Patent Publication Number: US-2023139499-A1

Title: Power tailgate cargo load sensor

Description:
FIELD OF THE DISCLOSURE 
     This disclosure relates generally to vehicles and, more particularly, to a method of detecting load on a tailgate by a touch sensor located under part of the tailgate in a vehicle. 
     BACKGROUND 
     The “background” description provided herein is for generally presenting the context of the disclosure. 
     Vehicle sensors are used to detect obstructions mostly when closing a sliding door or a liftgate of a vehicle for safety reasons. These vehicle sensors are usually exposed to vehicle interiors only and these vehicle sensors can easily be damaged by exterior objects. Therefore, an improvement of vehicle sensor assemblies is needed. 
     SUMMARY 
     A vehicle tailgate structure of a vehicle is disclosed. The vehicle tailgate structure may include a power tailgate located at the rear of the vehicle; a garnish covering a top surface of the tailgate and configured to deform when an external load applies on the garnish, the garnish including a plurality of rib structures along an interior surface of the garnish and a screw portion including the garnish around a screw of the screw portion; and a touch sensor extending along the top surface of the tailgate and covered by the garnish, the touch sensor configured to detect deformation of the garnish, the touch sensor including touch sensor wires connecting to a control system of the vehicle. 
     The foregoing paragraphs have been provided by way of general introduction and are not intended to limit the scope of the following claims. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments of this disclosure will be described in detail with reference to the following figures. 
         FIG.  1    is a perspective view of a vehicle having a tailgate, in accordance with the teachings of this disclosure; 
         FIG.  2    is a block diagram of a control system, in accordance with the teachings of this disclosure; 
         FIG.  3    is a right perspective view of a tailgate of a vehicle, in accordance with the teachings of this disclosure; 
         FIG.  4    is a side sectional view of a tailgate of a vehicle cut along A-A in  FIG.  3   , in accordance with the teachings of this disclosure; 
         FIG.  5    is an enlarged view of the area in  FIG.  4    with the dashed box, in accordance with the teachings of this disclosure; 
         FIG.  6    shows a touch sensor in the tailgate, in accordance with the teachings of this disclosure; 
         FIG.  7    shows a deflection of the touch sensor in the tailgate, in accordance with the teachings of this disclosure; 
         FIG.  8    is a top view of a tailgate when the tailgate is open, in accordance with the teachings of this disclosure; 
         FIG.  9    is a perspective an underside view of the garnish  305 , in accordance with the teachings of this disclosure; 
         FIG.  10    is a vehicle side view with an example external load on the tailgate, in accordance with the teachings of this disclosure; 
         FIG.  11    is a side section cut view of the example external load on the tailgate, in accordance with the teachings of this disclosure; 
         FIG.  12    is an example perspective section view of a first example garnish structure, in accordance with the teachings of this disclosure; 
         FIG.  13    is a second example perspective section view of the first example garnish structure, in accordance with the teachings of this disclosure; 
         FIG.  14    is an enlarged side section view of the screw portion of the first example garnish structure from  FIG.  13    along B-B in the example garnish structure, in accordance with the teachings of this disclosure; 
         FIG.  15    is a perspective side view of a second example garnish structure, in accordance with the teachings of this disclosure; and 
         FIG.  16    is a perspective view of one example of the rib structures. 
         FIG.  17    is a perspective view of another example of the rib structures. 
     
    
    
     The figures are not to scale. In general, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. 
     DETAILED DESCRIPTION 
     The description set forth below in connection with the appended drawings is intended as a description of various aspects of the disclosed subject matter and is not necessarily intended to limit any aspect. In certain instances, the description includes specific details for providing an understanding of the disclosed subject matter. However, it will be apparent to those skilled in the art that aspects may be practiced without these specific details. In some instances, well-known structures and components may be shown in block diagram form to avoid obscuring the concepts of the disclosed subject matter. 
     Reference throughout the specification to “one aspect” or “an aspect” means that a particular feature, structure, characteristic, operation, or function described in connection with an aspect is included in at least one aspect of the disclosed subject matter. Thus, any appearance of the phrases “in one aspect” or “in an aspect” in the specification is not necessarily referring to the same aspect. Further, the particular features, structures, characteristics, operations, or functions may be combined in any suitable manner in one or more aspects. Further, it is intended that aspects of the disclosed subject matter can and do cover modifications and variations of the described aspects. 
