Approximate figures measuring system

• US 5,210,772 A
• Filed: 03/01/1991
• Issued: 05/11/1993
• Est. Priority Date: 03/16/1990
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Nakagawa, Yoshikatsu
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US07/663,301
• Time in Patent Office: 802 Days
• Field of Search: 340/933, 340/934
• US Class Current: 375/139
• CPC Class Codes: G08G 1/01 Detecting movement of traffic to be counted or controlled G08G1/07 - G08G1/14 take precedence

Abstract

An approximate figures measuring system includes a signal transmission device and a signal receiving device. The signal transmission device is arranged in each of any objects to be measured and emits a signal from which a peak can be generated at a receiving device in a predetermined period. The signal receiving device receives the signal transmitted from the signal transmission device and includes a peak detection circuit and a calculation circuit for obtaining an output corresponding to the number of the peaks of the signals from the objects.

Claims

1. A system for measuring an approximate number among a number of known objects in a particular place, comprising:

a signal transmission means arranged in each of the objects to be measured for emitting a PN signal of a specific group, wherein a peak of the PN signal can be generated at a receiving device in a predetermined period; and

a signal receiving means for receiving the PN signal transmitted from said signal transmission means, said signal receiving means having a peak detection means and a calculation means for obtaining an output corresponding to the quantity of the peaks of the PN signal emitted from said objects and for counting the peaks of self-correlation of the PN signal.

2. A system according to claim 1, wherein said calculation means sums an energy level of peaks of self-correlation of the PN signal.

3. A system according to claim 1, wherein said peak detection means includes a bandpass filter, a matched filter and an envelope detector connected in series.

4. A system according to claim 3, wherein said peak detection means further includes a threshold circuit connected to said envelope detector.

5. A system according to claim 1, wherein said peak detection means outputs a pulse series, each pulse corresponding to a respective peak of the PN signal.

6. A system according to claim 5, wherein said calculation means includes an integrator which integrates the pulses for a predetermined period.

7. A system according to claim 5, wherein said calculation means includes a counter circuit which counts the pulses.

8. A system according to claim 1, wherein a plurality of the PN signals of different groups are arranged for different sorts of object, respectively.

9. A system for measuring an approximate number among a number of known objects in a particular place, comprising:

a signal transmission means arranged in each of the objects to be measured for emitting an FM chirp signal, wherein a peak of the FM chirp signal can be generated at a receiving device in a predetermined period; and

a signal receiving means for receiving the FM chirp signal transmitted from said signal transmission means, said signal receiving means having a peak detection means and a calculation means for obtaining an output corresponding to the quantity of the peaks of the FM chirp signal emitted from said objects and for counting the peaks of self-correlation of the FM chirp signal.

10. A system according to claim 9, wherein said peak detection means outputs a pulse series, each pulse corresponding to a respective peak of the FM chirp signal, and includes a bandpass filter, an FM chirp filter and an envelope detector connected in series.

11. A system according to claim 10, wherein said calculation means includes a pulse counter which counts the pulses outputted from said peak detection means.

12. A system for measuring an approximate number along a number of known objects in a particular place, comprising:

a signal transmission means arranged in each of the objects to be measured for emitting a predetermined signal of a specific group, wherein a peak of the predetermined signal can be generated at a receiving device in a predetermined period; and

signal receiving means for receiving the predetermined signal transmitted from said signal transmission means, said signal receiving means having a peak detection means and a calculation means for obtaining an output corresponding to the quantity of the peaks of the predetermined signal emitted from said objects and for counting the peaks of self-correlation of the predetermined signal.

13. A system according to claim 12, wherein said peak detection means outputs a pulse series, each pulse corresponding to a respective peak of the predetermined signal, and includes a bandpass filter, a filter means and an envelope detector connected in series.

14. A system according to claim 13, wherein said calculation means includes a pulse counter which counts the pulses outputted from said peak detection means.