Abstract:
A method and apparatus ( 40 ) for testing an occupant position sensing system ( 12 ) of a vehicle ( 10 ) includes a motor ( 42 ) having a stationary portion ( 44 ) and a movable portion ( 46 ). A test object ( 90 ) is fixed relative to the movable portion ( 46 ) of the motor ( 42 ). A motor position sensor ( 64 ) senses a position of the movable portion ( 46 ) of the motor ( 42 ) relative to the stationary portion ( 44 ) and for providing a motor position signal indicative thereof. Motor drive electronics ( 58 ) are responsive to the motor position signal for controlling the motor ( 42 ) for moving the test object ( 90 ). A data recorder ( 80 ) is adapted to receive and record data from the occupant position sensing system ( 12 ) and is adapted to receive and record the motor position signal provided by the motor position sensor ( 64 ).

Description:
RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/503,962, which was filed on Sep. 17, 2003. 
     
    
     TECHNICAL FIELD  
       [0002]     The present invention relates to an apparatus and method for testing an occupant position sensing system of a vehicle. More particularly, the present invention relates to an apparatus and method for testing an occupant position sensing system that is used for controlling an actuatable occupant restraint system of a vehicle.  
       BACKGROUND OF THE INVENTION  
       [0003]     It is known to control the actuation of an actuatable occupant restraint system, such as an air bag, in response to a sensed position of the occupant of the vehicle. The position of the occupant is determined using an occupant position sensing system. Such systems generally determine a position of the occupant relative to a fixed reference point, such as, for example, the deployment door of an air bag module. Occupant position sensors may include forward mounted sensors such as cameras or ultrasonic sensors.  
         [0004]     The occupant position system provides sensed occupant position information to an air bag controller. The air bag controller is responsive to the sensed occupant position information for controlling the air bag. For example, the air bag controller may be responsive to the sensed occupant position information for inhibiting actuation of the air bag or for actuating the air bag in a low inflation mode, i.e., less than 100% maximum possible inflation pressure.  
         [0005]     Testing of a dynamic occupant position sensing system has generally resulted in damage to all or part of the vehicle in which the occupant position sensing system is located. For example, one known testing procedure for testing an occupant position sensing system includes placing a crash dummy on the occupant seat and sharply braking the vehicle. Given such a testing procedure, the ability to repeat test under various conditions, such as under differing ambient light conditions, becomes economically impractical.  
         [0006]     One known system for testing occupant position sensing systems uses pneumatics for launching a head-shaped form toward an instrument panel of a stationary vehicle. The pneumatic system, however, is likely to result in damage to the instrument panel of the vehicle. The pneumatic system also is unable to accurately mimic occupant movement for particular vehicle crash scenarios, such as a crash scenario involving pre-crash braking.  
         [0007]     U.S. Pat. No. 6,672,177 discloses another system for testing an air bag proximity suppression system. The system includes rails for enabling motion of an occupant model along three orthogonal axes. The system disclosed in the U.S. Ser. No. 6,672,177 patent is large and appears to require removal of the vehicle seat at the location at which testing is to occur.  
         [0008]     It is desirable to be able to test the occupant position sensing system without damaging the vehicle containing the occupant position sensing system. It is also desirable to enabling such testing to be repeatable under various environmental conditions, such as variable amounts of ambient light, and in some instances, to conduct the test without removing the vehicle seat or seat back.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention relates to an apparatus for testing an occupant position sensing system of a vehicle. The apparatus comprises a motor having a stationary portion and a movable portion. A test object is fixed relative to the movable portion of the motor and is configured to be monitored by the occupant position sensing system. The apparatus also comprises a motor position sensor for sensing a position of the movable portion of the motor relative to the stationary portion and for providing a motor position signal indicative thereof. Motor drive electronics are responsive to the motor position signal for controlling the motor for moving the test object. The apparatus further comprises a data recorder that is adapted to receive and record data from the occupant position sensing system and that is adapted to receive and record the motor position signal provided by the motor position sensor. The motor position signal provides a reference position of the test object against which the data from the occupant position sensing system may be compared.  
