Sensor for anti-entrapment system

A sensor for an anti-entrapment system of a vehicle for preventing an object within an opening of the vehicle defined by a movable panel from being pinched by the movable panel includes a seal adapted to be mounted to a portion of the vehicle, an electrically conductive mounting carrier disposed in the seal and having a formed shape and operable to detect the object in the path of the movable panel and to generate a pinch sensor signal indicative of the object either touching the seal or in close proximity to the seal, and a controller for monitoring the electrically conductive mounting carrier, wherein the controller controls the movable panel to prevent the movable panel from pinching the object in response to the pinch sensor signal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to an anti-entrapment system of a vehicle for preventing entrapment of an object and, more particularly to, an anti-entrapment system of a vehicle provided with a sensor for preventing entrapment of an object.

2. Description of the Related Art

Anti-entrapment systems use various types of sensors to detect pinching of an object such as a human body part. For example, in vehicles such as automotive vehicles, sensors are used for pinch sensing at electrically operated doors, windows, hatches, decks, hoods, lids, and the like.

A pinch sensor detects pinching of an object by a translating device such as a movable window, door, sunroof, etc. In operation, the pinch sensor generates a pinch sensor signal in response to the object such as a person's finger being pinched by the translating device such as a window as the window is closing. In response to the pinch sensor signal, a controller controls the window to reverse direction and open in order to prevent further pinching of the person's finger.

Accordingly, it is desirable to provide a sensor for an anti-entrapment system of a vehicle that detects a translating device pinching an object as soon as the translating device has applied a relatively small amount of pinching to the object and/or detects the presence of an object within an opening which may be closed by the translating device in order to prevent any pinching of the object by the translating device. It is also desirable to provide a sensor for use with existing structures of a vehicle such as a seal. Therefore, there is a need in the art to provide a sensor for an anti-entrapment system for preventing entrapment of an object

SUMMARY OF THE INVENTION

Accordingly, the present invention provides a sensor for an anti-entrapment system of a vehicle for preventing an object within an opening of the vehicle defined by a movable panel from being pinched by the movable panel. The sensor includes a seal adapted to be mounted to a portion of the vehicle, an electrically conductive mounting carrier disposed in the seal and having a formed shape, wherein the electrically conductive mounting carrier is operable to detect the object in the path of the movable panel and to generate a pinch sensor signal indicative of the object either touching the seal or in close proximity to the seal, and a controller for monitoring the electrically conductive mounting carrier, wherein the controller controls the movable panel to prevent the movable panel from pinching the object in response to the pinch sensor signal.

Further, the present invention provides an anti-entrapment system of a vehicle for preventing an object within an opening of the vehicle defined by a movable panel from being pinched by the movable panel. The system includes a motor adapted to move the movable panel for opening and closing the opening and a sensor adapted to be mounted to a portion of a vehicle operable to detect the object in the path of the moving panel and to generate a pinch sensor signal indicative of the object either touching the sensor or in close proximity to the sensor. The sensor includes a seal adapted to be mounted to a portion of the vehicle and an electrically conductive carrier disposed in the seal and having a formed shape. The system also includes a controller for monitoring the sensor, wherein the controller controls the motor to prevent the movable panel from pinching the object in response to the pinch sensor signal.

In addition, the present invention provides a method of sensing for an anti-entrapment system of a vehicle for preventing an object within an opening of the vehicle defined by a movable panel from being pinched by the movable panel. The method includes the steps of producing a sensor including a seal adapted to be mounted to a portion of the vehicle and an electrically conductive mounting carrier disposed in the seal and having a shape, wherein the electrically conductive mounting carrier is operable to detect the object in the path of the movable panel and to generate the pinch sensor signal indicative of the object either touching the seal or in close proximity to the seal. The method includes monitoring by a controller the electrically conductive mounting carrier and controlling the movable panel by the controller to prevent the movable panel from pinching the object in response to the pinch sensor signal.

One advantage of the present invention is that a new sensor is provided for an anti-entrapment system of a vehicle. Another advantage of the present invention is that the sensor uses a portion of an existing seal structure instead of adding a separate sensor strip or sensor strip components into a seal for use as a sensor to simplify construction and save cost. Yet another advantage of the present invention is that the sensor uses a portion of an existing seal structure, thereby eliminating the need to add a sensor strip and modify seal profiles that are already qualified and being produced. Still another advantage of the present invention is that the sensor is able to use the existing structure of a seal as a sensor element providing many benefits, including reduced tooling, structure change, and cost.

