Patent Publication Number: US-11396334-B2

Title: Deployable fairing system for use with vehicles

Description:
TECHNICAL FIELD 
     The present disclosure generally relates to vehicles, for example tractor trailer combinations, and more particularly with deployable fairing systems to enhancing fuel economy of vehicles, for example coupled vehicles. 
     BACKGROUND 
     Description of the Related Art 
     Vehicles move a large number of people and cargo. Often two or more vehicles are physically coupled together to move freight or other cargo, people, and/or animals. 
     A ubiquitous example of coupled vehicles is that of the tractor-trailer or semi-trailer combination, which employs a tractor, sometimes referred to as a primary mover, coupled to pull one or more trailers. Such tractor-trailers or semis come in a large variety of forms and are typically used to move freight over relatively long distances. The tractor is the drive mechanism that pulls or pushes the trailer. The tractor includes the engine, typically an internal combustion diesel engine, a transmission and drive wheels. The tractor typically includes a cab where the driver or operator sits to operate the tractor. The tractor may also include a sleep cab which provides accommodations for the driver or operator when not in motion. The trailers are typically removably coupled to the tractor via a coupler such as a fifth wheel carried by the tractor and kingpin carried by the trailer, or less commonly via an automatic coupling. A semi-trailer typically does not have a front axle, relying on the tractor for support of a portion of the trailer&#39;s weight, and may have one or typically more rear axles. In some instances, a tractor may pull multiple trailers, forming a train. In such a case, the following trailer(s) may not have front axels and may rely on the proceeding trailers for supporting a portion of the trailer&#39;s weight. Trailers come in a large variety, for example box, bus, curtain side, flatbed, “low boy”, refrigerated or “reefer”, tanker, dry bulk, car carrier, drop deck, “double decker” or sidelifter. Trailers are often substantially rectangular, having a front end which is coupled to the tractor and a back end spaced remotely from the tractor. The back end often includes a door or more commonly a pair of doors to provide access to an interior of the trailer from an exterior thereof. The front end, back end, and sides of a trailer tend to be vertically extending surfaces. In some instances, a portion of a trailer or an accessory thereof may extend horizontally from these vertically extending surfaces, for example a refrigeration system or heater or nose cone may extend forward from the front of a trailer in to a gap region between a tractor and coupled trailer. 
     Another example of coupled vehicles is railroad trains. Rail road trains typically include one or more locomotives that pull a number of cars along a set of tracks. The cars may include passenger cars and/or freight cars. The freight cars can take a large variety of forms, similar in some respects to the various types of trailers. 
     Tractor-trailers or semis and railroad trains are increasingly used to move containerized cargo. This multi-modal approach allows containerized cargo to be conveniently moved between ships (e.g., ocean going container ships, barges), tractor trailers, and/or railroad trains. For instance, containers may arrive by ship from overseas. Tractor-trailers may move some of the containers over roads to warehouses or to retail locations. Tractor-trailers may move some of the containers to rail yards. Some containers may be moved via railroad trains, and subsequently moved to a desired location via tractor-trailers. 
     Coupled vehicles typically must be capable of operating in a variety of environments. For example, coupled vehicles must be capable of carrying loads at relatively high speed over long distance. For instance, tractor-trailer combinations typically must be able to haul freight over highways such as toll roads or freeways within some posted speed limit. Such highways are typically relatively straight over long distances, and do not require much turning or maneuvering. Such tractor-trailers typically must also be able to haul freight over surface streets at much lower posted speed limits. Travel over surface streets typically requires higher maneuverability than travel over highways, often requiring essentially right angle turns in relatively confined spaces or navigating steep elevational changes. 
     Fuel efficiency is typically an important concern when operating coupled vehicles. A large portion of the cost of moving freight or people is attributable to fuel costs and the majority of fuel at highway speeds is spent overcoming aerodynamic drag. Fuel efficiency tends to decrease as speed increases. Fuel efficiency while traveling on highways is particularly a concern since the average speed is higher than on surface roads and, for most operations, more time is spent on highways than on surface streets. 
     Numerous approaches have been suggested for increasing fuel efficiency of vehicles. These approaches typically employ ferrules, fairings, cowlings, air dams, deflectors, and/or spoilers located at various locations, for instance on a front of the tractor or over a roof of the tractor. Some approaches for increasing fuel efficiency specifically address the problem created by the fact that there is a gap between the tractor and trailer. Some of the approaches for increasing fuel efficiency are illustrated in U.S. Pat. Nos. 3,697,120; 3,711,146; 3,934,923; 4,036,519; 4,750,772; 5,078,448; and 6,585,312. 
     BRIEF SUMMARY 
     Deployable fairing systems are disclosed that enhance fuel efficiency of vehicles (e.g., coupled vehicles), yet which adapt to a current situation (e.g., type of trailer or specific physical configuration of trailer) and/or adapt to current conditions (e.g., climate, wind speed, wind direction, temperature of ambient environment). 
     A fairing system for use with vehicles may be summarized as including: a deployable fairing structure selectively moveable between a fully retracted configuration of the fairing structure and a fully deployed configuration of the fairing structure, the deployable fairing structure extending at least partially into a gap region when in the fully deployed configuration, the deployable fairing structure occupying a deployed region when in the fully deployed configuration; at least one actuator drivingly coupled to move the fairing structure between the fully retracted configuration of the fairing structure and the fully deployed configuration of the fairing structure; at least one sensor positioned to sense obstacles, if any, in at least a portion of the deployed region; and a controller communicatively coupled to the at least one sensor to receive information representative of a presence or absence of any obstacles in the deployed region, and communicatively coupled to directly or indirectly control the at least one actuator at least in part based on the presence or the absence of any obstacles in the deployed region. For example, the controller may determine the presence or the absence of one or more of a cooling unit, a heating unit or a nose cone that extends forward from a vertically extending front of the trailer into the gap region. 
     The controller may include at least one processor and determines the presence or the absence of any obstacles in the deployed region based at least in part on the information received via the at least one sensor. At least one sensor may be positioned to sense obstacles that are distinct and separate from the deployable fairing structure. The at least one sensor may include at least one distance sensor. The at least one sensor may include at least one proximity sensor. The at least one at least one of proximity sensor may include at least one of: an ultrasonic; sensor, a capacitive sensor, a photoelectric sensor, an inductive sensor, or a magnetic sensor. The at least one sensor may include at least one image sensor. The at least one sensor may include at least one sensor of a first type of sensor and at least one sensor of a second type of sensor, the second type of sensor different from the first type of sensor. The at least one processor may determine the presence or the absence of a portion of the trailer in the deployed region based at least in part on the information received via the at least one sensor. 
     The deployable fairing may be attached to a back of a cab of a tractor having a fifth wheel and a set of drive wheels. The gap region may encompass a volume between the back of the cab of the tractor and a front of a trailer coupled to the tractor via the fifth wheel of the tractor and a kingpin of the trailer, and which extends upwards above the set of drive wheels of the tractor. 
     The at least one actuator may include at least one piston, a pressure source fluidly coupled to the at least one piston, and at leave one valve selectively operable to control a pressure in at least a portion of the piston. The at least one actuator may include at least one of an electric motor or a solenoid. 
     A method of operation of a fairing system for use with vehicles, the fairing system may be summarized as including: receiving signals by the controller from the at least one sensor; determining by the controller whether an obstacle is in the deployed region; and in response to determining that an obstacle is in the deployed region, at least limiting deployment or further deployment of the deployable fairing structure into the deployed region. 
     At least limiting deployment or further deployment of the deployable fairing structure into the deployed region may include preventing movement of the deployable fairing structure. At least limiting deployment or further deployment of the deployable fairing structure into the deployed region may include sending signals to the at least one actuator to cause the at least one actuator to move the deployable fairing structure a limited amount into the deployed region, short of the fully deployed configuration. At least limiting deployment or further deployment of the deployable fairing structure into the deployed region may include sending signals to the at least one actuator that cause the at least one actuator to retract the deployable fairing structure into the fully retracted configuration. At least limiting deployment or further deployment of the fairing structure into the deployed region may include sending signals to lock the deployable fairing structure in the fully retracted configuration. At least limiting deployment or further deployment of the deployable fairing structure into the deployed region may include controlling at least one valve to adjust a pressure in at least one piston. 
     Determining by the controller whether an obstacle is in the deployed region may include determining whether an obstacle that is distinct and separate from the deployable fairing structure is within the deployed region. Determining by the controller whether an obstacle is in the deployed region may include determining whether one or more of a cooling unit, a heating unit or a nose cone that extends forward from a vertically extending front of a trailer extends into the gap region. 
     Receiving signals by the controller from the at least one sensor may include receiving signals from at least one distance sensor. Receiving signals by the controller from the at least one sensor may include receiving signals from at least one proximity sensor. Receiving signals from at least one proximity sensor may include receiving signals from at least one of: an ultrasonic sensor, a capacitive sensor, a photoelectric sensor, an inductive sensor, or a magnetic sensor. Receiving signals by the controller from the at least one sensor may include receiving signals from at least one image sensor. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       In the drawings, identical reference numbers identify similar elements or acts. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not necessarily drawn to scale, and some of these elements are arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn, are not necessarily intended to convey any information regarding the actual shape of the particular elements, and have been solely selected for ease of recognition in the drawings. 
         FIG. 1A  is a left side elevational view of a coupled vehicle comprising a tractor and a trailer, and which employs deployable faring to close a gap between the tractor and the trailer, according to one illustrated implementation, the deployable faring illustrated in a fully deployed configuration expanded proximate one of the vehicles. 
         FIG. 1B  is a rear, left side, isometric view of the coupled vehicle and deployable faring of  FIG. 1A , the deployable faring illustrated in the fully deployed configuration. 
         FIG. 1C  is a front, left side, isometric view of the coupled vehicle and deployable faring of  FIG. 1A , the deployable faring illustrated in the fully deployed configuration. 
         FIG. 1D  is a rear, left side, isometric view of the tractor and deployable faring of  FIG. 1A , the deployable faring illustrated in the fully deployed configuration. 
         FIG. 2A  is a left side elevational view of a coupled vehicle comprising a tractor and a trailer, and which employs deployable faring to close a gap between the tractor and the trailer, according to one illustrated implementation, the deployable faring illustrated in a fully retracted or un-deployed configuration retracted against one of the vehicles. 
         FIG. 2B  is a rear, left side, isometric view of the coupled vehicle and deployable faring of  FIG. 2A , the deployable faring illustrated in the fully retracted configuration. 
