Abstract:
A sector-scanning sonar imaging system with at least one sonar imaging element housed within a transducer housing coupled to a self-reciprocating mechanism, and a drive mechanism housed within a waterproof housing. The oscillating motion of the transducer housing produces a highly-detailed, photo like sector scan sonar image of the bottom and other objects surrounding the boat on which it is mounted. The drive mechanism housing may be rigidly attached to either a boat hull or to a trolling motor. The sonar imaging element housing may be removably attached to the drive mechanism, and shielded by an acoustically transparent shroud to protect the elements from damage. The sector-scanning sonar imaging system connects to a control head with display either directly, or through some other communications protocol, such as a wireless protocol.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
       [0001]    This patent application claims the benefit of U.S. Provisional Patent Application No. 61/794,502, filed Mar. 15, 2013, the entire teachings and disclosure of which are incorporated herein by reference thereto. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to sonar imaging systems for use in sport fishing applications such as in a fish finder, sonar depth sounder, etc., and more particularly to a sector-scanning sonar imaging systems for imaging of the underwater environment all around the watercraft rather than just below or to the sides of the watercraft. 
       BACKGROUND OF THE INVENTION 
       [0003]    Sonar devices that transmit sound waves have been used previously to obtain information about underwater articles, including fish, structures and obstructions, and the bottom. The sound waves travel from a transducer mounted to a bottom surface of the vessel through the water. The sound wave transmits from the sonar devices in diverging patterns. The sound waves contact underwater articles, which create return echoes. The transducer receives the return echoes and the sonar device analyzes the received echoes. A display device displays representations of the received echoes, for locating fish and other underwater articles. 
         [0004]    Embodiments of the present invention represent an advancement over the current state of the art with respect to sonar imaging systems. Certain advantages of the invention, as well as various inventive features, will be apparent from the description of the invention provided herein. 
         [0005]    Conventional “search light” rotating sonar systems use a conical beam configuration to find schools of fish in the water column. Such systems tend to provide a large “footprint” of the bottom of a given body of water. This large footprint results in sonar images that lack detail and may be difficult to read, especially for inexperienced users. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    In one aspect, embodiments of the invention provide a sonar imaging system that includes a sonar imaging element housed within a housing, and a self-reciprocating mechanism configured to produce oscillating movement of the housing and the first sonar imaging element therein. In a specific embodiment of the invention, the sonar imaging element is long in the horizontal dimension (e.g., 3-7 inches) to provide a narrow beam in the side-to-side orientation and is very narrow (e.g., less than 0.5 inches) in the vertical dimension to provide a very wide beam in the vertical, or top-to-bottom, orientation. The oscillating movement allows the first sonar imaging element to produce a highly detailed photo-like sonar image where logs look like logs, trees looks like trees, fish look like fish, and rocks look like rocks, all without requiring movement of the boat. 
         [0007]    In a particular embodiment, the transducer housing is pivotably attached at a pivot point to a support member, and the self-reciprocating mechanism has a linear actuator attached to the support member. The linear actuator has an actuating member attached to the housing. The oscillatory movement of the actuating member causes the oscillatory movement of the transducer housing about the pivot point. The linear actuator may be powered electrically, hydraulically, or pneumatically. 
         [0008]    In a particular embodiment, the housing is rigidly attached to the shaft of a stepper motor. The stepper motor rotates back and forth sweeping the sonar imaging element through an angle. The stepper motor is connected to an external stepper motor controller which controls the sweep speed and angle that the sonar imaging elements travel through, as well as syncing the motor movement to the sonar so that the transducer housing is not moving while the sonar is transmitting and receiving. In a particular embodiment, the sweep angle of the stepper motor may be set or adjusted, by the user for example. In a more particular embodiment, the sweep angle of the stepper motor may be set or adjusted by the user in real time. 
         [0009]    In a particular embodiment, the housing is rigidly attached to the shaft of a motor equipped with a rotary encoder. The encoder relays information about position and speed of the housing movement and sonar imaging elements allowing an external controller to determine the sweep speed and angle that the sonar imaging elements travel through. In an additional embodiment, the transducer housing is attached to the shaft of a motor through a slip clutch mechanism. 
         [0010]    In a particular embodiment, the housing has a slot and is pivotably anchored in place at a pivot point. In embodiments, the self-reciprocating mechanism has a wheel adjacent to the slot in the housing. The wheel has a post attached to a face thereof, the post being held within the slot. Turning of the wheel causes the post to move within the slot which produces an oscillatory movement of the housing about the pivot point. The wheel may be driven electrically, hydraulically, or pneumatically. In an additional embodiment, the wheel is coupled to the drive mechanism through a slip clutch mechanism. 
