G01S 13/18 wherein range gates are used
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/9314 Parking operations
• CPC Class Codes: G01S 2013/9315 Monitoring blind spots
• CPC Class Codes: G01S 2013/9317 Driving backwards
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/9323 Alternative operation using light waves
• CPC Class Codes: G01S 2013/9325 for inter-vehicle distance regulation, e.g. navigating in platoons
• CPC Class Codes: G01S 2013/9327 Sensor installation details
• CPC Class Codes: G01S 2013/93272 in the back of the vehicles
• CPC Class Codes: G01S 2013/93277 in the lights
• CPC Class Codes: H01Q 1/3233 particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems
• CPC Class Codes: H01Q 1/3283 side-mounted antennas, e.g. bumper-mounted, door-mounted mounted on windscreens H01Q1/1271
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching

Abstract

A radar system is described for use in vehicular applications. The radar system is particularly suited to backup warning systems and lane-change warning systems. The radar minimizes many of the problems found in the prior art by providing programmable delays and programmable gain. The radar uses a range search algorithm to detect and sort targets at various ranges within the field of view of the radar. Each target range corresponds to a particular delay and gain setting. The radar searches for targets at the various ranges by running a target search algorithm. For each target range, the search algorithm causes the proper time delay and gain setting. Targets within the selected range are detected and catalogued. Speed of the targets is obtained through Doppler processing. A display is used to warn the driver of the vehicle of the presence of targets at the various ranges. The warning may be visual and/or audible. When used in a lane-change system, issuance of an audible warning is based on the speed of the vehicle.

Claims

1. A pulse radar comprising:

a radio frequency oscillator;

a transmit pulse generator;

a transmit antenna;

a transmit switch which connects said oscillator to said transmit antenna said transmit switch operated by an output of said transmit pulse generator to transmit a radio frequency pulse of energy, said radio-frequency pulse having a leading edge and a trailing edge; and

a receive antenna which provides received signals to a receiver, wherein said receiver measures a range to a target by calculating a time required for said radio frequency pulse to traverse a path from said transmit antenna, to said target, and then to said receive antenna, wherein said receiver calculates said time by detecting said trailing edge.

2. A method of using a pulse radar to search for targets and to measure a downrange distance to the targets, comprising the steps of:

transmitting a pulse of radio frequency energy, said pulse having a leading edge and a trailing edge;

receiving reflections of said pulse of radio frequency energy, said reflections produced by said pulse of radio frequency energy being reflected by target objects; and

measuring a time when said pulse is received by sensing said trailing edge.

3. A radar sensor for tracking and discriminating one or more Doppler shifted targets in downrange distance, said radar sensor comprising:

a radio frequency transmitter which transmits pulses of radio frequency energy;

a radio frequency receiver which receives said pulses of radio frequency energy and converts said pulses of radio frequency energy into an intermediate frequency signal;

a digital to analog converter which converts said intermediate frequency signal into a stream of digital samples in response to a programmable time delay; and

a controller unit which programs said programmable time delay to detect targets with a field of view of said sensor at different downrange distances, said distances measured according to a trailing edge of said pulses of radio frequency energy.

4. The radar sensor of claim 3, wherein said controller unit computes a velocity of said targets.

5. The radar sensor of claim 3, wherein said controller unit computes an acceleration of said targets.

6. The radar sensor of claim 3, wherein said sensor is connected to an information bus.

7. The radar sensor of claim 6, wherein said sensor supplies information about said targets to an airbag deployment system.

8. The radar sensor of claim 3, further comprising a visual warning device which projects a visual warning signal, said visual warning signal projecting a first warning when said radar sensor detects a target having a first velocity, said visual warning signal projecting a second warning when said radar sensor detects a target having a second velocity.

9. An array of light sources to be placed in a field of view of an antenna while still allowing the antenna to radiate and receive electromagnetic energy, comprising:

a first plurality of power supply lines, said power supply lines oriented substantially orthogonal to an E-field produced by an antenna, said E-field propagating through a plane defined by at least two of the power supply lines in said first plurality of power supply lines;

a second plurality of power supply lines, said power supply lines oriented substantially orthogonal to an E-field produced by said antenna; and

a plurality of light sources, each source having a first terminal and a second terminal, said first terminal provided to at least one power supply line in said first plurality of power supply lines, said second terminal provided to at least one power supply line in said second plurality of power supply lines.

10. The array of claim 9, further comprising a power supply bus, said power supply bus provided to each of said first plurality of power supply lines, said first plurality of power lines lying in a plane through which said E-field propagates.

11. A method for transmitting RF electromagnetic energy through a plurality of light sources comprising the steps of:

providing a power supply conductor to each of said light sources; and

orienting a substantial portion of said power supply conductors orthogonal to an E-field of said RF electromagnetic energy.

12. A method for transmitting electromagnetic energy through a plurality of light sources comprising the steps of:

providing a conductor to power a light source in an array comprising a plurality of light sources; and

arranging said conductor to reduce electromagnetic coupling between said conductor and an E-field produced by an antenna disposed to radiate or receive said electromagnetic energy through said array.

13. A radar sensor for tracking and discriminating one or more Doppler shifted targets in downrange distance, said sensor integrated into a vehicle taillight, said radar sensor comprising:

a radio frequency transmitter which transmits pulses of radio frequency energy;

a radio frequency receiver which receives said pulses of radio frequency energy and converts said pulses of radio frequency energy into an intermediate frequency signal;

a digital to analog converter which converts said intermediate frequency signal into a stream of digital samples in response to a programmable time delay;

a controller unit which programs said programmable time delay to detect targets with a field view of said sensor at different downrange distances; and

a vehicle taillight comprising an array of light emitting diodes.

