Abstract:
An autonomous vehicle washing and drying apparatus ( 10 ) that is truly portable, easily stored, and capable of fully independent and automatic operation. The apparatus ( 10 ) is self-contained and requires no connection to a water or power source. One or more tanks ( 175 ) hold the necessary water, detergent and automotive chemicals used for washing the exterior surface of the vehicle (A). A power source such as a battery ( 250 ), fuel cell, or electrical energy generated by an onboard electrical generator powered by a gasoline, ethanol, or hybrid engine provides electrical power for the various electrical components that comprise the apparatus. One or more sensors ( 210, 212 ) constantly determine the distance of the apparatus ( 10 ) in relation to the vehicle (A). The one or more sensors ( 210, 212 ) provide the distance information to an electronic control system ( 200 ) for guiding the movement of the apparatus ( 10 ) on a circumferential path (P) around the vehicle. The apparatus ( 10 ) can also dry the vehicle (A) in a manner similar to the washing operation.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Statement of the Technical Field 
         [0002]    The invention relates to an apparatus for washing and drying vehicles. More particularly, this invention relates to a personal, self-contained and autonomous vehicle washing and drying system. 
         [0003]    2. Description of the Related Art 
         [0004]    Vehicle washes and systems for washing vehicles are well known in the art. Typically, such systems are commercial in nature and not intended for personal use. These systems usually involve an arrangement of pumps, one or more movable sprayer heads and/or sprayer arms, tanks for detergents and waxes, and a bay wherein the arrangement is fixated so that the washing operation is directed towards washing the vehicle within the bay. More recent improvements to these arrangements include the use of sensors and electronic controls for guiding the operation of the sprayer arms and sprayer heads in relation to the vehicle. 
         [0005]    Also known in the art are portable vehicle washing and cleaning systems that are intended for personal use, such as at home on the driveway. These arrangements enable vehicle owners to more conveniently wash their vehicles without going to a car wash. This can save both time and money. For example, in U.S. Pat. No. 5,638,843, there is provided a portable, collapsible car wash shower which includes an overhead conduit extending between a pair of vertical conduits such that a vehicle can be driven between and beneath the conduits. A plurality of spray nozzles project interiorly from the conduits to spray water onto the associated vehicle. The conduits are connected together by selectively flexible corner couplings which permit the conduits to be selectively pivoted into a parallel orientation for storage. 
         [0006]    In U.S. Pat. No. 6,766,966, a portable, battery powered spray applicator car wash device capable of holding and dispensing liquid cleansers and waxes for rubbing into the body and windows of a vehicle is shown; enabling complete and portable mobile washing and cleaning services and complete detailing of a vehicle without the use of water. 
         [0007]    U.S. patent application Ser. No. 2005/0133071A1 discloses an apparatus designed for washing cars in a casual environment, such as outside a residential home, by a homeowner or other untrained user. The apparatus is easily transportable, for instance, from a garage into the driveway or street, and is easily stowed. The apparatus is also self-propelled, and remotely controlled. 
         [0008]    However, one drawback to the home car washing devices known in the art is that the vehicle owner is required to be involved in the cleaning and washing operation, at least at some level. Another drawback to some of the known home car washing devices is that an overhead arm is utilized for holding and positioning the sprayer heads over the top of the vehicle. The overhead arms make these devices bulky and hard to store. The use of multiple sprayer heads substantially reduces the amount of fluid pressure available to each of the sprayer heads diminishing the overall cleaning effectiveness of the device. Additionally, no other device known in the art delivers a heated fluid source or provides the capability of drying the surface of the vehicle after the vehicle has been washed. 
         [0009]    Still another drawback is that some of these devices are required to be connected to a source of water or power which limits the portability and operation of the device. Specifically, if the device is connected to a source of water or power then the device is not free to completely move around the perimeter of the vehicle during the washing operation. Further, the tethered water and power connections would preclude the device from being a truly portable and automatic washing and cleaning system which is capable of being used virtually anywhere. 
         [0010]    In view of the forgoing, there remains a need for an improved vehicle washing and drying system that is truly portable, effective, easily stored, and capable of fully independent and automatic operation. The system must be self-contained requiring no operating power or tethered water source connections, self-directing around the perimeter of a vehicle, and fully automatic with respect to the washing and drying cycles performed on the vehicle. The present invention fulfills this need by providing a self-contained, self-guided autonomous vehicle washing system capable of independent movement around a vehicle for washing and drying a vehicle. 
       SUMMARY OF THE INVENTION 
       [0011]    An autonomous vehicle washing and drying apparatus that is portable, easily stored, and capable of fully independent and automatic operation is provided. In one embodiment of the invention, the apparatus is comprised of a motorized base portion, a surface treating system mounted on the motorized base portion for washing and drying the exterior surface of the vehicle, and an electronic control system for autonomously guiding the motorized base portion on a circumferential path around the vehicle. The surface treating system includes at least one spray head delivering pressurized cleaning fluid to the exterior surface of the vehicle as the apparatus moves along the circumferential path around the vehicle. 
