Patent Publication Number: US-2007095595-A1

Title: Anti-squeeze method utilizing airbag information

Description:
TECHNICAL FIELD  
      An anti-squeeze control utilizes information provided by airbag system sensors to initiate a high safety level of operation for window movement control once a child is identified within a vehicle.  
     BACKGROUND OF THE INVENTION  
      Children can be left momentarily in a vehicle or can be playing inside a vehicle, while the vehicle is parked or while the vehicle is in some type of non-driving mode of operation. The children are often able to release seatbelts such that they are able to move within a passenger compartment area. Sometimes these children are able to insert a key within a vehicle ignition or are able to activate other types of vehicle systems by using keyless entry. This could have unfortunate consequences.  
      If a child is playing inside a vehicle and manages to activate a window closing mechanism for example, the child could have a head, neck, arm, fingers, or other body parts pinched between a moving window pane and a vehicle frame member. This could cause serious injury to the child.  
      Many different anti-squeeze control systems have been proposed to address this problem. These systems often do not work effectively to provide desired window movement control for various different operational conditions. One proposed solution reduces a pinch detection threshold for a motor that raises a window. However, when the vehicle is driving, especially when experiencing rough road conditions, there are vertical accelerations of the vehicle and the windows. Having a reduced pinch detection threshold in these circumstances could cause undesired reversing of window movement.  
      Another proposed solution is to reduce raising speed of the window for certain conditions. This allows the amount of window travel to be reduced between pinching detection and actual window movement reversal. Reduced raising speed can be applied when the vehicle is stationary, for example. However, an adult may view slow movement of the window, which is an associated result of having a reduced pinch detection threshold, as a potential system failure.  
      Thus, there is a need for a simple and effective method to identify when a child is playing within a vehicle such that certain vehicle operations, such as raising windows for example, can be performed at higher safety levels to prevent injury to the child.  
     SUMMARY OF THE INVENTION  
      An anti-squeeze control utilizes information provided by a safety restraint system, such as an adaptive, i.e. “smart,” airbag system for example, to vary at least one of window raising speed and a squeezing detection threshold in accordance with vehicle occupant type. The airbag system includes at least one occupant sensor that generates data related to at least one of a weight and size of a vehicle occupant. When a vehicle is equipped with a smart airbag system, a controller utilizes this available data concerning weight and/or size of the vehicle occupant to vary deployment conditions of an airbag based on occupant type. The subject anti-squeeze control uses this already available data to identify whether the vehicle occupant is an adult or child for anti-squeeze purposes. If a child is identified, the anti-squeeze controller modifies window driving and/or pinching threshold parameters to allow reversal before high pinching forces are reached.  
      The anti-squeeze control has a high safety level and a standard safety level. The high safety level is activated when the vehicle occupant is classified in the child classification, and the standard safety level is activated when the vehicle occupant is classified in the adult classification. The high safety level is defined as having a first maximum allowable window raising speed and a first maximum allowable pinching force, and the standard safety level is defined as having a second maximum allowable window raising speed and a second maximum allowable pinching force. The first maximum allowable window raising speed is less than the second maximum allowable window raising speed and the first maximum allowable pinching force is less than the second maximum allowable pinching force. The anti-squeeze control reverses a window direction of movement when either the first or second maximum allowable pinching force is exceeded.  
      The anti-squeeze control utilizes existing occupant sensor data from an airbag system to identify whether or not a child is playing in a vehicle when the vehicle is not in motion. Once a child is identified, the anti-squeeze control operates at high safety level to prevent the child from suffering an injury resulting from having appendages pinched or caught between a window pane and a vehicle frame member, if the child is somehow able to initiate movement of window panes toward a closed position. The controller information could also be used to prohibit the vehicle from being started, or prevent a parking brake from being released, if only a child is identified in the vehicle when the vehicle is in a non-driving mode of operation.  
      These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a schematic view of a vehicle having an anti-squeeze control incorporating the subject invention.  
       FIG. 2  is a schematic side view of a vehicle door with a movable window pane.  