         FIG. 2C  is a front, left side, isometric view of the coupled vehicle and deployable faring of  FIG. 2A , the deployable faring illustrated in the fully retracted configuration. 
         FIG. 2D  is a rear, left side, isometric view of the tractor and deployable faring of  FIG. 2A , the deployable faring illustrated in the fully retracted configuration. 
         FIG. 3A  is a rear, left side, isometric view of the tractor and deployable fairing of  FIGS. 1D and 2D , with the deployable faring illustrated in an intermediate configuration, between the deployed and the retracted configurations. 
         FIG. 3B  is a left side elevational view of the tractor and deployable fairing of  FIGS. 1D and 2D , with the deployable faring illustrated in an intermediate configuration, between the fully deployed and the fully retracted configurations. 
         FIG. 4  is a bottom, rear, left side elevational view of a deployable fairing of  FIGS. 1A-3B , which better illustrates a frame and an actuator selectively operable to move the deployable fairing between the fully retracted and fully deployed configurations. 
         FIG. 5  is a top plan view of a deployable fairing showing the right and left side panels with a bent edge moving through a variety of configurations, from the fully deployed configuration to the fully retracted or un-deployed configuration and therebetween, and better illustrating a plurality of intermediate configurations between the fully deployed configuration and the fully retracted or un-deployed configuration. 
         FIG. 6A  is a top, rear, right-side isometric view of a deployable fairing in which the deployable fairing is shown in a deployed configuration, according to at least another illustrated implementation. 
         FIG. 6B  is a rear elevational view of the deployable fairing of  FIG. 6A  in which the deployable fairing is shown in the deployed configuration, according to at least one illustrated implementation. 
         FIG. 7  is a rear, left side, isometric view of a vehicle comprising a trailer, which employs deployable faring as a tail end to improve aerodynamic efficient, according to one illustrated embodiment, the deployable faring illustrated in a fully retracted or un-deployed configuration. 
         FIG. 8  is a rear, left side, isometric view of the deployable fairing of  FIG. 7  in the fully extended or fully deployed configuration. 
         FIG. 9A  is a top plan view of a hinge shown in an extended configuration in which one end of an actuator is rotatably coupled to a base of the hinge and an opposite end of the actuator is rotatably coupled to a portion of the arm of the hinge, according to at least one illustrated implementation. 
         FIG. 9B  is a top plan view of the side panel hinge of  FIG. 9A  shown in a retracted configuration, according to at least one illustrated implementation. 
         FIG. 10  is a schematic diagram of a control system for the deployable fairing system according to one illustrated implementation, the deployable fairing system operable to automatically selectively move a deployable fairing between an un-deployed configuration to a partially or fully deployed configuration based on a signal indicative or representative of a situation (e.g., presence or absence of obstacle in region of deployment) and/or other conditions (e.g., wind speed, wind direction, temperature of the ambient environment). 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, certain specific details are set forth in order to provide a thorough understanding of various disclosed embodiments. However, one skilled in the relevant art will recognize that embodiments may be practiced without one or more of these specific details, or with other methods, components, materials, etc. In other instances, well-known structures associated with coupled vehicles, for example tractor-trailer combinations, and with wireless communications have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the embodiments. 
     Unless the context requires otherwise, throughout the specification and claims which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense, that is as “including, but not limited to.” 
     Reference throughout this specification to “one embodiment,” “one implementation,” “an embodiment,” or “an implementation” means that a particular feature, structure or characteristic described in connection with the embodiment or implementation is included in at least one embodiment or one implementation. Thus, the appearances of the phrases “in one embodiment,” “in one implementation,” “in an embodiment,” “or “in one implementation” in various places throughout this specification are not necessarily all referring to the same embodiment or to the same implementation. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments or implementations. 
     As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise. 
     The headings and Abstract of the Disclosure provided herein are for convenience only and do not interpret the scope or meaning of the embodiments. 
     This disclosure describes various apparatus, methods and articles related to increasing fuel efficiency for coupled vehicles. While described in terms of a tractor-trailer combination, such may be used in conjunction with other coupled vehicles. 
       FIGS. 1A, 1B, 1C, and 1D  show a vehicle  10  in the form of a coupled vehicle comprising a tractor  10   a  and a trailer  10   b , and a deployable fairing system  12  with a deployable fairing  16  shown in a fully extended or fully deployed configuration  20 , according to one illustrated implementation.  FIGS. 2A, 2B, 2C, and 2D  show the coupled vehicle  10  with the deployable fairing  16  in a fully retracted or fully un-deployed configuration  18 , according to one illustrated implementation. 
     The vehicle  10  includes, for example, a lead vehicle, which in typical operation is at the front or ahead of a trailing vehicle with respect to a direction of travel during normal operation. It is recognized that in some instances, the lead vehicle may at times be behind the trailing vehicle, for example when backing up. In the illustrated implementation, the lead vehicle is the tractor  10   a , which includes an engine (e.g., internal combustion diesel engine, not shown), a transmission (not shown), drive wheels, steering wheel, throttle (not shown), and brakes (not shown). The tractor  10   a  may be typical of those commonly used in long haul trucking within the United States, such as those manufactured and sold under the Kenworth and Peterbilt trademarks. The tractor  10   a  may include a cab  10   c  in which the driver or operator sits while driving or operating the tractor  10   a . The tractor  10   a  may also include a sleeper cab  10   d , located behind the cab  10   c , which a driver or operator may use as a residence or sleep area when the tractor  10   a  is parked. The back of the tractor may have a width  10   e . The tractor may have one or more ferrules, fairings, cowlings, air dams, deflectors, and/or spoilers located at various locations to reduce aerodynamic drag and thereby increase fuel efficiency. 
     The trailer  10   b  may take any of a variety of forms. For example, the trailer  10   b  may take the form of a semi-trailer, which includes a set of rear wheels, relying on the tractor  10   a  to support a portion of the weight of the trailer  10   b  at a front end of the trailer  10   b , instead of having a front axle. The trailer  10   b  may take the form of a box trailer, or any variety of other types of trailers, for instance bus, curtain side, flatbed, “low boy”, refrigerated or “reefer”, tanker, dry bulk, car carrier, drop deck, “double decker” or sidelifter trailers. As illustrated the trailer typically has a front that extends substantially vertically, although one or more portions or objects may extend horizontally forward of from the front of the trailer, e.g., a cooler unit, a heater unit, a nose cone. 
     The trailer  10   b  is physically coupled to the tractor  10   a . For example, the tractor  10   a  may carry a fifth wheel, to which the trailer  10   b  is removably or detachably physically coupled. Fifth wheels include metal plates skid plates and jaws on one vehicle, usually the tractor, and which receive a kingpin carried by the other vehicle, usually the trailer. Fifth wheels are commonly employed in tractor trailer combinations  10 , so will not be described in detail. There may be additional couplings between the tractor  10   a  or components thereof and the trailer  10   b  or components thereof. For example, there may be one or more electrical couplings, pneumatic couplings and/or hydraulic couplings. Such may, for example, provide electrical power or signals to the trailer  10   b  or component thereof, for instance a refrigeration system, turn signal indicators and/or brake lights. Such may, for example, supply pressurized fluid or air to the trailer  10   b  or a component thereof, for instance brakes. 
     Notably, a gap region  14  exists between the tractor  10   a  and the trailer  10   b . The gap region  14  is sufficiently large as to allow the tractor-trailer combination  10  to maneuver as need, for example through surface streets of a city of town. For instance, the gap  14  may be approximately 1.5 meters or 4.5 feet in length. This gap region  14  negatively affects aerodynamic and hence hinders fuel efficiency, particularly at higher speeds such as highway speeds (e.g., 55-75 mph). Without being bound to such, Applicant believes that closing the gap  14  may result in an approximately 8% reduction in fuel costs. 
     As illustrated, the deployable fairing system  12  includes a deployable fairing  16  and optionally a static cab fairing  17 . As previously noted,  FIGS. 2A-2D  illustrate the deployable fairing  16  in an extended or deployed configuration  20 . In particular, the deployable fairing  16  does not extend the full length of the gap region  14  between the tractor  10   a  and trailer  10   b  in the un-deployed or unextended position or configuration  18 , and in fact is preferably retracted to be close to the back of the cab  10   c ,  10   d , for example against or proximate the static cab fairing  17 . As previously noted,  FIGS. 1A-1D  illustrate the deployable fairing  16  in a fully deployed or fully extended position or configuration  20 . In particular, the combination of the static cab fairing  17  and the deployable fairing  16  extends the full length or almost the full length of the gap region  14  between the tractor  10   a  and trailer  10   b  when the deployable fairing  16  is in the deployed or extended configuration or position  20 . Thus, the combination of the static cab fairing  17  and the deployable fairing  16  extends over halfway, and preferably over three quarters of the way or over seven eighths of the way across the gap region  14 . 
     As discussed in detail below, the deployable fairing system  12  can automatically selectively move the deployable fairing  16  between the un-deployed or unextended configuration or position  18  and the deployed or extended configuration or position  20  in response to, or based on, a speed or expected speed of at least one of the coupled vehicles  10   a ,  10   b . Thus, the deployable fairing  16  may be in the fully deployed or fully extended configuration or position  20  when the tractor-trailer combination  10  is operating at relatively fast speeds or on roads or portions of roads where a posted speed limit is relatively fast or high. This can advantageously reduce aerodynamic drag, thereby increasing fuel efficiency. Likewise, the deployable fairing  16  may be in the fully un-deployed or fully unextended configuration or position  18  when the tractor-trailer combination  10  is operating at relatively slow speeds or on roads or portions of roads where a posted speed limit is relatively slow or low. This may advantageously improve maneuverability on such roads or during such times that maneuverability is most desired and when or where the gap  14  least adversely affects fuel efficiency. Further, the deployable fairing  16  may be placed in or constrained to in an intermediate configuration between the fully deployed or fully extended configuration or position  20  and the fully un-deployed or fully unextended configuration or position  18  based on the existence or absence of obstacles or obstructions in the gap region  14 , for instance a portion of the trailer (e.g., refrigeration unit, heater unit, nose cone) that extends forward of the generally vertical front of the trailer. Additionally or alternatively, the deployable fairing  16  may be placed in or constrained to an intermediate configuration between the fully deployed or fully extended configuration or position  20  and the fully un-deployed or fully unextended configuration or position  18  based on one or more other conditions, for example wind speed, wind direction, temperature in the ambient environment or other environmental conditions. 