         [0012]    The at least one spray head moves back and forth along a track comprised of a vertical portion, an arcuate portion, and a horizontal portion. The spray head delivers pressurized cleaning fluid to the vertical surfaces of the vehicle as the spray head moves back and forth along the vertical portion of the track. The horizontal portion of the track is varied in height by a spherical guide member disposed on a distal end of the horizontal portion. The spherical guide member is configured to be disposed on horizontal surfaces of the vehicle. The spherical guide member urges against the horizontal surfaces causing the height of the horizontal portion to conform to the varying heights of the horizontal surfaces of the vehicle. The horizontal portion of the track supports the spray head over the horizontal surfaces as the spray head delivers pressurized cleaning fluid to the horizontal surfaces. 
         [0013]    The at least one spray head is movably mounted on the track by a pair of guide rollers. At least one of the guide rollers is motorized by an electric motor for propelling the spray head back and forth along the track. The pair of guide rollers allows the spray head to seamlessly transition between the vertical portion, arcuate portion, and horizontal portion of the track. In addition, the spray head can direct pressurized air to the exterior surface of the vehicle for drying the vehicle. 
         [0014]    The electronic control system includes at least one sensor for continuously determining distance information between the motorized base portion and the vehicle. The electronic control system uses the distance information to provide error correcting signals to the motorized base portion to maintain the motorized base portion a predetermined distance from the vehicle as the motorized base portion is propelled on the circumferential path. In one embodiment of the invention, the predetermined distance is twelve inches. 
         [0015]    The motorized base portion includes at least one wheel for steering the motorized base portion along the circumferential path. The at least one wheel is steered by a servomotor receiving the error correcting signals from the electronic control system. The motorized base portion further includes at least one wheel for propelling the motorized base portion on the circumferential path. The at least one wheel is provided rotary power by an electric motor. 
         [0016]    The apparatus is powered by a power source. In one embodiment of the invention, the power source is a rechargeable battery. In other embodiments of the invention, the power source is a fuel cell or an onboard electrical generator. The electrical generator is supplied rotary power by an engine fueled by gasoline, ethanol, or a hybrid engine powered by gasoline and ethanol. 
         [0017]    There are one or more tanks for storing at least one fluid used in conjunction with the surface treating system. The at least one fluid is pressurized by a pump for delivering the fluid to the spray head. The at least one fluid in the one or more tanks is pre-heated by a pre-heater which is energized prior to the apparatus being used. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    Embodiments will be described with reference to the following drawing figures, in which like numerals represent like items throughout the figures, and in which: 
           [0019]      FIG. 1  is a perspective view of an autonomous vehicle washing apparatus that is useful for understanding the invention. 
           [0020]      FIG. 2  is another perspective view of the apparatus of  FIG. 1  showing its intended use for washing a vehicle. 
           [0021]      FIG. 3  is an elevated side view of the apparatus of  FIG. 1  showing its intended use for washing a vehicle. 
           [0022]      FIG. 4  is an elevated front view of the apparatus of  FIG. 1 . 
           [0023]      FIG. 5  is a cross-sectional view of the apparatus of  FIG. 1  along line  5 - 5  of  FIG. 4 . 
           [0024]      FIG. 6  is a schematic diagram of an electronic control system for the apparatus of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0025]    Referring to  FIGS. 1 and 2 , shown is a perspective view of an autonomous vehicle washing and drying unit  10  and its intended use with a vehicle that is useful for understanding the invention. In one embodiment of the invention, the vehicle A to be washed and dried is an automobile. However, the invention is not limited in this regard in that the unit  10  can be configured and used to wash and dry other items or vehicles such as motorcycles, trucks, buses, recreational vehicles, and airplanes. The unit  10  is comprised of a mobile base portion  100  partially formed of a housing  101  containing some of the operational components of the invention. The washing unit  10  can be used anywhere there is a large enough area so that a vehicle A can be located in a target area T and the washing unit  10  can move around the vehicle A in a circumferential path P. Typically, a washing unit  10  would be utilized on a driveway but this is not meant to be limiting. Other places where the unit  10  can be used for washing a vehicle A includes parking lots and larger garages. 
