Abstract:
A system according to an exemplary aspect of the present disclosure includes, among other things, a slidable bar, a connecting bar attached to the slidable bar and a charging device carried by the connecting bar and movable with the slidable bar.

Description:
TECHNICAL FIELD 
       [0001]    This disclosure relates to a charging system, and more particularly, but not exclusively, to an electrified vehicle charging system that includes an automatic alignment system. 
       BACKGROUND 
       [0002]    Generally, electrified vehicles differ from conventional motor vehicles in that they are selectively driven using one or more battery powered electric machines. Conventional motor vehicles, by contrast, rely exclusively on an internal combustion engine to drive the vehicle. Electrified vehicles may use electric machines instead of, or in addition to, internal combustion engine. The electric machines are typically powered by high voltage batteries. 
         [0003]    One barrier to adopting a more widespread use of electrified vehicles is the lack of supporting infrastructure for charging the high voltage batteries of the vehicles. Wireless charging systems are known that utilize electromagnetic fields to transfer energy between two objects. However, these systems require precise locating of a transmitting coil relative to a receiving coil that is mounted to the vehicle to ensure maximum power transfer between the coils. 
       SUMMARY 
       [0004]    A system according to an exemplary aspect of the present disclosure includes, among other things, a slidable bar, a connecting bar attached to the slidable bar and a charging device carried by the connecting bar and movable with the slidable bar. 
         [0005]    In a further non-limiting embodiment of the foregoing system, the slidable bar is movable relative to at least one slide rail. 
         [0006]    In a further non-limiting embodiment of either of the foregoing systems, the at least one slide rail is mounted to a wheel plate assembly. 
         [0007]    In a further non-limiting embodiment of any of the foregoing systems, the wheel plate assembly includes a first wheel plate, a second wheel plate and a base that connects between the first wheel plate and the second wheel plate. 
         [0008]    In a further non-limiting embodiment of any of the foregoing systems, at least one wheel guide is mounted to the slidable bar. 
         [0009]    In a further non-limiting embodiment of any of the foregoing systems, the at least one wheel guide includes a first wheel guide mounted to a first side of the slidable bar and a second wheel guide mounted to a second side of the slidable bar. 
         [0010]    In a further non-limiting embodiment of any of the foregoing systems, the at least one wheel guide is curved in a direction toward the connecting bar. 
         [0011]    In a further non-limiting embodiment of any of the foregoing systems, at least one wheel stop is mounted to the slidable bar. 
         [0012]    In a further non-limiting embodiment of any of the foregoing systems, the charging device includes a coil pad that houses a transmitting coil. 
         [0013]    In a further non-limiting embodiment of any of the foregoing systems, a visual target is positioned in front of the slidable bar. 
         [0014]    In a further non-limiting embodiment of any of the foregoing systems, the charging device is movable in unison with the slidable bar to a position relative to a receiving device mounted to an electrified vehicle. 
         [0015]    In a further non-limiting embodiment of any of the foregoing systems, the charging device is movable between a first position in which a transmitting coil of the charging device is offset from a receiving coil of the receiving device and a second position in which the transmitting coil is aligned with the receiving coil. 
         [0016]    A vehicle charging system according to another exemplary aspect of the present disclosure includes, among other things, a charging device and an alignment system that includes at least one wheel guide that engages a wheel of an electrified vehicle to position the charging device relative to a receiving device of the electrified vehicle. 
         [0017]    In a further non-limiting embodiment of the foregoing vehicle charging system, the alignment system includes a first wheel guide that engages a first wheel of the electrified vehicle and a second wheel guide that engages a second wheel of the electrified vehicle. 
         [0018]    In a further non-limiting embodiment of either of the foregoing vehicle charging systems, the at least one wheel guide is curved to travel along an inner surface of the wheel. 
         [0019]    In a further non-limiting embodiment of any of the foregoing vehicle charging systems, the alignment system includes a slidable bar and a connecting bar that extends from the slidable bar and carries the charging device. 
