Abstract:
A low-profile, surface mount vehicle energy harvester including a low-profile, surface mount subunit having an upper surface forming a roadway surface; a vehicle activated treadle on the subunit, the vehicle activated treadle moveable between a first position in which an upper surface of the treadle is at an angle with respect to the upper surface of the roadway surface and a second position in which the upper surface of the treadle is flush with the upper surface of the roadway surface; a generator that generates power in response to movement of the vehicle activated treadle; and an entry ramp at a first end of the harvester roadway surface; and an exit ramp at a second end of the harvester roadway surface.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present invention claims the benefit of U.S. Provisional Patent Application No. 61/147,747, filed Jan. 27, 2009, and entitled “TRANSIENT ABSORBER FOR POWER GENERATION SYSTEM”, U.S. Provisional Patent Application No. 61/147,748, filed Jan. 27, 2009, and entitled “WEATHER RESPONSIVE TREADLE LOCKING MEANS FOR POWER GENERATION SYSTEM”, U.S. Provisional Patent Application No. 61/147,749, filed Jan. 27, 2009, and entitled “LOW PROFILE, SURFACE-MOUNTED POWER GENERATION SYSTEM”, U.S. Provisional Patent Application No. 61/147,750, filed Jan. 27, 2009, and entitled “VEHICLE SPEED DETECTION MEANS FOR POWER GENERATION SYSTEM”, U.S. Provisional Patent Application No. 61/147,752, filed Jan. 27, 2009, and entitled “RECIPROCAL SPRING ARRANGEMENT FOR POWER GENERATION SYSTEM”, and U.S. Provisional Patent Application No. 61/147,754, filed Jan. 27, 2009, and entitled “LOSSLESS SHORT-DURATION ELECTRICAL STORAGE MEANS FOR POWER GENERATION SYSTEM”, the entire contents of which are incorporated herein by reference in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention is directed toward devices and methods of harvesting vehicle energy, and more specifically, toward a Low Profile, Surface-Mounted Power Generation System for harvesting vehicle energy. 
       BACKGROUND OF THE INVENTION 
       [0003]    Very few devices that capture energy from passing vehicles have been implemented, despite numerous designs put forth by various parties over the years. Issues of efficiency, reliability, and manufacturability, among others, have limited the practicality of vehicle energy harvesting devices. Added to the challenge is the variability of vehicle sizes, speeds, axle configurations, and lane positions, all of which can greatly influence the operation of a device trying to capture the motion energy of vehicles and convert it into a useful form of energy. 
         [0004]    Therefore, a need exists for an energy capture device and method having improved efficiency, reliability, and manufacturability, as well as practicality. A need also exists for an energy capture device and method that takes into account the variability of vehicle sizes, speeds, axle configurations, and lane positions in converting the captured motion energy of vehicles into a useful form of energy. 
       SUMMARY OF THE INVENTION 
       [0005]    These problems and others are addressed by the present invention, which provides a novel vehicle energy harvester that overcomes many of the issues with the conventional devices and is therefore better suited for real-world implementation than the conventional devices. 
         [0006]    The exemplary embodiments of the invention make productive use of the energy that is normally wasted (in the form of heat) in reducing the speed of motor vehicles on exit ramps, toll plazas etc., etc. The vehicle energy harvester can absorb mechanical energy from passing (or breaking) vehicles and convert the mechanical energy to electrical energy using, for example, shaft driven generators. 
         [0007]    The disclosed embodiments provide a vehicle energy harvester and power generation system that is simple to install, provides a short payback period, and has a scalable configuration. More particularly, the disclosed embodiments can provide a simple and reliable mechanical configuration that can withstand sever environments. The low cost configuration of the system may provide for faster payback of the expense of the system, and therefore, make the system more practical and desirable for practical applications. 
         [0008]    Additionally, the ease with which the system can be installed also may make the system more practical and desirable for practical applications. The disclosed embodiments require little or no excavation and can be installed in a few hours, instead of over several days as with conventional devices. 
         [0009]    The disclosed embodiment also can provide a scalable configuration that may be particularly advantageous for use at locations, such as exits ramps, toll plazas, hills, among other locations. 
         [0010]    The exemplary embodiments provide a low profile unit mounted directly on top of the existing roadway. In addition to this, other conventional devices do not have a means for determining the speed of oncoming vehicles. The disclosed embodiments provide important advantages in that vehicles traveling faster than the posted speed limit can be slowed by the vehicle energy harvester unit and a portion of the vehicle&#39;s kinetic energy can be converted to electricity rather than wasted as heat from the vehicles braking system. Conversely, vehicles traveling at or below the posted speed limit can be allowed to pass unimpeded. 