         [0026]    An electronic control system  200  ( FIG. 6 ) is located in base portion  100  which when used in conjunction with a pair of positioning sensors  210 ,  212  (see also  FIG. 4 ), guides the unit  10  relative to the vehicle A being washed by staying a predetermined distance X ( FIG. 3 ) from the vehicle A. In one embodiment of the invention, the distance X is twelve inches. However, the invention is not limited in this regard as other predetermined distances could be selected according to user preference. The unit  10  has a spray head  115  movably mounted on a track comprised partially of a post  110 , an arcuate track portion  112 , and a guide arm  150  (hereinafter “track”) for directing a high pressure jet of cleaning spray onto the exterior surfaces of vehicle A. The post  110  extends upwardly from the base portion  100 . The spray head  115  is mounted to post  110 , arcuate track portion  112 , and guide arm  150  with a pair of resilient rollers  115   a,    115   b  that extend from the rear of spray head  115 . The rollers  115   a,    115   b  are made from a material that is resilient but also has a high coefficient of friction. The rollers  115   a,    115   b  are mounted on the rear of spray head  115  in an opposing configuration for receiving therebetween the respective portions of the track. The rollers  115   a,    115   b  are concave towards the center to form a recess wherein the respective portions of the track are received. The rollers  115   a,    115   b  grip the post  110 , arcuate track portion  112 , and guide are  150  therebetween for supporting spray head  115 . One of the rollers  115   a  is provided rotary power from an electric motor  230  ( FIG. 6 ). The other roller  115   b  is mounted on a spindle (not shown) and is free to rotate as spray head  115  moves back and forth along the track. The motorized roller  115   a  urges against the respective track portions and due to the high friction between motorized roller  115   a  and the respective tract portions, spray head  115  is propelled along the post  110 , arcuate track portion  112 , and the guide arm  150 . 
         [0027]    The guide arm  150  is movably mounted on post  110  by a sliding bracket  149 . The arcuate track portion  112  transitions rollers  115   a,    115   b  from the post  110  to the guide arm  150  as spray head  115  moves back and forth along the resulting track. The arcuate track portion  112  moves concurrently along post  110  with the guide arm  150  as the guide arm  150  moves vertically as discussed below. At least a portion of the arcuate track portion  112  partially surrounds the post  110  and extends in the same longitudinal direction. This portion of arcuate track portion  112  attaches one end of arcuate track portion  112  to post  110  while allowing arcuate track portion  112  to move relative thereto. The arcuate track portion  112  assures a seamless transition of spray head  115  as spray head  115  moves from the post  110  to the guide arm  150  as spray head  115  moves back and forth along the track. 
         [0028]    The guide arm  150  has a spherical guide member  170  at the distal end which engages the horizontal surfaces of vehicle A (best seen in  FIG. 3 ). The spherical guide member  170  is mounted to the guide arm  150  with a frame member  172  and a mounting member  171 . The spherical guide member  170  is rollably mounted to frame member  172  with an axle  173 . The frame member  172  is mounted on a spindle (not shown) on mounting member  171  and is free to rotate about the spindle (not shown). The spherical guide member  150  is made from a resilient material having a high coefficient of friction and has a texture mimicking a tire tread. The resilient material prevents scratching and marring of the vehicle A exterior surfaces. 
         [0029]    The guide arm  150  is for guiding the spray head  115  over the varying height horizontal surfaces of the vehicle A including the roof, hood and trunk. For example, as the unit  10  moves from a position adjacent the roof of the vehicle A in  FIG. 2  to a position adjacent the hood (not shown), the guide arm  150  guided by the spherical member  170  will follow the contour of the vehicle A so that the guide arm  150  will be lowered by gravity to a position just above the hood of the vehicle A. In this manner, as the spray head  115  traverses back and forth along the guide arm  150  (discussed in more detail below), cleaning spray from spray head  115  is directed onto the hood of the vehicle A. The cleaning spray is delivered to spray head  115  from a cleaning fluid tank  175  pressurized by a pump  260  ( FIGS. 5 and 6 ). Oppositely, when the unit  10  moves from a position adjacent the hood (not shown) of vehicle A to a position adjacent the roof ( FIG. 2 ) of vehicle A, the guide arm  150  guided by spherical member  170  will follow the contour of the vehicle A so that the guide arm  150  is urged upward by spherical member  170  to a position just above the roof of vehicle A. Thus, as the spray head  115  traverses back and forth along guide arm  150 , cleaning spray from spray head  115  is directed onto the roof of vehicle A. Similarly, cleaning spray is directed to the vertical surfaces of the vehicle A as spray head moves back and forth along the portion of the track comprised of post  110 . 
         [0030]    In performing the washing and drying operation, the unit  10  moves relative to the vehicle along a circumferential path P around vehicle A such that one complete washing or drying cycle is completed during one complete revolution around vehicle A. In one embodiment of the invention, the unit  10  moves in a clockwise circumferential path P around the vehicle A. Arrows  500  show the direction of movement of unit  10  around vehicle A. The unit  10  moves at a speed such that is takes approximately ten minutes to perform one complete revolution and washing cycle or drying around vehicle A. Although the unit  10  may be configured to move at differing speeds around vehicle A, a cycle time of approximately ten minutes has been found to be optimal to perform each of the washing and drying operations considering the amount of cleaning fluid available onboard as well as available power from a rechargeable battery  250  power source ( FIG. 5 ). 
