Radio detection device and method

• US 7,868,816 B2
• Filed: 02/20/2009
• Issued: 01/11/2011
• Est. Priority Date: 02/22/2008
• Status: Expired due to Fees

• Current Assignee: Omron Automotive Electronics Company Limited (Nidec Corporation)
• Original Assignee: Omron Corporation
• Inventors: Ichiyanagi, Hoshibumi, Ohara, Hideyuki, Numata, Hiroyuki, Nishidai, Tetsuo
• Primary Examiner(s): Sotomayor; John B
• Application Number:
  US12/390,200
• Publication Number:
  US 20090213964A1
• Time in Patent Office: 690 Days
• Field of Search: 342 70- 72, 342/80, 342 91- 92, 342/147, 342149-152, 342194-196
• US Class Current: 342/70
• CPC Class Codes: G01S 3/32 derived from different combinations of signals from separate antennas, e.g. comparing sum with difference

Abstract

A radio detection device includes two or more reception antennas, for detecting a detecting object by a mono-pulse method; the radio detection device including: a variable gain unit for discretely changing respective signal intensity of a difference signal and a sum signal of each reception signal received by the two or more reception antennas; an A/D conversion unit for performing A/D conversion process on the difference signal or the sum signal, the difference signal or the sum signal having the signal intensity changed by the variable gain unit; an angle calculating portion for calculating an angle by the mono-pulse method using the difference signal and the sum signal after the A/D conversion process by the A/D conversion unit; and a control unit for performing a control of individually switching a conversion magnification of the signal intensity by the variable gain unit with respect to the difference signal and the sum signal.

Claims

1. A radio detection device including two or more reception antennas, for detecting a detecting object by a mono-pulse method;

the radio detection device comprising;

a variable gain unit for discretely changing respective signal intensity of a difference signal and a sum signal of each reception signal received by the two or more reception antennas;

an A/D conversion unit for performing A/D conversion process on the difference signal or the sum signal, the difference signal or the sum signal having the signal intensity changed by the variable gain unit;

an angle calculating portion for calculating an angle by the mono-pulse method using the difference signal and the sum signal after the A/D conversion process by the A/D conversion unit; and

a control unit for performing a control of individually switching a conversion magnification of the signal intensity by the variable gain unit with respect to the difference signal and the sum signal.

2. The radio detection device according to claim 1, wherein the control unit compares the respective signal intensity of the difference signal and the sum signal with a predetermined threshold value, and performs a control of switching the conversion magnification of the variable gain unit based on the result.

3. The radio detection device according to claim 2, wherein the control unit comprises:

a difference signal peak/holding portion for holding a peak value and a bottom value of the difference signal outputted in a predetermined period by the A/D conversion unit;

a difference signal threshold value determining portion, set with a peal value threshold value and a bottom value threshold value as the predetermined threshold value, for comparing the peak value held in the difference signal peak/bottom holding portion and the peak value threshold value, comparing the bottom value held in the difference signal peak/bottom holding portion and the bottom value threshold value, and determining a conversion magnification with respect to the difference signal of the variable gain unit based on the results of the comparisons;

a sum signal peak/bottom holding portion for holding a peak value and a bottom value of the sum signal outputted in a predetermined period by the A/D conversion unit; and

a sum signal threshold value determining portion, set with a peak value threshold value and a bottom value threshold value as the predetermined threshold value, for comparing the peak value held in the sum signal peak/bottom holding portion and the peak value threshold value, comparing the bottom value held in the sum signal peak/bottom holding portion and the bottom value threshold value, and determining a conversion magnification with respect to the sum signal of the variable gain unit based on the results of the comparisons.

4. The radio detection device according to claim 3, wherein the threshold value determining portion determines one of A times and B times, wherein A and B are different numerical values as the conversion magnification on the difference signal and the sum signal of the variable gain unit.

5. The radio detection device according to claim 4, wherein

as a state of the radio detection device, a first state in which the conversion magnification of the variable gain unit is A times and a second state in which the conversion magnification of the variable gain unit is B times independently exist for the sum signal and the difference signal;

as the peak value threshold value, a threshold value used when the conversion magnification of the variable gain unit is B times is set as +Th_H, and a threshold value used when the conversion magnification is A times is set as +Th_L;

as the bottom value threshold value, a threshold value used when the conversion magnification of the variable gain unit is B times is set as −

Th_H, and a threshold value used when the conversion magnification is A times is set as −

Th_L;

a full scale range of the A/D conversion unit is described as FSR, a center value of the FSR is described as zero, a value of half of the FSR on the peak side with respect to zero is described as +FSR/2, and a value of half of the FSR on the bottom side with respect to zero is described as −

FSR/2; and

the difference signal threshold value determining portion or the sum signal threshold value determining portion performs a control with respect to a target signal, which is the difference signal or the sum signal, to determine the conversion magnification on the target signal of the variable gain unit, wherein the control comprises;

maintaining the first state when a peak value is between +Th_L and +FSR/2 or a bottom value is between −

Th_L and −

FSR/2 in the first state with respect to the target signal of a predetermined period,

transitioning to the second state when a peak value is between +Th_L and 0 and a bottom value is between −

Th_L and 0 in the first state with respect to the target signal of the predetermined period,

maintaining the second state when a peak value is between +Th_H and 0 and a bottom value is between −

Th_H and 0 in the second state with respect to the target signal of the predetermined period, and

maintaining the second state when a peak value is between +Th_H and +FSR/2 or a bottom value is between −

Th_H and −

FSR/2 in the second state with respect to the target signal of the predetermined period.

6. The radio detection device according to claim 4, wherein the angle calculating portion

calculates the angle using a quantity of (1/A) times a quantity corresponding to the signal intensity of the target signal after the A/D conversion process when the conversion magnification with respect to the target signal of the variable gain unit is A times;

and

calculates the angle using a quantity of (1/B) times a quantity corresponding to the signal intensity of the target signal after the A/D conversion process when the conversion magnification with respect to the target signal of the variable gain unit is B times.

7. A radio detection method of a radio detection device including two or more reception antennas, for detecting a detecting object by a mono-pulse method;

wherein when the radio detection device includes,

a variable gain unit for discretely changing respective signal intensity of a difference signal and a sum signal of each reception signal received by the two or more reception antennas;

an A/D conversion unit for performing A/D conversion process on the difference signal or the sum signal the difference signal or the sum signal having the signal intensity changed by the variable gain unit; and

an angle calculating portion for calculating an angle by the mono-pulse method using the difference signal and the sum signal after the A/D conversion process by the A/D conversion unit;

wherein the radio detection method comprises;

performing a control of individually switching a conversion magnification of the signal intensity by the variable gain unit with respect to the difference signal and the sum signal.