         [0010]     According to another aspect, the present invention relates to an apparatus for testing an occupant position sensing system that is adapted to monitor a position of an occupant of a seat of a vehicle. The apparatus comprises a test object that is configured to be monitored by the occupant position sensing system. The apparatus also includes a motor for moving the test object so that the test object may be monitored by the occupant position sensing system. The apparatus further comprises means for positioning the test object in front of a backrest portion of the seat of the vehicle at a location for which the position of the occupant is to be determined.  
         [0011]     According to yet another aspect, the present invention relates to a method for testing an occupant position sensing system of a vehicle. The method comprises the steps of: fixing a test object that is configured to be monitored by the occupant position sensing system to a movable portion of a motor that includes a stationary portion and the movable portion; positioning the test object in the vehicle; controlling the motor to move the movable portion of the motor and the test object, which is fixed to the movable portion, within the vehicle and relative to the stationary portion of motor; sensing a position of the movable portion of the motor relative to the stationary portion; providing a motor position signal indicative of the sensed position; sensing a position of the test object with the occupant position sensing system of the vehicle; providing an occupant position signal indicative of the sensed occupant position; and recording the motor position signal and the occupant position signal. The motor position signal provides a reference position of the test object against which the data from the occupant position sensing system may be compared. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The foregoing and other features and advantages of the present invention will become apparent to those skilled in the art to which the present invention relates upon reading the following description with reference to the accompanying drawings, in which:  
         [0013]      FIG. 1  schematically illustrates a vehicle that includes an occupant position sensing system and an apparatus constructed in accordance with an exemplary embodiment of the present invention for testing the occupant position sensing system of the vehicle;  
         [0014]      FIG. 2  is a schematic block diagram of the apparatus of  FIG. 1  connected to the occupant position sensing system of the vehicle;  
         [0015]      FIG. 3  schematically illustrates an exemplary motor position sensor for a motor of the apparatus of  FIG. 1 ;  
         [0016]      FIG. 4  schematically illustrates a vehicle that includes an occupant position sensing system and an apparatus constructed in accordance with a second exemplary embodiment of the present invention for testing the occupant position sensing system of the vehicle; and  
         [0017]      FIG. 5  schematically illustrates a vehicle that includes an occupant position sensing system and an apparatus constructed in accordance with a third exemplary embodiment of the present invention for testing the occupant position sensing system of the vehicle. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0018]     Referring to  FIG. 1 , a vehicle  10  includes an occupant position sensing system  12 . The occupant position sensing system  12  includes a sensor element  14  and a controller  16 . The sensor element  14  is adapted for obtaining data indicative of the position of an occupant of the vehicle  10  relative to a fixed reference. The fixed reference may be part an inflatable restraint module. For example,  FIG. 1  illustrates as an air bag module  20  mounted in the instrument panel  22  of the vehicle  10 . The air bag module includes a deployment door  24 . In the occupant position sensing system  12  of  FIG. 1 , a rearward most portion of the deployment door  24  is the fixed reference.  
         [0019]     The sensor element  14  of the occupant position sensing system  12  may be any device for obtaining occupant position data and providing a signal indicative of the sensed data. For example, the sensor element  14  may include one or more cameras for obtaining images of the occupant in the interior of the vehicle  10 . Other examples of the sensor element  14  include one or more of an infrared sensor, an ultrasonic sensor, or a microwave or laser sensor.  
         [0020]     The controller  16  of the occupant position sensing system  12  is operatively connected to the sensor element  14  and receives the signal provided by the sensor element. The controller  16  is adapted for analyzing the occupant position data provided in the signal for determining the position of the occupant relative to the fixed reference. The controller  16  runs a known algorithm for analyzing the occupant position data for determining the position of the occupant. For example, when the sensor element  14  includes one or more cameras for obtaining images of the occupant within the interior of the vehicle  10 , the controller  16  may run a known pattern recognition algorithm for determining the position of the occupant.  