         [0020]    In a further non-limiting embodiment of any of the foregoing vehicle charging systems, the at least one wheel guide includes a first wheel guide mounted to a first side of the slidable bar and a second wheel guide mounted to a second side of the slidable bar. 
         [0021]    In a further non-limiting embodiment of any of the foregoing vehicle charging systems, the alignment system is pivotable about a locking pivot. 
         [0022]    In a further non-limiting embodiment of any of the foregoing vehicle charging systems, the charging device is movable between a first position in which a transmitting coil of the charging device is offset from a receiving coil of the receiving device and a second position in which the transmitting coil is aligned with the receiving coil. 
         [0023]    A method according to another exemplary aspect of the present disclosure includes, among other things, automatically aligning a charging device of a charging system relative to a receiving device of an electrified vehicle using motion of the electrified vehicle to move the charging device. 
         [0024]    The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible. 
         [0025]    The various features and advantages of this disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  schematically illustrates a powertrain of an electrified vehicle. 
           [0027]      FIG. 2  illustrates a parking space equipped with a vehicle charging system. 
           [0028]      FIG. 3  illustrates a perspective view of a vehicle charging system. 
           [0029]      FIG. 4  illustrates a top view of a vehicle charging system. 
           [0030]      FIGS. 5A and 5B  schematically illustrate a vehicle charging method according to one non-limiting embodiment of this disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0031]    This disclosure relates to a charging system for wirelessly charging a battery of an electrified vehicle. The charging system includes an alignment system that is adapted to engage the electrified vehicle to accurately position a charging device in a charging position relative to the electrified vehicle. Once the charging device is properly positioned relative to a receiving coil mounted to the electrified vehicle, electrical energy is transferred from the charging device to the receiving coil. This electrical energy can subsequently be converted to electricity that is used to power and recharge the battery of the electrified vehicle. These and other features are discussed in greater detail herein. 
         [0032]      FIG. 1  schematically illustrates a powertrain  10  of an electrified vehicle  12 . It should be understood that the concepts described herein are not limited to HEV&#39;s and could extend to other electrified vehicles, including but not limited to PHEV&#39;s. 
         [0033]    In one embodiment, the powertrain  10  is a power split system that employs a first drive system that includes a combination of an engine  14  and a generator  16  (i.e., a first electric machine) and a second drive system that includes at least a motor  36  (i.e., a second electric machine), the generator  16  and a battery  50 . For example, the motor  36 , the generator  16  and the battery  50  may make up an electric drive system  25  of the powertrain  10 . The first and second drive systems generate torque to drive one or more sets of vehicle drive wheels  30  of the electrified vehicle  12 . 
         [0034]    The engine  14 , such as an internal combustion engine, and the generator  16  may be connected through a power transfer unit  18 . In one non-limiting embodiment, the power transfer unit  18  is a planetary gear set. Of course, other types of power transfer units, including other gear sets and transmissions, may be used to connect the engine  14  to the generator  16 . The power transfer unit  18  may include a ring gear  20 , a sun gear  22  and a carrier assembly  24 . The generator  16  is driven by the power transfer unit  18  when acting as a generator to convert kinetic energy to electrical energy. The generator  16  can alternatively function as a motor to convert electrical energy into kinetic energy, thereby outputting torque to a shaft  26  connected to the carrier assembly  24  of the power transfer unit  18 . Because the generator  16  is operatively connected to the engine  14 , the speed of the engine  14  can be controlled by the generator  16 . 
         [0035]    The ring gear  20  of the power transfer unit  18  may be connected to a shaft  28  that is connected to vehicle drive wheels  30  through a second power transfer unit  32 . The second power transfer unit  32  may include a gear set having a plurality of gears  34 A,  34 B,  34 C,  34 D,  34 E, and  34 F. Other power transfer units may also be suitable. The gears  34 A- 34 F transfer torque from the engine  14  to a differential  38  to provide traction to the vehicle drive wheels  30 . The differential  38  may include a plurality of gears that enable the transfer of torque to the vehicle drive wheels  30 . The second power transfer unit  32  is mechanically coupled to an axle  40  through the differential  38  to distribute torque to the vehicle drive wheels  30 . 