       FIGS. 3A and 3B  show the tractor  10   a , the static cab faring  17  and the deployable fairing  16  in a partially deployed or intermediate configuration  22 . The deployable fairing  16  can, for example, take on the partially deployed or intermediate configuration  22  while moving or transiting between the fully deployed or fully extended configuration and the fully retracted or fully un-deployed configuration. Alternatively or additionally, the deployable fairing  16  can, for example, take on the partially deployed or intermediate configuration  22  when there is no trailer  10   b  coupled to the tractor  10   a , when there is an object or obstacle in the gap region  14  which might cause damage to the deployable fairing  16  or portion thereof, and/or when environmental conditions (e.g., wind speed and/or wind direction, temperature of the ambient environment) meet certain criteria or thresholds. Thus, in at least some instances the deployable fairing  16  can be moved from, for example, the fully retracted or fully un-deployed configuration  18  to the partially deployed or intermediate configuration  22  and held in the partially deployed or intermediate configuration  22 , without moving to the fully deployed or fully extended configuration  20 . Such may advantageously increase fuel efficiency even when the vehicle  10  is not a coupled vehicle or train of vehicles. Additionally or alternatively, in at least some instances the deployable fairing  16  can be moved from, for example, the fully extended or fully deployed configuration  20  to the partially deployed or intermediate configuration  22  and held in the partially deployed or intermediate configuration  22 , without moving to the fully retracted or fully un-deployed configuration  18 . 
       FIG. 4  shows a deployable fairing system  12  with a deployable fairing  16  shown in an extended or deployed configuration  20 , according to one illustrated implementation. In some implementations, the deployable fairing system  12  includes a static D-gap panel  24  ( FIGS. 1A-D ,  2 A- 2 D,  3 A), upper and lower horizontal panel assemblies  26  and  28 , respectively, left and right side panels  30  and  32 , respectively, a frame  34 , and an actuator  36 . The static D-gap panel  24  is attached to the back of the cab  10   c ,  10   d  and extends horizontally rearward towards the trailer  10   b . The static D-gap panel  24  may be used to accommodate various shapes and configurations for the back of the cab  10   c ,  10   d , thus enabling the deployable fairing system  12  to be installed, for example, as a retrofit on existing tractors  10   a  without creating a gap between the deployable fairing system  12  and the back of the cab  10   c ,  10   d . In some implementations, the deployable fairing system  12  may not include the static D-gap panel  24 . 
     In some implementations, the frame  34  attaches to the cab  10   c ,  10   d  at a lower attachment  38 , a middle attachment  40 , and an upper attachment  42 . The lower, middle, and upper attachments  38 ,  40 , and  42  are each physically coupled to the cab  10   c ,  10   d  using one or more bolts or other fasteners (e.g., rivets, screws, clamps). In many instances, there may be a limited number of locations on a cab  10   c ,  10   d  which are strong enough to provide a secure attachment location. Each of the lower, middle, and upper attachments  38 ,  40 , and  42 , respectively, includes one or more rods  44  that project outwardly from the respective attachments  38 ,  40 , and  42  to provide support for the remaining portion of the deployable fairing system  12 . In some implementations, a proximal end of each rod  44  may be affixed or otherwise physically coupled to one of the lower, middle, or upper attachment  38 ,  40 , or  42 , respectively, and project upwardly and rearwardly from the respective lower, middle, or upper attachment  38 ,  40 , or  42 , to which it is affixed. The distal end of each rod  44  may be attached to one of an upper bar  46 , a middle bar  48 , or a lower bar  50 . 
     Each of the upper bar  46 , the middle bar  48 , and the lower bar  50  extends in a lateral direction across the width  10   e  of the cab  10   a , horizontal with respect to the ground and perpendicular with respect to the direction of forward travel during normal operation of the vehicle  10 . The upper bar  46  is attached to the distal, substantially straight edge  27  of the static D-gap panel  24 . One or more hinges positioned along the upper bar  46  form an upper lateral axis  47  and pivotally couple the upper horizontal panel assembly  26  to the upper bar  46 , enabling the upper horizontal panel assembly  26  to rotate about the upper lateral axis  47 , as described below. The lower bar  50  may be directly below the upper bar  46  such that the lower bar  50  and the upper bar  46  form a vertical plane that is perpendicular with respect to the direction of forward travel during normal operation of the vehicle  10 . In some implementations, a left and a right vertical support  52  and  54 , respectively, are affixed or otherwise physically coupled to the upper bar  46  and the lower bar  50  to provide additional bracing and support for the frame  34 . The lower bar  50  may be located about one-third of the way up from the bottom of one or both of the left and the right side panels  30  and  32 , respectively. One or more hinges positioned along the lower bar  50  form a lower lateral axis  51  and physically couple the lower horizontal panel assembly  28  to the lower bar  50 , enabling the lower horizontal panel assembly  28  to rotate about the lower lateral axis  51 , as described below. 
     The middle bar  48  may be located in a vertical position about half way between the upper bar  46  and the lower bar  50 . In some implementations, the middle bar  48  is located in a horizontal position between the back of the cab  10   c ,  10   d  and the vertical plane formed by the upper bar  46  and the lower bar  50 . One or more horizontal supports (e.g., left horizontal support  56  and right horizontal support  58 ) may project rearwardly from the middle bar  48  and attach to the left vertical support  52  and the right vertical support  54  to provide additional bracing and support for the frame  34 . The proximal end of the actuator  36  is pivotally coupled to the middle bar  48  with one or more hinges that enable the actuator  36  to pivot about a horizontal, lateral axis that extends through the hinges that couple the actuator  36  to the middle bar  48 . The actuator  36  rotates about this horizontal, lateral axis as the deployable fairing  16  moves between the unextended configuration or position  18  and the extended position  20 . The distal end of the actuator  36  is located upward and rearward from the proximal end of the actuator  36 , and is attached to the upper horizontal panel assembly  26  with one or more hinges. These hinges enable the actuator  36  and the upper horizontal panel assembly  26  to rotate relative to each other as the actuator  36  moves the deployable fairing  16  between the fully unextended position or configuration  18  and the fully extended position or configuration  20 . 
     The upper horizontal panel assembly  26  includes a deployable upper panel  60 , a left upper wing panel  62 , and a right upper wing panel  64 . The deployable upper panel  60  is shaped like a trapezoid, with two bases, or parallel sides, (longer base  66  and shorter base  68 ) that extend in a lateral direction across the width  10   e  of the cab  10   c . In some implementations, the deployable upper panel  60  may be shaped like a trapezoid but with one or more corners along the longer base cut off to form two additional short sides. Further in some implementations, the deployable upper panel  60  may be elongated at the shorter base  68 , such as shown in  FIG. 4A , thus forming two short sides (e.g., left short side  68   a  and right short side  68   b ) perpendicular to short base  68 . In some implementations, the longer base  66  of the deployable upper panel  60  is located proximate the static D-gap panel  24  and forms a major edge that is pivotally coupled to the upper bar  46  or the substantially straight edge  27  of the static D-gap panel  24  using one or more hinges. The hinges enable the deployable upper panel  60  to rotate about the upper lateral axis  47  that extends in a lateral direction across the width  10   e  of the cab  10   c , parallel to the longer base  66  and perpendicular to the direction of travel during normal operation, as discussed below. The two legs (left leg and right leg) of the deployable upper panel  60  form axes (left axis and right axis) that have non-zero acute angles with respect to the longer base and the upper lateral axis of the deployable upper panel  60 . The left upper wing panel  62  is pivotally coupled to the deployable upper panel  60  using one or more hinges that form the left axis along the left leg, and the right upper wing panel  64  is pivotally coupled to the deployable upper panel  60  using one or more hinges that form the right axis along the right leg. 
     The left upper wing panel  62  has a trapezoidal profile with two parallel base edges (longer base edge and shorter base). The longer base edge forms the outside left edge of the upper horizontal panel assembly  26  when the deployable fairing  16  is in the fully extended position  20 . The longer base edge is pivotally coupled to the left side panel  30  using one or more hinges that enable the left upper wing panel  62  to pivot relative to a left horizontal axis formed by the top edge of the left side panel  30 . The hinges that pivotally couple the left upper wing panel  62  to the deployable upper panel  60  along the left axis enable the left upper wing panel  62  and the deployable upper panel  60  to pivot relative to one another as the deployable fairing  16  moves between the fully retracted position or configuration  18  and fully extended position  20 . In some implementations, the left upper wing panel  62  is triangular in shape with a first edge adjacent, and pivotally coupled, to the deployable upper panel  60 , and a second edge adjacent, and pivotally coupled, to the left side panel  30 . 
     The right upper wing panel  64  is located opposite the left upper wing panel  62  from a centerline formed in the middle of the deployable upper panel  60 . The right upper wing panel  64  has a trapezoidal profile with a longer base edge and a shorter base. The longer base edge forms the outside right edge of the upper horizontal panel assembly  26  when the deployable fairing  16  is in the extended position  20 . The longer base edge is pivotally coupled to the right side panel  32  using one or more hinges that enable the right upper wing panel  64  to pivot relative to a right horizontal axis formed by the top edge of the right side panel  32 . The hinges that pivotally couple the right upper wing panel  64  to the deployable upper panel  60  along right axis enable the right upper wing panel  64  and the deployable upper panel  60  to pivot relative to one another as the deployable fairing  16  moves between the fully retracted position or configuration  18  and the fully extended position or configuration  20 . In some implementations, the right upper wing panel  64  is triangular in shape with a first edge that is adjacent, and pivotally coupled, to the deployable upper panel  60  along the right leg, and a second edge that is adjacent, and pivotally coupled, to the right side panel  32 . 
     The lower horizontal panel assembly  28  includes a deployable lower panel  80 , a left lower wing panel  82 , and a right lower wing panel  84 . The deployable lower panel  80  may have two parallel, lateral sides (longer base  86   b  and shorter base) that extend in a lateral direction across the width  10   e  of the cab  10   c ,  10   d . In some implementations, the longer base of the deployable lower panel  80  is located proximate the cab  10   c ,  10   d  and forms a major edge that is pivotally coupled to the lower bar  50  or a part of the cab  10   c ,  10   d . The hinges enable the deployable lower panel  80  to rotate about the lower lateral axis that extends in a lateral direction across the width  10   e  of the back of the cab  10   c ,  10   d , parallel to the longer base  86  and perpendicular to the direction of travel during normal operation, as discussed below. In some implementations, the deployable lower panel  80  may be shaped like a trapezoid but with one or more corners along the longer base cut off to form two additional short sides perpendicular to the longer base, as shown in  FIG. 4 . Further in some implementations, the deployable lower panel  80  may be elongated at the shorter base thus forming two short sides perpendicular to shorter base. 
