Abstract:
Disclosed herein are a system and a method for controlling a rear vision assembly (RVA) of a vehicle, the system comprising a sender, receivers, an orientation device, a controller, and a motor. At least one said receiver disposed at the RVA may receive a reference signal from the sender to generate a relative positioning signal. The orientation device, disposed at the RVA, senses the orientation thereof in the three-dimensional space. Based on the relative positioning signal, the controller determines a relative position of the RVA and the sender and compares it with a default relative position, in addition to comparing the sensed orientation with a default orientation, thus generating a driving signal that directs the motor to restore the RVA to its default configuration when the determined relative position has deviated from the default for a predefined time and the sensed orientation deviates from the default.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 102143257 filed in Taiwan, R.O.C. on Nov. 27, 2013, the entire contents of which are hereby incorporated by reference. 
       TECHNICAL FIELD 
       [0002]    The present disclosure relates to the provision of rear vision to a vehicular driver, particularly to a system and a method for automatically maintaining the default configuration of a rear vision assembly. 
       BACKGROUND 
       [0003]    In a vehicle, a rear-view mirror, if any, shows the driver what is (approximately) behind him/her, whereas a side-view or wing mirror reflects the exterior side to which it is attached. Despite the gradual prevalence of reverse radars and rear cameras in the vehicular market, rear- and side-view mirrors, for their simplicity, remain over the years the most familiar and dependable standard safety equipment to drivers. 
         [0004]    Adjusting a rear- or side-view mirror, especially its orientation, depends on the build, habits, and driving pose of the vehicular operator as an observer. A mirror misconfigured obviously fails to display a proper view of the rear. A mirror affixed to the outside of the vehicle, however, protrudes from and usually forms the widest part of the vehicle. It is not uncommon then that on the road such a mirror is bent or damaged due to collision with another vehicle, or due to the inertial difference between the vehicular body and the mirror induced by rough or neglected pavement. Even an interior mirror is likely to divert from the preferred configuration because of the movements of the driver or passengers in a limited space. The most recommended course to restore the mirror to its default is for the driver to pull over and adjust it manually. Nevertheless, drivers are reluctant or unable to halt their trip, and as a result often jeopardize themselves distractedly making adjustments. 
       SUMMARY 
       [0005]    In light of the above, the present disclosure provides a system and a method for controlling a rear vision assembly of a vehicle. The rear vision assembly, usually a rear- or side-view mirror, includes a reflecting component or a set thereof along with the likes of a frame, shaft, stand, or pedestal for support, extension, enclosure, etc. 
         [0006]    The system for controlling vehicular rear vision, as provided by this disclosure, comprises a sending device, a plurality of receiving devices, an orientation device, a control device, and a motor. The receiving devices, the orientation device, and the motor are disposed at the rear vision assembly. The sending device is adapted for sending a reference signal. The receiving devices are adapted for receiving the reference signal to generate a relative positioning signal. The orientation device is adapted for sensing an orientation of the rear vision assembly in the three-dimensional space. The control device is adapted for determining a first relative position of the rear vision assembly and the sending device based on the relative positioning signal. The control device compares the first relative position with a default relative position and compares the orientation with a default orientation, in order to generate a driving signal, whereby the motor adjusts the rear vision assembly. In particular, the driving signal is adapted for directing the motor to restore the rear vision assembly to the default relative position and orientation when the determined first relative position has deviated from the default for a predefined time and the sensed orientation is also different from the default. 
         [0007]    In the method for controlling vehicular rear vision, as provided by this disclosure, a reference signal from a sending device is received to generate a relative positioning signal, based on which a first relative position of the rear vision assembly and the sending device is determined. Meanwhile, an orientation of the rear vision assembly in the three-dimensional space is sensed. The rear vision assembly is adjusted to a default relative position and a default orientation when the determined first relative position has deviated from the default for a predefined time and the sensed orientation is also different from the default. 
         [0008]    In short, the default configuration of the rear vision assembly is memorized in the system and method of the present disclosure and automatically restored to when it is discovered that the assembly has gone askew. Road conditions vary, hence multiple factors, including a reference object (the sending device), its relative position to the assembly, the predefined time, and the conditional driving signal, are considered to avoid misjudgment. Furthermore, in some embodiments, the rear vision assembly is actively adjusted to provide a more useful view, based on the direction to which the vehicle turns. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0009]    The present disclosure will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only and thus are not limitative of the present disclosure and wherein: 
           [0010]      FIG. 1  illustrates the disposition of a sending device and receiving devices, in accordance with an embodiment of the present disclosure. 
           [0011]      FIG. 2  is a high-level block diagram of a system for controlling vehicular rear vision, in accordance with an embodiment of the present disclosure. 
           [0012]      FIG. 3  illustrates the disposition of a sending device, a setup button, and receiving devices, in accordance with an embodiment of the present disclosure. 
           [0013]      FIGS. 4 ,  5 , and  6  are flowcharts of methods for controlling vehicular rear vision, in accordance with various embodiments of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawings. 