These and other objects, advantages, and features of the present invention will become better understood from the following detailed description of one exemplary embodiment of the present invention that is described in conjunction with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

Referring to the drawings, one embodiment of an object sensing or anti-entrapment system10for a vehicle (not shown) is shown inFIGS.8and9. The vehicle includes an opening (not shown). The anti-entrapment system10includes a sensor12and a controller14inFIG.8and a sensor/controller13inFIG.9. The vehicle includes a translating device20such as a movable panel for opening and closing the opening of the vehicle. The translating device20may be, for example, a window, door, or sunroof of the vehicle. The sensor12is adapted to be mounted to a portion of the vehicle adjacent the opening operable for detecting an object16in the path of the translating device20and to generate a pinch sensor signal indicative of the object16either touching the sensor12or in close proximity to the sensor12. The anti-entrapment system10also includes a motor18adapted to move the translating device20for opening and closing the opening. It should be appreciated that the controller14controls the motor18to prevent the translating device20from pinching the object16in response to the pinch sensor signal.

The sensor12is generally a capacitance sensor that is operable to detect touching by the object16to the sensor and/or the presence (i.e., proximity) of the object16near the sensor12. In response to the object16, including human body parts, touching the sensor12, the capacitance of the sensor12changes. Likewise, in response to an electrically conductive object16, including human body parts, coming within the proximity of the sensor12, the capacitance of the sensor12changes even without the object16actually touching, or applying any force, to the sensor12. This provides for zero force detection of a human body part before contact to the sensor12is made by the body part. As such, the sensor12is a contact (i.e., touch) and a non-contact (i.e., proximity) sensor.

The controller14can have switch inputs, communications capability with other sensors and controllers, and various outputs for controlling and monitoring various aspect of the translating device20. For instance, the controller14can have sensor inputs for the motor18as designated by line19inFIG.8or other moving members, such as a door, to determine the position, direction of movement, speed of movement, etc. of the translating device20. It should be appreciated that such sensor inputs could be for receiving signals from Hall Effect sensors and the like as well as optic, resistive, and inductive sensors.

In the case of the controller14receiving the sensor signals19responsive to the motor18or other moving members, the controller14would have additional anti-entrapment capabilities by making use of motor current and/or commutator pulses and/or sensor signals from Hall (or other type) sensors. This would have the added benefit of being able to detect obstructions while the moving member and the obstruction are too far away from the sensor12to be sensed by the sensor12. It should be appreciated that such a controller14is disclosed in U.S. Pat. No. 7,513,166 to Shank et al., the entire disclosure of which is hereby expressly incorporated by reference.

Referring toFIGS.6and6AandFIGS.7and7A, two different embodiments of a sensor396and405, respectively, are used to detect the presence of the object16. InFIGS.6and6AandFIGS.7and7A, these types of sensor396and405are manufactured by co-extruding elements together to form a profile that is desired for various applications. The basic elements of each sensor396and405are a sensor jacket400and406, wire sensing element397,398, and409, metallic strip sensing element407, dielectric399, air gaps403,404,410, and411, and conductive elastomer401,402, and408.

Referring now toFIGS.6and6A, the sensor396includes the first and second wire sensing elements397and398. The sensor jacket400has a hollow interior encases the first wire sensing element397and holds each end of the first conductive elastomer401and encases the second wire sensing element398and holds each end of the second conductive elastomer402. The conductive elastomers401and402divide the interior of the sensor jacket406into two air gaps403and404. The air gaps403and404are filled with air or other dielectric399. The sensor396registers a change in capacitance whenever the distance between the first and second wire sensing elements397and398changes as a result of the object16touching the sensor jacket400and/or as a result of an electrically conductive object coming into proximity with either of the wire sensing elements397and398.

Referring now toFIGS.7and7A, the sensor405is a combination proximity/displacement sensor with an internal fabric conductive element that can also be used as a heating element and temperature sensor. When pressure is applied to the sensor jacket406, the air gaps410and411compress to move the sensor jacket406toward the strip sensing element407which is sheathed inside the conductive elastomer408. To this end, the air gaps410and411can be air, foam, or any dielectric material formulated to allow for low force.

The wire sensing element409is used to make an electrical connection for the sensor jacket406. The sensor405registers a change in capacitance whenever the distance between the strip sensing element407and the sensor jacket406changes as a result of the object16touching the sensor jacket406and/or as a result of an electrically conductive object coming into proximity with the sensor jacket406. It should be appreciated that the change in capacitance is signaled to the controller14.