     The deployable lower panel  80  may have two diagonal legs (left leg and right leg) that form diagonal axes (left axis and right axis) having non-zero acute angles with respect to the lower lateral axis and the longer base of the deployable lower panel  80 . The deployable lower panel  80  is pivotally coupled to the left lower wing panel  82  along the left axis using one or more hinges along the left leg, and the deployable lower panel  80  is pivotally coupled to the right lower wing panel  84  along the right axis using one or more hinges along the right leg. The lower horizontal panel assembly  28  may further optionally be physically coupled to the upper horizontal panel assembly  26  using one or more cables, rods, or other links (not shown). 
     The left lower wing panel  82  has four sides, including a left side edge and a shorter base. The longer base edge forms the outside left edge of the lower horizontal panel assembly  28  when the deployable fairing  16  is in the fully extended position  20 . The left side edge  92  is pivotally coupled to the left side panel  30  using one or more hinges that enable the left lower wing panel  82  to pivot relative to a lower left horizontal axis that extends through the left side panel  30 . The hinges that pivotally couple the left lower wing panel  82  to the deployable lower panel  80  enable the left lower wing panel  82  to pivot relative to the deployable lower panel  80  as the deployable fairing  16  moves between the fully retracted position or configuration  18  and the fully extended position or configuration  20 . In some implementations, the left lower wing panel  82  is triangular in shape with a first edge that is adjacent, and pivotally coupled, to the deployable lower panel  80  along the left leg, and a second edge that is adjacent, and pivotally coupled, to the left side panel  30 . 
     The right lower wing panel  84  is located opposite the left lower wing panel  82  from a centerline formed in the middle of the deployable lower panel  80 . The right lower wing panel  84  has four sides, including a right side edge  96 . The right side edge  96  forms the outside right edge of the lower horizontal panel assembly  28  when the deployable fairing  16  is in the extended position  20 . The longer base edge  96  is pivotally coupled to the right side panel  32  using one or more hinges that enable the right lower wing panel  84  to pivot relative to a lower right horizontal axis that extends across the right side panel  32 . The hinges that pivotally couple the right lower wing panel  84  to the deployable lower panel  80  enable the right lower wing panel  84  and the deployable lower panel  80  to pivot relative to one another as the deployable fairing  16  moves between the fully retracted position or configuration  18  and the fully extended position or configuration  20 . In some implementations, the right lower wing panel  84  is triangular in shape with a first edge that is adjacent, and pivotally coupled, to the deployable lower panel  80  along the right leg, and a second edge that is adjacent, and pivotally coupled, to the left side panel  30 . 
     The left and the right side panels  30  and  32 , respectively, are each pivotally coupled to one or both of the upper and lower horizontal panel assemblies  26  and  28 . The left side panel  30  and the right side panel  32  pivot about vertical axes (left vertical axis and right vertical axis) that extend along or beside a proximal edge of the left side panel  30  and a proximal edge of the right side panel  32 , both relative to the cab  10   c . In some implementations, neither the proximal edge of the left side panel  30  nor the proximal edge of the right side panel  32  includes any hinges. In some such implementations, the left and the right side panels  30  and  32 , respectively, are physically coupled to the other components of the fairing system  12  only through the pivotal couplings with the upper wing panels  62  and  64  of the upper horizontal panel assembly  26 , and the lower wing panels  82  and  84  of the lower horizontal panel assembly  28 . In some implementations, the left and the right side panels  30  and  32 , respectively, are physically coupled to the fairing system  12  only through the pivotal couplings with upper left wing panel  62  and the right upper wing panel  64  of the upper horizontal panel assembly  26 . Further, in such implementations, the fairing system  12  may not have any vertical hinges between the deployable fairing  16  and the tractor  10   a  or the cab  10   c ,  10   d.    
     The left and the right side panels  30  and  32 , respectively, each extend vertically with respect to the cab  10   c ,  10   d  when the deployable fairing  16  is both in the unextended or fully retracted or fully un-deployed position or configuration  18  and in the fully extended or fully deployed position or configuration  20 . When the deployable fairing  16  is in the fully extended or fully deployed position  20 , the left and the right side panels  30  and  32  may be substantially parallel to the direction of travel during normal operation and substantially perpendicular to the upper horizontal panel assembly  26 , extending rearwardly from the cab  10   c . In some implementations, the left and the right side panels  30  and  32  may alternatively be at a positive slope, slightly flaring out from vertical planes that extend rearwardly from the side of the cab  10   c , when the fairing system  12  is in the fully extended or fully deployed position  20 . When the deployable fairing  16  is in the unextended or fully retracted or fully un-deployed position or configuration  18 , the left and the right side panels  30  and  32  pivot inward toward the back of the cab  10   c  to form a negative slope with respect to a vertical plane that extends parallel to a direction of travel during normal operation. In some implementations in which the deployable fairing  16  is in the unextended or fully retracted or fully un-deployed position or configuration  18 , the left and the right side panels  30  and  32  may pivot into positions in which the left and the right side panels  30  and  32  each extend laterally along the width  10   e  of the cab  10   c , to be substantially perpendicular to the direction of travel during normal operation. When the deployable fairing  16  is in the intermediary position  22 , the left and the right side panels  30  and  32  may be substantially vertical with respect to the ground; in addition the left and the right side panels  30  and  32  may be rotated inward towards the back of the cab  10   c  by a certain angle (e.g., rotated inward by about 45° from their respective locations in the extended position  20 ). 
     The actuator  36  is illustrated as piston and a cylinder. The cylinder may have an interior or chamber. The piston includes a piston head (not visible) and piston arm coupled to the piston head. The piston head is translatable received within the chamber of the cylinder, typically with a fairly tight tolerance. The piston head divides the chamber into two portions, the volume of each portion varying inversely proportional to one another as the piston head translates back and forth with the chamber. One or more valves are selectively operable to control a pressure in each portion of the chamber of the cylinder. Pressure may come from a pressure source or reservoir via one or more fluidly communicative paths, e.g., lines or hoses. The piston and reservoir may be pneumatic or hydraulic, and one or more compressors may maintain a pressure in the reservoir. The compressor and/or reservoir may be a dedicated part of the deployable fairing system, or may be part of the vehicle. Alternatively, the actuator  36  may take the form of one or more solenoids or electric motors (e.g., stepper motor) along with a suitable transmission (e.g., linkage). 
     In some implementations, the left and right side panels  30  and  32  may include one or more elastic or conformable portions that enable portions of the left and the right side panels  30  and  32  to bend or to alter their shape. For example, a left trailing edge  31  of the left side panel and a right trailing edge  33  of the right side panel  32  may be comprised of an elastic or resilient, deformable or conformable material that enables the trailing edges  31  and  33  to alter their shapes. Such elastic, deformable material may extend the entire length of the left and the right trailing edges  31  and  33 . As a result, in such implementations, the left and the right side panels  30  and  32  of the deployable fairing  16  may extend across the entire gap region  14  such that left and the right side panels  30  and  32  apply rearward forces to the trailing edges  31  and  33 , thereby engaging the trailing edges  31  and  33  with corresponding, opposing edges of the trailer  10   b . Because the left and the right trailing edges  31  and  33  are deformable or conformable, the shapes of each of the trailing edges  31  and  33  may be altered to become complementary to the shapes of the opposing edges of the trailer  10   b  when the trailing edges  31  and  33  are engaged with and pressed into the respective opposing edges of the trailer  10   b . The elasticity of the trailing edges  31  and  33  further enables the vehicle  10  to make minor turns, such as those that might be encountered in changing lanes on a highway, by providing some flexibility and give between the left and the right side panels  31  and  33  and the trailer  10   b . Some or all of a trailing edge  29  of the deployable upper horizontal panel assembly may also be comprised of a deformable, elastic substance to engage with the leading top edge of the trailer  10   b.    
       FIG. 5  is a top plan view of the deployable fairing system  12  showing the right and left side panels  30  and  32  with a bent edge moving through a variety of configurations, from the fully deployed configuration  20  to the fully retracted or fully un-deployed configuration  18  and a plurality of intermediate configurations therebetween, and better illustrating a rotation of the left and the right side panels  30  and  32  about vertical axes  102  and  104  (out of drawing sheet) and rotation of the deployable upper panel  60  about the upper lateral axis  47  (planar with drawing sheet). 
     As the deployable fairing  16  transitions from the fully unextended or fully retracted or fully un-deployed configuration  18 , the deployable upper panel  60  rotates about the upper lateral axis  47  such that the short base  68  of the deployable upper panel  60  rotates successively upward and rearward in each of the intermediary stages  22   a ,  22   b , and  22   c  shown in  FIG. 9  until the deployable upper panel  60  is in a substantially horizontal position when the deployable fairing  16  is in the fully extended or fully deployed configuration  20 , assuming that the deployable fairing  16  is no constrained to one of the intermediate configurations. The upward and rearward transition of the short base  68  of the deployable upper panel results in the short bases  75  and  77  of the left and the right upper wing panels  62  and  64 , respectively, likewise rotating rearward and upward. This rotation, in turn, causes the trailing edges of the left and the right upper wing panels  62  and  64  to rotate rearward towards the trailer  10   b  through the intermediary configurations  22   a ,  22   b , and  22   c  until the left and the right upper wing panels  62  and  64  are in a substantially horizontal position when the deployable fairing  16  is in the fully extended configuration  20 . 
     The rotation of the trailing edges  140  and  142  of the left and the right upper wing panels  62  and  64  results in the rotation of the left and the right side panels  30  and  32  about the vertical axes  102  and  104 , respectively. This rotation continues until the left and the right side panels  30  and  32  extend rearwardly from the back of the cab  10   c  towards the trailer  10   b  when the deployable fairing  16  is in the fully extended configuration  20 . In some implementations, the proximal edges  98  and  100  of the left and the right side panels  30  and  32 , respectively, are separated by distances  160  and  162  from the vertical axes  102  and  104 . 