         [0031]    Still referring to  FIGS. 1 and 2 , and also now to  FIG. 3 , in use the unit  10  is initially placed a distance X from the vehicle A. The unit  10  can initially be placed at any position adjacent the vehicle A at the distance X. The guide arm  150  is positioned over the adjacent horizontal surface of the vehicle A so that the spherical guide member  170  at the distal end engages the horizontal surfaces of vehicle A. The power switch  215  is then switched to the on position. A propulsion drive motor  205  ( FIGS. 5 and 6 ) driving a pair of drive wheels  155 ,  156  ( FIG. 5 ) then begins to propel the unit  10  in a clockwise direction along the circumferential path P around vehicle A. A pair of position sensors  210 ,  212  continually monitors the distance between the unit  10  and vehicle A to maintain the distance X. If the unit  10  comes closer to vehicle A than the distance X, the electronic control system  200  ( FIG. 6 ) sends an electrical signal to a servomotor  215  ( FIGS. 5 and 6 ) to steer a pair of steering wheels  150 ,  151  ( FIG. 5 ) to the left to cause the unit  10  to open the distance to vehicle A. The unit  10  is steered to the left until the sensors  210 ,  212  detect that the unit  10  is again at a distance greater than distance X. When the sensors  210 ,  212  detect the unit  10  is again at distance X, within a predetermined amount of error, an electrical signal is sent to the servomotor  215  (FIGS.  5  and  6 ) to causes the steering wheels  150 ,  151  to straighten so that the unit  10  again follows the circumferential path P. The sensors  210 ,  212  are mounted to housing  101  in slots  109  (see also  FIG. 4 ) so that sensors  210 ,  212  can be adjusted vertically for vehicles of different sizes. 
         [0032]    Similarly, if the unit  10  moves farther from vehicle A than distance X, the electronic control system  200  ( FIG. 6 ) sends an electrical signal to a servomotor  215  ( FIGS. 5 and 6 ) to steer the steering wheels  150 ,  151  to the right to cause the unit  10  to close the distance to vehicle A to distance X. The sensors  210 ,  212  also cause the unit  10  to be steered around the four corners of vehicle A by sensing when the unit  10  moves outside of the distance X along circumferential path P. The servomotor  215  ( FIGS. 5 and 6 ) then steers the steering wheels  150 ,  151  ( FIG. 5 ) left or right until the unit  10  is again at distance X. For example, when the unit  10  must turn around the front left corner of the vehicle A, the servomotor  215  ( FIGS. 5 and 6 ) must cause steering wheels  150 ,  151  to turn to the right. This cannot occur until the unit  10  moves past the front end of the vehicle A and the sensors  210 ,  212  detect that the unit  10  has moved a distance greater than distance X from the vehicle A. When this occurs, servomotor  215  ( FIGS. 5 and 6 ) then causes steering wheels  150 ,  151  to be steered to the right until unit  10  moves within distance X. This cycle is repeated as the unit  10  moves along the circumferential path P and must maneuver around each of the remaining three corners of vehicle A. 
         [0033]    When the wash cycle is completed by the unit  10  completing one complete revolution around vehicle A, the user can move the power switch  215  to the off position and the unit  10  can then be returned to storage. The rechargeable battery  250  ( FIGS. 5 and 6 ) can be recharged and the cleaning fluid supply tank  175  can be refilled with cleaning fluid. Alternately, the unit  10  could be set to perform a drying operation by again switching power switch  215  to the on position and letting the unit  10  again circumscribe the vehicle A. However, this can only be done if the cleaning fluid in cleaning fluid supply tank  175  has been exhausted during the wash cycle. When the cleaning fluid in cleaning fluid supply tank  175  has been exhausted, pump  260  ( FIGS. 5 and 6 ) will function as a blower and direct a blast of high pressure air through spray head  115  onto the exterior surfaces of vehicle A for drying. Pump  260  ( FIGS. 5 and 6 ) is a positive displacement type pump which can run dry for over an hour. For example, a Hydra-Cell F/G-20 Series pump is one positive displacement pump that could be used. The Hydra-Cell F/G-20 Series pump is available from Wanner Engineering, Inc. of Minneapolis, Minn. The unit  10  can be allowed to circumscribe the vehicle A until the power in battery  250  ( FIGS. 5 and 6 ) is exhausted or power switch  215  is moved to the off position by the user. 
