Patent Publication Number: US-2023143644-A1

Title: Roof device for vehicle and control method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims under 35 U.S.C. § 119(a) the benefit of Korean Patent Application No. 10-2021-0151799, filed on Nov. 5, 2021, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     (a) Technical Field 
     The present disclosure relates to a roof device for a vehicle and a control method thereof, more particularly, to the roof device that may be opened and closed in a sliding manner or in a hinged manner. 
     (b) Description of the Related Art 
     The contents described in this section merely provide background information for the present disclosure and do not constitute the prior art. 
     As autonomous driving technology of vehicles has developed, the understanding of a vehicle has expanded from simply a mode of transportation to now encompassing a living space. In particular, the arrangement of an indoor space in a vehicle is becoming a factor that contributes to vehicle competitiveness. An indoor space of a vehicle is partitioned from the outside by a vehicle body, a windshield, a window, a roof, and the like. Since a conventional vehicle has an indoor space fixedly determined by a vehicle body or the like, it is not possible to change the indoor space in response to an occupant&#39;s lifestyle. 
     SUMMARY 
     In view of the above, the present disclosure provides a roof device for a vehicle configured to be opened and closed in a sliding manner or in a hinged manner to change an indoor space of the vehicle, e.g., to correspond to a lifestyle of an occupant. 
     In addition, the control method of the roof device according to an embodiment of the present disclosure has an effect of improving fuel efficiency of the vehicle by adjusting the degree of opening of the roof device based on a speed of the vehicle. 
     The problems to be solved by the present disclosure are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description. 
     As described above, the roof device according to an embodiment of the present disclosure is configured to be opened and closed in a sliding manner or in a hinged manner, so that an indoor space of the vehicle may be changed to correspond to a lifestyle of an occupant. 
     A roof device for a vehicle may include: a plurality of plate members; and a frame coupled to a vehicle body and configured to support the plurality of plate member, where at least a portion of the frame is configured to rotate around its edge, and at least one of the plurality of plate members is configured to slide along an inner edge of the frame. 
     In addition, the control method of the roof device according to an embodiment of the present disclosure has an effect of improving fuel efficiency of the vehicle by adjusting the degree of opening of the roof device based on a speed of the vehicle. 
     A control method of a roof device for a vehicle may include a control unit for controlling a first motor configured to supply power to a power transmission mechanism such that at least one of a plurality of plate members slides on supporting members, and control a second motor configured to supply its power to at least one of the supporting members to rotate the at least one of the supporting members around its edge, where the control method includes steps of: receiving, by the control unit, a speed of the vehicle from a wheel speed sensor; determining, by the control unit, whether the vehicle is driving; and controlling, by the control unit, a rotation amount of each of the first motor and the second motor, so that a change in the rotation amount of the first motor with respect to a change in the speed of the vehicle, and a change in the rotation amount of the second motor with respect to a change in the speed of the vehicle have a value less than or equal to 0, when it is determined that the vehicle is driving. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a top view illustrating a roof device for a vehicle according to an embodiment of the present disclosure. 
         FIG.  2    is a side cross-sectional view illustrating a roof device for a vehicle according to an embodiment of the present disclosure. 
         FIG.  3    is a perspective view illustrating a driving state of a power transmission mechanism according to an embodiment of the present disclosure. 
         FIG.  4    is a perspective view illustrating a driving state of a second motor according to an embodiment of the present disclosure. 
         FIG.  5    is a side cross-sectional view illustrating a driving state of a roof device for a vehicle according to an embodiment of the present disclosure. 
         FIG.  6    (includes FIGS. A-D) is a perspective view illustrating a state in which a roof device for a vehicle is opened by moving a plate member according to an embodiment of the present disclosure. 
         FIG.  7    (includes  FIGS.  7 A-D ) is a perspective view illustrating a state in which a roof device for a vehicle is opened by rotating a supporting member according to an embodiment of the present disclosure. 
         FIG.  8    is a side view illustrating a tent cover and a pole according to an embodiment of the present disclosure. 
         FIG.  9    is a block diagram schematically illustrating a configuration of a roof device for a vehicle according to an embodiment of the present disclosure. 
         FIG.  10    is a flowchart illustrating a control method according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Throughout the specification, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements. In addition, the terms “unit”, “-er”, “-or”, and “module” described in the specification mean units for processing at least one function and operation, and can be implemented by hardware components or software components and combinations thereof. 