       FIGS. 6A and 6B , and show another type of deployable fairing system  1000  with a deployable fairing  1002  shown in an extended or deployed configuration  1004 , according to one illustrated implementation. In some implementations, the deployable fairing system  1000  includes a static D-gap panel  1006 , upper horizontal panel assemblies  1008 , left and right side panels  1010  and  1012 , respectively, and a center actuator  1014 , a left actuator  1016 , and a right actuator  1018 . In some implementations, the deployable fairing system  1000  may only include the center actuator  1014 . In some implementations, the deployable fairing system  1000  may only include the left actuator  1016  and the right actuator  1018 . In some implementations, one or more of the center actuator  1014 , the left actuator  1016 , and/or the right actuator  1018  may be a respective piston and cylinder pair. In some implementations, one or more of the center actuator  1014 , the left actuator  1016 , and/or the right actuator  1018  may be an electric motor or a solenoid. 
     The static D-gap panel  1006  is attached to the back of the cab  10   c ,  10   d  and extends horizontally rearward towards the trailer  10   b . The static D-gap panel  1006  may be physically coupled to the back of the cab  10   c ,  10   d  via one or more elongated straps  1026  that extend rearward from the cab  10   c ,  10   d  towards the trailer  10   b . The static D-gap panel  1006  has a D-shaped profile, with a minor edge  1020  proximate the back of the cab  10   c ,  10   d . The minor edge  1020  may be substantially straight in some implementations. The static D-gap panel  1006  may have a major edge  1022  opposing the minor edge  1020  that is distal to the cab  10   c ,  10   d . In some implementations, the length of the major edge  1022  may be greater than the length of the minor edge  1020 . One or more side edges  1024  may extend between the minor edge  1020  and the major edge  1022 . Such one or more side edges  1024  may meet one or both of the minor edge  1020  and the major edge  1022  at a non-perpendicular angle. The static D-gap panel  1006  may be used to accommodate various shapes and configurations for the back of the cab  10   c ,  10   d , thus enabling the deployable fairing system  1000  to be installed, for example, as a retrofit on existing tractors  10   a  without creating a gap between the deployable fairing system  1000  and the back of the cab  10   c ,  10   d . In some implementations, the deployable fairing system  1000  may not include the static D-gap panel  1006 . 
     The proximal end of the center actuator  1014  is pivotally coupled to the back of the cab  10   c ,  10   d  with one or more center hinges  1028  that enable the center actuator  1014  to pivot about a horizontal, lateral axis  1030  that extends through the center hinges  1028  that couple the center actuator  1014  to the back of the cab  10   c ,  10   d . The center actuator  1014  rotates about the horizontal, lateral axis  1030  as the deployable fairing  1002  moves between the retracted configuration  1100  ( FIGS. 11A and 11B ) and the deployed configuration  1004 . When the deployable fairing  1002  is in the deployed configuration  1004 , the distal end of the center actuator  1014  is located upward and rearward from the proximal end of the center actuator  1014 , and is attached to the upper horizontal panel assembly  1008  with one or more upper hinges  1031 . The upper hinges  1031  enable the center actuator  1014  and the upper horizontal panel assembly  1008  to rotate relative to each other as the center actuator  1014  moves the deployable fairing  1002  between the retracted configuration  1100  and the deployed configuration  1004 . 
     The upper horizontal panel assembly  1008  may include a deployable upper panel  1032 , a left upper wing panel  1034 , and a right upper wing panel  1036 . The deployable upper panel  1032  may be shaped like a trapezoid, with two bases, or parallel sides, (leading edge  1038  and trailing edge  1040 ) that extend in a lateral direction across the width  10   e  of the cab  10   c . In some implementations, the deployable upper panel  1032  may be shaped like a trapezoid but with one or more corners along the longer base cut off to form two additional short sides. In some implementations, the leading edge  1038  of the deployable upper panel  1032  is located proximate the static D-gap panel  1006  and forms a major edge that is pivotally coupled to the major edge  1022  of the static D-gap panel  1006  using one or more hinges. The hinges enable the deployable upper panel  1032  to rotate about an upper horizontal axis  1042  that extends in a lateral direction across the width  10   e  of the cab  10   c , parallel to the major edge  1022  and perpendicular to the direction of travel during normal operation, as discussed below. When the deployable fairing  1002  is in the deployed configuration  1004 , the deployable upper panel  1032  may extend rearwardly from the upper horizontal axis  1042  and be titled relatively upward from the upper horizontal axis  1042  in which the trailing edge  1040  of the deployable upper panel  1032  is positioned relatively above the leading edge  1038  of the deployable upper panel  1032 . The two legs (left leg  1044  and right leg  1046 ) of the deployable upper panel  1032  form axes (left axis  1048  and right axis  1050 ) that have non-zero acute angles with respect to the major edge  1022  and the upper horizontal axis  1042  of the deployable upper panel  1032 . The left upper wing panel  1034  is pivotally coupled to the deployable upper panel  1032  using one or more hinges that form the left axis  1048  along the left leg  1044 , and the right upper wing panel  1036  is pivotally coupled to the deployable upper panel  1032  using one or more hinges that form the right axis  1050  along the right leg  1046 . 
     The left upper wing panel  1034  has a triangular profile with a distal edge  1052 , an outside edge  1054 , and an interior edge  1056 . The outside edge  1054  forms the outside left edge of the upper horizontal panel assembly  1008  when the deployable fairing  1002  is in the deployed configuration  1004 . The outside edge  1054  may be pivotally coupled to the left side panel  1010  using one or more hinges that enable the left upper wing panel  1034  to pivot relative to a left horizontal axis  1058  formed by the top edge of the left side panel  1010 . The hinges that pivotally couple the left upper wing panel  1034  to the deployable upper panel  1032  along the left axis  1048  enable the left upper wing panel  1034  and the deployable upper panel  1032  to pivot relative to one another as the deployable fairing  1002  moves between the retracted configuration  1100  and the deployed configuration  1004 . 
     The right upper wing panel  1036  is located opposite the left upper wing panel  1034  across the deployable upper panel  1032 . The right upper wing panel  1036  has a triangular profile with a distal edge  1060 , an outside edge  1062 , and an interior edge  1064 . The outside edge  1062  forms the outside right edge of the upper horizontal panel assembly  1008  when the deployable fairing  1002  is in the deployed configuration  1004 . The outside edge  1062  may be pivotally coupled to the right side panel  1012  using one or more hinges that enable the right upper wing panel  1036  to pivot relative to a right horizontal axis  1066  formed by the top edge of the right side panel  1012 . The hinges that pivotally couple the right upper wing panel  1036  to the deployable upper panel  1032  along right axis  1050  enable the right upper wing panel  1036  and the deployable upper panel  1032  to pivot relative to one another as the deployable fairing  1002  moves between the retracted configuration  1100  and the deployed configuration  1004 . 
     The left and the right side panels  1010  and  1012 , respectively, are each pivotally coupled to the upper horizontal panel assembly  1008  along the left axis  1048  and right axis  1050 , respectively of the deployable upper panel  1032 . In some implementations, the left side panel  1010  may be coupled to a left hinge  1011  that is comprised of a base  1011   a  and an arm  1011   b . The base  1011   a  may be physically coupled to the back of the cab  10   c . As such, in some implementations, the left hinge  1011  may be the only hinge that directly couples the left side panel  1010  to the cab  10   c . In some implementations, the left side panel  1010  may rotatably couple to the cab  10   c  via multiple hinges. A proximal end of the arm  1011   b  of the left hinge  1011  may rotatably couple to the base  1011   a  and rotate about a left vertical hinge axis  1068 . A distal end of the arm  1011   b  may be physically coupled to the left side panel  1010 . In some implementations, for example, the left side panel  1010  may be spaced along the arm  1011   b  such that a proximal edge  1072  of the left side panel  1010  is located at least two inches from the base  1011   a  of the left hinge  1011 . In some implementations, the left side panel  1010  may be spaced along the arm  1011   b  by a distance that is one-half inch more than a length of the static cab fairing  17  that extends rearwardly from the back of the cab  10   c . As such, the left side panel  1010  may be translated away from the back of the cab  10   c  and pivot about the left vertical hinge axis  1068  when the deployable fairing  1002  transitions to the deployed configuration  1004  from the retracted configuration  1100 . In some implementations, a set of resilient shock absorbers  1011   d  may be interposed between the left side panel  1010  and the left hinge  1011  to absorb impacts, such as, for example, may occur with bumpy road or with objects hitting the left side panel  1010 . 
     The right side panel  1012  may be coupled to a right hinge  1013  that is comprised of a base  1013   a  and an arm  1013   b . The base  1013   a  may be physically coupled to the back of the cab  10   c . As such, in some implementations, the right hinge  1013  may be the only hinge that directly couples the right side panel  1012  to the cab  10   c . In some implementations, the right side panel  1012  may rotatably couple to the cab  10   c  via multiple hinges. A proximal end of the arm  1013   b  of the right hinge  1013  may rotatably couple to the base  1013   a  and rotate about a right vertical hinge axis  1070 . A distal end of the arm  1013   b  may be physically coupled to the right side panel  1012 . In some implementations, for example, the right side panel  1012  may be spaced along the arm  1013   b  such that a proximal edge  1074  of the right side panel  1012  is located at least two inches from the base  1013   a  of the right hinge  1013 . In some implementations, the right side panel  1012  may be spaced along the arm  1013   b  by a distance that is one-half inch more than a length of the static cab fairing  17  that extends rearwardly from the back of the cab  10   c . As such, the right side panel  1012  may be translated away from the back of the cab  10   c  and pivot about the right vertical hinge axis  1070  when the deployable fairing  1002  transitions to the deployed configuration  1004  from the retracted configuration  1100 . In some implementations, a set of resilient shock absorbers  1013   d  may be interposed between the right side panel  1012  and the right hinge  1013  to absorb impacts, such as, for example, may occur with bumpy road or with objects hitting the right side panel  1012 . 
     In some implementations, such as, for example, implementations in which a plurality of hinges rotatably couple the deployable upper panel  1032 , the left upper wing panel  1034 , and the right upper wing panel  1036 , the deployable fairing  1002  may be kinematically over-constrained, but for a combined flexibility of the left side panel  1010  and/or the right side panel  1012 . In such implementations, the left side panel  1010  and/or the right side panel  1012  may be comprised of a respective skin and frame, as discussed below. Such skins may be comprised of glass reinforced plastic (e.g., polypropylene and glass fiber) that may be attached to the frame. The frame may be comprised of one or more tubes. 
     Such vertical axes (left vertical axis  1068  and right vertical axis  1070 ) may extend along or parallel to the proximal edge  1072  of the left side panel  1010  and the proximal edge  1074  of the right side panel  1012 , both relative to the cab  10   c . Such vertical axes (left vertical hinge axis  1068  and right vertical hinge axis  1070 ) may be perpendicular to the upper horizontal axis  1042  about which the deployable upper panel  1032  rotates. In some implementations, the proximal edge  1072  of the left side panel  1010  and the proximal edge  1074  of the right side panel  1012  may be located away from the left vertical hinge axis  1068  and the right vertical hinge axis  1070 , respectively. In some implementations, neither the proximal edge  1072  of the left side panel  1010  nor the proximal edge  1074  of the right side panel  1012  includes any hinges. In some such implementations, the left and the right side panels  1010  and  1012 , respectively, are physically coupled to the other components of the fairing system  1000  only through the pivotal couplings with the upper left wing panel  1034  and right upper wing panel  1036  of the upper horizontal panel assembly  1008 . In some implementations, the left side panel  1010  and the right side panel  1012  may have no vertical hinges along the respective proximal edges  1072  and  1074 . 
     In some implementations, the left side panel  1010  may be rotatably translated and pivoted by the left actuator  1016 . The proximal end of the left actuator  1016  may be pivotally coupled to the base  1011   a  of the left hinge  1011  that is located proximate the back of the cab  10   c ,  10   d . This rotatable coupling to the base  1011   a  of the left hinge  1011  may enable the left actuator  1016  to pivot about a left actuator vertical axis  1078  that extends vertically through the base  1011   a  of the left hinge  1011 . A distal end of the left actuator  1016  may be coupled to the arm  1011   b  of the left hinge  1011  at a distance from the base  1011   a . Thus, the left hinge  1011  and left actuator  1016  may advantageously form an integral unit, installable or replaceable as a single unit. The left actuator  1016  rotates about the left actuator vertical axis  1078  as the deployable fairing  1002  moves between the retracted configuration  1100  ( FIGS. 11A and 11B ) and the deployed configuration  1004 , thereby applying an outward and rearward force on the left side panel  1010  to translate and pivot the left side panel  1010  away from the back of the cab  10   c . When the deployable fairing  1002  is in the deployed configuration  1004 , the distal end of the left actuator  1016  is located rearward and outward from the proximal end of the left actuator  1016 , and is attached to the arm  1011   b  of the left hinge  1011  and/or to the left side panel  1010  with one or more left side panel hinges  1080 . The left side panel hinges  1080  enable the left actuator  1016  to rotate relative to the arm  1011   b  of the left hinge  1011  and/or to the left side panel  1010  as the deployable fairing  1002  moves between the retracted configuration  1100  and the deployed configuration  1004 . In some implementations, the left actuator vertical axis  1078  may be co-located with the left vertical hinge axis  1068 . In some implementations, such as that shown in  FIGS. 6A and 6B  the left actuator vertical axis  1078  may be offset from the left vertical hinge axis  1068 . In some implementations, the left actuator  1016  may be directly, rotatably, physically coupled to either or both of the back of the cab  10   c  and/or the left side panel  1010 . 
     In some implementations, the right side panel  1012  may be rotatably translated and pivoted by the right actuator  1018 . The proximal end of the right actuator  1018  is pivotally coupled to the base  1013   a  of the right hinge  1013  that is located proximate the back of the cab  10   c ,  10   d  that enables the right actuator  1018  to pivot about a right actuator vertical axis  1084  that extends through the right hinge  1013 . A distal end of the right actuator  1018  may be coupled to the arm  1013   b  of the right hinge  1013  at a distance from the base  1013   a . Thus, the right hinge  1013  and right actuator  1018  may advantageously form an integral unit, installable or replaceable as a single unit. The right actuator  1018  rotates about the right actuator vertical axis  1084  as the deployable fairing  1002  moves between the retracted configuration  1100  ( FIGS. 11A and 11B ) and the deployed configuration  1004 , thereby applying an outward and rearward force on the right side panel  1012  to translate and pivot the right side panel  1012  away from the back of the cab  10   c . When the deployable fairing  1002  is in the deployed configuration  1004 , the distal end of the right actuator  1018  is located rearward and outward from the proximal end of the right actuator  1018 , and is attached to the arm  1013   b  of the right hinge  1013  and/or to the right side panel  1012  with one or more right side panel hinges  1086 . The right side panel hinges  1086  enable the right actuator  1018  and the right side panel  1012  to rotate relative to each other as the deployable fairing  1002  moves between the retracted configuration  1100  and the deployed configuration  1004 . In some implementations, the right actuator vertical axis  1084  may be co-located with the right vertical hinge axis  1070 . In some implementations, such as that shown in  FIGS. 10A through 10E  the right actuator vertical axis  1084  may be offset from the right vertical hinge axis  1070 . In some implementations, the right actuator  1018  may be directly, rotatably, physically coupled to either or both of the back of the cab  10   c  and/or the right side panel  1012 . 
     The left and the right side panels  1010  and  1012 , respectively, each extend vertically with respect to the cab  10   c ,  10   d  when the deployable fairing  1002  is both in the unextended or retracted or un-deployed configuration  1100  and in the extended or deployed configuration  1004 . When the deployable fairing  1002  is in the deployed configuration  1004 , the left and the right side panels  1010  and  1012  may be substantially parallel to the direction of travel during normal operation and substantially perpendicular to the upper horizontal panel assembly  1008 , extending rearwardly from the cab  10   c . In some implementations, the left and the right side panels  1010  and  1012  may alternatively be at a positive slope, slightly flaring out from vertical planes that extend rearwardly from the side of the cab  10   c , when the deployable fairing  1002  is in the deployed configuration  1004 . As such, the left side panel  1010  and the right side panel  1012  may taper outwardly in a direction going from a front of the fairing system  1000  toward a rear of the fairing system  1000 . When the deployable fairing  1002  is in the retracted configuration  1100 , the left and the right side panels  1010  and  1012  pivot into the back of the cab  10   c  to extend laterally with respect to the cab  10   c , to be substantially perpendicular to the direction of travel during normal operation. In some implementations, the left and the right side panels  1010  and  1012  may be rotated inward towards the back of the cab  10   c  by a certain angle (e.g., rotated inward by about 45° from their respective locations in the deployed configuration  1004 ). 
     In some implementations when the deployable fairing  1002  is in the deployed configuration  1004 , the left side panel  1010  and the right side panel  1012  may taper outwardly in a direction going from a front of the fairing system  1000  toward the rear of the fairing system, and at the same time, the deployable upper panel  1032  may be titled relatively upward from the upper horizontal axis  1042  in which the trailing edge  1040  of the deployable upper panel  1032  is positioned relatively above the leading edge  1038  of the deployable upper panel  1032 . In such an implementation, an area enclosed by a perimeter defined by the deployable upper panel  1032 , the left side panel  1010 , and the right side panel  1012  distal from the front of the fairing system  1000  may be greater than an area enclosed by a perimeter defined by the deployable upper panel  1032 , the left side panel  1010 , and the right side panel  1012  proximate the front of the fairing system  1000 . 
       FIG. 7  shows a vehicle in the form of a trailer  10   b  having a deployable fairing  700  attached to a rear or back  702  of the trailer  108   b  according to one illustrated implementation, the deployable fairing  700  in a fully retracted or fully un-deployed configuration.  FIG. 8  shows the trailer  10   b  of  FIG. 7  with the deployable fairing  700  in a fully extended or fully deployed configuration. 
     The trailer  10   b  may, for example include a pair of doors  704   a ,  704   b  at the rear or back  702  of the trailer  10   b , which selectively provide access to an interior of the trailer  10   b  from an exterior thereof. The deployable fairing  700  should accommodate any doors  704   a ,  704   b . For example, the deployable fairing  700  may be provided in to distinct sections  700   a ,  700   b , each of which can pivot or swing open and closed about respective axes with a respective one of the doors  704   a ,  704   b . Alternatively, the entire deployable fairing  700  may be mounted to pivot or swing about a single axis. 
     While generally illustrated in a fully retracted or fully un-deployed configuration ( FIG. 7 ) and in a fully extended or fully deployed configuration ( FIG. 8 ), the deployable fairing  700  can be placed in a plurality of intermediate configurations between the fully retracted or fully un-deployed configuration ( FIG. 7 ) and the fully extended or fully deployed configuration. One such intermediate configuration is illustrated via broken line  706  ( FIG. 8 ). 
       FIGS. 9A and 9B  show a hinge  1800  comprised of a base  1806  and an arm  1810  along with a hinge actuator  1802  in which a proximal end  1804  of the hinge actuator  1802  is rotatably coupled to the base  1806  and an opposing distal end  1808  of the hinge actuator  1802  is rotatably coupled to a portion of the arm  1810 , according to at least one illustrated implementation. The base  1806  of the s hinge  1800  may be physically coupled to the back of the cab  10   c  along a first surface  1812 , via bolts, rivets, screws, or other similar physical coupling components. A proximal end  1814  of the arm  1810  may rotatably couple to the base  1806  and rotate about a vertical hinge axis  1816 . A distal end  1818  of the arm  1810  may physically couple to a panel or portion of a frame. In some implementations, such coupling may occur via one or more coupling features  1820  spaced along the arm  1810  in which the coupling features  1820  may be, for example, one or more posts that extend outward from the arm  1810  to engage with corresponding apertures on the panel or portion of a frame, thereby physically coupling the arm  1810  with the panel or frame member. In some implementations, coupling features  1820  may be spaced along the arm  1810  such that a proximal edge of the panel is located at least two inches from the associated base  1806 . In some implementations, the coupling features  1820  may be spaced along the arm  1810  such that a proximal end of the panel is separated from the static cab fairing  17  by a distance of at least one-half inch. As such, the hinge  1800  may translate and pivot the side panel away from the back of the cab  10   c  about the vertical hinge axis  1816  when the deployable fairing system transitions to the deployed configuration from the retracted configuration. 
     The arm  1810  and the attached panel or portion of a frame may be rotatably translated and pivoted by the associated hinge actuator  1802 . For example, a proximal end  1804  of the hinge actuator  1802  may be pivotally coupled to the base  1806  that is located proximate the back of the cab  10   c ,  10   d  via one or more hinges  1822 . In some implementations, the one or more hinges  1822  may include a sleeve that extends from a first side  1826  of the base  1806  through an aperture on the proximal end  1804  of the hinge actuator  1802  to an opposing second side of the base  1806 . Such a sleeve  1824  may be held in place by a screw that extends between and secured at the first side  1826  and the second side of the base  1806 . This rotatable coupling to the base  1806  may enable the hinge actuator  1802  to pivot about an actuator vertical axis that extends vertically through the base  1806 . A distal end  1808  of the hinge actuator  1802  may be coupled to a portion of the arm  1810  with one or more hinges  1832  at a distance from the base  1806 . Such hinges  1832  enable the actuator  1802  and the arm  1810  to rotate relative to each other as the base  1806  rotates between a fully deployed configuration and a fully retracted configuration with a plurality of intermediate configurations therebetween. 
     In some implementations, the actuator  1802  may include a housing  1802   a  and an extendable arm  1802   b . When the side panel hinge  1800  is in the fully retracted or fully un-deployed configuration ( FIG. 18B ), at least some of the extendable arm  1802   b  may be contained within the housing  1802   a . To transition the hinge  1800  to the fully deployed configuration or an intermediate configuration (e.g., partially deployed configurations), the actuator  1802  may extend the extendable arm  1802   b  from the distal end  1808  of the actuator  1802 , thereby applying an outward and rearward force on the distal end  1818  of the arm  1810  that results in the distal end  1818  of the arm  1810  and the attached panel or frame member translating and pivoting away from the back of the cab  10   c  or trailer. When the hinge  1800  is in the fully deployed configuration, the extendable arm  1802   b  may have been laterally translated fully out of one end of the housing  1802   a  to increase a length of the actuator  1802 . In some implementations, when the hinge  1800  is in the fully deployed configuration, the distal end  1808  of the actuator  1802  may be located rearward and outward from the proximal end  1804  of the actuator  1802 . In some implementations, one or more positional sensors may be placed along a direction of travel of the actuator  1802  and/or within the actuator  1802 . Such positional sensors may include, for example, Reed switches position encoders, rotary encoders, that may be used to indicate the positions of the components being pivoted, translated, or otherwise moved by the actuators  1802 . In some implementations, multiple positional sensors may be placed within the actuator  1802 . Such signals from multiple positional sensors may be used to determine a rate of travel of the component(s) being moved by the actuator  1802 . 
       FIG. 10  shows a control subsystem  2100  for a deployable fairing system according to one illustrated embodiment. 
     The control subsystem  2100  is configured to automatically selectively move a deployable fairing  16  between a fully un-deployed or fully unextended configuration and a fully deployed or fully extended configuration, and optionally one or more partially deployed or intermediate configurations based on one or more conditions (e.g., speed of vehicle, location of vehicle, presence or absence of any obstacles in path of deployment, wind speed and/or wind direction, and/or temperature in an ambient environment. 
     The control subsystem  2100  may include a controller  2102 . The controller  2102  may include one or more hardware or circuitry based processors (e.g., microprocessor, digital signal processor, programmable gate array, application specific integrated circuit, microcontroller)  2104 . The controller  2102  may include one or more processor-readable media for example memories or other storage mediums. For example, the controller  2102  may include read only memory  2106  and/or random access memory  2108 . The memories  2106 ,  2108  may store processor executable instructions that cause the processor  2104  to assess speed, location, or one or more thresholds, and to control a configuration or position of the deployable fairing  16  in response thereto. 
     The controller  2102  may include one or more busses  2110  coupling the processor  2104  and memories  2106 ,  2108 . For example, the controller  2102  may include a power bus, instruction bus, data bus, address bus, etc. The busses may also provide signal paths to communicate with other devices or elements of the control subsystem  2100 . The control subsystem  2100  may also include one or more digital-to-analog (D/A) converters  2110  to convert digital signals from the processor  2104  into an analog form suitable to drive certain components. The control subsystem  2100  may also include one or more analog-to-digital (A/D) converters  2112  to convert analog signals from certain components into a digital form suitable for processing by the processor  2104 . 
     The control subsystem  2100  may include one or more actuators  2114  operable to move the deployable fairing  16  between the fully un-deployed or fully retracted or fully unextended configuration and the fully extend or a fully deployed configuration, and optionally into any one or more of a number of partially deployed or partially extended configurations between the fully un-deployed and fully deployed configurations. As previously explained, the actuator(s)  2114  may, for example, take the form of a piston/cylinder pair  2114   a , a solenoid  2114   c , and/or an electric motor (e.g., stepper motor)  2114   c . In addition, at least one valve  2126  may be attached to or incorporated into the actuator  2114 , e.g., a piston cylinder  2114   a . The valve  2126  may be a mechanical control valve, a solenoid, or other like device that can selectively vent the actuator  2114  or provide a fluid (e.g., air, hydraulic fluid) under an elevated pressure. In the event of an error or a loss of power, the valve  2126  can be biased in the event of a power loss to deactivate the actuator  2114  such as, for example, by venting the air within a pneumatic actuator or hydraulic fluid. In this situation, the components of the deployable fairing  16  default to returning to the fully retracted or fully unextended configuration  18  as a result of the components of the deployable fairing  16  applying a downward force to the deactivated actuator  2114 . In some implementations, the control subsystem  2100  may control the actuator  2114  (e.g., the left actuator  1011 ), such as through controlling a fluid supply, to cause the actuator  2114  to retract the left side panel  1010  to elastically deform the left side panel  1010  without causing plastic deformation to the left side panel  1010  or the deployable upper panel  1032 . In some implementations, the control subsystem  2100  may control the actuator  2114  (e.g., the right actuator  1018 ), such as through controlling a fluid supply, to cause the actuator  2114  to retract the right side panel  1012  to elastically deform the right side panel  1012  without causing plastic deformation to the right side panel  1012  or the deployable upper panel  1032 . 
     The valve  2126  may biased to deactivate the actuator  2114  in various conditions, resulting in the components of the deployable fairing  16  automatically returning to the fully retracted or fully unextended configuration  18 . Such conditions may arise, for example, in the event of a power loss to the vehicle  10  or to the deployable fairing system  12 , or in the event that the deployable fairing system  12  is unable to communicate with the rest of the control subsystem  2100 , including the processor  2104 . In addition, such conditions may arise when one or more gauges or sensors indicate a potentially unsafe operating condition. Additionally or alternatively, some conditions may indicate that it may be efficient or desirable to transition the deployable fairing  16  into a partially deployed or partially extended (i.e., intermediate) configuration, for example as explained elsewhere herein. 
     The control subsystem  2100  may include one or more speed sensors  2116 , which provide signals indicative or representative of a speed of the vehicle to the processor(s)  2104 , either directly or indirectly. The speed sensor  2116  (e.g., rotational encoder, Reed switch) may be an integral part of the vehicle  10  as manufactured by the vehicle manufacturer, used as part of the speedometer of the vehicle  10 . Alternatively, the speed sensor  2116  may be added later, e.g. as a retrofit. In some implementations, the speed sensor  2116  is a dedicated part of the control subsystem  2100  and is unrelated to, or not part of, the conventional feedback system (e.g., speedometer) of the vehicle  10 . 
     The processor(s)  2104  may receive signals indicative or representative of speed from an on-board computer  2118  associated with the vehicle  10 . Such on-board computers are commonly referred to as a black box. These on-board computers track various parameters of operation such as speed, distance, total time, elapsed time, and/or location. The on-board computers are typically an after-market device added to the vehicle  10  after manufacture of the vehicle  10 . 
     The processor(s)  2104  may receive signals indicative or representative of speed from a global positioning system (GPS) receiver  2120 . The (GPS) receiver  2120  may determine location information indicative or representative of a current location of the vehicle  10 . The processor may be configured to associate the location information with a particular road or section of road, and hence with a posted speed limited or expected speed of travel for the vehicle  10 . For example, the processor  2104  may be configured to determine whether the vehicle  10  is on a highway or a surface street based on the location information. 
     The processor(s)  2104  may receive signals indicative or representative of speed or location from a wireless receiver  2122 . The wireless receiver  2122  may be part of the control subsystem  2100 , or may be a dedicated part of the vehicle  10 . The wireless receiver  2122  may determine speed information or location information indicative or representative of a current speed or location of the vehicle  10 . For example, the wireless receiver  2122  may receive information indicating that the vehicle  10  is at an entrance ramp or exit ramp of a highway, or at a toll booth or toll plaza associate with an entrance or exit of a highway. Additionally, or alternatively, the information may indicate another location along a high way or surface street. The location information may itself be indicative or representative of a posted speed. Additionally or alternatively, the received information may provide a measure of the actual speed of the vehicle  10 , for example as measured by radar or laser speed sensors positioned along the road. The processor may be configured to associate the location information with a particular road or section of road, and hence with a posted speed limit or expected speed of travel for the vehicle  10 . For example, the processor  2104  may be configured to determine whether the vehicle  10  is on a highway or surface street based on the location information. 
     Additionally, the control subsystem  2100  may include one or more positional or orientation sensors  2124  which provides signals to the one or more processor(s)  2104  indicative or representative of the current positions or orientations of one or more components of the deployable fairing  16 , such as, for example, the upper and lower horizontal panel assemblies  26  and  28 , respectively, and the left and right side panels  30  and  32 , respectively. The positional or orientation sensors  2124  may be, for example, a proximity sensor, a Reed switch, a positional encoder, a rotational encoder, an optical encoder, or other like device that can sense the position or orientation of one or more components in the deployable fairing  16 . The processor(s)  2104  may be configured to determine a correct position or orientation for each of the components of the deployable fairing  16  in each of various configurations (e.g., fully retracted or fully unextended configuration  18 , intermediate configurations  22 , and fully deployed or fully extended configuration  20 ). The processor(s)  2104  may further be configured compare the current position or orientations for each component of the deployable fairing  16  as indicated by the signals received from the positional or orientation sensors  2124  with the expected configuration or position for each component of the deployable fairing  16  to identify a potential error condition. Such an error condition may arise, for example, if the current configuration or position or orientation of one or more of the components of the deployable fairing  16  differs from the expected configuration or position or orientation for the one or more components. In some implementations, a time out period, such as may be stored in memories  2106 ,  2108 , may be used to determine if the deployable fairing  16  has successfully transitioned from the fully retracted or un-deployed configuration  18  to the fully extended or fully deployed configuration  20  or some intermediate configuration therebetween. If the processor  2104  determines that such an error condition exists (e.g., the positional sensors  2124  indicate that one or more components of the deployable fairing  16  have not reached the expected positions or orientations in the fully or partially deployed configuration  20  within the timeout period), the processor may transition the deployable fairing  16 , if necessary, into the fully retracted or full un-deployed configuration  18 . 
     The control subsystem  2100  may include one or more object sensors  2132  positioned and oriented to monitor regions in which a deployable fairing will deploy (i.e., deployed region), or alternatively encompass, when in the fully deployed or fully extended configuration. The deployed region may in some instances encompass or be encompassed by a gap region between two coupled vehicles (e.g., coupled tractor trailer combination). The deployed region may in some instances only those volumes in which a portion of the deployable fairing will reside when fully deployed or fully extended, for instance omitting a large central volume the is encompassed by the fully deployed fairing but which no fairing structure will reside. This allows a more refined determination of whether or not full deployment of the deployable fairing may cause a collision with some obstacle (e.g., structure on the trailer), where collision may result in damage to the fairing or even to the object or obstacle. 
     The object sensor(s)  2132  are communicatively coupled to provide signals to the processor(s)  2104 , either directly or directly, indicative or representative of whether there is an object or obstacle in the deployed region. In some implementations the object sensors will determine whether an object or obstacle is present or absent from the deployed region. In some implementations the processor(s)  2104  will determine whether an object or obstacle is present or absent from the deployed region. 
     The object sensor(s)  2132  can any of a variety of forms. For example, the object sensor(s)  2132  can include any one or more of: distance sensors  2132   a , proximity sensors  2132   b , image sensors  2132   c . Distance sensors may, for example, include one or more of: laser range finders, distance measuring devices or sensors. Proximity sensors may, for example, include one or more of: ultrasonic sensors, capacitive sensors, photoelectric sensors, inductive sensors or a magnetic sensors. Image sensors may, for example, include single digital cameras, binocular digital cameras, Vidicons, CMOS based image sensors, etc. It may be advantageous in some implementations to include at least one sensor of a first type of sensor and at least one sensor of a second type of sensor, the second type of sensor different from the first type of sensor. 
     The control subsystem  2100  may include one or more environmental sensors. 
     For example, the control subsystem  2100  may include one or more wind sensors  2134   a ,  2134   b  that detect wind speed, relative wind direction or both. The wind sensors  2134   a ,  2134   b  are communicatively coupled to provide signals to the processor(s)  2104  indicative or representative of wind speed (e.g., magnitude) and/or relative wind direction (e.g., cross wind relative to the vehicle). In some implementations, the wind sensors  2134   a ,  2134   b  determine the wind speed and the wind direction and provide that information to the processor(s)  2104 . In other implementations, the processor(s)  2104  determines the wind speed and/or the wind direction from information provided by the wind sensors  2134   a ,  2134   b.    
     For example, the control subsystem  2100  may include one or more temperature sensors  2136  position to determine a temperature in an ambient environment in which the vehicle is operating. The temperature sensors can take a variety of forms, for example thermocouples. The temperature sensors  2136  are communicatively coupled to provide signals to the processor(s)  2104  indicative or representative of temperature. In some implementations, the temperature sensors  2136  determines the temperature and provides that information to the processor(s)  2104 . In other implementations, the processor(s)  2104  determines the temperature from information provided by the temperature sensors  2136 . 
     In one implementation, the processor(s)  2014  use information from the object sensor(s)  2132  to determine whether the deployment region has any objects or obstacles that would hinder deployment or even result in damage. Such may be assessed for example before the start of a trip, for instance when a trailer is coupled to a tractor. This approach advantageously allows the system to accommodate various styles of trailer (e.g., reefer). Additionally or alternatively, such may be assessed one or more times during a trip, for instance periodically or in response to a change in conditions. This approach advantageously allows the system to accommodate any travel in the fifth wheel. 
     If the processor(s) determines that any object or obstacle is present, the processor can determine that deployment of the deployable fairing should either be prevented or limited to an intermediate configuration. Such determination may be based at least in part on a position or location of the object or obstacle. Deployment into an intermediate configuration means moving the deployable fairing to the intermediate configuration, or leaving the deployable fairing in the intermediate configuration, and stopping the deployment in the intermediate configuration. This is to distinguish over simply transitorily passing through an intermediate configuration while deploying to the fully deployed or fully retracted configurations. 
     In some implementations, the presence or absence of an object or obstacle in the deployment region is the only factor considered in determining whether to deploy the deployable fairing and into which configuration the deployable fairing will be deployed. Thus, the processor(s)  2014  may determine to deploy the deployable fairing to an intermediate configuration that places a distal end of the deployable fairing close, but short of the object or obstacle, for example leaving a safety margin to limit or eliminate the chance of damage. 
     In other implementations, the determination may take into account a variety of other factors, for example factors related to enhancing fuel efficient. Factors may include vehicle speed, braking or change in vehicle speed, wind speed, wind direction and/or temperature in the ambient environment. 
     For example, a speed sensor  2116 , discussed herein, may provide a signal indicating that the vehicle  10  is traveling at a relatively high speed, such as may occur when the vehicle  10  is traveling over a highway or freeway. Alternatively, the processor(s)  2104  may rely on location instead of, or in addition to, vehicle speed in determining whether to deploy the deployable fairing. In this situation, the processor(s)  2104  may determine if the speed indicated by the signal from the speed sensor  2116  falls above a threshold speed value stored in memories  2106 ,  2108  or whether a present location corresponds to a highway versus a surface street. If the speed is above the threshold or the location corresponds to a highway, the processor(s)  2104  determines to deploy the deployable faring. The extent of deployment may depend on whether an object or obstacle is present in the deployment region. The processor(s)  2104  sends signals to control the valve  2126  to activate the actuator  2114  to deploy the deployable faring into the fully deployed configuration, or alternatively into an intermediate configuration if an object or obstacle is present. In these modes of operation, the processor(s)  2014  may perform a real-time assessment of whether there is an object or obstacle in the deployment region, and/or may rely on a previously stored assessment, for instance an assessment when a trailer is first coupled to a tractor. 
     Also for example, the speed sensor  2116 , discussed herein, may provide a signal indicating that the vehicle  10  is traveling at a low speed, such as may occur when the vehicle  10  is traveling over surface streets. Alternatively, the processor(s)  2104  may rely on location, determining that the vehicle is on a surface street or not on a highway or freeway. In this situation, the processor  2104  may determine if the speed indicated by the signal from the speed sensor  2116  falls below a threshold speed value stored in memories  2106 ,  2108 . If the vehicle speed is below the threshold speed or the current position indicates that the vehicle is on a surface street or parking lot, then the valve  2126  may be used to deactivate the actuator  2114 . 
     The processor  2104  may optionally receive signals from various other sensors that result in the valve  2126  being used to activate or deactivate the deployable fairing  16 . For example, the processor  2104  may receive signals from one or more wind sensors, for instance one or more wind speed sensors  2128   a , and/or one or more wind direction sensors  2128   b  indicating a speed and direction of wind, for instance a strength of a cross wind. The processor  2104  may determine whether the wind speed and/or direction exceed a cross wind threshold. For example, the processor  2104  may receive signals from one or more a temperature sensors  2130 , indicating a temperature of the environment around the actuator  2114 . The processor  2104  may determine whether the sensed temperature falls below a low temperature threshold or exceeds a high temperature threshold. In some implementations, the processor  2104  may use the valve  2126  to activate or deactivate the actuator  2114 . 
     The processor(s)  2104  then determines which intermediate configuration is safe, and sends signals to one or more actuators to deploy the deployable faring to the identified intermediate configuration, stopping in the intermediate configuration. 
     Whether independent of vehicle speed or in conjunction with vehicle speed, the processor(s)  2104  may determine to deploy the deployable fairing in response to wind speed, wind direction and/or temperature in the ambient environment. In each instance, the processor(s)  2104  may determine to not deploy the deployable fairing or to move the deployable fairing to the fully retracted or fully un-deployed configuration is an objector or obstacle is present in the deployment region. Alternatively, the processor(s)  2104  may determine which intermediate configuration is safe in light of the presence of an object or obstacle in the deployment region, and sends signals to one or more actuators to deploy the deployable faring to the identified intermediate configuration. 
     The above description of illustrated embodiments, including what is described in the Abstract, is not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. Although specific embodiments of and examples are described herein for illustrative purposes, various equivalent modifications can be made without departing from the spirit and scope of the disclosure, as will be recognized by those skilled in the relevant art. The teachings provided herein of the various embodiments can be applied to other systems and vehicles, not necessarily the exemplary automatic gap closing system on a tractor-trailer combination generally described above. For example, a gap closing system may be employed between two trailers, or between a locomotive and a car of a train, and/or between cars of a train. Also for example, the automatic gap closing system may be an integral part of one of the vehicles as the vehicle is manufactured or sold. Alternatively, the automatic gap closing system may be an aftermarket product, installed in one of the vehicles after manufacture or sale of the vehicle. The methods described herein may include additional acts, omit some acts, and/or perform some acts in a different order. One or more thresholds may be employed. 
     The foregoing detailed description has set forth various embodiments of the devices and/or processes via the use of block diagrams, schematics, and examples. Insofar as such block diagrams, schematics, and examples contain one or more functions and/or operations, it will be understood by those skilled in the art that each function and/or operation within such block diagrams, flowcharts, or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In one embodiment, the present subject matter may be implemented via Application Specific Integrated Circuits (ASICs). However, those skilled in the art will recognize that the embodiments disclosed herein, in whole or in part, can be equivalently implemented in standard integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more controllers (e.g., microcontrollers) as one or more programs running on one or more processors (e.g., microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of ordinary skill in the art in light of this disclosure. 
     In addition, those skilled in the art will appreciate that the mechanisms taught herein are capable of being distributed as a program product in a variety of forms, and that an illustrative embodiment applies equally regardless of the particular type of physical signal bearing media used to actually carry out the distribution. Examples of signal bearing media include, but are not limited to, the following: recordable type media such as floppy disks, hard disk drives, CD ROMs, digital tape, and computer memory. 
     The contents of U.S. patent application Ser. No. 12/563,426; International patent application PCT/US2017/063728, and U.S. Provisional Patent Application No. 62/814,725, filed Mar. 6, 2019 and entitled DEPLOYABLE FAIRING SYSTEM FOR USE WITH VEHICLES, are each incorporated herein by reference in their entireties. 
     The various embodiments described above can be combined to provide further embodiments. Aspects of the embodiments can be modified, if necessary, to employ systems, circuits and concepts of the various patents, applications and publications identified herein to provide yet further embodiments. 
     These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.