Electromagnetic sensor system

• US 6,411,250 B1
• Filed: 05/15/2000
• Issued: 06/25/2002
• Est. Priority Date: 09/01/1997
• Status: Expired due to Fees

• Current Assignee: Cambridge Solutions Limited (DXC Technology Company)
• Original Assignee: Cambridge Solutions Limited (DXC Technology Company)
• Inventors: Oswald, Gordon Kenneth Andrew, Richardson, Alan Trevor, Kerry, Nicholas John
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US09/486,323
• Time in Patent Office: 771 Days
• Field of Search: 342/70, 342/71, 342/72, 342/89, 342/90, 342/91, 342/92, 342/93, 342/101, 342/111, 342/115, 342/116, 342/159, 342/162, 342/192, 342/195, 342/196, 342/198
• US Class Current: 342/70
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 13/18 wherein range gates are used
• CPC Class Codes: G01S 13/22 using irregular pulse repetition frequency G01S13/12 takes precedence
• CPC Class Codes: G01S 13/24 using frequency agility of carrier wave
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/9317 Driving backwards
• CPC Class Codes: G01S 2013/93272 in the back of the vehicles
• CPC Class Codes: G01S 2013/93275 in the bumper area
• CPC Class Codes: G01S 7/023 Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36
• CPC Class Codes: G01S 7/285 Receivers
• CPC Class Codes: G01S 7/2927 by deriving and controlling a threshold value

Abstract

A vehicle (160) such as a motor road vehicle is fitted with an electromagnetic sensor system comprising transmitting means (e.g. 4, 1) for transmitting a radio frequency signal, receiving means (e.g. 2, 6) for receiving reflections of said signal from remote objects, sampling means (20, 28) operable to sample the received reflected signal (or a signal derived therefrom), and processing means (e.g. 36) for processing the sampled signal, and operable to detect said reflections in the sampled signal, and to determine information on the presence, position and/or range of said object. The system includes filter means (e.g. 34) for preventing radio signals transmitted by other sources or noise spikes from causing interference which results in spurious detections or indications of range by the processing means.

Claims

1. A electromagnetic sensor system comprising transmitting means for transmitting a radio frequency signal, receiving means for receiving reflections of said signal from remote objects, sampling means operable to sample the received reflected signal or a signal processing the sampled signal, and operable to detect said reflections in the sampled signal, and to determine information on the presence, position and/or range of said object, and filter means for preventing radio signals transmitted by other sources or noise spikes from causing interference which results in spurious detections or indications of range by the processing means, wherein the filter means has a threshold detector for preventing operation of the sampling means when a characteristic of the received reflected signal exceeds a threshold.

2. A electromagnetic sensor system according to claim 1, in which the filter means consists of a non-linear filter means.

3. A electromagnetic sensor system according to claim 1, in which the threshold detector determines whether the received signal is above said threshold and, if it is not, generates an enabling signal for enabling the sampling means to operate, the system further compromising delay means for delaying the passage of the received signal from the receiving means to the sampling means so that the operating of the threshold detector and the sampling means are synchronized in relation to the received signal.

4. A electromagnetic sensor system according to claim 2, which electromagnetic sensor system further comprises a threshold setting means for adaptively adjusting the threshold applied to ensure that the majority of genuine reflected pulses lie below the threshold.

5. An electromagnetic sensor system according to claim 1 in which the transmitting means, in use, generates a train of radio frequency pulses, the system functioning as an impulse radar system.

6. A vehicle fitted with an electromagnetic sensor system according to claim 1.

7. A vehicle according to claim 6, in which the vehicle is a motor road vehicle.

8. A electromagnetic sensor system comprising transmitting means for transmitting a radio frequency signal, receiving means for receiving reflections of said signal from remote objects, sampling means operable to sample the received reflected signal processing means for processing the sampled signal, and operable to detect said reflections in the sampled signal, and to determine information on the presence, position and/or range of said object, and filter means for preventing radio signals transmitted by other sources or noise spikes from causing interference which results in spurious detections and indications of range by the processing means, wherein the filter means has a threshold detector for inhibiting operation of the sampling means when a characteristic of the received reflected signal for inhibiting exceeds a threshold.