     Further, the control logic of the present disclosure may be embodied as non-transitory computer readable media on a computer readable medium containing executable program instructions executed by a processor, controller or the like. Examples of computer readable media include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart cards and optical data storage devices. The computer readable medium can also be distributed in network coupled computer systems so that the computer readable media is stored and executed in a distributed fashion, e.g., by a telematics server or a Controller Area Network (CAN). 
       FIG.  1    is a top view illustrating a roof device for a vehicle according to an embodiment of the present disclosure. 
     Referring to  FIG.  1   , a roof device  100  for a vehicle according to an embodiment of the present disclosure includes all or some of plate members  111  to  114 , a frame  130 , a power transmission mechanism  150 , a second motor  170 , and a sealing member  190 . 
     A window for mounting the frame  130  is perforated on a roof of the vehicle. In the present disclosure, a state in which the roof device  100  covers the window to partition the outside of the roof and the interior of the vehicle is referred to as a closed state of the roof device  100 . A state in which the roof device  100  partially covers the window or does not cover the window is referred to as an open state of the roof device  100 . The frame  130  is mounted on the periphery of the window, and a plurality of plate members  111  to  114  are mounted on an inner edge of the frame  130 . At least one of the plurality of plate members  111  to  114  are mounted to be slidable on the inner edge of the frame  130 . An occupant of the vehicle may adjust a position of the frame  130  or the plate members  111  to  114  so that the plurality of plate members  111  to  114  completely cover the roof of the vehicle. Here, the occupant adjusting the position may include a case in which a driving signal for driving a motor configured for the occupant to adjust the position of supporting members  131  to  133  or the plate members  111  to  114  is generated. In order to prevent the roof device  100  from being unintentionally opened or closed by an external force, the supporting members  131  to  133  or the plate members  111  to  114  may be configured to be slidable only by a driving signal. 
     The roof device  100  according to an embodiment of the present disclosure may include four plate members. In the present disclosure, the four plate members  111  to  114  include a first plate member  111 , a second plate member  112 , a third plate member  113 , and a fourth plate member  114 . However, the roof device  100  of the present disclosure is not limited to having four plate members  111  to  114 . For example, the roof device  100  may include two plate members. The roof device  100  may adjust positions of the first to fourth plate members  111  to  114  by allowing the first to fourth plate members  111  to  114  to slide on the inner edge of the frame  130 . The first to fourth plate members  111  to  114  may be configured to completely cover the window of the roof in a state in which the first to fourth plate members  111  to  114  are sequentially arranged. The first to fourth plate members  111  to  114  may each be formed to have a rectangular shape. The first to fourth plate members  111  to  114  may be formed of a material allowing light to be transmitted therethrough. For example, the first to fourth plate members  111  to  114  may be formed of tempered glass. Outer or inner surfaces of the first to fourth plate members  111  to  114  may be coated with ultraviolet (UV) blocking paint. 
     In the present disclosure, the front, rear, left, and right sides of the vehicle refer to a front side of the vehicle, a rear side of the vehicle, a left side of the vehicle, and a right side of the vehicle, respectively. In the present disclosure, a direction in which the front and rear of the vehicle are connected is referred to as a longitudinal direction, and a direction in which the left and right sides of the vehicle are connected is referred to as a transverse direction. A transverse length of the first to fourth plate members  111  to  114  may be formed to correspond to a transverse length of a hollow (hereinafter, ‘hollow of the frame’) bordering the inner edge of the frame  130 . The sum of the lengths of the first to fourth plate members  111  to  114  in the longitudinal direction may correspond to a longitudinal length of the hollow so that the interior of the vehicle is partitioned from an external space in a state in which the first to fourth plate members  111  to  114  are sequentially arranged in the longitudinal direction. In the drawings of the present disclosure, it is illustrated that the first to fourth plate members  111  to  114  have the same shape and are arranged in the longitudinal direction. However, the roof device  100  of the present disclosure is not limited thereto. For example, the first to fourth plate members  111  to  114  may have different shapes, or the first to fourth plate members  111  to  114  may be sequentially arranged in a transverse direction. 
       FIG.  2    is a side cross-sectional view illustrating a roof device according to an embodiment of the present disclosure. 