       FIG. 3  is a schematic end view of the vehicle door of  FIG. 2  showing a potential pinching of an object between the movable window pane and a frame member. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      A vehicle  10  encloses a passenger compartment  12 . Vehicle occupants  14  (only one is shown) can occupy the passenger compartment  12  during non-driving modes of operation for various reasons. For example, a child  14   a  can be left in a running vehicle  10  while a parent or adult is outside the vehicle  10 . Or, the child  14   a  could enter a vehicle without adult permission or knowledge. In either event, the child  14   a  could intentionally or inadvertently activate certain vehicle systems that could be potentially harmful to the child  14   a , or to others if the child  14   a  initiates movement of the vehicle  10 .  
      The vehicle  10  includes a safety restraint system  16  that is used to prevent or reduce injuries to vehicle occupants  14  during collisions or other impact events. The safety restraint system  16  includes a seatbelt assembly  18  and an airbag system  20 . The seatbelt assembly  18  is used to secure a vehicle occupant  14  to a vehicle seat  22 . The airbag system  20  is deployed under predetermined collision conditions to prevent the vehicle occupant  14  from impacting vehicle components such as a steering wheel, instrument panel, or console, for example.  
      The airbag system  20  is in communication with a vehicle or system electronic control unit (ECU)  24 , and can control deployment force of an airbag  26 , or can prevent deployment, based on vehicle occupant size, weight, and/or proximity to an instrument panel  30  as known. The airbag system  20  utilizes a plurality of sensors that generate occupant signals to determine such information as occupant weight, size, and position within the passenger compartment  12 . A power source  32 , such as a vehicle battery for example, provides power to operate the sensors and the ECU  24  when the vehicle is in a driving or non-driving mode of operation.  
      Many different types of sensors can be used to generate data for the vehicle occupant  14 . In one example, at least one weight sensor  34  is associated with the vehicle seat  22 . The weight sensor  34  transmits a weight signal  36  to the ECU  24 , which determines vehicle occupant weight based on the weight signal  36 . Other sensors from the airbag system  20 , such as occupant position and/or or seatbelt sensors  38 , can also be utilized to generate vehicle occupant data. The occupant position and seatbelt sensors  38  also generate occupant signals  40  that are transmitted to the ECU  24 , which determines occupant position within the vehicle  10  based on the signals  40 . Any type of weight sensor or occupant sensor suitable for a restraint system, and which can be used to determine occupant morphology, can be used.  
      The ECU  24  uses data from the occupant signals  40  and the weight signal  36  to classify the type of vehicle occupant  14  that is in the vehicle. The ECU  24  can use the occupant signals  40  to determine position and/or size of the vehicle occupant. The ECU  24  could also compare the measured weight to a predetermined weight level or threshold to determine whether or not the vehicle occupant  14  is a child. An example of one predetermined weight threshold is approximately thirty kilograms (30 kg). If the ECU  24  determines that the weight of the vehicle occupant  14  is less than the predetermined weight threshold, or that the size of the vehicle occupant  14  is smaller than a predetermined size, the ECU  24  classifies the vehicle occupant as a child. If the ECU  24  determines that the weight of the vehicle occupant  14  is greater than the predetermined weight threshold, or that the size of the vehicle occupant  14  is greater than a predetermined size, the ECU  24  classifies the vehicle occupant as an adult.  
      Thirty kilograms is just one example of a predetermined weight threshold. It should be understood that while two weight and/or size classifications are discussed as an example (one above and one below a threshold), additional classifications could also be utilized. For example, the predetermined weight and size thresholds could be comprised of multiple weight and size thresholds to provide multiple classifications, such as infant, toddler, small child, large child, small adult, large adult, etc. The ECU  24  could then make control decisions based on what type of occupant is found within the vehicle  10 .  
      The vehicle  10  also includes an anti-squeeze control  50 , see  FIGS. 2 and 3 , that is used to prevent an object, such as a finger F for example, from being pinched between a window pane  52  and a frame member  54  as the window pane  52  moves toward a closed position. The anti-squeeze control  50  is in communication with the ECU  24 . If the ECU  24  determines that a child  14   a  is in the vehicle  10 , the ECU  24  transmits a signal  56  to the anti-squeeze control  50 , which causes the anti-squeeze control  50  to change operating characteristics for a window regulator  58 .  