         [0034]    During the wash cycle, spray head  115  moves back and forth along the track partially formed from the post  110  that extends upwardly from the base portion  100 . As discussed, a portion of the track also comprises a portion of guide arm  150  so that spray head  115  is moved back and forth over the horizontal surfaces of the vehicle A. In one embodiment of the invention, an electric motor  230  ( FIGS. 5 and 6 ) integrally mounted with spray head  115  causes spray head  115  to move back and forth along the track when the power switch  215  is moved to the on position. In this manner, spray head  115  moves back and forth along a path extending from the lower end of post  110  to a point adjacent the spherical guide member  170  on the distal end of guide arm  150 . A relay switch  231  ( FIGS. 5 and 6 ) located in spray head  115  could be used to cause the electric motor  230  ( FIGS. 5 and 6 ) propelling spray head  115  to reverse directions when the spray head  115  reaches the lower end of post  110  or the most distal point on guide arm  150 . The relay switch  231  ( FIGS. 5 and 6 ) could reverse the direction of the electric motor  230  ( FIGS. 5 and 6 ) by engaging projections (not shown) located at the lower end of post  110  and the most distal point of travel on guide arm  150 . Still, the invention is not limited in this regard. Alternately, the relay switch  231  ( FIGS. 5 and 6 ) in spray head  115  could reverse the direction of the electric motor  230  ( FIGS. 5 and 6 ) with the use of sensors located at the lower end of post  110  and the most distal point on guide arm  150 . 
         [0035]    In another embodiment of the invention, an arrangement of belts and pulleys (not shown) could be used to move spray head  115  back and forth along track. In this arrangement, an electric motor (not shown) would be mounted in housing  101  for providing rotary power to the arrangement of belts (not shown) moving spray head  115  back and forth over the track. A switch (not shown) on spray head  115  could be used to cause the electric motor (not shown) propelling spray head  115  to reverse directions when the spray head  115  reaches the lower end of post  110  or the most distal point on guide arm  150 . The switch (not shown) could reverse the direction of the electric motor (not shown) with the use of projections or sensors located at the lower end of post  110  and the most distal point of travel on guide arm  150 . 
         [0036]    The path of travel for spray head  115  is designed so that all of the exterior surfaces of vehicle A will receive a jet of cleaning spray in an overlapping pattern during the wash cycle. For example, as the spray head  115  moves from the lowest position along the tract at the lower end of post  110  upwards, the vertical exterior surfaces of vehicle A are washed. As the spray head  115  reaches the highest point on the exterior vertical surfaces of vehicle A, spray head  115  is caused to begin a ninety-degree turn along the arcuate portion  112  of the track. As spray head  115  continues along the track to the arcuate portion  112 , spray head  115  is guided on to guide arm  150  to the distal end of guide arm  150 . The distal end of the guide arm  150  extends to the approximate centerline of vehicle A. Thus, a jet of cleaning spray from spray head  115  is directed onto the exterior horizontal surfaces of vehicle A. Accordingly, the entire exterior surface of vehicle A is systematically washed by a high pressure jet of cleaning fluid from spray head  115  as the unit  10  moves in one complete revolution around vehicle A. 
         [0037]    The unit  10  is completely self-contained and requires no tethered connection to an external source of power of source of cleaning fluid such as water. In one embodiment of the invention, there is a rechargeable battery  250  ( FIGS. 5 and 6 ) for providing electrical power. Prior to use, the battery  250  ( FIGS. 5 and 6 ) must be charged, a process which requires the unit  10  be connected to a source of electrical power. An electrical cord and plug (not shown) could be provided for this purpose. The battery  250  ( FIGS. 5 and 6 ) could be a twelve volt automotive or marine type battery for supplying electrical power to the electronic control system  200  ( FIG. 6 ), pump  260  ( FIGS. 5 and 6 ), servomotor  215  ( FIGS. 5 and 6 ), propulsion motor  205  ( FIGS. 5 and 6 ), sensors  210 ,  212  and spray head motor  230  ( FIGS. 5 and 6 ). After use, the battery  250  ( FIGS. 5 and 6 ) must again be recharged by being connected to a source of electrical power such as conventional 120 vac household current. Alternately, the unit  10  could be equipped with a power generating unit  180  (not shown) which could include a fuel cell or a conventional electrical generator (not shown). The electrical generator (not shown) could be provided with rotary power by a prime mover such as an engine fueled by gasoline or ethanol, or a hybrid thereof. Alternately, a hybrid of the battery  250  ( FIGS. 5 and 6 ) and the power generating unit  180  could be used to supply the necessary electrical power. 
