Patent Application
20100085241
Moving vehicles, such as automobiles or aircraft, typically use systems to aid in avoiding obstacles. For example, aircraft typically use radar to detect obstacles which pose a threat to the aircraft. However, conventional radar systems do not adequately detect all potential hazardous obstacles. For example, conventional radar systems do not adequately detect cables which pose a serious threat to helicopters. In addition, weather conditions, such as dust clouds, prevent increased difficulty for conventional radar systems to detect obstacles such as cables.
For the reasons stated above and for other reasons which shall become apparent to one of ordinary skill in the art upon reading and studying the present application, there is a need in the art for an improved obstacle detection system.
In one embodiment an obstacle detection system is provided. The obstacle detection system a transmission antenna operable to radiate a radio frequency (RF) signal and a transmitter operable to control transmission of the RF signal from the antenna. The obstacle detection system also comprises a receiver antenna operable to receive a reflection of the RF signal; and processing circuitry operable to analyze a plurality of characteristics of a radar cross section (RCS) of the received reflection to identify an obstacle and one or more physical attributes of the obstacle.
Understanding that the drawings depict only exemplary embodiments of the present invention and are not therefore to be considered limiting in scope, the exemplary embodiments will be described with additional specificity and detail through the use of the accompanying drawings, in which:
In accordance with common practice, the various described features are not drawn to scale but are drawn to emphasize specific features relevant to the present invention. Like reference numbers and designations in the various drawings indicate like elements.
In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific illustrative embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical, and electrical changes may be made without departing from the scope of the present invention. Furthermore, the method presented in the drawing figures or the specification is not to be construed as limiting the order in which the individual steps may be performed. The following detailed description is, therefore, not to be taken in a limiting sense.
In one exemplary embodiment, transmission antenna 112 transmits a frequency modulated continuous wave (FMCW) RF signal. The FMCW RF signal enables processing circuitry 106 to calculate a range to a detected obstacle. In some such embodiments, the RF signal has a frequency band, and transmitter 102 and receiver 104 linearly sweep through the frequencies in the RF frequency band. The linear sweep of the transmitted RF signals is synchronous with the processing of the received reflection signals.
System 100 detects obstacles near the path of a moving vehicle in which system 100 is located. For example, in one embodiment, system 100 can detect cables near an aerial vehicle, such as a helicopter. However, it is to be understood that other types of vehicles can be used in other embodiments, such as an automobile or surface ship on water. Furthermore, as used herein, the term “obstacle” refers to stationary objects which pose a potential danger to the vehicle, such as light posts, cables, docks, etc.
An obstacle, such as a cable, will reflect the transmitted RF signal. Receiver antenna 110 receives the reflection of the RF signal and provides the reflected signal via receiver 104 to processing circuitry 106 for analysis. Processing circuitry 106 analyzes characteristics of the Radar Cross Section (RCS) of the received reflection signal to detect an obstacle, such as a cable. The RCS changes as transmission antenna 112 and receiver antenna 110 rotate. An exemplary graph of the RCS of reflection signals vs. incident angle is shown in
As used herein, the term “characteristic” of an RCS of the reflection signal refers to an electrical property or quality of the reflection signal (also referred to herein as a return signal). Hence, analysis of one or more characteristics of the RCS includes more than a simple detection of the reflection signal. Exemplary characteristics analyzed by processing circuitry 106 include, but are not limited to, peak amplitude 204, peak separation distance 202, peak width 208, and periodicity 206 of the peaks, as shown in
In other embodiments, processing circuitry 106 analyzes the values of the one or more characteristics to identify or detect an obstacle without comparison to a database. For example, threshold values can be set, such as minimum and/or maximum peak separation distance. The value of the peak separation distance in relation to the threshold value(s) is used to identify an obstacle.
Furthermore, in one embodiment, processing circuitry 106 analyzes one or more characteristics of a reflection signal's RCS to determine attributes of the obstacle in addition to detecting the obstacle. As used herein, the term “attributes” of an obstacle refers to a physical property or feature of the obstacle. For example,
When an obstacle is detected, processing circuitry 106 outputs a signal to an output device 108 (
In some embodiments, the RF signal is transmitted at a frequency of about 94 GHz. However, it is to be understood that, in other embodiments, other frequencies are used, such as about 35 GHz. In some such exemplary embodiments, as shown in
Furthermore, as shown in
All or some portions of the processing of reflection signals described above can be implemented in software instructions tangibly embodied on a computer readable medium and executed by a processing unit such as processing circuitry 106. Such computer readable media can be any available media that can be accessed by a general purpose or special purpose computer or processor, or any programmable logic device. Suitable computer readable media may include storage or memory media such as magnetic or optical media, e.g., disk or CD-ROM, volatile or non-volatile media such as RAM (e.g., SDRAM, DDR SDRAM, RDRAM, SRAM, etc.), ROM, EEPROM, flash memory, etc. as well as transmission media such as electrical, electromagnetic, or digital signals, conveyed via a communication medium such as a network and/or a wireless link
In another embodiment of an obstacle detection system 600 shown in
At 706, processing circuitry analyzes one or more characteristics of the received reflection signal. In particular, processing circuitry analyzes one or more of the peak amplitude, peak separation distance, peak width, and periodicity of the peaks. In addition, in some embodiments, the one or more characteristics of the reflection signal are analyzed to detect an obstacle and at least one attribute of the obstacle. In some embodiments, the obstacles detected are cables. In some such embodiments, the attributes detected by the analysis of the one or more characteristics of the reflection signal include, but are not limited to, strand diameter of individual strands, cable diameter of the entire cable, spacing between surfaces of the cable, and spacing between turns of a strand.
If an obstacle is identified or detected at 708, an alert is provided to a user at 710. Providing an alert to a user can include, but is not limited to, providing an audio alert, visual alert, or vibration of a mechanical component, as described above. In addition, providing an alert includes, in some embodiments, providing information regarding the at least one detected attribute of the obstacle as well as the range to the obstacle. Method 700 then repeats at 702 to continue transmitting RF signals to detect an obstacle. If an obstacle is not detected at 708, method 700 repeats at 702 to continue transmitting RF signals to detect an obstacle.
Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiment shown. This application is intended to cover any adaptations or variations of the present invention. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.
This application is related to the following co-pending United States patent applications filed on even date herewith, all of which are hereby incorporated herein by reference: U.S. patent application Ser. No. ______ (attorney docket number H0019377-5615 entitled “RADAR SYSTEM FOR OBSTACLE AVOIDANCE”) and which is referred to here as the '377 Application; U.S. patent application Ser. No. ______ (attorney docket number H0019378-5615 entitled “MULTI-SECTOR RADAR SYSTEM”) and which is referred to here as the '378 Application.