     It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. That is, unless clearly specified otherwise, as used herein the words “a” and “an” and the like carry the meaning of “one or more.” Additionally, it is to be understood that terms such as “upper,” “lower,” “front,” “rear,” “side,” “interior,” “exterior,” and the like that may be used herein, merely describe points of reference and do not necessarily limit aspects of the disclosed subject matter to any particular orientation or configuration. Furthermore, terms such as “first,” “second,” “third,” etc., merely identify one of a number of portions, components, points of reference, operations and/or functions as described herein, and likewise do not necessarily limit aspects of the disclosed subject matter to any particular configuration or orientation. 
       FIG.  1    illustrates a vehicle having a tailgate  103  at an end of a truck bed  101 . A tailgate handle  107  is provided on the tailgate  103  to operate a tailgate latch  105 . When the tailgate handle  107  is operated the tailgate latch  107  releases the tailgate  103  from the truck bed  101 , allowing the tailgate  103  to rotate to a closed position to an open position. A motor-operated occupant step  109  may be independently deployed with respect to the tailgate  103 . The tailgate  103  and the occupant step  109  may operate independently of each other with regard to their opening and closing range of motion and travel paths. The tailgate  103  may be also be operated by a remote, gesture, or other electronic methods. 
     In the current disclosure, in a case when a load or an object is detected on the tailgate  103 , a vehicle controller or an electronic control unit (ECU) of the vehicle  100  for the tailgate  103  may prevent the tailgate  103  from being opened. The load or the object may be, but not limited to, building materials, a person, furniture, or the like. 
     In the current disclosure, a touch sensor for detecting the load or the object on the tailgate  103  may be provided, which will be discussed in detail later. The touch sensor may be placed under a top protector or garnish  305  of the tailgate  103  to detect the load or the object. If the load or the object is detected, then the ECU or the vehicle controller may prevent the tailgate from being opened. 
       FIG.  2    is a block diagram of a control system in accordance with an exemplary aspect of the disclosure. The drawing is for purposes of explaining a basic controller and is nonlimiting. 
     The control system  200  may include a controller  201  (ECU) having a micro-processor  211  implemented as processing circuitry. The controller  201  may include a power supply  203  and a communications circuit  205  for interfacing with other controllers in the vehicle and/or other external control devices. The controller  201  may include one or more digital and/or analog interfaces for sensors, providing input signals to the controller  201 . The controller  201  may include specialized circuits and relays providing output control signals for control of actuators. 
     The micro-processor  211  may be an integrated circuit board having a processing chip, memory modules and I/O interfaces. The micro-processor  211  may include a security chip and other specialized processing devices such as a math co-processor. Memory modules may include Read Only Memory (ROM), Random Access Memory (RAM) and variants of nonvolatile and volatile memory. In the case of a security chip, the security chip may have a dedicated secure memory. Any or all of the processors may include one or more processor cores. 
     Types of sensors may include a handle switch  221 , an in-cabin operation switch  223 , touch sensors  225 ,  227 , and a kick sensor  229 . The control system  200  is not limited to the sensors depicted in the drawing. For example, there may be several handle switches  221  and in-cabin operation switches  223  depending on the arrangement of the vehicle. The number and arrangement of touch sensors  225 ,  227  are dependent on the size and configuration of a touch surface or various touch surfaces on the vehicle. There may be several different kick sensors, each of different type and arrangement, or similar sensors at different locations. In addition, the controller  201  may receive signals from other types of sensors depending on the configuration of a vehicle. 
     Types of actuators may include actuators for small motors that can perform operations such as open and close doors or lift gates. An actuator for a motor may rotate a spindle. An aspect is an actuator that rotates a spindle  231  that moves a door or tailgate to an opened position. The spindle actuator  231  may be controlled to stop operation of opening the door or tailgate at a position that is between fully closed or fully opened upon detection of an opposing force. In some embodiments an opposing force may be determined by detection of a predetermined torque on the respective motor spindle. The opposing force may be encountered when the door or tailgate comes into contact with a person or some other object and the person or other object is either not movable, or pushes back against the door or tailgate. There may be any number of actuators, e.g., close actuator  233 , spindle actuator  235 , and close actuator  237 , depending on the arrangement of doors and tailgate for a vehicle. 
     In an embodiment, as described earlier, the touch sensors  225 ,  227  in the control system  200  may be used for detecting the load or the object on the tailgate  103 . 
