Method and apparatus for adjusting orientation direction of array antenna of direction detection apparatus

• US 20080224918A1
• Filed: 11/27/2007
• Published: 09/18/2008
• Est. Priority Date: 12/07/2006
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Shimizu, Koji
• Granted Patent: US 7,755,537 B2
• Time in Patent Office: Days
• US Class Current: 342/147
• CPC Class Codes: G01S 13/34 using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
• CPC Class Codes: G01S 13/584 adapted for simultaneous range and velocity measurements
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/93185 Controlling the brakes
• CPC Class Codes: G01S 2013/932 using own vehicle data, e.g. ground speed, steering wheel direction
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles
• CPC Class Codes: G01S 2013/9329 cooperating with reflectors or transponders
• CPC Class Codes: G01S 7/4026 Antenna boresight
• CPC Class Codes: G01S 7/4086 in a calibrating environment, e.g. anechoic chamber
• 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 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching

Abstract

A direction detection apparatus transmits radar waves, with resultant reflected waves being received as incident waves by elements of an array antenna. Normally the direction of a target object is calculated based on analyzing respective received signals from the antenna elements, in calculations utilizing an estimated total number of incident wave directions. In an antenna direction adjustment mode, an actual number of target objects, and hence actual number of incident wave directions, is utilized in place of the estimated value, thereby enabling direction detection information to be obtained which does not fluctuate with time, thus facilitating the adjustment.

Claims

1. A method of adjusting an orientation direction of an array antenna of a direction detection apparatus to be aligned along a specific direction, said array antenna comprising a plurality of antenna elements and said direction detection apparatus comprising

a transmitting antenna and transmitting circuitry adapted to transmit radar waves, and receiving circuitry adapted to acquire respective received signals of said antenna elements, with said signals resulting from reflected radar waves that are incident on said antenna elements,

direction calculation circuitry adapted to calculate respective directions of said incident radar waves based on said received signals of said antenna elements, with said calculation being executed based on an assumption that a total number of said incident wave directions is a specific set value,

output circuitry adapted to output information expressing said directions that are calculated by said direction calculation means, and

estimation setting circuitry adapted to derive an estimated number of said incident wave directions, based on said received signals of said antenna elements, and to establish said estimated number as said set value that is utilized by said direction calculation means;

wherein said method comprises adjusting said orientation direction of the array antenna to become aligned in a predetermined relationship to one or more stationary objects from which reflected radar waves are received by said array antenna, by;

inhibiting said operation of said estimation setting circuitry for establishing said estimated number as said set value that is utilized by said direction calculation circuitry,

establishing a predetermined fixed number as said set value that is utilized by said direction calculation circuitry, and

adjusting said orientation direction based upon an estimated direction of at least one of said stationary reflecting objects as expressed by said information outputted by said output circuitry.

2. The method according to claim 1, wherein said predetermined fixed number is equal to a total number of said stationary reflecting objects.

3. The method according to claim 1, comprising a single stationary reflecting object, wherein said adjustment is performed to align said orientation direction of said array antenna along a direction of said single stationary reflecting object with respect to said array antenna.

4. A direction detection apparatus comprising

a transmitting circuit in combination with a transmitting antenna, for transmitting radar waves,

an array antenna comprising a plurality of antenna elements and a receiving circuit coupled to receive respective received signals of said antenna elements, with said signals resulting from reflected radar waves that are incident on said array antenna from one or more respectively different directions,

direction calculation circuitry adapted to calculate said directions of said incident radar waves, based on said received signals of said antenna elements, with said calculation being executed based on an assumption that a total number of said incident radar wave directions is a specific set value,

output circuitry adapted to produce information expressing said directions that are calculated by said direction calculation circuitry,

estimated value setting circuitry adapted to derive an estimated number of said incident radar wave directions, based on said received signals of said antenna elements;

fixed value setting circuitry adapted to predetermine a fixed number to be applied as said set value that is utilized by said direction calculation circuitry, and

operation control circuitry responsive to an externally supplied command signal for selectively establishing, as said set value that is utilized by said direction calculation circuitry, said estimated number of incident wave directions and said predetermined fixed number.

5. The apparatus according to claim 4, comprising an electronic apparatus capable of communication with said direction detection apparatus, said electronic apparatus comprising

an information display device,

an input device operable by a user for inputting external commands to said electronic apparatus,

display control circuitry adapted to acquire said direction information from said output circuitry of said direction detection apparatus, and to control said information display device for displaying said direction information, and

mode changeover circuitry responsive to an external command specifying a fixed incident wave number mode for transmitting a corresponding command signal to said operation control circuitry of said direction detection apparatus, designating that said predetermined fixed number be established as said set value, and responsive to an external command specifying an estimated incident wave number mode for transmitting a corresponding command signal to said operation control circuitry, designating that said estimated number be established as said set value.