     Referring to  FIG.  2   , in a closed state of the roof device  100 , the plurality of plate members  111  to  114  may be disposed to be spaced apart from each other in a height direction of the vehicle (hereinafter, ‘height direction’). The roof of the vehicle may be opened by sliding the plurality of plate members  111  to  114  spaced apart from each other in the height direction to overlap each other. The first plate member  111  and the second plate member  112  may be arranged to be spaced apart from each other in the height direction, and the third plate member  113  and the fourth plate member  114  may be arranged to be spaced apart from each other in the height direction. The first and fourth plate members  111  and  114  may be disposed at the same height as each other, and the second and third plate members  112  and  113  may be disposed at the same height as each other. The second and third plate members  112  and  113  may be disposed higher than the first and fourth plate members  111  and  114 . The second plate member  112  may be moved to be superimposed on an upper side of the first plate member  111 , or the third plate member  113  may be moved to be superimposed on an upper side of the fourth plate member  114  to open a portion of the roof device  100 . 
       FIG.  3    is a perspective view illustrating a driving state of a power transmission mechanism according to an embodiment of the present disclosure. 
       FIG.  4    is a perspective view illustrating a driving state of a second motor according to an embodiment of the present disclosure. 
       FIG.  5    is a side cross-sectional view illustrating a driving state of a roof device according to an embodiment of the present disclosure. 
     Referring to  FIGS.  1  to  5   , the frame  130  is coupled to a vehicle body to support the plurality of plate members  111  to  114 . The frame  130  is configured such that at least one of the plate members  111  to  114  may slide along an inner edge of the frame  130 . In order for the frame  130  to support the plate members  111  to  114 , an accommodation groove corresponding to an edge shape of the plate members  111  to  114  may be formed along the inner edge of the frame  130 . The accommodation groove is formed so that the plate members  111  to  114  are guided on the accommodation groove to slide in the longitudinal direction. In order to support the plurality of plate members  111  to  114  spaced apart from each other in the height direction, two accommodation grooves spaced apart from each other in the height direction may be formed on the inner edge of the frame  130 . 
     The frame  130  may include a plurality of supporting members  131  to  133 . A combination of the plurality of supporting members  131  to  133  is configured to form a perimeter of the window. The plurality of supporting members  131  to  133  may be configured to support a combination of different plate members  111  to  114  in a state in which the roof device  100  is closed. The plurality of supporting members  111  to  113  may include a first supporting member  131 , a second supporting member  132 , and a third supporting member  133  supporting the first plate member  111 , the second plate member  112 , the third plate member  113 , and the fourth plate member  114  in a state in which the roof device  100  is closed. The first supporting member  131  is disposed on one side of the second supporting member  132 , and the third supporting member  133  is disposed on an opposite side of the second supporting member  132 . Accommodation grooves for receiving edges of the plate members  111  to  114  are formed along an inner edge of the first to third supporting members  131  to  133 . The first supporting member  131  and the third supporting member  133  may have two accommodating grooves spaced apart from each other in the height direction on an inner side thereof to support two plate members. The second plate member  112  supported by the second supporting member  132  may slide toward the first supporting member  131  and may be supported by the first supporting member  131  together with the first plate member  111 . The third plate member  113  supported by the second supporting member  132  may slide toward the third supporting member  133  and may be supported by the third supporting member  133  together with the fourth plate member  114 . When the second or third plate member  112  or  113  overlaps the first or fourth plate member  111  or  114 , respectively, the vehicle roof is opened. 
     Referring to  FIG.  3   , the roof device  100  according to an embodiment of the present disclosure is configured to slide at least one of a plurality of plate members with respect to the frame  130  using power of a first motor  151 . The power transmission mechanism  150  may configured to transmit power of the first motor  151  to at least one of the plurality of plate members  111  to  114  to let the plate member  111  to  114  slide along the inner edge of the frame  130 . The power transmission mechanism  150  may include a driving gear  153  connected to the first motor  151  and a rail gear  155  coupled to at least one of the plurality of plate members. The driving gear  153  is configured to rotate using rotational power of the first motor  151 . The rail gear  155  is coupled to at least one of the plurality of plate members and is engaged with the driving gear  153 . When the driving gear  153  rotates together with the first motor  151 , the rail gear  155  engaged with the driving gear  153  moves. Accordingly, the plate member on which the rail gear  155  is mounted may slidably move on the frame  130 . The rail gear  155  may be mounted on the edge of each of the second and third plate members  112  and  113 . Although the rail gear  155  is illustrated as being mounted on the left side of the vehicle in  FIG.  3   , the roof device  100  of the present disclosure is not limited thereto. For example, the rail gear  155  may be mounted on the left side of the second plate member  112 , and the rail gear  155  may be mounted on the right side of the third plate member  113 . The power transmission mechanism  150  of the present disclosure is not limited to such a configuration. The power transmission mechanism  150  may have, for example, a piston operated by hydraulic pressure. 
