Moving object discriminating system

• US 4,899,158 A
• Filed: 09/13/1988
• Issued: 02/06/1990
• Est. Priority Date: 09/26/1987
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Asahi Matsushita Electric Works Ltd. (Panasonic Holdings Corporation)
• Inventors: Nakano, Haruo, Sakakibara, Hitoshi, Saeki, Takashi, Nii, Takayuki, Mishina, Toshiro, Fukui, Hirotake
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): Barron, Jr., Gilberto
• Application Number:
  US07/243,833
• Time in Patent Office: 511 Days
• Field of Search: 342/44, 342/50, 340/825.54
• US Class Current: 342/44
• CPC Class Codes: G01S 13/78 discriminating between different kinds of targets, e.g. IFF-radar, i.e. identification of friend or foe G01S13/75, G01S13/79 take precedence
• CPC Class Codes: G01S 13/825 with exchange of information between interrogator and responder
• CPC Class Codes: G07C 9/28 the pass enabling tracking or indicating presence

Abstract

A moving object discriminating system is arranged so that a signal transmitted from an interrogator is received by a responder where the signal received is processed at a control circuit, the processed signal is phase-modified by own stored data of the responder and returned to the interrogator as an answer signal, and the interrogator discriminates the moving object as based on the answer signal. The responder is thereby sufficiently minimized in size for achieving as improved mountability of the responder with respect to the moving object to be discriminated.

Claims

1. A moving object discriminating system comprising an interrogator which transmits a transmission signal, and a responder which is mounted to a moving object and stores data for said moving object, said responder including a control means for processing said transmission signal received from said interrogator and for answering said interrogator, wherein said responder further including a phase modulator which modulates the phase of an answer signal supplied from said responder to said interrogator with said data stored in the responder, and said interrogator further including means for processing said answer signal to discriminate therefrom said moving object, an oscillator which oscillates a non-modulated signal of a fixed frequency toward said responder, and a comparator for comparing the phase of said oscillated signal with that of said answer signal from said responder and a phase shifter disposed between said oscillator and said phase comparator for providing a phase shift to an output of said oscillator so as to provide the phase comparator with a reference signal to permit the phase comparator to generate a sufficient demodulating output for processing said answer signal.

2. A moving object discriminating system comprising an interrogator which transmits a transmission signal, and a responder which is mounted to a moving object and stores data for said moving object, said responder including a control means for processing said transmission signal received from said interrogator and for answering said interrogator, wherein said responder further including a phase modulator which modulates the phase of an answer signal supplied from said responder to said interrogator with said data stored in the responder, and said interrogator further including means for processing said answer signal to discriminate therefrom said moving object wherein said interrogator and responder are respectively provided with means for transmitting and receiving said data with a circularly polarized wave, said transmitting and receiving means of the interrogator and responder being of said circularly polarized waves mutually of the same turning direction and wherein a writing wave and a reading wave are employed for said data transmission between said interrogator and said responder, said circularly polarized wave employed for said writing wave being of one turning direction while the circularly polarized wave employed for said reading wave being of opposite turning direction.

3. A moving object discriminating system comprising an interrogator which transmits a transmission signal, and a responder which is mounted to a moving object and stores data for said moving object, said responder including a control means for processing said transmission signal received from said interrogator and for answering said interrogator, wherein said responder further including a phase modulator which modulates the phase of an answer signal supplied from said responder to said interrogator with said data stored in the responder, and said interrogator further including means for processing said answer signal to discriminate therefrom said moving object and means for providing a communication finish requesting signal upon termination of a series of communication operations, and said responder further comprises means for interrupting said communication operations with the interrogator for a predetermined time after receipt of said communication finish requesting signal.

4. A moving object discriminating system comprising an interrogator which transmits a transmission signal, and a responder which is mounted to a moving object and stores data for said moving object said responder including a control means for processing said transmission signal received from said interrogator and for answering said interrogator, wherein said responder further including a phase modulator which modulates the phase of an answer signal supplied from said responder to said interrogator with said data stored in the responder, and said interrogator further including means for processing said answer signal to discriminate therefrom said moving object and means for transmitting an answer requesting signal at a predetermined communicating sequence;

and said responder comprises means for storing its own communicating state in said communicating sequence of said answer requesting signal from the interrogator, and a state determining means which determines whether or not the answer requesting signal received coincides with said its own communicating state and restricts said transmission of said answer signal when the communicating state is inconsistent.

5. A moving object discriminating system comprising an interrogator which transmits a transmission signal, and a responder which is mounted to a moving object and stores data for said moving object, said responder including a control means for processing said transmission signal received from said interrogator and for answering said interrogator, wherein said responder further including a phase modulator which modulates the phase of an answer signal supplied from said responder to said interrogator with said date stored in the responder, and said interrogator further including means for processing said answer signal to discriminate therefrom said moving object and wherein said responder further includes means for storing preliminary a specific code signal, and starts a continued operation when a specific code signal received from said interrogator coincides with an stored specific code signal.

6. A system according to claim 5, wherein said interrogator adds to said specific code signal an end mark of a different signal level from the specific code signal, said end mark being followed by an answer waiting state.