Abstract:
A vehicle energy harvester including a 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 a vehicle speed detection device that detects a speed of a vehicle travelling over the roadway surface based on a speed of movement of the vehicle activated treadle.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     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 
     The present invention is directed toward devices and methods of harvesting vehicle energy, and more specifically, toward a vehicle speed detection means for harvesting vehicle energy. 
     SUMMARY OF THE INVENTION 
     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. 
     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. 
     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. 
     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. 
     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. 
     Furthermore, the exemplary embodiments can include a vehicle speed sensor. The embodiments can provide important advantages. For example, the exemplary unit can be used on exit ramps and other traffic lanes where motor vehicles approaching at a high rate of speed are required to reduce speed to comply with local road/traffic conditions. In normal operation, the disclosed embodiments can absorb a small portion of a vehicle&#39;s kinetic energy and convert it to electrical energy. In cases where slower moving vehicles are traveling at or below the local speed limit on the exit ramp, it may be desirable to allow such vehicles to pass unimpeded and not slow them any further. 
     An exemplary embodiment of the invention is directed to, for example, a vehicle energy harvester including a 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 a vehicle speed detection device that detects a speed of a vehicle travelling over the roadway surface based on a speed of movement of the vehicle activated treadle. 
     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, and a vehicle speed detection device that detects a speed of a vehicle travelling over the roadway surface based on a speed of movement of the vehicle activated treadle. 
     Another exemplary embodiment of the invention is directed to, for example, a vehicle energy harvester comprising a 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 vehicle speed detection means for detecting a speed of a vehicle travelling over the roadway surface based on a speed of movement of the vehicle activated treadle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         FIG. 1  is a schematic top view of a power absorber unit of a vehicle energy harvester. 
         FIG. 2  is a schematic perspective view illustrating a portion of a vehicle energy harvester. 
         FIG. 3  is a schematic side view of a vehicle energy harvester having vehicle speed detection means. 
         FIG. 4  is a schematic top view of a vehicle energy harvester having vehicle speed detection means. 
     
    
    
     DETAILED DESCRIPTION 
     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. 
     Referring now to the drawings,  FIGS. 1-4  illustrate an exemplary vehicle energy harvester  10 . 
     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 embodiment, each site can be equipped with wireless communications to monitor the status and/or output of the system. 
     Power Absorber Configuration 
     The disclosed embodiments can include individual assemblies with integral generators. Other generator configurations also are possible, such as separate generators. 
     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 . 
     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. 
     Power Conversion Unit 
     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. 
     Absorber Unit Operation 
     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. 
     Vehicle Speed Detection Means 
     Referring now to  FIGS. 3 and 4 , an exemplary embodiment of a vehicle energy harvester  10  having vehicle speed detection means will now be described. 
     The present invention recognizes that the known conventional devices do not have a means for determining the speed of oncoming vehicles. The embodiments of the invention address and solve these problems and improve the utility of a treadle based energy conversion systems according to the embodiments of the invention. 
     The exemplary embodiments can provide important advantages in that vehicles traveling faster than the posted speed limit can be slowed by the vehicle energy harvester unit  10  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. 
     An exemplary embodiment provides a vehicle energy harvester unit  10  that can be used, for example, on exit ramps and other traffic lanes where motor vehicles approaching at a high rate of speed are required to reduce speed to comply with local road/traffic conditions. In normal operation, the embodiments of the vehicle energy harvester unit  10  can absorb a small portion of a vehicle&#39;s kinetic energy and convert it to electrical energy. In cases where slower moving vehicles are traveling at or below the local speed limit on the exit ramp, it may be desirable to allow such vehicles to pass unimpeded and not slow them any further. The exemplary vehicle energy harvester unit  10  can be equipped with vehicle speed detection means, such as a vehicle speed sensor or the like, to accomplish this function. Various technologies have been considered and contemplated to perform this function and several examples thereof are illustrated and described in  FIGS. 3 and 4 . 
     As shown in  FIG. 3 , an exemplary embodiment of the vehicle energy harvester unit  10  can include vehicle speed detection means or a vehicle speed detection assembly having, for example, an infrared (IR) emitter  50 , an infrared (IR) detector  52 , and a rotating arm portion  54  coupled to the treadle  18 . Other known devices for detecting the speed of a moving part can be used to detect the velocity of the movement of the treadle. 
     In operation, the infrared (IR) detector  52  can detect an infrared beam from the infrared (IR) emitter  50 . The rotating arm portion  54  can be configured to interpose the infrared (IR) emitter  50  and the infrared (IR) detector  52  during movement of the treadle  18 . The rotating arm portion  54  of the treadle  18  can include one or more apertures  56  for permitting the infrared beam emitted from the infrared (IR) emitter  50  to pass through the rotating arm portion  54  of the treadle  18  and be detected by the infrared (IR) detector  52 . In operation, as the treadle  18  moves downward, the infrared beam from the infrared (IR) emitter  50  can be broken by the rotating arm portion  54  of the treadle  18  and the disruption of the infrared beam can be detected by the infrared (IR) detector  52 . The infrared beam can then be detected again by the infrared (IR) detector  52  as the apertures  56  in the rotating arm portion  54  pass by (i.e. correspond to) the infrared beam. In an embodiment, the time between the beams being detected by the infrared (IR) detector  52  can be used to calculate the speed of the vehicle entering the ramp  12 . The speed information can be used by the microcontroller unit (MCU) to engage or disengage one or more of the treadle subunits  16  depending on the calculated speed of the vehicle. 
     As shown in  FIG. 4 , an exemplary embodiment of the vehicle energy harvester unit  10  can include one or more treadles  18  on the entry ramp  12 . The treadles  18  can include vehicle speed detection means or a vehicle speed detection assembly, for example, as illustrated in  FIG. 3 . In this manner, the speed of the vehicle entering the ramp  12  can be calculated and the speed information can be used by the microcontroller unit (MCU) to engage or disengage one or more of the treadle subunits  16  depending on the calculated speed of the vehicle. 
     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. 
     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. 
     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. 
     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.” 
     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. 
     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.