14. The radar sensor of claim 13, wherein said controller unit computes a velocity of said targets.

15. The radar sensor of claim 13, wherein said controller unit computes a distance to said targets by locating a trailing edge of received pulses.

16. The radar sensor of claim 13, wherein said sensor is connected to a vehicle power circuit, and said sensor provides a modulated carrier onto said vehicle power circuit.

17. The radar sensor of claim 16, wherein said sensor supplies information about said targets to means for displaying a warning based on target data obtained from said vehicle power circuit.

18. The radar sensor of claim 16, wherein said sensor supplies information about said targets to an airbag deployment system.

19. The radar sensor of claim 16, wherein said sensor supplies information about said targets to other vehicle systems connected to said vehicle power circuit.

20. The radar sensor of claim 13, wherein said radio frequency transmitter transmits said pules of radio frequency energy through said array of light emitting diodes.

21. The radar sensor of claim 20, further comprising an antenna placed in front of said lighting array means such that a portion of the light from said lighting array means shines toward said antenna.

22. The radar sensor of claim 20, further comprising an antenna placed behind said lighting array means such that said lighting array means is at least partially in a field of view of said antenna.

23. The radar sensor of claim 13, further comprising a user interface.

24. The radar sensor of claim 13, further comprising an audible warning device which projects an audible warning signal, said warning signal projecting a firsts sound when said radar sensor detects a target having a first downrange distance, said warning signal projecting a second sound when said radar sensor detects a target having a second downrange distance.

25. The radar sensor of claim 13, further comprising an audible warning device which projects an audible warning signal, said warning signal projecting a first sound when said radar sensor detects a closest target having a first downrange distance, said warning signal projecting a second sound when said radar sensor detects a closest target having a second downrange distance.

26. The radar sensor of claim 13, further comprising an audible warning device which projects an audible warning signal, said warning signal projecting a first sound when said radar sensor detects a target having a first velocity, said warning signal projecting a second sound when said radar sensor detects a target having a second velocity.

27. The radar sensor of claim 13, further comprising a visual warning device which projects a visual warning signal, said visual warning signal projecting a first warning when said radar sensor detects a target having a first velocity, said visual warning signal projecting a second warning when said radar sensor detects a target having a second velocity.

28. The radar sensor of claim 13, wherein said array of light emitting diodes is placed in front of an antenna connected to said transmitter such that said antenna radiates toward said array of light emitting diodes.

29. The radar sensor of claim 13, wherein said array of light emitting diodes is placed behind an antenna connected to said transmitter such that a portion of the light emitted by said array shines toward said antenna.

30. A radar sensor for tracking and discriminating one or more Doppler shifted targets in downrange distance, said radar sensor comprising:

radar means for transmitting pulses of radio frequency energy and receiving reflected pulses of radio frequency energy and converting said reflected pulses of radio frequency energy into an intermediate frequency signal;

a digital to analog converter for converting said intermediate frequency signal into a stream of digital samples in response to a programmable time delay;

controller means for programming said programmable time delay to detect targets with a field view of said sensor at different downrange distances; and

lighting array means for signaling drivers of vehicles, said radar means transmitting and receiving said pulses of radio frequency energy through said lighting means.

31. A lane-change aid system for providing information to a driver of a vehicle about objects in a side-object region, said system comprising:

a vehicle taillight illumination source;

a radar sensor unit which provides radar target information to a user interface, said radar sensor unit disposed behind said illumination source; and

a speedometer pick-up which provides vehicle speed information to said user interface.

32. The lane change aid system of claim 31, wherein said radar sensor unit comprises:

a radio frequency transmitter which transmits pulses of radio frequency energy;

a radio frequency receiver which receives said pulses of radio frequency energy, and converts said pulses of radio frequency energy into an intermediate frequency signal;

a digital to analog converter which converts said intermediate frequency signal into a stream of digital samples in response to a programmable time delay; and

a controller unit which programs said programmable time delay to detect targets with a field of view of said sensor at different downrange distances.

33. The lane-change aid system of claim 32, wherein said user interface does not warn said driver about objects detected by said radar sensor beyond a maximum range when said vehicle is moving at less than a desired speed.

34. The lane-change aid system of claim 32, wherein said user interface does not audibly warn said driver about objects detected by said radar sensor beyond a range of about five feet when said vehicle is traveling less than about 15 miles per hour.

35. The lane-change aid system of claim 32, wherein each of said radar sensors comprises a controller unit which provides radar target information to an information bus.

36. The lane-change aid system of claim 32, wherein said user interface comprises a visual indicator.

37. The lane-change aid system of claim 32, wherein said user interface comprises an audible warning and a visual warning.

38. The lane-change aid system of claim 32, wherein said user interface comprises an audible warning.

39. The lane-change aid system of claim 32, wherein said user interface does not sound said audible warning when said vehicle is traveling at less than a desired speed.

40. The lane-change aid system of claim 32, wherein said user interface sounds an audible warning according to a distance to a detected target and a relative speed between said vehicle and said detected target.

41. The lane-change aid system of claim 32, further comprising a turn-signal pick-up, said array and said transmitter activated in response to said turn signal pickup.

42. The lane-change aid system of claim 41, wherein said user interface does not audibly warn a driver of left-side targets unless said turn-signal pick-up indicates that a left-side turn-signal has been activated.

43. The lane-change aid system of claim 32, wherein said user interface does not audibly warn a driver of right-side targets unless said turn-signal pick-up indicates that a right-side turn-signal has been activated.