     Referring to  FIG.  4   , at least a portion of the frame  130  is configured to rotate around its edge. The first supporting member  131  and the third supporting member  133  may be configured to rotate around its edge in a width direction of the vehicle body. The roof device  100  may include a second motor  170  for rotating at least a portion of the frame  130  around its edge. At least a portion of the frame  130  may be coupled to the vehicle body using a hinge, and the hinge may be coupled to a shaft of the second motor  170 . The vehicle front frame  130  of the first supporting member  131  and the vehicle rear frame  130  of the third supporting member  133  may be coupled to the vehicle body using a hinge. A damper  185  having both ends connected to the vehicle body and the first supporting member  131  or the third supporting member  133  may be mounted. The damper  185  may prevent a safety accident, such as a hand being caught due to abrupt closing of the first supporting member  131  or the third supporting member  133 . The first supporting member  131  may rotate around its edge on the opposite side of the second supporting member  132 . The third supporting member  133  may rotate around its edge on the opposite side of the second supporting member  132 . The first supporting member  131  according to an embodiment of the present disclosure may rotate in association with rotation of the second motor  170 . The third supporting member  133  may also rotate in association with rotation of the second motor  170 . Respective end portions of the supporting members may be inclined such that an end portion of the first supporting member  131  adjacent to the second supporting member  132  is located above an end portion of the second supporting member  132  adjacent to the first supporting member  131 . This is to prevent a free end of the first supporting member  131  from being caught by the second supporting member  132  and rotating. Similarly, respective end portions of the supporting members may be inclined such that an end portion of the third supporting member  133  adjacent to the second supporting member  132  is located above an end portion of the second supporting member  132  adjacent to the third supporting member  133 . 
     Referring to  FIG.  5   , the second plate member  112  slides toward the first supporting member  131  and is disposed above the first supporting member  131 . As a result, a portion of an area covered by the second supporting member  132  is opened. As the driving gear  153  connected to the second plate member  112  rotates counterclockwise, the second plate member  112  may be moved toward the first supporting member  131 . The third plate member  113  is disposed above the first plate member  111 . In a state in which the vehicle roof is closed, the third plate member  113  may slide upwardly of the first plate member  111  to be disposed above the fourth plate member  114 . As the driving gear  153  connected to the third plate member  113  rotates clockwise, the third plate member  113  may be moved toward the third supporting member  133 . The hinge disposed at the rear of the third supporting member  133  rotates clockwise. When the second motor  170  rotates clockwise, the hinge coupled to a shaft of the second motor  170  may rotate clockwise. Accordingly, the third supporting member  133  rotates upwardly of the vehicle body together with the third and fourth plate members  113  and  114 . 
     Referring to  FIGS.  1  to  5   , the frame  130  may be equipped with a sealing member for sealing the interior of the vehicle. The sealing member may be disposed to seal portions between the respective plate members when the roof device  100  is closed. The sealing member may not be mounted on the second supporting member  132 . Accordingly, rotation of the first and third supporting members  131  and  133  is facilitated, and when the roof device  100  is opened, the sealing member does not cross the middle of the window. The sealing member may be coupled to each of a free end of the first supporting member  131  and a free end of the third supporting member  133 . 
       FIG.  6    is a perspective view illustrating a state in which the roof device  100  is opened by moving a plate member according to an embodiment of the present disclosure. 
       FIG.  7    is a perspective view illustrating a state in which the roof device  100  is opened by rotating a supporting member according to an embodiment of the present disclosure. 
     The vehicle roof may be opened and closed by pushing the plate member, and the roof may be opened and closed by rotating the supporting member. An open shape of the roof device  100  may be different by changing a rotation angle of the supporting members  131  to  133  or by changing positions of the plate members  111  to  114 . An open shape of the roof device  100  may be selected by a vehicle occupant or an autonomous driving safety system of the vehicle. 