         [0038]    In one embodiment of the invention, there is a cleaning fluid tank  175  for storing cleaning fluid such as water used during the washing cycle. It has been found that a cleaning fluid tank  175  having a capacity of ten gallons (U.S.) is optimal for a washing cycle of approximately ten minutes. The cleaning fluid from cleaning fluid tank  175  is highly controlled and delivered under pressure to spray head  115  by pump  260  ( FIGS. 5 and 6 ). For example, it has been observed that the ten gallons of water from cleaning fluid tank  175  can be delivered to spray head  115  at a pressure of 1500 psi at a rate of 1 GPM. This is in contrast to the sixty to ninety gallons of water typically required to wash an automobile at home by hand washing. When empty, a filler cap  176  is provided for refilling cleaning fluid tank  175  with cleaning fluid such as water. Additives such as cleaning agents and detergents can also be added to the fluid for improved cleaning. Alternately, additional tanks (not shown) could be included in the housing  101  for an extended cleaning fluid supply or additives that could be mixed with the cleaning fluid supply. The unit  10  could include a pre-heater  280  ( FIG. 6 ) disposed in proximity to the cleaning fluid tank  175  for pre-heating the cleaning fluid for improved cleaning performance. The pre-heater  280  ( FIG. 6 ) would only be operative when the unit  10  is connected to a conventional source of electrical power such as household current. The pre-heated water remains at the desired temperature once disengaged from the pre-heater ( FIG. 6 ) for the period of time required to wash the vehicle. 
         [0039]    Referring now to  FIG. 4 , shown is helical fluid supply tube  118  that provides pressurized cleaning fluid from the cleaning fluid supply tank  175  located in base portion  100  to spray head  115 . The helical fluid supply tube  118  enables the spray head  115  to traverse the entire length of the track while maintaining the pressurized fluid supply between the cleaning fluid supply tank  175  to spray head  115 . This movement is best illustrated by the position of spray head  115  and the helical supply tube  118  towards the top of the track as opposed to the positions of spray head  115  and helical fluid supply tube  118  towards the lower end of post  110 , designated as  115 ′ and  118 ′, respectively. The movement of spray head  115  along the track is designated as S and S′. As discussed, cleaning fluid supplied from cleaning fluid supply tank  175  is pressurized by a pump  260  ( FIGS. 5 and 6 ) and pump motor  261  ( FIGS. 5 and 6 ) arrangement located in base portion  100 . An electrical power cable (not shown) is also embedded in the helical supply tube  118  for delivering electrical power to the electric motor (not shown) moving spray head  115  to move back and forth along the track. 
         [0040]    Also seen in  FIG. 4  are the positioning sensors  210 ,  212  for maintaining the unit  10  a distance X from the vehicle A as shown in  FIG. 3 . The sensors  210 ,  212  are embedded in the front wall of housing  101  above the steering wheel  150 ,  151  and servomotor  215 . The sensor  210 ,  212  could be any suitable type of distance sensor known in the art including infrared, ultrasonic and radar sensors. For example, ultrasonic sensors present the ideal solution for non-contact position and distance measurement in industrial areas where environmental conditions such as dust, smoke or steam may affect the sensors. Objects consisting of a variety of materials can be detected regardless of color or shape to within millimeters. These sensors use very high frequencies that are outside of the human hearing audible range. For example, an ultrasonic sensor model no. UB1000-18GM75-I-V14 available from Pepperl+Fuches of Twinsburg, Ohio could be used. This ultrasonic sensor is programmable for sensing range from 90 millimeters to 1 meter. The sensor can also be programmed to have a narrow beam angle or a wide beam angle. This sensor can also advantageously be combined with additional sensors for greater accuracy in determining the distance to the vehicle A. 
         [0041]    A first sensor  210  is located directly above a second sensor  212 . Both sensors  210 ,  212  are vertically adjustable for different vehicle types. The first sensor  210  is purposely located at a height higher than the wheels on a typical vehicle such as an automobile. The second sensor  212  is purposely located at height below the top of the wheels. This configuration is to ensure that an accurate reading of distance information is made by the sensors  210 ,  212  before any distance correcting signals are provided to the servomotor  215  ( FIGS. 5 and 6 ). Both of sensors  210 ,  212  must be in agreement as to the distance to the vehicle A or else no error correcting signal will be sent to the servomotor  215  ( FIGS. 5 and 6 ). This is a very important feature which eliminates errant electrical control signals being sent to servomotor  215  ( FIGS. 5 and 6 ) when the unit  10  is passing by the wheels of the vehicle A. For example, if there were only a single positioning sensor at height at or below the top of the vehicle wheel, the unit  10  could incorrectly be steered toward the vehicle because of faulty distance information taken at the gap between the wheel well and the wheel, or at the wheel itself which is generally more inboard than the exterior vertical body panels of the vehicle. With the addition of the second positioning sensor  212 , this possibility is eliminated because of the requirement that the distance information must match between the sensors  210 ,  212  before a distance correcting electrical signal is sent to the servomotor  215  ( FIGS. 5 and 6 ). 
