The present invention generally relates to sensors and more particularly to isolation of sensors from shock and vibration.
Small sensors are useful in aerospace applications because of their ruggedness and their low weight and volume. However, many aerospace applications, such as missiles and launch vehicles expose these small sensors to a high shock and vibration environment that may exceed the sensor's shock and vibration ratings. Because of their small size, it is difficult or impractical to employ conventional disturbance isolation systems for small sensors. This is because applying sufficient elastomer materials to reduce a small sensor's resonant frequency results in significantly increasing the physical volume which must be allotted to each sensor in the end application. Additionally, sensors such as accelerometers are typically mounted with an orthogonal orientation to each other. Individually applying a disturbance isolation system to each sensor degrades the overall performance of a navigation system due to the undesirable relative motion between the accelerometers under shock and vibration loading.
For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the specification, there is a need in the art for improved disturbance isolation systems and methods for small sensors.
The Embodiments of the present invention provide methods and systems for disturbance isolation of sensors and will be understood by reading and studying the following specification.
In one embodiment, a disturbance isolation bracket is provided. The bracket comprises a structural band having an inner surface and an outer surface, at least one isolating element coupled to the outer surface of the structural band, and at least one device mount coupled to the structural band and adapted to secure a sensor device to the structural band.
In another embodiment, a sensor system is provided. The system comprises one or more sensor devices; a disturbance isolation bracket including a structural band having an inner surface and an outer surface, at least one isolating element coupled to the outer surface of the structural band, and one or more device mounts coupled to the structural band and adapted to secure the one or more sensor devices to the structural band; and a housing adapted to accommodate insertion of disturbance isolation bracket.
In yet another embodiment, a method for isolating sensors from disturbances is provided. The method comprises securing one or more sensor devices onto a disturbance isolation bracket comprising a structural band having an inner surface and an outer surface, the disturbance isolation bracket further comprising at least one isolating element coupled to the outer surface of the structural band; and inserting the disturbance isolation bracket into a housing.
In still another embodiment, a disturbance isolation bracket is provided. The bracket comprises means for supporting at least one sensor device, the means for supporting having an inner surface and an outer surface; and means for absorbing one or both of shocks and vibrations, the means for absorbing coupled to the outer surface of the means for supporting.
Embodiments of the present invention can be more easily understood and further advantages and uses thereof more readily apparent, when considered in view of the description of the preferred embodiments and the following figures in which:
In accordance with common practice, the various described features are not drawn to scale but are drawn to emphasize features relevant to the present invention. Reference characters denote like elements throughout figures and text.
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. The following detailed description is, therefore, not to be taken in a limiting sense.
Embodiments of the present invention provide shock and vibration isolation to small sensors by constraining one or more sensors into a disturbance isolation bracket. Embodiments of the present invention comprise a ringed structure which provides an increased area for applying isolating elements with only a marginal increase in additional volume to accommodate tight spaces. Further, embodiments of the present invention provide an improved means for tuning the resonant frequency of sensors mounted to the disturbance isolation bracket of the present invention. Although examples of embodiments presented in this specification illustrate a circular disturbance isolation bracket, embodiments of the present invention are not limited to circular shapes. Instead, the bracket shape for embodiments of the present invention may be dictated by the housing in which the disturbance isolation bracket will be installed. In one embodiment, the bracket shape is one of, but not limited to, circular, elliptical, rectangular, triangular, and other poly-sided bracket shapes.
As would be appreciated by one skilled in the art upon reading this specification, the exact disturbance absorbing material chosen to create isolating element 120 is determined based on the source and type of the dynamic disturbance causing the shock or vibration. The material is then chosen based on loads it will need to support, the dynamic operating conditions of its environment and the dynamic response of the material to the dynamic operating conditions (e.g. the natural frequency and dampening qualities of the material). In one embodiment, isolating element 120 is one of, but limited to, rubber, felt, and an elastomeric material such as, but not limited to a silicone material.
As illustrated in
The resonant frequency of disturbance isolation bracket 100 of embodiments of the present invention can also be tuned by varying the weight of the structure. In one embodiment, the inclusion of one or more additional device mounts 130 and sensors 140 are used to vary the resonant frequency of disturbance isolation bracket 100. In one embodiment, one or more tuning weights 145 are coupled to structural band 110 to vary the resonant frequency of disturbance isolation bracket 100. In one embodiment, the material used to construct one or more of structural band 110 and device mounts 130 are chosen based on weight, to vary the resonant frequency of disturbance isolation bracket 100.
As illustrated in
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.
The U.S. Government may have certain rights in the present invention as provided for by the terms of Contract No. DASG60-00-C-0072 awarded by the U.S. Department of the Army.