         [0011]    An exemplary embodiment of the invention is directed to, for example, a low-profile, surface mount vehicle energy harvester including a low-profile, surface mount subunit having an upper surface forming a roadway surface, a vehicle activated treadle on the subunit, the vehicle activated treadle moveable between a first position in which an upper surface of the treadle is at an angle with respect to the upper surface of the roadway surface and a second position in which the upper surface of the treadle is flush with the upper surface of the roadway surface, a generator that generates power in response to movement of the vehicle activated treadle, an entry ramp at a first end of the harvester roadway surface, and an exit ramp at a second end of the harvester roadway surface. 
         [0012]    Another exemplary embodiment of the invention is directed to, for example, a vehicle energy harvester comprising a plurality of subunits each having an upper surface forming a roadway surface, a vehicle activated treadle on at least one of the plurality of subunits, the vehicle activated treadle moveable between a first position in which an upper surface of the treadle is at an angle with respect to the upper surface of the roadway surface and a second position in which the upper surface of the treadle is flush with the upper surface of the roadway surface, a generator that generates power in response to movement of the vehicle activated treadle, an entry ramp at a first end of the harvester roadway surface, and an exit ramp at a second end of the harvester roadway surface. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    These and other aspects and features of embodiments of the present invention will be better understood after a reading of the following detailed description, together with the attached drawings, wherein: 
           [0014]      FIGS. 1  is a schematic top view of a power absorber unit of a vehicle energy harvester. 
           [0015]      FIG. 2  is a schematic perspective view illustrating a portion of a vehicle energy harvester. 
           [0016]      FIG. 3  is a schematic top view of a low-profile, surface mount vehicle energy harvester. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    The present invention now is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
         [0018]    Referring now to the drawings,  FIGS. 1-3  illustrate an exemplary vehicle energy harvester  10 . 
         [0019]    The exemplary embodiments can make productive use of the energy that is normally wasted (in the form of heat) in reducing the speed of motor vehicles on exit ramps, toll plazas etc., etc. The vehicle energy harvester  10  can absorb mechanical energy from passing (or breaking) vehicles and convert the mechanical energy to electrical energy using, for example, shaft driven generators. Other means for converting the mechanical energy to electrical energy also are contemplated. In an exemplary embodiment, the electric power from the generators can be converted, metered, and fed into the commercial power grid. In another exemplary aspect, each site can be equipped with wireless communications to monitor the status and/or output of the system. 
         [0020]    Power Absorber Configuration 
         [0021]    The disclosed embodiments can include individual assemblies with integral generators. Other generator configurations also are possible, such as separate generators. 
         [0022]    As shown in  FIG. 1 , the vehicle energy harvester unit  10  can be a low-profile surface mounted assembly. The vehicle energy harvester unit  10  can include an entry ramp  12  and an exit ramp  14 . The vehicle energy harvester unit  10  can include a plurality of subunits  16  having a top surface or driving surface  17 . Each subunit can include one or more vehicle activated treadles  18 . In an embodiment, each subunit  16  can include a generator unit  20 . 
         [0023]    In other embodiments, the vehicle energy harvester unit  10  can be set into the road surface. The surface mounted assembly may require minimal installation effort. Additionally, the unit count can be scaled to road/breaking needs. In an embodiment, each generator unit  20  can feed a common power summing/conversion unit  22 . A simple cable interconnect  24  can be provided to connect each generator unit  20  to the common power summing/conversion unit  22 . A fail safe configuration can protect the system against individual unit failures. 
         [0024]    Power Conversion Unit 
         [0025]    In a disclosed embodiment, the individual absorber units  16  can be connected via cable assemblies  24 . The input power can be summed and applied to a low-loss inverter unit. The power can be converted immediately to a form that is transmittable to the power grid. The output can be metered and applied to the power grid for transmission. 
         [0026]    Absorber Unit Operation 
         [0027]    With reference to  FIG. 2 , an exemplary embodiment of a subunit  16  of a vehicle energy harvester unit  10  can include spring-loaded treadles  18  having a treadles gear  30  engaging a drive gear  32 . The drive gear  32  is coupled to a shaft  34 . In operation, one or more vehicle tires force the spring-loaded treadles  18  down as they roll over the treadles  18 . The treadle gears  30  drive the plurality of drive gears  32 , which rotate the shaft  34 . The shaft  34  winds a torsion spring  36 , thereby absorbing the treadle drive transient. A pawl can lock the shaft  34  as rotation ends. The torsion spring  36  rotates a flywheel  38 , thereby spreading the impulse of the treadle drive over time to extend output to a generator  40 . The flywheel  38  can turn a generator  40 , such as a hydro pump. The generator  40 , in turn, can generate electric power for sale/use/storage. 