         [0015]    Please refer to  FIG. 1 , which shows in part a steering head of a motorcycle. The steering head may include a directional indicator  2 , a headlamp  3 , a handlebar  4 , and most importantly a rear vision assembly (RVA)  1  serving as a wing mirror. The receiving devices  53   a,    53   b,  and  53   c  (three of them as an example) of a system of the present disclosure may be mounted on top of the RVA  1  and adapted for receiving a wireless reference signal from a sending device  51 . The reference signal may be an infrared one; as such, on the steering head the sending device  51  needs to be disposed at a place other than the RVA  1  and where line-of-sight propagation of the signal to the receiving devices is not obstructed. For instance, in  FIG. 1 , the sending device  51  is located near where the dials usually are, the dashed arrow signifying the path of propagation of the reference signal. Since it is the receiving device  53   b  that happens to be on the path and receives the signal (or detects the strongest level of the signal among the three), the direction of the reference signal falls close to the center line of the RVA  1  by default. If the receiving device  53   a  on the outside received the signal instead, then the RVA  1  might have been bent counterclockwise when viewed from the top. If the signal levels at both receiving devices  53   b  and  53   c  were roughly equal, then a slight clockwise tilt of the RVA  1  toward the front of the vehicle could be deduced. If the reference signal was not detected by any of the receiving devices, the RVA  1  might be severely bent, or there was a malfunction within the system. The present disclosure does not prescribe the exact number and locations of the receiving devices, other than that they must be disposed at the RVA  1 . Beyond the line-of-sight requirement, the sending device  51  may also be placed anywhere with a fixed relative position to the RVA  1 , barring the effects of an unforeseeable external force, if installed on a motorcycle or any other vehicle. 
         [0016]    Please refer to  FIG. 2  with regard to  FIG. 1 . As shown in the block diagram of the system  5 , the receiving device  53   b  picking up the reference signal generates a relative positioning signal for the control device  57 , while the break line represents the other receiving devices. The control device  57  determines the relative position of the sending device  51  and the RVA  1  based on the signal generated by one or more of the receiving devices, as described in the previous paragraph. The orientation device  55 , mounted on or embedded in the RVA  1 , may be a gyroscope adapted for sensing and reporting to the control device  57  the current orientation of the RVA  1  in the three-dimensional space. The control device  57 , disposed at the vehicle (inside or outside the RVA  1 ), comprises a storage module  571  along with a microcontroller, a processor, or a comparator. The storage module  571 , which may include a flash memory or other types of electrically erasable programmable read-only memory (EEPROM), records a default relative position of the 
         [0017]    RVA  1  and the sending device  51 , and a default orientation of the RVA  1  in the three-dimensional space. The default relative position and orientation may be factory-programmed or configured by the operator of the vehicle. When the relative position determined by the control device  57  disagrees with the default relative position, and the default orientation does not match the current orientation sensed by the orientation device  55 , the RVA  1  is deemed to be at a slant, and under certain conditions (detailed later) the control device  57  drives the motor  59  to adjust the frame, stand, or the reflecting component (set) of the RVA  1  in order to restore it to its default configuration. 
         [0018]    Please refer to  FIG. 3 , which depicts a symmetric pair of systems for controlling vehicular rear vision in another embodiment. The sending device  51  in this case is not affixed to the steering head or the body of the motorcycle, but to a wearable accessory of the rider, e.g. the helmet  6 , for simulating the rider&#39;s line of sight when observing the RVA  1 . The operator of a travelling vehicle constantly moves his/her head around to keep an eye on road conditions, changing the relative position of the sending device  51  and the RVA  1  frequently. Though unpredictable, this is not out of the ordinary. Upon detecting that the current and default relative positions disagree, therefore, the control device  57  must consider also whether the disagreement has been, say, for a predefined time. Only when the disagreement is confirmed to be persistent does the control device  57  make subsequent decisions or drive the motor  59 . 
         [0019]    Please note that in  FIG. 3  and on the helmet  6  there is also a setup button  54  for assisting the control device  57  in recording the default relative position and orientation. Before setting off, the rider may adjust the length, angle, etc of the frame, stand, or reflecting component of the RVA  1  to an ideal configuration, look toward the normal travelling direction of the vehicle, and press the setup button  54  to write the instantaneous orientation of the RVA  1  and relative position of the sending device  51  and the RVA  1  (equivalent to the rider&#39;s line of sight) into the storage module  571 . The setup button  54  does not have to be on the helmet  6 , and is merely an example of a setup mechanism. On the vehicle the setup button  54  may be disposed anywhere readily accessible to the operator maintaining a regular posture, such as beside the dials, on the RVA  1 , or on the sending device  51 . A setup mechanism not incorporating the setup button  54  may, for instance, employ gestures associated with the sending device  51  and one or more receiving devices. As an example, the rider may rhythmically block or let through the propagation of the reference signal with her hand after a relative position is established between the sending device  51  and the receiving device  53   b,  influencing the generated relative positioning signal, whereby the control device  57  commences writing into the storage module  571 . 