The strip sensing element407may be used as a heating element when the anti-pinch strip system is inactive. The heating element function can be used to heat the sensor405, which may be used as a weather seal, keeping the conductive elastomer408and air gaps410and411pliable in cold weather conditions. It is a goal to have the weather seal properties maintained to application compliance standards while heated. Additionally, the heated weather seal could be used to prevent the window or sliding panel from freezing and/or to aid in thawing a frozen window or sliding panel while in the closed position. The strip sensing element407would be engaged as a heating element when powered by relays turned on by the controller14with inputs from a temperature sensor, which could be from the vehicle outside temperature sensor. It should be appreciated that the temperature input could also originate from a separate temperature sensor located on a device inside the vehicle door, or anywhere else outside the vehicle.

The temperature setting to turn on the strip sensing element407is optional, but would likely be set for temperatures at or below 40 degrees Fahrenheit. where cold weather pliability is required. When the set temperature is reached, the controller14will turn the strip sensing element407on to make the weather seal pliable. The circuit in the controller14can also be configured to automatically cycle the strip sensing element407on and off after the desired pliability is achieved to thereafter maintain pliability.

By using relays or transistors, the strip sensing element407can be powered such that an appropriate amount of current flows through the element. The current flow through the resistive element will produce the required amount of heat following the well-known equation Power (Watts)=Current (A)2times Resistance (Ohms). The power can be applied for a given amount of time and then removed. During the time power is removed, the strip sensing element407can be connected to a circuit that provides a small amount of current flow through the element and through a series connected resistor.

The strip sensing element407and the series connected resistor form a voltage divider. The voltage that is developed can then be interpreted by a microprocessor, or other device such as an op-amp, to determine the temperature of the strip sensing element407. If the temperature is below a determined set-point, the strip sensing element407can again be connected such that power is applied to it increasing the amount of heat generated. After the temperature sensor determines that the temperature is above the set point, the controller14will turn off the relays or transistors providing power to the strip sensing element407.

In another embodiment, the controller14can be configured to inhibit a user input command to open a window or sliding panel when, anytime during the time of heating the strip sensing element407, no window or panel movement is sensed, indicating a stalled motor condition such as may be caused by ice buildup in the weather seal. During such an event, the controller14continues to inhibit user commands to open the window or sliding panel until the strip sensing element407inside the weather seal has achieved a temperature sufficient to free the window or sliding panel. The controller14could be configured to recognize the above condition from temperature sensor inputs at all times, including when vehicle ignition and/or other vehicle power is off. It should be appreciated that implementation of this function could reduce warranty costs related to the window or sliding panel drive mechanism, seals, and motor.

In another embodiment, the strip sensing element407could be used as a heating element inside a weather seal not using an anti-pinch strip system. In this case, the controller14is configured to only control the heating element function as described above. It should also be appreciated that the controlling function could also be integrated as part of other electronics being employed within the application system.

In yet another embodiment, the strip sensing element407could be used as a temperature sensor, either as a stand-alone sensor, or in combination with the anti-pinch system. The function to switch between temperature sensing and anti-pinch sensing would be configured through the controller14. The temperature sensing function of the strip sensing element407could be used to provide the same temperature inputs required to operate the anti-pinch system as described above.

While the aforementioned sensors396and405can be used by themselves, it is sometimes advantageous or necessary to add them to, or incorporate them into, a seal459, as shown inFIGS.5and5A. As an example, a sensor449illustrated inFIG.5Ais incorporated into the seal459inFIG.5. To manufacture this seal459, a recessed area is added to the seal459to accept the sensor449. In this embodiment, the sensor449includes sensor elements450and451and dielectric structure452being co-extruded inside a sensor jacket457. The sensor449is then attached to the seal459by a suitable mechanism such as an adhesive or by other means. It should be appreciated that this assembly or sensor is then used with the translating device20such as window glass458commonly used in the automotive industry for the opening in the vehicle.

As shown inFIG.5, the sensor elements450,451of the sensor449are constructed in a serpentine pattern with spaced slots. This configuration provides flexibility for conforming the sensor449to shapes that would apply a load perpendicularly to the flat planar surface of the sensor elements450,451in certain applications. The spaced slots are preferably 0.5 mm wide and 5 mm in length, spaced 2.5 mm apart along the entire length of the sensor elements450,451. It should be appreciated that other slot sizes, spacings, and patterns could be used to accomplish the same flexibility purpose specific to a given application of the sensor449. It should also be appreciated that, by increasing the widths of the sensor elements450,451, a larger overall sensor can be created to allow for a greater surface area of entrapment protection.