         [0011]    Embodiments of the sonar imaging system include a second imaging element located adjacent the first sonar imaging element. The oscillatory movement of the housing about a pivot point produces two sector scan sonar images, some with respective centers spaced from five degrees to 90 degrees apart. 
         [0012]    In another aspect, embodiments of the invention provide a sonar imaging system configured to attach to a propeller pod of a trolling motor. Directly attaching to the propeller pod of a trolling motor allows for the user to easily deploy and retract the sonar imaging system in a manner they are already familiar with. The sonar imaging system is also oriented along the axis of the trolling motor propeller pod, allowing the user to aim the self-reciprocating sonar imaging device using the same foot pedal or electric control used to steer the trolling motor without requiring motion of the trolling motor itself to generate the images. 
         [0013]    In a particular embodiment, the transducer housing and self-reciprocating mechanism are attached to a track system that allows the sonar imaging system to move from beyond an end of the motor pod to a position towards the center of the motor pod. The track system may be spring loaded. 
         [0014]    In certain embodiments, the self-reciprocating mechanism is configured to periodically stop movement of the transducer housing while the first sonar imaging element transmits and receives. A sweep angle of the transducer housing between periodic stops may be variable. In a further embodiment, the first sonar imaging element and the transducer housing are removably attached to the self-reciprocating mechanism. The first sonar imaging element and the transducer housing are protected, in some embodiments, by a rigid shroud that surrounds the first sonar imaging element and the transducer housing. The rigid shroud may be made of an acoustically transparent material. Embodiments of the first sonar imaging element produce a fan-shaped beam that is wider in a vertical orientation than in a horizontal orientation. In more particular embodiments, the fan-shaped beam is greater than 40 degrees in the vertical orientation, and less than five degrees in the horizontal orientation. 
         [0015]    Embodiments of the sonar imaging system include an onboard compass to detect orientation of the sonar imaging system. The sonar imaging system may be connected to a control head display which displays a current GPS location. In particular embodiments, the control head is able to mark a waypoint on a sector-scanning sonar image and relate the waypoint to a GPS location using GPS data and the orientation of the sonar imaging system. 
         [0016]    Other aspects, objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings: 
           [0018]      FIG. 1  is a side view of a sector-scanning sonar imaging system, constructed in accordance with an embodiment of the invention; 
           [0019]      FIG. 2  is a schematic diagram of an alternate sector-scanning sonar transducer assembly that includes a stepper motor, constructed in accordance with an embodiment of the invention; 
           [0020]      FIG. 3  is a schematic diagram of an alternate sector-scanning sonar transducer assembly with a rotating wheel, constructed in accordance with an embodiment of the invention; 
           [0021]      FIG. 4  is a schematic diagram of a sector-scanning sonar transducer assembly using a linear actuator, constructed in accordance with an embodiment of the invention; 
           [0022]      FIG. 5  is a schematic diagram of a trolling motor scanning mount, constructed in accordance with an embodiment of the invention; 
           [0023]      FIG. 6  is a side view of a sonar transducer assembly with multiple sonar imaging elements, according to an embodiment of the invention; 
           [0024]      FIG. 7  is a perspective view of a boat that includes a sector-scanning sonar imaging system, in accordance with an embodiment of the invention; and 
           [0025]      FIG. 8  is a screen shot illustration of an exemplary sector-scanning sonar image with waypoint, according to an embodiment of the invention. 
       
    
    
       [0026]    While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    In this application, several embodiments of a sector-scanning sonar imaging system will be discussed. It should be noted, however, that while a number of embodiments will be illustrated and/or discussed hereinbelow, such embodiments should be taken by way of example and not by way of limitation. In these exemplary embodiments, the sector-scanning sonar imaging system may connect directly to a control head with display via the transducer connection and a control communications port, although other embodiments may communicate using other technology, e.g. Ethernet, Wi-Fi, Bluetooth, etc. 
         [0028]    The sector scan sonar imaging system may be assembled in such a way to allow the removal of the sonar imaging transducer housing by the user. This allows the user to replace the transducer housing with one of a different design, allowing for different beam shapes, frequency optimization, or to replace a damaged transducer with a new one. In particular embodiments, when the sector-scanning sonar imaging system is connected to a control head, several menus and views are added to the existing user interface. 
         [0029]      FIG. 7  provides an illustration of the boat  104  having a console  109  with control head  110  that includes a sonar display at the control head and a second display  111  at the bow of the boat  104 . In the embodiment shown, the boat  104  has a bow-mounted trolling motor  112  with a propeller pod  119  suspended from shaft  116 . However, it is conceivable that this embodiment of the invention could be employed in a transom-mounted trolling motor. In the embodiment of  FIG. 7 , a transducer assembly  122  is attached to the propeller pod  119 . 