         [0020]    Please refer to  FIG. 4  with regard to  FIG. 2 . As shown in the flowchart, in step  5401  the storage module  571  records a default relative position of the RVA  1  and the sending device  51 . In step S 402 , the storage module  571  records a default orientation of the RVA  1  in the three-dimensional space. One or more of the receiving devices  53   a,    53   b,  and  53   c  receives the reference signal from the sending device  51  to generate the relative positioning signal in step S 403 . In step S 405 , the orientation device  55  senses an orientation of the RVA  1  in the three-dimensional space. Please note that steps S 403  and S 405  are not necessarily carried out in that order and together they represent a monitoring mode of the system  5 . The control device  57  determines, based on the relative positioning signal, a first relative position of the present between the RVA  1  and the sending device  51 , and determines in step S 407  whether the first relative position matches the default. If it does, monitoring continues in step S 403  or S 405 ; if not, step S 409  is executed. In step S 409 , the control device  57  determines whether the first relative position has deviated from the default for a predefined time. If so, step S 411  is executed; if the predefine time has not yet expired, the flow returns to step S 403  or S 405 . In step S 411 , the control device  57  determines whether the current orientation of the RVA  1  agrees with the default. If it does, step S 403  or S 405  is performed; if not, the motor  59  is driven to adjust the RVA  1  in step S 415 . In one embodiment, before step S 415  the control device  57  further determines whether a given condition is satisfied in step S 413 . If it is, step S 415  is carried out, otherwise step S 403  or S 405  is resumed. Step S 413  aims at reaffirming that the RVA  1  requires adjustment because it is abnormally bent and not that the RVA  1  is oriented and positioned differently as a result of the vehicle turning. (There is no way to predict how a driver would turn her head when she goes around a corner.) The condition may be a command from the vehicular operator similar to the gestures mentioned above, such as the motorcyclist turning head, temporarily making the receiving device  53   c  the one receiving the reference signal instead of the receiving device  53   a,  which may have been picking up the signal since the RVA  1  went askew. 
         [0021]    The system and method of the present disclosure are also capable of actively adjusting a RVA on a cornering vehicle to provide a more useful view to the operator. Generally, this means extending the RVA outwards (counterclockwise when turning right and clockwise when turning left, viewed from the top) so that it reflects the road conditions at the back of the car opposite the original travelling direction. Please refer to  FIG. 5  with regard to  FIGS. 1 ,  2 , and  4  for an illustration, and assume that in this embodiment the sending device  51  is disposed at the vehicle and the control device  57  is coupled with the vehicle&#39;s directional indicator  2  indicating left turns. The steps not related to the active adjustment are omitted in  FIG. 5 , where step S 502  is equivalent to step S 402  in  FIG. 4 , S 505  is to S 405 , and S 511  to S 411 . After step S 505 , the control device  57  determines in step S 510  whether the switch of the directional indicator  2  is flipped so that it is actuated (and flashing). If so, step S 511  is executed; if not, monitoring continues in step S 505 . If in step S 511  the control device  57  determines that the current orientation sensed by the orientation device  55  disagrees with the default one (signifying that the vehicle is turning, in accordance with the actuation of the directional indicator  2 ), the RVA  1  is adjusted in step S 517  based on the direction indicated. 
         [0022]    Alternatively, assume that the sending device  51  is not disposed at the vehicle, then naturally the relative position of the RVA  1  and the sending device  51  changes when the vehicle corners. Please refer to  FIG. 6  with regard to  FIGS. 2 ,  4 , and  5  for an illustration of the active adjustment with the relative position accounted for. In  FIG. 6 , steps S 601 , S 603 , S 607 , and S 609  correspond to  FIG. 4  steps S 401 , S 403 , S 407 , and S 409 , respectively; step S 602  is equivalent to step S 402  or step S 502  in  FIG. 5 , as step S 605  is to step S 405  or S 505 , and step S 611  is to step S 411  or S 511 ; steps S 610  and S 617  respectively correspond to steps S 510  and S 517 .  FIGS. 6 and 4  depict different functions that may coexist in the system  5 , the difference being primarily that if it is determined in step S 609  that the first relative position has not yet deviated from the default for the predefined time, then the control device  57  deduces that the vehicle may simply be turning at the moment. Similar to  FIG. 5 , the control device  57 , concluding with steps S 610  and S 611 , proceeds with step S 617  to adjust the RVA  1 . If the first relative position has deviated long enough, the procedure in  FIG. 4  is followed to confirm whether the RVA  1  is abnormally bent. 
         [0023]    To summarize, the system and method of the present disclosure can be integrated with a vehicle such as an automobile or a motorcycle to memorize the default configuration of a RVA and automatically recover it when it has gone awry. The sending device included may be wearable or mounted. The system and method may further incorporate a setup mechanism, e.g. a setup button, for the default configuration. Road conditions vary; hence multiple factors are recognized to avoid misjudgment. The factors include whether the first relative position matches the default, whether the mismatch has lasted for a predefined time, whether the current and default orientations of the RVA agree, and whether a given condition is satisfied. Furthermore, in some embodiments, the rear vision assembly is actively adjusted to enhance safety, based on the direction to which the vehicle turns.