       FIG.  3    a right perspective view of the tailgate  103  of a vehicle in accordance with the teachings of this disclosure. The front of the vehicle is on the right of  FIG.  3   . A tailgate assembly includes the tailgate  103 , a touch sensor  304  ( FIG.  4   ), and a garnish  305 . The garnish  305  extends along a top surface of the tailgate  103  and provides a protective and decorative function. The tailgate  103  may be located at the rear of the truck bed  103 . The tailgate  103  may be used for loading or unloading heavy freight at locations without docks and forklifts. The tailgate  103  may be able to be opened and closed. The open position having an inner surface of the tailgate  103  substantially in line with the truck bed  101 . The control system  200  may be able to control the opening of the tailgate  103  by use of the spindle actuator  231 . The tailgate  103  may be made of, but not limited to, aluminum, steel, or the like. The material of the tailgate  103   may be different from the materials of the vehicle, the motors of the vehicle, and latches of the vehicle, to offset a total weight of the whole vehicle. 
     The garnish  305  may be a protector to make loading and unloading items from the truck bed easier. The garnish  305  may protect the tailgate  103  from scratches and rust. The garnish  305  may be made of, but not limited to, plastic, polypropylene, or the like. The garnish  305  may be lightweight and resistant to heat, fatigue, and most organic solvents. In some embodiments, the garnish may have insulating properties. 
     The touch sensor  304  ( FIG.  4   ) may be placed under the garnish  305  in  FIG.  3    to detect a load  308  on the garnish  305 . The load  308  may be a plywood, wooden boards, or the like, and the load  308  is applied on the garnish  305 . The load  308  may be furniture on the garnish  305 . The load  308  may have a magnitude and direction downward to allow the touch sensor  304  to contact a sensor trigger location  312  ( FIG.  5   ) on an inner surface of the garnish  305 . When the load  308  is detected, the control system  200  may prevent the tailgate  103  from being opened. For example, the control system  200  may determines if the load  308  is resting on the tailgate  103  or the garnish  305  using the touch sensor  304 . If the load  308  is detected, then the control system  200  may not allow the opening of the tailgate  103  by restricting the use of the spindle actuator  231 . 
       FIG.  4    is a side sectional view of the tailgate  103  of a vehicle cut along A-A of  FIG.  3    in accordance with the teachings of this disclosure. The front of the vehicle is on the right of  FIG.  4   . As mentioned earlier, the tailgate assembly includes the tailgate  103 , the touch sensor  304 , and the garnish  305 . The control system  200  may be able to control the folding of the tailgate  103 . The touch sensor  304  may be hidden from exterior view or exterior access by garnish  305 . The touch sensor  304  may be able to detect the load  308  as shown in  FIG.  3    on an exterior panel for preventing the truck tailgate door from opening. A bracket  804  may support a bottom of the touch sensor  304 , which will be discussed in  FIG.  8   . The area in  FIG.  4    with a dashed box  5  is further described in  FIG.  5   . 
       FIG.  5    is an enlarged view of the area in  FIG.  4    with the dashed box  5  in accordance with the teachings of this disclosure.  FIG.  5    shows additional detail of the tailgate assembly including the touch sensor  304 , and the garnish  305 . The bracket  804  is also shown in  FIG.  5    and the bracket  804  supports the touch sensor  304 . The bracket  804  is mounted to tailgate frame  309 . The bracket  804  provided between the tailgate frame  309  and the touch sensor  304 . A deflection of the garnish  305  may trigger the touch sensor  304 . Further, the control system  200  may prevent the tailgate  103  from being opened due to the trigger of the touch sensor  304 . For example, when a load  308  such as a cargo load rests on the garnish  305 , it deflects the garnish  305  at the sensor trigger location  312 . The deflection of the garnish  305  further triggers the touch sensor  304 . Therefore, the touch sensor  304  may transmit the signal to the control system  200  to indicate that the load  308  is on the tailgate  103  or the garnish  305 . The control system  200  may further determine that the tailgate  103  may not be opened. 
       FIG.  6    shows a touch sensor  304  in the tailgate  103 , in accordance with the teachings of this disclosure. 
     The garnish  305  is on an upper surface of the tailgate  103  to protect the tailgate  103 . The touch sensor  304  may be under the garnish  305 . The touch sensor  304  may include touch sensor wires  602 . The touch sensor wires  602  may be connected to the control system  200  ( FIG.  2   ). The shape of the touch sensor  304  may be, but not limited to, a circle or a square. 
     The external load  308  may be plywood, wooden boards, or the like, and the load  308  is applied on the garnish  305 . When the external load  308  is detected, the control system  200   ( FIG.  2   ) may prevent the tailgate  103  from being opened. In addition, when the external load  308  is detected by the touch sensor  304 , it may trigger the touch sensor wires  602  to communicate with the control system  200 . As mentioned earlier, the control system  200  may determine that the tailgate  103  should be closed when the external load  308  is present on the garnish  305 . 
       FIG.  7    shows a deflection of the touch sensor  304  in the tailgate  103 , in accordance with the teachings of this disclosure. Similar to the description in  FIG.  6   , the garnish  305  of  FIG.  7    surrounds the tailgate  103  to protect the tailgate  103 . The touch sensor  304  may be under the garnish  305 . The touch sensor  304  may include touch sensor wires  602 . The touch sensor wires  602  may be connected to the control system  200  mentioned earlier in  FIG.  2   . 
     The shape of the touch sensor  304  in  FIG.  6    may have a circular cross-section but is not so limited. After the external load  308  rests on the garnish  305 , the garnish  305  may be rotated or deflected. The rotation or the deflection of the garnish  305  may also deform or deflect the touch sensor  304  due to contact with the garnish  305 . The cross-section of the touch sensor  304  is exaggerated in  FIG.  7    to illustrate the deformation or deflection of the touch sensor  304  to cause the sensor wires  602  to contact and therefore  602  to be in a closed circuit. As discussed earlier, the touch sensor  304  and the touch sensor wires  602  may communicate with the control system  200  mentioned earlier in  FIG.  2   . Therefore, when the external load  308  is detected by the touch sensor  304 , it may trigger the touch sensor wires  602  to communicate with the control systems  200 . The control system  200  may determine that the tailgate  103  should remain closed when the external load  308  is present on the garnish  305 . 
     In some aspects, the touch sensor  304  can detect a resistance value of the touch sensor wires  602 . The resistance value varying with response to a load applied to the touch sensor  304 . Using a predetermined resistance value within the circuit, a travel amount of the garnish  305  can be determined by measuring the change in the resistance value. The internal resistance of the unloaded touch sensor  304  can be, for example, 4700 Ω. When the internal resistance of the touch sensor  304  drops below a threshold value (e.g. 500 Ω), due to pressure on the touch sensor causing the internal resistance to drop, the ECU can determine that the tailgate  103  is not allowed to unlock and/or open. This determination of the internal resistance of the touch sensor  304  being below the threshold value is an example of a determined or detected actuation event of the touch sensor  304 . 
       FIG.  8    is a top view of the top surface of the tailgate  103 , in accordance with the teachings of this disclosure. 
     In an embodiment, a direction to the top of  FIG.  8    is the vehicle front. The touch sensor  304  is extending along the bracket  804 . The bracket  804  may be made of, but not limited to, a metal, a plastic, or the like. The shape of the bracket  804  may be adjusted according to the shape of the tailgate  103 , the touch sensor  304 , or the garnish  305 . 
       FIG.  9    is a perspective an underside view of the garnish  305 . The garnish  305  in  FIG.  9    includes a plurality of the rib structures  314 . Standoff portions  1202  are also shown in  FIG.  9   , which will be discussed with respect to  FIG.  12   . The rib structures  314  may be spaced apart to contact the touch sensor  304  at specific locations as shown in  FIG.  9   . As discussed earlier, after the external load  308  rests on the garnish  305  may deflect and contact the touch sensor  304 . Specifically, when the garnish  305  deflects, the rib structures  314  contact the touch sensor  304 . The deflection of the garnish  305  may also deform the touch sensor  304  into a different shape such as an ellipse shown in  FIG.  7    thereby forcing contact between the touch sensor wires  602 . The deflection of the touch sensor  304  at those rib structures  314  may also cause the touch sensor wires  602  to be in a closed circuit. Therefore, when the external load  308   is detected by the touch sensor  304 , it may trigger the touch sensor wires  602  to communicate with the control system  200 . The control system  200  may determine that the tailgate  103  should remain closed when the external load  308  is present on the garnish  305 . 
       FIG.  10    is a vehicle side view with an example external load on the tailgate  103 , in accordance with the teachings of this disclosure.  FIG.  11    is a perspective view of the example external load on the tailgate  103 , in accordance with the teachings of this disclosure. 