         [0042]    In another embodiment of the invention, sensors  210 ,  212  could be replaced with roller devices (not shown) extending from the unit  10  to maintain the distance X between the unit  10  and the vehicle A. The roller devices (not shown) would be required to maintain continuous contact with the vehicle A surfaces. If the unit  10  begins to move further from the vehicle than the distance X, sensors (not shown) mounted in the rollers (not shown) could be used to provide feedback information to the servomotor  215  ( FIGS. 5 and 6 ) to maintain the unit  10  on the circumferential path P ( FIG. 2 ). 
         [0043]    Still referring to  FIG. 4 , the spherical guide member  170  is shown at the distal end of guide arm  150 . Thus, it should be understood that as the spherical guide member  170  moves from one horizontal surface of a vehicle of a first height to a second horizontal surface of the vehicle of a second height, the spherical guide member  170  imparts the same movement to guide arm  150  causing it to follow the same movement. The sliding bracket  149  ( FIG. 1 ) at the proximal end of the guide arm  150  not only attaches guide arm  150  to post  110 , but allows the vertical movement of guide arm  150  relative to post  110 . Simultaneously, the movement of guide arm  150  over the varying horizontal contours of vehicle A also causes the arcuate track portion  112  of the tract to make an identical vertical movement relative to post  110 . The design of the track and the arcuate track portion  112  is seamless such that spray head  115  can transition from the lower portion of the track to the arcuate track portion  112  and then further to the guide arm  150  regardless of the position of guide arm  150  relative to post  110 . 
         [0044]    Still referring to  FIG. 4  but also to  FIG. 5 , a portion of the steering wheel  150  can be seen beneath housing  101 . The steering wheel  150  is located adjacent another steering wheel  151  being separated therebetween by a small gap. The steering wheels  150 ,  151  are mounted in a housing  155  and steered by a servomotor  215 . The propulsion wheels  155 ,  156  are mounted on an axle  157 . The axle  157  has a pair of pulleys  158  that are provided rotary power by a pair of belts  159 . The pair of belts  159  are rotated by a pair of pulleys  160  rotated by propulsion motor  205 . Propulsion motor  205  is energized when switch  215  is moved to the on position. 
         [0045]    Referring now particularly to  FIG. 5  shown is a cross-sectional view of the unit  10  taken along line  5 - 5  of  FIG. 4  showing the various electrical components comprising electronic control system  200  (shown schematically in  FIG. 6 ). In one embodiment of the invention, electronic control system  200  ( FIG. 6 ) includes the rechargeable battery  250 , a direct current propulsion motor  205 , an electrical bus  270  for distributing power, and servomotor  215  for steering the unit  10  along the circumferential path P ( FIG. 2 ). The positioning sensors  210 ,  212  previously shown in  FIG. 4  are also part of the electronic control system  200 . 
         [0046]    Referring now to  FIG. 6 , shown is a schematic diagram of the electronic control system  200  of the autonomous vehicle washing and drying unit  10 . An electrical bus  270  distributes electrical power to the propulsion motor  205 , pump  260 , positioning sensors  210 ,  212 , servomotor  215 , and spray head motor  230 . Electrical power is provided to the electrical bus  270  from a rechargeable battery  250 . In one embodiment of the invention, rechargeable battery  250  is a twelve volt battery. Thus, the electronic control system  200  is configured to operate on direct current at twelve volts. Still, the invention is not limited in this regard as one with ordinary skill in the art could design the electronic control system  200  to operate at a different voltage or with alternating current from an onboard alternating current source. 
         [0047]    A power switch  215  selectively controls the electrical power being provided to electrical bus  270 . Thus, when power switch  215  is switched to the on position, electrical bus  270  is energized. Accordingly, propulsion motor  205 , pump  260 , poritioning sensors  210 ,  212 , servomotor  215 , and spray head motor  230  are also energized. There is a fuse  106  between battery  250  and switch  215  which will short out in the case of current overload. 
         [0048]    In one embodiment of the invention, a relay switch  231  is located on spray head motor  230  for reversing the polarity of the voltage applied to spray head motor  230  as spray head motor  230  traverses back and forth along the track ( FIG. 4 ) and the guide arm  150  ( FIG. 3 ). Relay switch  231  could be configured to be manually switched for changing the polarity of the voltage applied to spray head motor  230  by engaging projections (not shown) at the opposing ends of the track ( FIG. 4 ) and guide arm  150  ( FIG. 3 ) reverse the direction of travel of spray head motor  230 . Still, the invention is not limited in this regard. The polarity of the voltage applied to spray head motor  230  could be reversed by sensors (not shown) located at the opposing ends of the track ( FIG. 4 ) and guide arm  150  ( FIG. 4 ) which signal switch  230  when it is desired to reverse the direction of travel of spray head motor  230 . 