         [0030]    In particular embodiments, the boat  104  or the sonar imaging system has an onboard compass and the control head  110  is GPS-enabled. As shown in  FIG. 8 , using orientation data from the onboard compass in conjunction with the GPS data from the control head  110 , the user is able to mark one or more waypoints  124  on the sector scan sonar image. The waypoint  124  may be recorded at the boat&#39;s current location or the user may choose some point on the displayed sonar image to record the waypoint  124 . The waypoint  124  may be stored in the control head  110  memory until recalled by the user. 
         [0031]    Embodiments of the present invention provide a new and improved sonar imaging system, employing a mechanically-sweeping, or mechanically-scanning, sonar that is capable of being connected to a surface watercraft, such as a fishing boat. In a particular embodiment, the boat does not need to be moving in order to generate the high-quality photo-like sonar imagery. It is a further objective to provide a new and improved sonar imaging system that provides photograph-like imaging of the underwater environment for sectors around and below the watercraft. A sonar imaging system that provides such photograph-like imaging is described in U.S. patent application Ser. No. 13/774,143, filed on Feb. 22, 2013, the entire contents and disclosure of which is incorporated herein by reference thereto. 
         [0032]      FIG. 1  is a side view of a sector-scanning sonar imaging system  100 , constructed in accordance with an embodiment of the invention. In particular embodiments of the invention, one or more sonar imaging elements  102  are potted inside of a sonar transducer assembly, which is protected by an acoustically transparent shroud  104  that is rigidly attached to the drive housing. Other embodiments may include additional protection measures. In a particular embodiment, the sonar imaging system  100  is attached to the propeller pod  119  of a trolling motor via pivoting legs, or a track system, which allows the sonar imaging system  100  to move back and out of the way in the event of a collision, or to absorb the impact of the collision without sustaining significant damage. The acoustically transparent shroud  104  may be used to protect any of the embodiments described hereinbelow. 
         [0033]      FIG. 2  illustrates an exemplary embodiment of a sector-scanning sonar transducer assembly  340  designed to produce a sector scan sonar image, in accordance with an embodiment of the invention. The sonar transducer assembly  340  includes a sonar imaging element  342 . In particular embodiments, the sonar transducer assembly  340  includes two or more sonar imaging elements  342  configured to provide two or more complementary sector scan sonar images whose respective centers are spaced from five degrees to 90 degrees apart. 
         [0034]    In a particular embodiment of the invention, one or more sonar elements  342  form sonar beams that are wide in the vertical direction for a good area of coverage and very narrow in the horizontal direction for good image definition. A narrow beam may be thought of as one less than about five degrees, while a wide beam may be thought of as one greater than about 40 degrees, the respective beam widths measured at the 3 dB points. This beam configuration aids in producing high-resolution, high quality, photo-like images on the display used for the sector scan sonar imaging system. Alternate embodiments of the invention described below may also use this same beam configuration to produce high-resolution, high quality, photo-like images 
         [0035]    In particular embodiments, the one or more sonar imaging elements  342  are housed within a housing  344  having an integral support member  345 . The housing  344  is pivotably anchored in place at a pivot point  348 . The support member  345  is positioned adjacent a stepper motor  350  which has a shaft or post  352  designed to fit in an opening  354  in the support member  345 . The stepper motor  350  may be controlled electronically to act as a self-reciprocating mechanism, which reciprocates, or oscillates to create a sector-scanned sonar image. In the context of this application, “self-reciprocating” means that, once activated, the self-reciprocating mechanism oscillates continuously through a particular sweep angle without intervention by the user. In the embodiment of  FIG. 2 , the stepper motor  350  rotate includes a shaft that attaches the housing  344 , where the shaft rotates the housing back and forth through a variable, user-defined sweep angle. In particular embodiments, the user-defined sweep angle is adjustable in real-time allowing the user to set the angle of the sector scan to be displayed. Power and or control signals may be delivered to the stepper motor  350  via some type of shielded cable. 
         [0036]    In particular embodiments, the multiple sonar imaging elements are spaced along the axis of rotation to prevent shading of one sonar imaging element by one or more other sonar imaging elements when the elements are depressed from the horizontal plane by some degrees. Such a configuration is shown in  FIG. 6 , which illustrates a sonar transducer assembly  360  having a first sonar imaging element  362  and a second sonar imaging element  364  mounted on a single shaft  366  such that the first and second sonar imaging elements  362 ,  364  have the same axis or rotation. The first and second sonar imaging elements  362 ,  364  are surrounded by a water-flooded protective acoustically-transparent shroud  368 . 
         [0037]    As with the sonar transducer assemblies  300 ,  320  shown above, the sonar transducer assembly  340  may be housed in a pod attached directly to the hull of the boat or to a fairing block attached to the hull of the boat. The pod may or may not be oil-filled. Alternately, the sonar transducer assembly  340  may be housed in a pod attached to the propeller pod  119  (see  FIG. 5 ) of trolling motor  112 , or at the bottom end of a transom-mounted shaft, for example. 