     In an embodiment, the external load may be lumber  1002 . The lumber  1002  may rest on the tailgate  103 . As discussed earlier, the lumber  1002  resting on top of the tailgate  103  may deflect the garnish  305  of the vehicle. The deflected garnish  305  may deform the touch sensor  304 , and further trigger the touch sensor wires  602  to communicate with the control system  200 . The control system  200  may determine that the tailgate  103  should be closed when the lumber  1002  is present on the garnish  305 . 
       FIG.  12    is a first side view of a first example garnish structure, in accordance with the teachings of this disclosure. 
     In an embodiment, the garnish  305  may have a standoff portion  1202 , the standoff portion  1202  on an underside surface of the garnish  305 . The standoff portion may be modified to have a flexible spring shape. That is, the standoff portion has a shape or material that plastically deforms under load and returns to the original shape when the load is removed. The standoff portion  1202  may be used to bias the garnish  305  upwards against the external load  308 . The standoff portion  1202  which includes the flexible spring shape may be sensitive to the deflection of the garnish  305  when the external load  308  is on the tailgate  103 . The standoff portion  1202  may be able to be compressed under an external load (e.g. load  308 ). The standoff portion  1202  may expand when going from a loaded position to an unloaded position. The spring constant of the flexible spring shape of the standoff portion  1202  may be set so that a predetermined load will deflect the garnish  305  sufficiently to trigger the touch sensor  304 . 
       FIG.  13    is a second side view of the first example garnish structure, in accordance with the teachings of this disclosure. 
     In  FIG.  13   , a second standoff portion  1302  is located at the rear of the garnish  305  of the tailgate  103 . The front of the garnish  305  may have an ability to rotate around the second standoff portion  1302  since the second standoff portion  1302  is not flexible, which is different from the flexible spring shape of the standoff portion  1202 . The first example garnish structure may also include a screw portion  1304 . The screw portion  1304  may allow an actuation movement when the garnish  305  rotates. The screw portion  1304  may allow the garnish  305  to slide up and down relative to the screw portion, which will be shown in  FIG.  14   . 
       FIG.  14    is an enlarged view of the screw portion  1304  in the first example garnish structure, in accordance with the teachings of this disclosure. Here, the screw portion  1304  penetrates the garnish  305 , tailgate cover  1402  and the tailgate frame  309 . 
     In an embodiment, the size of the screw of the screw portion  1304  is smaller than the diameter of the opening of the garnish  305  so that the screw portion  1304  can move within the opening. Accordingly, the garnish  305  near the screw portion  1304  may move up and down depending on the external load  308  applied on the garnish  305 . 
       FIG.  15    is a side view of a second example garnish structure, in accordance with the teachings of this disclosure. The second example garnish structure includes a second flexible spring structure.  FIG.  15    includes a standoff portion  1502  which is shorter and placed at an alternate location relative to the standoff portion  1202  (see also  FIG.  12   ). The second flexible spring structure may be used to increase a sensitivity of the external load on the garnish  305  in the vehicle. That is, the standoff portion  1502  and the standoff portion  1202  can have different spring rates and work progressively. In some embodiments, the second flexible spring structure may be used to reset the position of the garnish  305  after the external load  308  is removed from the garnish  305 . 
       FIG.  16    is a perspective view of one example of the rib structures. An underside perspective of garnish  305  is shown including a wedge-shaped rib structure  314   a . The shape of the rib structure  314  can varying depending upon the design of the garnish  305  and the type, direction, and amount of deflection the garnish  305  has under load. If the garnish  305  is designed to rotate around a rearward pivot point, the wedge-shaped rib structure  314   a  may be used to allow greater contact with the touch sensor  304  during the rotating movement of the garnish  305 . 
       FIG.  17    is a perspective view of another example of the rib structures. An underside perspective of garnish  305  is shown including a straight rib structure  314   b . If the garnish  305  to move in a vertical direction under load, as discussed above with regard to  FIG.  12    to  FIG.  14   , then the straight rib structure  314   b  arranged horizontally to the touch sensor  314  may be used to allow greater contact with the touch sensor  304  during the vertical movement of the garnish  305 . 
     Although certain example apparatus, systems, and methods have been disclosed herein, the scope of coverage of this patent is not limited thereto. Obviously, numerous modifications and variations are possible considering the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. 
     Thus, the foregoing discussion discloses and describes merely exemplary embodiments of the present invention. As will be understood by those skilled in the art, the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting of the scope of the invention, as well as other claims. The disclosure, including any readily discernible variants of the teachings herein, defines, in part, the scope of the foregoing claim terminology such that no inventive subject matter is dedicated to the public.