         [0049]    The electrical power from electrical bus  270  provided to servomotor  215  is selectively controlled by positioning sensors  210 ,  212 . Positioning sensors  210 ,  212  constantly determine distance information to vehicle A and input this information to servomotor  215 . The distance information from positioning sensors  210 ,  212  must match or no error correcting signal will be sent to servomotor  215  to make any adjustments to steering wheels  150 ,  151 . The ultrasonic sensor model no. UB1000-18GM75-I-V14 available from Pepperl+Fuchs of Twinsburg, Ohio previously described used as positioning sensors  210 ,  212  can be programed to compare distance information between sensors  210 ,  212  before outputting an error correcting signal to a control relay  213  controlling sevomotor  215 . Only when positioning sensors  210 ,  212  are in mutual agreement that unit  10  has deviated from the distance X to vehicle A, and whether the deviation is greater that or less than the distance X, will appropriate steering corrections be made by servomotor  215  to steering wheels  150 ,  151 . The steering corrections are made until positioning sensors  210 ,  212  again determine that unit  10  is at distance X from vehicle A. 
         [0050]    Propulsion motor  205  and pump  260  are continuously energized when power switch  215  is moved to the on position. Propulsion motor  205  propels the unit  10  along the circumferential path P ( FIG. 2 ) as guided by positioning sensors  210 ,  212 , servomotor  215 , and steering wheels  150 ,  151  until power switch  215  is moved to the off position. Similarly, pump  260  pressurizes cleaning fluid from the cleaning solution tank  175  provided to spray head  115  until cleaning solution tank  175  ( FIG. 4 ) is empty or power switch  215  is moved to the off position. Pump  260  will continue to run dry even after cleaning solution tank  175  ( FIG. 4 ) is empty. When pump  260  is run dry, a blast of air is generated which could be used for drying the vehicle A. Pump  260  will continue to operate in this manner until power switch  215  is moved to the off position. 
         [0051]    The battery  250  is required to be re-charged before use by being connected to a source of electrical power such as conventional 120 vac household current. Accordingly, a battery charging circuit  275  is provided connected to a power connector  214  for connecting to the conventional source of 120 vac power. However, the invention is not limited in this regard as the battery charging circuit  275  could be designed to connect to other sources of electrical power. The unit  10  is connected to the 120 vac power source when not in use or sometime prior to use. It is envisioned that the unit  10  will be stored in the garage when not in use and plugged into a 120 vac receptacle located in the garage. A power supply for rectifying and transforming the 120 vac current to direct current at a voltage such as twelve volts could be built into the battery charging circuit  275 . Electrical power from the power supply could be provided to a pre-heater  280  for heating the cleaning fluid in cleaning fluid tank  175  prior to use. The pre-heater  280  would only be energized when the battery charging circuit/power supply  275  is connected to the conventional 120 vac power source. Prior to use, the power connector  214  must be disconnected from the 120 vac or other power source. 
         [0052]    In another embodiment of the invention, electrical power could be provided to electrical bus  270  by an electrical power source (not shown) that generates electrical power onboard unit  10 . The electrical power source could include a fuel cell (not shown) which generates electrical power from hydrogen and oxygen. The electrical power source could also include a conventional electrical generator (not shown). The electrical generator (not shown) could be provided rotary power by a prime mover such as an engine fueled by fuels such as gasoline or ethanol. Alternately, electrical power could be provided to electrical bus  270  by a hybrid of battery  250  power and the electrical power source onboard unit  10 . 
         [0053]    In another embodiment of the invention, the electronic control system  200  could include a microprocessor (not shown) which could input the distance information from positioning sensor  210 ,  212  for further controlling the operation of the servomotor  215  controlling the steering wheels  150 ,  151 . The microprocessor (not shown) could also be used to control the operation of the pump  260  and pump motor  261  arrangement, the recharging of battery  250 , the heater (not shown) preheating the cleaning fluid in cleaning solution tank  175  if so equipped, and the electric motor (not shown) causing the spray head  115  to move back and forth along the track ( FIG. 1 ). The use of a microprocessor (not shown) allows more flexibility to be designed into how and when these components function, either independently or in conjunction with one another. For example, the microprocessor (not shown) could be programmed to control the amount of pressure delivered by spray head  115  as a function of the distance X of unit  10  to vehicle A. The microprocessor could be programmed to allow the user to select the speed of the unit  10  as it circumscribes vehicle A and the length of the wash and drying cycles. The microprocessor (not shown) could be programmed to allow the user to pre-select the number of wash and dry cycles that are desired to be performed. There are many such possibilities for using a microprocessor (not shown) to control the operation of the unit  10  and all are intended to be within the scope of the invention without limitation. 
         [0054]    All of the apparatus, methods and algorithms disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the invention has been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the apparatus, methods and sequence of steps of the method without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain components may be added to, combined with, or substituted for the components described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined.