Abstract:
A panoramic vehicle sunroof system is provided. The panoramic sunroof system has a movable roof panel operable to define a sunroof opening extending generally from a front pillar to a rear pillar. A sunroof controller is configured to receive input indicative of vehicle speed and automatically control movement of the panel. The sunroof controller commands movement of the roof panel from a first open position to a second open position having an opening distance less than in the first position when speed exceeds a threshold. In the second position, wind noise is reduced.

Description:
TECHNICAL FIELD 
     Various embodiments relate to panoramic roof module assemblies for a vehicle. 
     BACKGROUND 
     Vehicle roof assemblies are typically mounted on vehicle bodies to enclose interiors of the vehicles. Various types of roof assemblies have been employed. Some roof assemblies include sunroofs which include may be transparent and/or open to allow occupants to look out the roof the vehicle. Typically, sunroofs only cover a portion of the roof assembly. However, panoramic sunroofs, like those described in U.S. Pat. No. 7,922,242 or 7,828,373 may cover substantially the entire roof to allow passengers to look out almost the entire roof of the vehicle as well as adding aesthetic styling to the vehicle. 
     SUMMARY 
     In one embodiment, a panoramic vehicle sunroof system is provided. The panoramic sunroof system has a movable roof panel operable to define a sunroof opening extending generally from a front pillar to a rear pillar. A sunroof controller is configured to receive input indicative of vehicle speed and automatically control movement of the panel. The sunroof controller commands movement of the roof panel from a first open position to a second open position having an opening distance less than in the first position when speed exceeds a threshold. In the second position, wind noise is reduced. 
     In another embodiment, the panoramic sunroof system includes a vehicle network in communication with a vehicle sensor and sunroof controller wherein the communication network continuously provides a speed signal to the sunroof controller. 
     In another embodiment, the vehicle network includes a CAN bus. 
     In another embodiment, the sunroof system includes a wind deflector. The sunroof panel does not extend above the wind deflector with the sunroof panel is in one of the first and second open positions. 
     In another embodiment, the threshold value is based on the vehicle speed that produces buffeting in a passenger compartment at a critical noise level. 
     In another embodiment, the panoramic sunroof system includes a sunroof actuator in communication with the controller for moving the roof panel between the first panoramic position and the second position. 
     In another embodiment, the actuator is adapted to determine the position of the roof panel. 
     In one other embodiment sunroof system for a vehicle is provided. The sunroof system includes a sunroof panel and a sunroof controller. The sunroof controller is configured to control movement of the sunroof panel from a first panoramic open position to a second open position when a relative wind speed exceeds a threshold value. 
     In another embodiment, the sunroof panel extends from a front pillar to a rear pillar of the a four-door vehicle when the sunroof panel is in a closed position. 
     In another embodiment, the second position has an opening distance less than in the panoramic position. 
     In another embodiment, the panoramic sunroof system includes at least one vehicle sensor in communication with the controller for providing a vehicle speed signal to the controller. 
     In another embodiment, the panoramic sunroof system includes a vehicle communication network having a CAN bus for providing the vehicle speed signal to the controller. 
     In another embodiment, the relative wind speed is based on a vehicle speed. 
     In another embodiment, the threshold value is based on the relative wind speed that produces buffeting in the passenger compartment at a critical noise level. 
     In another embodiment, the second position has an opening distance of at least 430 millimeters. 
     In another embodiment, in the first panoramic position, the sunroof panel overlaps a driver&#39;s field of vision through a rear-view window. 
     In another embodiment, the panoramic sunroof includes a sunroof panel actuator in communication with the controller for moving the panel between the panoramic position and the second position. 
     In another embodiment, the actuator is adapted to determine a position of the panel. 
     In one other embodiment, a method for controlling a panoramic sunroof system is provided. The method adjusts a roof panel from a panoramic open position to a second open position if a relative wind speed exceeds a threshold value. 
     In another embodiment, the method includes receiving a wind speed signal from a CAN bus. A sunroof actuator commands the roof panel to the second position based on the wind speed signal. 
     In another embodiment, the method includes basing the relative wind speed on a vehicle speed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side perspective view of a vehicle having a panoramic roof module assembly according to an embodiment; 
         FIG. 2  is another side perspective view of a vehicle wherein the panoramic roof module is illustrated in a plurality of open positions; 
         FIG. 3  is a rear perspective view of the vehicle having a panoramic roof module assembly from  FIG. 1 ; 
         FIG. 4  is a top perspective view of the vehicle having a panoramic roof module assembly from  FIG. 1 , wherein the panoramic roof module illustrated in a closed position; 
         FIG. 5  is another top perspective view of the vehicle having a panoramic roof module assembly from  FIG. 2 , the panoramic roof module illustrated in one of the open positions; 
         FIG. 6  is a schematic illustration of a panoramic roof module control system provided on a vehicle; and 
         FIG. 7  illustrates a process flowchart for the panoramic roof module control system. 
     
    
    
     DETAILED DESCRIPTION 
     As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely examples of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. 
     Referring to  FIGS. 1 through 5 , a four-door passenger vehicle is illustrated and referenced generally by numeral  10 . The passenger vehicle  10  has a vehicle body  12 , which provides a body structure for the vehicle  10 . As illustrated in  FIG. 1 , the vehicle body structure  12  is for a sedan having four doors including front doors  14  and rear doors  16 . The body structure  12  generally defines an opening for the front doors  14  between an A-pillar  18  and a B-pillar  20 . Likewise, the body structure  12  generally defines the rear doors  16  between the B-pillar  20  and a C-pillar  22 . As in the embodiment illustrated in  FIG. 1 , the B-pillar may be located inboard of the front doors  14  and rear doors  16  so that the B-pillar is not visible from the exterior of the vehicle  10 . The body structure  12  may also include a D-pillar  24  rearward of the C-Pillar  22 . 
     As shown in  FIG. 1 , the vehicle body structure  12  further defines an opening for a roof  26 . As further illustrated in  FIG. 1 , the roof  26  may be a panoramic roof module assembly  28  such that the roof  26  is formed of transparent material, such as glass or polycarbonate, and collectively forms the entire roof  26 . 
     The body structure  12  includes a front cross member  30  which generally extends between the A-pillars  18  on the lateral sides of the vehicle  10 . The body structure  12  also includes a rear cross member  32  which generally extends between the C-pillars  22  and/or D-pillars  24  on the lateral sides of the vehicle  10 . The panoramic roof module  28  extends longitudinally between the front cross member  30  and the rear cross member  32 . The front and rear cross members  30 ,  32 , in addition to providing torsional support to the vehicle  10  may also provide support for the panoramic roof module  28 . 
     The body structure  12  further includes side beam portions  34  which generally extend longitudinally from the A-pillars  18  to the C-pillars  22  along the lateral sides of the vehicle  10 . The side beam portions  34  may be formed integrally with the A-pillar  18  and/or C-pillar  22 , or may be formed as a separate structure extending there between. The panoramic roof module  28  extends laterally between the side beam portions  34 . 
     In the illustrated embodiment, the panoramic roof module assembly  28  allows an occupant to look through the entire roof  26  from an interior of the vehicle  10  for the majority of the panoramic roof  26  so that the panoramic opening is unimpeded by structural members, such as an intermediate cross member between the B-pillars. Typically, four door vehicles require intermediate cross members maintain the structural integrity of the vehicle along the lateral length spanning front and rear doors. The body structure  12  provides structural support against dynamic vehicle forces while still allowing for a moveable panoramic roof panel  26 . 
     A rear-view window  40  is defined laterally between the D-pillars  24 . The rear-view window slopes downward from the rear cross member  32  to a rear structure of the vehicle such as the trunk compartment  44 . Similarly, a front windshield  42  is defined laterally between the A-pillars  18 . The windshield  42  slopes downward from the front cross member  30  to a front structure of the vehicle such as an engine compartment or a hood  46 . 
     As illustrated in  FIG. 2 , the panoramic roof module  28  is operable so that the roof  26  can be opened to reveal a roof opening  50 . The roof  26  may be moved to a plurality of positions corresponding to different sized roof openings  50 . In the fully opened position, illustrated by reference numeral  52 , the roof  26  is moved so that the roof  26  over laps the rear-view window  40 . 
     In the illustrated embodiment in  FIG. 2 , in the fully open position  52 , the roof  26  overlaps at least 80% of the rear-view window  40 . When the roof  26  overlaps the rear-view window  40 , the driver or other occupants can look out the rear over vehicle through both the roof  26  and the rear-view window  40  simultaneously. 
     In the fully open position  52 , a panoramic roof opening extends generally from the front cross member  30  to the rear cross member  32 . The panoramic roof opening extends substantially past the B-pillar  20  so that occupants including passengers in the back seat can look through the panoramic roof opening  54 . The panoramic roof opening is unimpeded by any vehicle structures, such as intermediate cross members between the B-pillars, as in prior art designs. The panoramic opening may have an opening distance of more than 600 millimeters open in the longitudinal direction. In another embodiment, the panoramic opening distance may be from 500 to 550 millimeters. 