         [0036]    The motor  36  can also be employed to drive the vehicle drive wheels  30  by outputting torque to a shaft  46  that is also connected to the second power transfer unit  32 . In one embodiment, the motor  36  and the generator  16  are part of a regenerative braking system in which both the motor  36  and the generator  16  can be employed as motors to output torque. For example, the motor  36  and the generator  16  can each output electrical power to a high voltage bus  48  and the battery  50 . 
         [0037]    The battery  50  may be a high voltage battery that is capable of outputting electrical power to operate the motor  36  and the generator  16 . Other types of energy storage devices and/or output devices can also be incorporated for use by the electrified vehicle  12 . In a non-limiting PHEV embodiment of the electrified vehicle  12 , the battery  50  may be recharged or partially recharged using a charging adapter  45  that is connected to a charging station powered by an external power source, such as an electrical grid, a solar panel, or the like. 
         [0038]    The motor  36 , the generator  16 , the power transfer unit  18 , and the power transfer unit  32  may generally be referred to as a transaxle  42 , or transmission, of the electrified vehicle  12 . Thus, when a driver selects a particular shift position, the transaxle  42  is appropriately controlled to provide the corresponding gear for advancing the electrified vehicle  12  by providing traction to the vehicle drive wheels  30 . 
         [0039]    The powertrain  10  may additionally include a control system  44  for monitoring and/or controlling various aspects of the electrified vehicle  12 . For example, the control system  44  may communicate with the electric drive system  25 , the power transfer units  18 ,  32  or other components to monitor and/or control the electrified vehicle  12 . The control system  44  includes electronics and/or software to perform the necessary control functions for operating the electrified vehicle  12 . In one embodiment, the control system  44  is a combination vehicle system controller and powertrain control module (VSC/PCM). Although it is shown as a single hardware device, the control system  44  may include multiple controllers in the form of multiple hardware devices, or multiple software controllers within one or more hardware devices. 
         [0040]    A controller area network (CAN)  52  allows the control system  44  to communicate with the transaxle  42 . For example, the control system  44  may receive signals from the transaxle  42  to indicate whether a transition between shift positions is occurring. The control system  44  could also communicate with a battery control module of the battery  50 , or other control devices. 
         [0041]    Additionally, the electric drive system  25  may include one or more controllers  54 , such as an inverter system controller (ISC). The controller  54  is configured to control specific components within the transaxle  42 , such as the generator  16  and/or the motor  36 , such as for supporting bidirectional power flow. In one embodiment, the controller  54  is an inverter system controller combined with a variable voltage converter (ISC/VVC). 
         [0042]    In one non-limiting embodiment, the electrified vehicle  12  has two basic operating modes. The electrified vehicle  12  may operate in an Electric Vehicle (EV) mode where the motor  36  is used (generally without assistance from the engine  14 ) for vehicle propulsion, thereby depleting the battery  50  state of charge up to its maximum allowable discharging rate under certain driving patterns/cycles. The EV mode is an example of a charge depleting mode of operation for the electrified vehicle  12 . During EV mode, the state of charge of the battery  50  may increase in some circumstances, for example due to a period of regenerative braking. The engine  14  is generally not permitted to operate under a default EV mode but could be operated as necessary based on a vehicle system state or as permitted by the operator. 
         [0043]    The electrified vehicle  12  may additionally be operated in a Hybrid (HEV) mode in which the engine  14  and the motor  36  are both used for vehicle propulsion. The HEV mode is an example of a charge sustaining mode of operation for the electrified vehicle  12 . During the HEV mode, the electrified vehicle  12  may reduce the motor  36  propulsion usage in order to maintain the state of charge of the battery  50  at a constant or approximately constant level by increasing the engine  14  propulsion usage. The electrified vehicle  12  may be operated in other operating modes in addition to the EV and HEV modes. 