The sensor449is sized for a typical automobile door window seal application, and has a minimum profile designed to not reduce viewing through the window opening. As shown inFIG.5, the sensor449is attached to a weather seal459. The weather seal459is attached to an automobile window frame460. The frame460and the weather seal459have an opening for receiving an automobile window458when the window is in a fully closed position.

If a non-compressible material is used, then the sensor449provides proximity sensing only operation. If compressible material is used, then the sensor449provides both pinch and proximity sensing operations. A preferred material for dielectric medium452of the sensor449is an electrically non-conductive flexible polyurethane foam, such as Rogers Corporation Poron 4701-30-20062-04. Other foam materials, such as EPDM, thermoplastic rubber, thermoplastic elastomer, or TPV could also be used for dielectric medium452. These materials are currently used in window seals to meet the appearance and reliability requirements for window closures. Santoprene, a thermoplastic elastomer material made by Advanced Elastomer Systems, maintains stable compression characteristics over temperature, whereas EPDM compression characteristics decrease as temperature is reduced.

Stiff compression characteristics increase pinch forces. A material, which maintains flexibility and compression characteristics when cold, is preferred for pinch operation of the sensor449. The material for dielectric medium452could be introduced by co-extrusion as any of the materials mentioned, or made by foaming the sensor jacket457in the dielectric space between the sensor elements450,451. It should be appreciated that a foamed space would be made up of the material of the sensor jacket457and air as the dielectric.

A preferred material of the sensor jacket457is a non-electrically conductive thermoplastic rubber or elastomer material, such as Santoprene. The surface resistivity of the sensor jacket457and dielectric medium452is to be set greater than 10.sup.6 ohm/cm to avoid electrical shorting potential between the sensor elements450,451. The thickness of the material of the sensor jacket457between the sensor element450and the sensing surface of the sensor jacket457contains the optimal sensor jacket material thickness required to (a) completely enclose the sensor elements450,451and dielectric medium452(i.e., completely enclose the sensor449) with the sensor jacket457to prevent moisture infiltration; (b) reduce the possibility of voids; and (c) keep the dimension between the sensor elements450,451at a useful spacing to provide useful proximity mode detection and sensitivity.

Referring toFIG.1, an electrically conductive mounting carrier100is comprised of wire110that is bent into a serpentine shape where bend spacing is between approximately three (3) millimeters (mm) and approximately ten (10) mm between serpentine bends. The wire110may be made of cold drawn steel, aluminum, or other suitable metal. The wire110may include filaments120woven or sewn into the serpentine shaped wire, typically polyester and polypropylene, to aid in the positioning, bonding, and stability of the wire110in the seal459. The carrier100is bent into a ‘U’ shape and co-extruded into a weather seal125resulting in a construction illustrated inFIG.3. It should be appreciated that, in seals, particularly automotive weather seals, the metallic structures internal to the seal allow for attaching the seal to a surface of the vehicle.

Another embodiment of an electrically conductive mounting carrier200is shown inFIG.2. The carrier200is a metal strip. The strip may be made of steel, aluminum, or other suitable metal. The strip may be lanced or slit. In one embodiment, the strip of the carrier200is of a lance and stretch type and formed and co-extruded into a seal profile. InFIG.4, a cross-sectional view of a sensor including a seal126with the carrier200is shown in position surrounding a mounting surface140of the vehicle. It should be appreciated that the carriers100and200, as well as other carrier configurations, can be formed into a ‘U’ shape or any other desired shape including flat or planar, and that carrier strips can be used with a seal and produced by co-extrusion, layering of materials, adhesive bonding, or any other advantageous method. It should be appreciated that the carrier100and200may made be of a metal material or any other conductive material such as a conductive plastic. It should also be appreciated that the carrier100and200may be in the form of a continuous non-apertured channel or may be slotted or have slits or otherwise apertured to increase its flexibility.

Referring now toFIG.8, one embodiment of the anti-entrapment system10in accordance with the present invention is shown. As illustrated, the anti-entrapment system10includes the sensor12and the controller14. The sensor12may be a contact (i.e., touch) and a non-contact (i.e., proximity) type sensor. In one embodiment, the sensor12is generally a capacitance sensor that is operable to detect touching of, or proximity to, the electrically conductive object16where the electrically conductive mounting carrier100or200is driven with an electrical charge from the controller14. In response to the electrically conductive object16, including human body parts, touching the sensor12, the capacitance of the sensor12changes. Likewise, in response to the electrically conductive object16, including human body parts, coming within proximity of the sensor12, the capacitance of the sensor12changes. It should be appreciated that proximity sensing provides for zero force detection of a human body part before contact to the sensor12is made.

