|Publication number||USRE42316 E1|
|Application number||US 12/615,014|
|Publication date||May 3, 2011|
|Filing date||Nov 9, 2009|
|Priority date||Dec 19, 2005|
|Also published as||EP1798568A2, EP1798568A3, EP1798568B1, US7295151, US20070139259|
|Publication number||12615014, 615014, US RE42316 E1, US RE42316E1, US-E1-RE42316, USRE42316 E1, USRE42316E1|
|Inventors||David C. Vacanti|
|Original Assignee||Honeywell International Inc.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (12), Non-Patent Citations (1), Referenced by (2), Classifications (14), Legal Events (5)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application is related to co-pending U.S. patent application Ser. No. 11/306,185. The contents of which are hereby incorporated by reference.
Frequency Modulated/Continuous Wave (FM/CW) Radar Altimeters need ways in which to verify proper operation. In current radar altimeters, self-testing is performed in a system that uses a Bulk Acoustic Wave (BAW) device that is relatively expensive. These systems fail to accurately detect improper system operation.
Therefore, there exists a need to replace expensive BAW devices and to implement a self-test that more effectively identifies when the radar altimeter is performing outside of acceptable limits.
The present invention provides systems and methods for testing a signal generated by a Direct Digital Synthesizer (DDS) in a radar altimeter. In an embodiment of the method, a voltage signal derived by comparing a fixed reference frequency to a ramped frequency signal generated by the DDS based on a clock-based reference signal is generated. The generated voltage signal is integrated over a predefined number of clock signals. The integration is sampled at a previously defined clock tick. The sample is compared to a desired value and an indication that the radar altimeter is malfunctioning is provided if the comparison exceeds a predefined threshold value.
The radar altimeter system is deactivated if an indication that the radar altimeter is malfunctioning has been provided.
The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings.
The output of the phase/frequency detector 114 is integrated by the integrator 118. The output of the integrator 118 is compared at the comparator 120 to a reference voltage Vref. The output of the comparator 120 is sent to the sample and holding device 124 that retains the sampled comparator output until it is requested by the PLD 26. This permits the PLD 26 to operate asynchronously from the transmitter 24. The comparator 120 determines if the product of the integrator 118 as compared to the Vref is outside of a threshold value as was performed at the decision block 60 from FIG. 2. The DDS 100 and the integrator 118 are controlled by the PLD 26.
Referring now to
Referring back to
While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4503433 *||Dec 14, 1981||Mar 5, 1985||U.S. Philips Corporation||Range measurement by means of frequency modulated continuous wave radar|
|US4806935||Sep 17, 1987||Feb 21, 1989||Fosket Timothy G||Closed loop velocity/altitude sensor for FM-CW doppler radars|
|US5151661 *||Aug 26, 1991||Sep 29, 1992||Westinghouse Electric Corp.||Direct digital FM waveform generator for radar systems|
|US5160933||May 20, 1991||Nov 3, 1992||Honeywell Inc.||Radar altimeter with self-calibration feature|
|US5673050 *||Jun 14, 1996||Sep 30, 1997||Moussally; George||Three-dimensional underground imaging radar system|
|US5821897 *||Dec 20, 1996||Oct 13, 1998||Wiltron Company||Simulator for testing a collision avoidance radar system|
|US7023378 *||Jan 20, 2004||Apr 4, 2006||Harris Corporation||Self-calibrating wideband phase continuous synthesizer and associated methods|
|US20050156781 *||Jan 20, 2004||Jul 21, 2005||Harris Corporation||Self-calibrating wideband phase continuous synthesizer and associated methods|
|US20070081611 *||Oct 11, 2005||Apr 12, 2007||Fudge Gerald L||Swept bandpass filter frequency modulated continuous wave (FMCW) receiver and related method|
|US20070139259 *||Dec 19, 2005||Jun 21, 2007||Honeywell International Inc.||Systems and methods for self-test of a radar altimeter|
|US20070192391 *||Feb 10, 2006||Aug 16, 2007||Mcewan Thomas E||Direct digital synthesis radar timing system|
|GB2372649A||Title not available|
|1||European Patent Office, "European Search Report", Jul. 14, 2008, Published in:EP.|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US9019154 *||Jan 17, 2012||Apr 28, 2015||Infineon Technologies Ag||Radar circuit, radar system and method for testing|
|US20130082869 *||Jan 17, 2012||Apr 4, 2013||Herbert Jaeger||Radar circuit, radar system and method for testing|
|U.S. Classification||342/173, 342/121, 342/122|
|International Classification||G01S7/40, G01S13/32|
|Cooperative Classification||H03L7/06, G01S7/35, G01S7/4004, G01S13/882, G01S13/34|
|European Classification||G01S7/35, G01S13/34, H03L7/06, G01S7/40A|
|Dec 8, 2010||AS||Assignment|
Owner name: HONEYWELL INTERNATIONAL INC., NEW JERSEY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:VACANTI, DAVID C.;REEL/FRAME:025479/0023
Effective date: 20051219
|Jun 20, 2011||REMI||Maintenance fee reminder mailed|
|Sep 23, 2011||FPAY||Fee payment|
Year of fee payment: 4
|Sep 23, 2011||SULP||Surcharge for late payment|
|Apr 24, 2015||FPAY||Fee payment|
Year of fee payment: 8