         [0044]    It may be desirable to wirelessly charge the battery  50  of the electrified vehicle  12 . Exemplary charging systems for achieving this purpose are described in greater detail below. 
         [0045]      FIG. 2  schematically illustrates a parking space  56 . The parking space  56  may be located in a parking lot, a garage, a driveway or at any other surface where a vehicle  99  is parked. The vehicle  99  could be any type of electrified vehicle, including but not limited to the electrified vehicle  12  of  FIG. 1 . The parking space  56  is equipped with a charging system  58  that is adapted to wirelessly charge a battery  50  of the vehicle  99 . 
         [0046]    In one embodiment, the charging system  58  includes an alignment system  60  for accurately positioning a charging device  62  relative to the vehicle  99 . As is discussed in greater detail below, the alignment system  60  may automatically move the charging device  62  in a lateral direction L 1  in order to position the charging device  62  relative to a receiving device  65  that is mounted to the vehicle  99 . 
         [0047]    As known, proper alignment of the charging device  62  relative to the receiving device  65  is necessary to wirelessly transmit electromagnetic energy between the devices. The electrical energy that is wirelessly transferred to the receiving device  65  of the vehicle  99  may be converted into electricity for powering and/or charging the battery  50 . 
         [0048]      FIGS. 3 and 4  illustrate an exemplary charging system  58  for wirelessly charging a high voltage battery of an electrified vehicle. The charging system  58  may include a visual target  64 , an alignment system  60  and a charging device  62 . In one embodiment, the visual target  64  is separated from the alignment system  60  and may be positioned laterally in front of the alignment system  60  (i.e., forward of the alignment system  60  in a direction away from a parked vehicle). 
         [0049]    The visual target  64  may extend to a height H (see  FIG. 3 ) that is tall enough to be visible by a vehicle driver. In one non-limiting embodiment, the visual target  64  is positioned directly in front of a driver seat of the electrified vehicle (see also  FIG. 5A ). This positioning substantially reduces any parallax error that may arise as the vehicle is parked. As discussed below with respect to  FIGS. 5A and 5B , the vehicle driver may utilize the visual target  64  to properly orient the electrified vehicle relative to the charging system  58 . 
         [0050]    The alignment system  60  may include a slidable bar  66 , a connecting bar  68 , one or more wheel guides  70 , and a wheel plate assembly  72 . The slidable bar  66  is movable in lateral directions L 1  (i.e., to the left or to the right) relative to one or more slide rails  74 . Two slide rails are illustrated in  FIG. 4 ; however, the alignment system  60  could employ any number of slide rails  74 . The slide rails  74  are stationary and may be mounted to the wheel plate assembly  72 , which acts as a base of the charging system  58 . In one embodiment, the slide rails  74  include ball bearing arrangements such that the slidable bar  66  glides smoothly in the lateral directions L 1  within the slide rails  74 . 
         [0051]    The slidable bar  66  may additionally be equipped with one or more wheel stops  76  (see  FIG. 4 ). The wheel stops  76  represent obstacles that are positioned to stop the forward motion (in longitudinal direction L 2 ) of a parking vehicle. In one non-limiting embodiment, the wheel stops  76  are triangular shaped and extend to a height above the slidable bar  66  (see, for example,  FIG. 5A ). However, the wheel stops  76  could include any size or shape and could be positioned at any location of the slidable bar  66  to inhibit the forward motion of a vehicle. 
         [0052]    The connecting bar  68  may be attached to the slidable bar  66  and carries the charging device  62  at an end opposite from the slidable bar  66 . Accordingly, movement of the slidable bar  66  also moves the connecting bar  68  and the charging device  62 . In other words, the charging device  62  moves in unison with the slidable bar  66 . In one embodiment, the connecting bar  68  is transverse to the slidable bar  66 . In still another embodiment, the connecting bar  68  is perpendicular to the slidable bar  66 . 
         [0053]    The wheel guides  70  are mounted to the slidable bar  66  and extend in the same direction from the slidable bar  66  as the connecting bar  68 . The wheel guides  70  may be curved in a direction toward the connecting bar  68 . In other words, in one exemplary implementation, the wheel guides  70  are curved bars. 
         [0054]    In one non-limiting embodiment, a first wheel guide  70 A is mounted at a first side  78  of the slidable bar  66  and a second wheel guide  70 B is mounted at a second side  80  of the slidable bar  66 . The first and second wheel guides  70 A,  70 B may engage opposing wheels of a vehicle. For example, as the vehicle wheels contact and move relative to the wheel guides  70 A,  70 B, the slidable bar  66  slides relative to the slide rails  74  to force the wheel guides  70 A,  70 B into alignment with the wheels. Therefore, the alignment system  60  can automatically locate the charging device  62  at a charging position relative to the vehicle in response to engaging the wheels of the vehicle with the wheel guides  70 A,  70 B. In other words, via the wheel guides  70 A,  70 B of the alignment system  60 , the charging system  58  is automatically self-located at a precise location relative to the vehicle in order to charge a battery of the vehicle. 
         [0055]    The wheel guides  70 A,  70 B may be spaced by a distance D 1  and the charging device  62  may be positioned at a distance D 2  from the slidable bar  66  (see  FIG. 4 ). The distances D 1 , D 2  can be set during installation of the charging system  58  to accommodate a specific vehicle having specific wheel-to-wheel dimensions and a specifically located receiving device (such that includes a receiving coil). This particular arrangement may be suitable for home use of the charging system  58 . 
         [0056]    Alternatively, the charging system  58  can be adapted to provide automatic positioning of the distances D 1 , D 2 . Automatic positioning may be particularly suited for use in parking lots where different vehicles are charged using the charging system  58 . For example, the charging system  58  could include a communication system  55  (see  FIG. 4 ), such as a Wi-Fi system, cellular system or the like, that can communicate with a vehicle to obtain vehicle data (wheel-to-wheel dimensions, etc.) and automatically set the distances D 1 , D 2  as necessary to accommodate that particular vehicle. 
         [0057]    The wheel plate assembly  72  of the alignment system  60  may include a first wheel plate  82  and a second wheel plate  84 . A base  86  may extend between the first wheel plate  82  and the second wheel plate  84  (see  FIG. 4 ). In one embodiment, the slide rails  74  are mounted to the base  86 . Each of the first wheel plate  82 , the second wheel plate  84  and the base  86  are in direct contact with a surface S of a parking space, in one embodiment. 
         [0058]    As a vehicle approaches the charging system  58 , the vehicle wheels may ride onto the first wheel plate  82  and the second wheel plate  84 . The charging system  58  is not be pushed away from the approaching vehicle even though it may contact portions of the vehicle because the vehicle wheels ride on top of the first wheel plate  82  and the second wheel plate  84  to hold its positioning. Therefore, the energy created by movement of the oncoming vehicle is used to align the wheel guides  70 A,  70 B relative to the vehicle wheels. In this way, the charging system  58  may be installed and used without the need to hard mount the system to the surface S, thereby reducing installation costs and increasing reusability. 
         [0059]    The alignment system  60  may additionally include a locking pivot  88  (see  FIG. 4 ). In one non-limiting embodiment, the charging system  58  is pivotable about the locking pivot  88  to change a rotational positioning a of the charging system  58  relative to the surface S. The locking pivot  88  may be selectively released to rotate the charging system  58 . For example, the charging system  58  may need rotated relative to an oncoming vehicle in order to better align the charging system  58  relative to the vehicle. 
         [0060]    In one non-limiting device, the charging device  62  is an inductive charging device. Other types of wireless charging systems are also contemplated as within the scope of this disclosure. The charging device  62  may include a coil pad  98  that houses a transmitting coil  95 . The charging device  62  could additionally include other components necessary to wirelessly transmit energy to a nearby device, such as a receiving device that is mounted to the vehicle that requires charging. 
         [0061]      FIGS. 5A and 5B  schematically illustrate a vehicle charging method that may employ the charging system  58  described above (see  FIGS. 3 and 4 ) to automatically align a charging device  62  relative to a receiving device  65  of a vehicle  99  to wirelessly charge a battery  50  of the vehicle  99 . Although the battery  50  is shown connected to the receiving device  65  in this embodiment, it should be understood that other components could be positioned therebetween for converting the electrical energy received by the receiving device  65  into electricity that can be used to power and/or recharge the battery  50 . 
         [0062]    Referring first to  FIG. 5A , the exemplary vehicle charging method begins when the electrified vehicle  99  enters a parking space  56  that is equipped with the charging system  58 . As the vehicle  99  enters the parking space  56 , the vehicle driver may utilize the visual target  64  to guide the vehicle  99  into a proper orientation relative to the alignment system  60  of the charging system  58 . In one non-limiting embodiment, the visual target  64  is positioned in a direct line of sight LOS in front of a driver side  92  of the vehicle  99 . This positioning may reduce the onset of parallax error that may otherwise occur as the vehicle enters the parking space  56 . The vehicle  99  may be driven longitudinally forward until the vehicle wheels  94  abut the wheel stops  76  of the charging system  58 , indicating that the vehicle  99  has reached a proper longitudinal positioning relative to the charging system  58 . 
         [0063]    Referring now to  FIG. 5B , as the vehicle  99  is moved longitudinally forward in a direction toward the visual target  64 , the wheel guides  70  of the alignment system  60  may engage the vehicle wheels  94 . The wheel guides  70  may glide or otherwise travel along an inner surface  96  of the vehicle wheels  94  as the vehicle  99  continues to approach the visual target  64 . As the wheel guides  70  engage the vehicle wheels  94 , the slidable bar  66  of the alignment system  60  may move in the lateral directions L 1  (left or right) to position the charging device  62  at a charging position relative to the vehicle  99 . In other words, in one non-limiting embodiment, the charging device  62  is automatically aligned relative to the receiving device  65  using the motion of the vehicle  99  to move the charging device  62  (via the slidable bar  66 ). 
         [0064]    In one non-limiting embodiment, movement of the slidable bar  66  moves the connecting bar  68  and the attached charging device  62  between a first position X in which a transmitting coil  95  of the charging device  62  is offset from a receiving coil  90  of the receiving device  65  of the vehicle  99 , and a second position X′ (shown in phantom lines) in which the transmitting coil  95  is aligned with the receiving coil  90  such that power may be wirelessly transferred from the transmitting coil  95  to the receiving coil  90 . For example, proper alignment may be achieved when the receiving coil  90  is located directly above the transmitting coil  95 . Once properly aligned, an electromagnetic field is produced between the transmitting coil  95  and the receiving coil  90  such that electrical energy may be transferred to the receiving device  65 . The electrical energy may subsequently be used to charge the battery  50 . 
         [0065]    The charging system and method described herein provide precise locating of a charging device both laterally and longitudinally relative to a vehicle in a hands-free manner. The proposed alignment system uses a single moving part and includes no electronics, is robust, and provides repeatable results. 
         [0066]    Although the different non-limiting embodiments are illustrated as having specific components or steps, the embodiments of this disclosure are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments. 
         [0067]    It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should be understood that although a particular component arrangement is disclosed and illustrated in these exemplary embodiments, other arrangements could also benefit from the teachings of this disclosure. 
         [0068]    The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would understand that certain modifications could come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.