       FIGS.  6  and  7   ( a ) show a state in which the roof device  100  is closed. In  FIG.  7 ( a ) , the first to fourth plate members  111  to  114  are sequentially disposed from the front to the rear of the vehicle.  FIG.  6 ( b )  shows a state in which the second plate member  112  is supported by the first supporting member  131 . The second plate member  112  is positioned above the first plate member  111  so that a portion of the roof is opened.  FIG.  6 ( c )  shows a state in which the third plate member  113  is supported by the third supporting member  133 . The third plate member  113  is positioned above the fourth plate member  114  so that a portion of the roof is opened.  FIG.  6 ( d )  shows that the first supporting member  131  supports the first and second plate members  111  and  112 , and the third supporting member  133  supports the third and fourth plate members  113  and  114 . In this case, the roof device  100  is opened by an area corresponding to an area of the second plate member  112  and the third plate member  113 . 
       FIG.  7 ( a )  illustrates a state in which the first supporting member  131  rotates upwardly of the vehicle while supporting the first and second plate members  111  and  112 .  FIG.  7 ( c )  shows a state in which the roof device  100  is maximally opened. The roof device  100  is maximally opened when the first supporting member  131  supports the first and second plate members  111  and  112 , the third supporting member  133  supports the third and fourth plate members  113  and  114 , and the supporting members  131  and  133  are rotated upwardly of the vehicle to the maximum. The first supporting member  131  may be configured to be disposed parallel to a windshield of the vehicle in a state of being maximally rotated. 
       FIG.  8    is a side view illustrating a tent cover and a pole according to an embodiment of the present disclosure. 
     Referring to  FIG.  8   , the roof device  100  may include a pole  710  having both ends respectively mounted on the first supporting member  131  and the third supporting member  133  and a tent cover (tent cover,  730 ) supported by the first supporting member  131 , the pole  710 , and the third supporting member  133  in a state in which the vehicle roof is completely opened. 
     One of the technical effects of the roof device  100  according to an embodiment of the present disclosure is that the indoor space of the vehicle may be further expanded using the sliding method and the hinged method, compared with a case in which only the sliding method or only the hinged method is used. In this way, the roof device  100  may be opened in various forms according to the preference of the occupant. In addition, the occupant may open the roof of the vehicle simply by inputting a driving signal to the input device by the power transmission mechanism  150  and the second motor  170 . The roof device  100  may be controlled by a control method of the roof device  100  to be described below. 
       FIG.  9    is a block diagram schematically illustrating a configuration of a roof device according to an embodiment of the present disclosure. 
       FIG.  10    is a flowchart illustrating a control method according to an embodiment of the present disclosure. 
     Referring to  FIGS.  1  to  10   , the first motor  151  supplies power to the power transmission mechanism  150 . The power transmission mechanism  150  is configured to move at least one of the plurality of plate members from any one of the plurality of supporting members to the other of the supporting members. The second motor  170  is configured to let at least one of the supporting members rotate around its edge. In the present disclosure, a rotation amount of each motor when the roof device  100  is closed may be set to zero. The power transmission mechanism  150  may be configured to increase the degree of opening of the roof as the rotation amount of the first motor  151  increases. A control unit  910  may control the rotation amount of the first motor  151  and the second motor  170  to adjust an opening state of the roof device  100 , that is, the degree of opening or the form of opening. 
     The vehicle occupant may input an automatic control driving signal of the roof device  100  to an input unit  930 . The driving signal may be, for example, an electrical signal generated as the occupant touches a display unit  940  disposed on the front of the driver&#39;s seat. The vehicle occupant may execute an automatic control process by inputting a driving signal. In contrast, when the vehicle occupant does not want automatic control, the vehicle occupant may input a driving stop signal or may not input a driving signal to stop the automatic control process. In step S 1010 , the control unit  910  receives an automatic control driving signal input by the vehicle occupant from the input unit  930 . In step S 1020 , the control unit  910  receives a vehicle speed value from a wheel speed sensor  920 . In step S 1030 , the control unit  910  determines whether the vehicle is driving based on the received speed value. 