     The panoramic roof module  28  may also move the roof  26  to a second position, illustrated by reference numeral  56 . The second position  56  has an opening distance less than the panoramic opening distance. In one embodiment, the second position  56  has an opening distance of 400 to 450 millimeters. In another embodiment, the second position  56  has an opening distance generally 100 millimeters less than the panoramic position  52 . Alternatively, the second position  56  may have an opening distance of 430 millimeters. 
     The roof  26  may be formed with an arc. The roof may be formed with an arc that is substantially similar to the arc of the rear-view window  40 . In the fully open position  52 , the roof panel  26  may be positioned at an offset distance substantially parallel to the rear window  40 . As discussed previously, in at least one embodiment, the roof panel  26  is formed of a polycarbonate material that is transparent. By employing a polycarbonate material for the roof panel  26  the weight for the roof module  28  is reduced when compared to roof assemblies utilizing glass. Additionally, utilization of polycarbonate may permit molded arcuate shape or contour to cost-effectively form the panel  26 . 
     Referring now to  FIGS. 3 through 5 , the panoramic roof module  28  is described more detail. The panoramic roof module  28  includes, a first side rail  62  and a second side rail  64  that extend longitudinally adjacent each of the side beams  38 . Both the first side rail  62  and the second side rail  64  may be elongated along an entire upper side profile of the vehicle  10  between the front cross member  30  and the rear cross member  32 . The first side rail  62  and the second side rail  64  may be mounted to the vehicle body structure  12  along the side beam portions  34 . 
     As illustrated, both the first side rail  62  and the second side rail  64  moveably support the roof panel  26 . The side rails  62 ,  64  may extend past the rear door  16  and C-Pillars  22 . The side rails  62 ,  64  may extend generally parallel to the D-pillar  24  and along the rear-view window  40 . The side rails  62 ,  64  may be formed as exposed tracks  66  adjacent the rear-view window  40  and parallel to the D-pillars  24 . 
     The side rails,  62 ,  64  facilitate movement of the roof panel  26  so that a panoramic opening is created when the roof panel  26  is moved from a closed position, as seen in  FIG. 4  to an opened position, as seen in  FIG. 5 . The side rails  62 ,  64  cooperate with sliding mechanisms mounted to the roof panel  26 . The sliding mechanisms may be mounted to the roof panel  26  in any suitable manner. The sliding mechanisms may slide along the side rails to move the roof panel  26  in a direction indicated by arrow A. In at least one embodiment, the sliding mechanisms are connected to an electrically powered drive unit, such as a motor driven unit, by a cable to move the sliding mechanisms and roof panel  26  along the side rails  62 .  64 . 
     The panoramic roof module  28  also includes a lifting mechanism to translate the roof panel  26  in direction indicated by arrow B. When the roof panel  26  is opened, the roof panel  26  is lifted in a generally vertical direction B. Collectively, the sliding mechanisms and the lifting mechanism in the panoramic roof module  28  move the roof panel to an open position, such as the position shown in  FIG. 5 , without pivoting or tilting of the roof panel  26 . By lifting the panel a relatively low distance and sliding the panel without pivoting, the amount of drag created by the roof panel  26  is minimized. 
     In at least one embodiment, each of the sliding mechanisms and the lifting mechanism may be connected to an electrically powered drive unit, such as a motor driven gear unit, by a cable to move the sliding mechanisms and roof panel  26  along the side rails  62 .  64 . Once the roof panel  26  is in an open position, the motor can be reversed to move the sliding mechanisms and the lifting mechanism to return to the closed position, for example. Any suitable motor or electrically powered drive gear unit can be employed within the scope of the embodiments disclosed herein. 
     The panoramic roof module  28  further includes a wind deflector  70 . Generally, when sunroofs are open, wind noise is produced in the passenger compartment  76  of the vehicle. In addition to the broadband noise, resonant interactions between the exterior air flow and the air inside the vehicle create low frequency pressure fluctuations that produce buffeting or a throbbing noise. At critical frequencies, the buffeting or throbbing can be extremely uncomfortable to the vehicle passengers. 
     The wind deflector  70  is packaged along a forward portion of the panoramic roof module  28  and deploys when the roof panel  26  is moved to an open position. The wind deflector  70  extends above a roof surface  72  when the roof panel  26  is open in order to deflect the air flow away from the panoramic opening  56 . In the embodiments illustrated, the deflector  72  may extend above the roof surface  72  to a height that is generally as high as or higher than a top surface of the roof panel  26  when it is an open position. 
     Wind deflectors generally reduce the broadband noise and also reduce buffeting of air within the vehicle by deflecting air flow away from a sunroof opening. However, in order to effectively reduce the noise and buffeting at higher speeds for a larger panoramic opening  56 , as shown in  FIG. 2 , a wind deflector would be required to extend above the roof surface a significant distance. A large wind deflector may be difficult to package and may be undesirable for aesthetic reasons. 
     In order to reduce been noise and prevent buffeting, the panoramic roof module  28  may move to different open positions based on the vehicle speed.  FIG. 6  illustrates a panoramic roof control system  100  provided on a vehicle  10 . The panoramic roof control system  100  may control the open position of the vehicle  10  based on the vehicle speed, or other environmental factors. 
     As shown, the panoramic roof control system  100  includes a vehicle controller  110  or microprocessor that is operable to process instructions to and from various components of the panoramic roof control system  100 . This microprocessor  110  could be a dedicated processor or the panoramic roof control system  100  could share a controller with other vehicle-based systems. 
     The panoramic roof control system  100  may also be provided with one or more vehicle-based sensors  112 . For example, the sensors  112  may include vehicle speed sensors, wind speed sensors, environmental sensors or any other suitable sensors. For example, a wind speed sensor  112  may detect the resulting wind speed based on the vehicle speed in combination with any ambient wind. 
     The microprocessor  110  may be in communication with a vehicle network  116 . The vehicle network  116  continuously broadcasts data and information to the vehicle-based systems. The vehicle network  116  may be a controlled area network (CAN) bus used to pass data to and from the microprocessor  110  (or components thereof). 
     For example, the vehicle communication network  116  may continuously provide the vehicle speed signal or information for use by dynamic vehicle systems such as the braking system. A roof module controller  120  may also be in communication with the vehicle network  116 . The roof module controller  120  may continuously access the real time vehicle information, such as vehicle speed. If the vehicle&#39;s speed is at a threshold speed above which makes wind buffeting likely or possible, the roof module controller  120  may be moved to the roof panel  26  to position to reduce the wind buffeting effects. Alternatively, a warning may be given to the driver through a visual display  122  in communication with vehicle network  116  or the microprocessor  110 . 
     The roof module controller  120  may be in communication with a roof drive unit  124 . In one embodiment, the roof drive unit  124  moves the roof panel  26  based on information from the vehicle network  116 . The drive unit  124  may be a motor, as discussed previously. A motor may detect the position of the roof panel  26  based on a count of revolutions by the motor. In another embodiment, the panoramic roof control system  100  may include sensors in the panoramic roof module  28  which detect the position of the roof panel  26 . However, any suitable drive unit and/or position detection mechanism may be employed for moving and detecting the position of the roof panel  26 . 
     Turning now to  FIG. 7 , a process  200  for controlling the panoramic roof module  28  is illustrated. The roof module controller may control the roof module if it is in an open position, as represented by block  210 . If the roof module is open, the controller monitors vehicle information from the vehicle communication network. In particular, the controller may monitor the vehicle speed. 
     Based on the vehicle data, the controller determines the vehicle&#39;s relative wind speed, as represented by block  214 . The relative wind speed of the vehicle may be a combination of the vehicle speed and ambient wind speed. If the vehicle is not equipped to sense ambient wind speed, the controller may infer vehicle speed as relative wind speed. 
     Next, the controller determines the roof module position, as represented by block  216 . As discussed above, the controller may count the number of rotations of the motor to determine the roof panel position. However, the controller may use other suitable methods for determining the roof panel position. 
     Finally, the controller may command a drive unit to adjust the roof module position based on the relative wind speed, as represented by block  218 . For example, if the roof panel is in a fully open position, and the vehicle speed exceeds a threshold value, the controller may command the drive unit to move the roof panel to a second position, which decreases the opening distance of the panoramic roof module and reduces wind buffeting. 
     In one example, the panoramic roof module  28  may position the roof panel  26  in the fully open position  52 . When the roof module controller  120  receives information that the vehicle speed is at least 65 km/h, the controller  120  moves the roof panel  26  to the second open position  56  in order to prevent wind buffeting in the passenger compartment of the vehicle  10 . In another example, the controller receives information about vehicle speed and wind speed, the controller  120  may move the roof panel  26  to the second position  56  when the vehicle speed is 70 km/h and no headwind is detected. 
     While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.