         [0028]    The exemplary embodiments improve the durability of the system under practical use scenarios. 
         [0029]    Conventional devices generally require a large installation effort that may include roadbed excavation (and attendant construction) or other significant modifications to the road surface. The exemplary embodiments provide a low profile vehicle energy harvester unit  10  mounted directly on top of the existing roadway. In addition to this, other conventional devices do not have a means for determining the speed of oncoming vehicles. The speed of oncoming vehicles is beneficial such that vehicles traveling faster than the posted speed limit can be slowed by the vehicle energy harvester unit and a portion of the vehicle&#39;s kinetic energy is converted to electricity rather than wasted as heat from the vehicles braking system. Conversely, vehicles traveling at or below the posted speed limit will be allowed to pass unimpeded. These improvements are discussed below. 
         [0030]    Low Profile, Surface-Mounted Design 
         [0031]    With reference to  FIGS. 1-3 , an exemplary embodiment of a low-profile, surface mount vehicle energy harvester unit  10  will now be described. 
         [0032]    An exemplary embodiment provides a vehicle energy harvester unit  10  that is designed as a low-profile assembly that can be mounted directly atop existing roadways with little or no modifications to the roadway. This configuration provides practical benefits with respect to installation and maintenance. It also may provide a significant cost advantage as compared to other approaches requiring elaborate installation/construction efforts. The embodiments of the exemplary vehicle energy harvester units  10  can be installed in a matter of hours vs. days. Likewise, maintenance can be greatly improved whereby defective components can be replaced quickly and easily without any major construction work and accompanying delays to traffic. A preferred component used in achieving this configuration is a custom designed permanent magnet alternator that has, for example, a cylindrical form factor approximately 4 inches in diameter and 2 inches in height. The overall operation of the vehicle energy harvester unit  10  is shown in  FIGS. 1-3 . 
         [0033]    The vehicle energy harvester unit  10  can include a modular construction having a plurality of subunits  16 , thereby providing a simple and easy installation and maintenance of the vehicle energy harvester unit  10 . The modular construction of the plurality of subunits  16  can enable a scalable configuration such that the vehicle energy harvester unit  10  can be configured for various applications, space requirements, desired power generation, etc. 
         [0034]    In an exemplary embodiment, a height of each of the subunits  16  preferably is limited to less than or equal to three (3) inches. However, other heights are possible, for example, for entry ramps  12  and exit ramps  14  having a variety of slopes and lengths. 
         [0035]    A length and slope of the entry ramps  12  and exit ramps  14  can be selected based on the height of the subunits  16  and the particular application of the vehicle energy harvester unit  10 . For example, the length of the entry ramp  12  and/or the exit ramp  14  can be increased, thereby reducing the slope of the entry ramp  12  and/or the exit ramp  14  for a given height of the subunits  16  and minimizing the impact on the vehicle energy harvester unit  10  by a vehicle, as well as minimizing a discomfort the user of the vehicle driving over the vehicle energy harvester unit  10 . The vehicle energy harvester unit  10  has a simplified arrangement that provides ample space and adaptability for structural reinforcement. 
         [0036]    The present invention has been described herein in terms of several preferred embodiments. However, modifications and additions to these embodiments will become apparent to those of ordinary skill in the art upon a reading of the foregoing description. It is intended that all such modifications and additions comprise a part of the present invention to the extent that they fall within the scope of the several claims appended hereto. 
         [0037]    Like numbers refer to like elements throughout. In the figures, the thickness of certain lines, layers, components, elements or features may be exaggerated for clarity. 
         [0038]    The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and/or clarity. 
         [0039]    As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. As used herein, phrases such as “between X and Y” and “between about X and Y” should be interpreted to include X and Y. As used herein, phrases such as “between about X and Y” mean “between about X and about Y.” As used herein, phrases such as “from about X to Y” mean “from about X to about Y.” 
         [0040]    It will be understood that when an element is referred to as being “on”, “attached” to, “connected” to, “coupled” with, “contacting”, etc., another element, it can be directly on, attached to, connected to, coupled with or contacting the other element or intervening elements may also be present. In contrast, when an element is referred to as being, for example, “directly on”, “directly attached” to, “directly connected” to, “directly coupled” with or “directly contacting” another element, there are no intervening elements present. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature. 
         [0041]    Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper”, “lateral”, “left”, “right” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the descriptors of relative spatial relationships used herein interpreted accordingly.