     When it is determined that the vehicle is driving, the control unit  910  may perform a process (S 1035 ) of controlling the display unit  940  of the vehicle to inform the occupant that the opening amount of the roof device  100  is limited. The display unit  940  may be a portion of audio, video, navigation (AVN) of the vehicle. The control unit  910  controls a rotation amount of the first motor  151  so that the change in the amount of rotation of the first motor  151  with respect to the change in a speed of the vehicle has a value less than or equal to 0. In addition, the control unit  910  controls the rotation amount of the second motor  170  so that the change in the amount of rotation of the second motor  170  with respect to the change in the speed of the vehicle has a value less than or equal to 0 (S 1041  to S 1044 ). According to such a control method, as the speed of the vehicle increases, the amount of opening of the roof may be reduced. Here, the amount of opening is a value that changes depending on a rotation angle of the supporting member and a position of the plate member and may be understood to have a greater value as the rotation angle of the supporting member increases and as an area in which the plurality of plate members overlap each other increases. 
     When it is determined that the vehicle is not driving, the occupant may adjust the rotation angle of the supporting member or a sliding distance of the plate member according to his/her preference using the control method of the present disclosure. Here, the sliding distance refers to a distance from the position of each plate member in a state in which the roof device is closed. The occupant inputs information on the rotation angle of the supporting member and information on the sliding distance of the plate member to the input unit  930 . When an animation representing the roof device  100  is displayed on the display unit  940  of the vehicle, the occupant may input information on the rotation angle of the supporting member or the sliding distance of the plate member by moving the displayed supporting member or the plate member by touching a screen. Information on the rotation angle or the like may be input. In step S 1051 , the control unit  910  receives the information on the rotation angle of the supporting member and the sliding distance of the plate member input by the occupant from the input unit  930 . In step S 1052 , the control unit  910  controls the amount of rotation of the first motor  151  and the second motor  170  according to the information on the rotation angle of the supporting member and the information on the sliding distance of the plate member. Here, the rotation amount of the first motor  151  and the second motor  170  may be a rotation amount that allows the roof device  100  to be opened as intended by the occupant. 
     When it is determined that the vehicle is driving, the control unit  910  may determine whether the occupant of the vehicle is at risk based on the speed of the vehicle (S 1041 ). Whether the occupant of the vehicle is at risk may be determined by a safety logic of the autonomous driving system of the vehicle. Whether or not the occupant is at risk may be determined using a slope of a road, a pavement condition of the road, a speed of the vehicle, a distance to a nearby vehicle, the weather, and the like. For example, when the speed of the vehicle is greater than or equal to a preset speed and the slope of the road is downhill in a traveling direction of the vehicle, the control unit  910  may determine that the occupant of the vehicle is at risk. When it is determined that the occupant is at risk in step S 1041 , the control unit  910  controls the first motor  151  and the second motor  170  to close the roof of the vehicle (S 1043 ). In contrast, when it is determined that the occupant is not at risk, the control unit  910  determines whether the vehicle is driving at a high speed based on a speed value of the vehicle (S 1042 ). 
     When it is determined that the vehicle is not driving at a high speed, the control unit  910  controls the rotation amount of the first motor  151  so that the change in the amount of rotation of the first motor  151  with respect to the a change in a speed of the vehicle has a value less than or equal to 0. In addition, the control unit  910  controls the rotation amount of the second motor  170  so that the change in the amount of rotation of the second motor  170  with respect to the change in the speed of the vehicle has a value less than or equal to 0 (S 1044 ). Air resistance increases as the speed of the vehicle is higher and as the area of the vehicle of a component perpendicular to a driving direction of the vehicle increases. As the air resistance increases, fuel efficiency of the vehicle decreases. Accordingly, according to the control method of an embodiment of the present disclosure, the area of the vehicle of the component perpendicular to the driving direction of the vehicle decreases as the speed of the vehicle increases, thereby preventing an excessive reduction of fuel efficiency of the vehicle. 
     When it is determined that the vehicle is driving at a high speed, the control unit  910  controls the second motor  170  so that the rotation amount of the second motor  170  is a minimum rotation amount. That is, when it is determined that the vehicle is driving at a high speed, the control unit  910  prevents the supporting member from rotating upwardly of the vehicle. According to the control method of the roof device  100 , the opening amount of the roof is limited in a high-speed driving situation, so that the vehicle may safely transport an occupant.