      The window regulator  58  includes a moving mechanism such as a motor (not shown) that is coupled to the window pane  52  to move the window pane  52  between raised and lowered positions. Raising speed of the window pane  52  correlates to a pinching force that is generated when an object is placed in the path of the moving window pane  52 . Once a pinching force is generated, the motor can be reversed to move the window pane  52  back toward the lowered position. Once the anti-squeeze control  50  determines that an object is caught, a certain period of time is necessary to allow movement of the window pane  52  to be braked and stopped before reversing movement. During this period of time, the pinching force keeps rising. Sometimes, if the raising speed of the window pane  52  is high, this pinching force can be very high, and the anti-squeeze control  50  may not be able to reverse the direction of window pane movement quickly enough to avoid injury.  
      The anti-squeeze control  50  of the present invention has at least a high safety level and a standard safety level that are activated based on vehicle occupant type. The anti-squeeze control  50  utilizes existing sensor data from the airbag system  20  to classify whether the vehicle occupant  14  is an adult or a child. The high safety level is activated when the vehicle occupant  14  is classified in a child classification and the standard safety level is activated when the vehicle occupant  14  is classified in an adult classification.  
      The high safety level is defined as having a first maximum allowable window raising speed and a first maximum allowable pinching force, and the standard safety level is defined as having a second maximum allowable window raising speed and a second maximum allowable pinching force. The first maximum allowable window raising speed is less than the second maximum allowable window raising speed and the first maximum allowable pinching force is less than the second maximum allowable pinching force. The anti-squeeze control  50  reverses a window direction of movement when either the first or second maximum allowable pinching force is exceeded. However, injury to children is prevented by modifying squeeze control operational characteristics to keep the raising speed and maximum allowable pinching forces as low as possible once a child is identified in the vehicle  10 .  
      As an alternative, the high safety level is defined as having a first maximum allowable pinching force threshold before reversing window movement, and the standard safety level is defined as having a second maximum allowable pinching force threshold before reversing window movement. The first maximum allowable pinching force threshold is less than the second maximum allowable pinching force threshold. The anti-squeeze control  50  reverses a window direction of movement when either the first or second maximum allowable pinching force threshold is exceeded.  
      Optionally, a combination of window raising speed and maximum allowable pinching force thresholds could be used to define the high and standard safety levels. The high safety level would have a window raising speed that is less than the window raising speed for the standard safety level. The high safety level would also have a maximum allowable pinching force threshold that would be lower than that of the standard safety level. The anti-squeeze control  50  controls window raising speed in combination with reversing a direction of movement of the window when the maximum allowable pinching forces for either the high or standard safety level is exceeded.  
      In any of the embodiments described above, injury to children is prevented by modifying squeeze control operational characteristics to keep the maximum allowable pinching forces as low as possible once a child  14   a  is identified in the vehicle  10 .  
      The anti-squeeze control  50  utilizes existing occupant sensor data from the airbag system  20  to identify whether or not a child is playing in the vehicle  10 , which typically occurs when the vehicle is not in motion, i.e. parked with ignition on or off. Once a child is identified, the anti-squeeze control  50  operates at the high safety level to prevent the child from suffering from an injury resulting from having appendages pinched or caught between the window pane  52  and the frame member  54 , if the child is somehow able to initiate window pane movement toward a closed position.  
      The ECU  24  could also be used to prevent an engine  60 , see  FIG. 2 , from being started, and/or prevent a parking brake  62  from being released, and/or a gear position to be modified by a gear selector  66  once a child is identified in the vehicle. These types of situations could occur when the vehicle is parked or in a non-driving mode with the ignition on or off. If at least one adult is in the vehicle with at least one child, the system may detect an adult in the vehicle and will not enter into the high safety level. If the system has classified a small adult as a child, a high safety level deactivation mechanism  64  can be activated to allow the adult to start the engine  60 , release the parking brake  62 , and/or move the gear selector  66  to engage transmission gears. The deactivation mechanism  64  could be a hidden button, touch screen, lever, or a key cylinder such as for deactivating a front passenger air bag when a child seat is on a front passenger seat, for example. A dedicated warning light on a vehicle dashboard could be used to indicate when the high safety level is deactivated, or an on-board computer could be used to generate messages that the high safety level is deactivated.  
      Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.