         [0038]    A system and method of deploying a sector-scanning sonar imaging system using a trolling motor scanning mount, is shown in  FIG. 5 , in accordance with an embodiment of the invention. As can be seen from  FIG. 5 , a sonar imaging system  117  is attached to a top portion of the trolling motor  112  suspended from shaft  116 , although other embodiments may attach to the side or bottom of the motor. The sonar transducer assembly  300  may be housed in a pod attached directly to the hull of the boat or to a fairing block attached to the hull of the boat. The pod may or may not be oil-filled. Alternately, the sonar transducer assembly  300  may be housed in a pod attached to the propeller pod  119  of trolling motor  112 , or at the bottom end of a transom-mounted shaft, for example. 
         [0039]    In certain embodiments of the invention, a sector-scanning sonar transducer assembly may be employed to produce a sector scan sonar image.  FIG. 4  shows a schematic diagram of a sector-scanning sonar transducer assembly  300  that includes at least one sonar imaging element  302 . In particular embodiments, the sonar transducer assembly  300  includes two sonar imaging elements  302  configured to provide two complementary sector scan sonar images whose respective centers are spaced between five and 90 degrees apart. In certain embodiments, the sonar imaging elements are spaced along the axis of rotation to prevent shading of one element by the others. In the embodiment shown, the sonar imaging element  302  is housed within a housing  304 , which has a central attachment  306 . A support member  308  is pivotably attached to the housing  304  at the central attachment  306 , creating a pivoting connection  307 , or pivot point  307 , at the point of attachment. A linear actuator  310  is attached to the support member  308 . The linear actuator  310  may be powered by numerous means, i.e., electrically, hydraulically, pneumatically, etc. The power may be delivered to the linear actuator  310  via some type of shielded cable, which may or may not be routed through the support member  308 . An actuating member  312  of the linear actuator  310  is attached to an outer attachment  314  of the housing  304 . 
         [0040]    The sonar transducer assembly  300  is designed to provide a sector scan image when the actuating member  312  moves back and forth, causing the housing  304  and sonar imaging element  302  to oscillate back and forth about the pivoting connection  307  between the central attachment  306  and the support member  308 . The oscillatory back and forth movement of the sonar imaging element  302  results in a sector scan sonar image whose angle is determined by the range of motion of the sonar imaging element  302 . Thus, if a larger sector scan is desired, the actuating member  312  can be set to extend and retract a greater distance, such that the housing  304  oscillates further in each direction. 
         [0041]      FIG. 3  illustrates yet another sector-scanning sonar transducer assembly  320  designed to produce a sector scan sonar image, in accordance with an embodiment of the invention. The sonar transducer assembly  320  includes a sonar imaging element  322 . In particular embodiments, the sonar transducer assembly  320  includes two or more sonar imaging elements  322  configured to provide two or more complementary sector scan sonar images whose respective centers are spaced from five degrees to 90 degrees apart. In particular embodiments, the multiple sonar imaging elements  322  are spaced along the axis of rotation to prevent shading of one sonar imaging element  322  by the others. 
         [0042]    The sonar imaging element  322  is housed within a housing  324  having an integral support member  325  with a slot  326  therein. The housing  324  is pivotably anchored in place at a pivot point  328 . The support member  325  is positioned adjacent a wheel  330  which has a post  332  designed to fit in slot  326 , and attached near a perimeter of the wheel  330 . The wheel  330  may be driven by numerous means, i.e., electrically, hydraulically, pneumatically, etc. The power may be delivered to the wheel  330  via some type of shielded cable, which may or may not be routed through the housing  324 . 
         [0043]    As the wheel  330  turns, the post  332  in slot  326  causes the housing  324  and the sonar imaging element  322  therein, to oscillate back and forth. This oscillatory movement allows the sonar imaging element  322  to produce a sector-scanned sonar image whose boundaries are determined, at least partly, by the diameter of the wheel  330  and the distance between the wheel  330  and the pivot point  328 . 
         [0044]    In contrast to conventional “search light” rotating sonar systems that use a circular beam configuration to find schools of fish in the water column, a true imaging sonar system, such as described herein, uses a “fan” shaped beam that is wide (e.g., &gt;40 degrees) in the top-to-bottom orientation and very narrow (e.g., &lt;5 degrees) in the side-to-side orientation. This beam orientation, along with a downward tilt (e.g., −10 to −40 degrees from the horizontal), provides a very narrow and short insonified “footprint” of the bottom at any given time in the transmitted wave front propagation path. This small “footprint” along with the proper signal processing provides for photograph-like images of an area of the bottom. 
         [0045]    All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
         [0046]    The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
         [0047]    Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.