Referring again toFIG.8, the controller14controls the motor18associated with the translating device20such as a movable panel, for example, a window, door, sunroof, etc. in order to move the translating device20between opened and closed positions. Using a window as an example of the translating device20, the controller14controls the motor18to move the window as the translating device20in an opening direction when opening the opening of the window as the translating device20is desired. Similarly, the controller14controls motor18to move the window as the translating device20in a closing direction in order to close off the opening when closing of the opening is desired. It should be appreciated that the motor18may also send signals19to the controller14to aid in operation. It should further be appreciated that the device used to move a translating panel, such as the motor18, may instead be a pneumatic device such as an air cylinder with a position sensor being used to provide position signals19.

In operation, generally, an operator (not shown) actuates a switch (not shown) to have the controller14control the opening and closing of the window as the translating device20. Such a switch may be configured to provide express-up (i.e., express close) and express-down (i.e., express open) functionality such that a single switch actuation (as opposed to a continuous actuation) causes the controller14to control the window as the translating device20until the window as the translating device20has fully moved into its opened or closed position.

The sensor12is placed adjacent to the opening such that the object16touches the sensor12and/or becomes in close proximity to the sensor12if the object16is caught between the opening and the window as the translating device20and is about to be pinched by the window as the translating device20. The sensor12generates a pinch sensor signal21in response to the object16touching the sensor12and generates a proximity sensor signal23in response to the object16being in close proximity to the sensor12. The sensor12provides pinch and proximity sensor signals21,23to the controller14. In response to receiving pinch and/or proximity sensor signals, the controller14controls the window as the translating device20via the motor18accordingly.

For instance, if the operator has actuated the switch to have the controller14close the window as the translating device20and the window as the translating device20is now closing (for example, when the window is in express-up operation), the controller14controls the window as the translating device20to stop closing and then open in response to a detection by the sensor12of the object16within the opening or path of the translating device20. Reversing the direction of the window as the translating device20and opening the window as the translating device20causes the opening to increase in size in order to prevent any pinching of the object16and to give time for the object16to be removed from the opening. Similarly, if the sensor12detects the presence of the object16within window opening or path of the translating device20, the controller14prevents the window as the translating device20from subsequently moving in the closing direction until the object16has been removed from the opening or path of the translating device20.

Referring now toFIG.9, in another embodiment, the sensor12and controller14may be integrated with one another to form the sensor/controller13. The sensor/controller13effectively provides the same function as the non-integrated sensor12and controller14. It should be appreciated that the description regarding the sensor12and the controller14also refers to the sensor and controller functionality provided by the sensor/controller13.

In operation, the sensor12ofFIG.8and the sensor portion of the sensor/controller13ofFIG.9are electrically connected to the controller14and sensor/controller13, respectively, and energized such that a generated signal can be used to determine if a human or other electrically conductive object is in close proximity to the sensor12. It should be appreciated that using the carrier100ofFIG.3and the carrier200ofFIG.4, instead of adding a sensor strip, simplifies the construction and assembly of the sensor12.

In order for the internal carriers100and200to be used as sensing element, the carriers100and200are isolated from other metal or electrically conductive features such as metal mounting flange140of the vehicle as illustrated inFIG.4. It should be appreciated that the mounting flange140is typically part of a vehicle body structure of the vehicle and, as such, is typically connected to vehicle electrical ground. It should also be appreciated that the carriers100and200are isolated from the mounting flange140by use of an insulator such as a high resistivity isolation material such as a non-conductive rubber and/or thermoplastic to prevent the carrier100or200from shorting to a metal portion of the vehicle.

The present invention also provides a method of sensing for the anti-entrapment system10of a vehicle for preventing the object16within the opening of the vehicle defined by the translating device20from being pinched by the translating device20. The method includes the steps of producing a sensor12comprising a seal459adapted to be mounted to a portion of the vehicle and an electrically conductive mounting carrier100,200disposed in the seal459and having a “U” shape operable to detect the object16in the path of the translating device20and to generate a pinch sensor signal indicative of the object16either touching the seal459or in close proximity to the seal459. The method also includes the steps of monitoring by the controller14the electrically conductive mounting carrier100,200and controlling the translating device20by the controller14to prevent the translating device20from pinching the object16in response to the pinch sensor signal. The method includes the steps of producing the sensor12includes coextruding the seal459and the carrier100,200, energizing the carrier100,200by the controller14, and sensing a change in pinch sensor signal based on proximity of the object16to the carrier100,200. It should be appreciated that the above method also applies to the sensor/controller13.

Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, the present invention may be practiced other than as specifically described.