         [0021]     The controller  16  of the occupant position sensing system  12  is operatively connected to an air bag controller (not shown) for controlling actuation of the air bag module  20 . Alternatively, a single controller, shown as controller  16  in  FIG. 1 , may control both the occupant position sensing system  12  and the air bag module  20 . When controller  16  controls both the occupant position sensing system  12  and the air bag module  20 , the controller  16  is responsive to the determined occupant position relative to the fixed reference for controlling actuation of the air bag module  20 . For example, if the controller  16  determines that an occupant is within a zone  26  located proximate the deployment door  24 , the controller  16  may inhibit, or otherwise limit, the actuation of the air bag module  20 . Ways that the controller  16  may otherwise limit actuation of the air bag module  20  include venting or actuating a multi-stage inflator in a low power mode.  
         [0022]     The dashed line  28  of  FIG. 1  illustrates the leftward most boundary of the zone  26 . In an exemplary vehicle, the leftward most boundary  28  is located approximately 200 millimeters from the deployment door  24  of the air bag module  20 .  
         [0023]     The controller  16  of the occupant position sensing system  12  also includes an output, indicated schematically at  30  in  FIGS. 1 and 2 . The controller  16  is adapted for providing, via the output  30 , an occupant position signal that is indicative of the determined position of the occupant. The output  30  may be connected to a bus (not shown) of the vehicle  10 . Alternatively, the output  30  may be an output dedicated for testing of the vehicle, such as, for example, a dedicated RS232 port.  
         [0024]      FIG. 1  also schematically illustrates an apparatus  40  constructed in accordance with an exemplary embodiment of the present invention.  FIG. 2  illustrates a schematic block diagram of the apparatus  40  of  FIG. 1  connected to the occupant position sensing system  12  of the vehicle  10 .  
         [0025]     The apparatus  40  includes a linear motor  42 . As best shown in  FIG. 2 , the linear motor includes a stationary portion  44  and a movable portion  46 . The stationary portion  44  of the linear motor  42  includes a base  48  and plurality of permanent magnets  50 . The movable portion  46  of the linear motor  42  includes a plurality of electromagnets  52 . Alternatively, the movable portion  46  of the linear motor  42  may include the permanent magnets  50  and the stationary portion  44  may include the electromagnets  52 . In a preferred embodiment of the linear motor  42 , however, the electromagnets  52  are located in the movable portion  46 . Preferably, a mass of the movable portion  46  of the linear motor  42  is kept to a minimum. Thus, the electromagnets  52 , which generally weigh significantly less than the permanent magnets  50 , preferably are incorporated in the movable portion  46 .  
         [0026]     The electromagnets  52  of the linear motor  42  are electrically coupled to motor drive electronics  58 . The motor drive electronics  58  include known structures for receiving electrical power from a power source  60  and for providing electric power to the electromagnets  52 . When the electromagnets  52  are incorporated in the movable portion  46  of the linear motor  42 , as shown in  FIG. 1 , the electric power provided to the electromagnets  52  causes the movable portion  46  of the linear motor  42  to move relative to the stationary portion  44  of the linear motor. Preferably, the power source  60  provides three-phase alternating current to the motor drive electronics  58 . The motor drive electronics  58 , in turn, control energization of the electromagnets  52  to control movement of the movable portion  46  of the linear motor  42  relative to the stationary portion  44 .  
         [0027]     The apparatus  40  also includes a motor position sensor  64  that is associated with the linear motor  42 . The motor position sensor  64  is a high resolution position sensor that is adapted to provide feedback signals to the motor drive electronics  58  indicative of the relative position between the stationary portion  44  and the movable portion  46  of the linear motor  42 . In response to the feedback signals from the motor position sensor  64 , the motor drive electronics  58  control commutation of the linear motor  42 .  
         [0028]      FIG. 3  illustrates an exemplary embodiment of the motor position sensor  64 . The motor position sensor  64  of  FIG. 3  is a high resolution optical encoder  66 . The optical encoder  66  is fixedly mounted to the movable portion  46  of the linear motor  42 . Markings  68 , that may appear similar to bar codes, are located on a surface of the stationary portion  44  of the linear motor  42  in a location adjacent the optical encoder  66 . The optical encoder  66  is adapted to read the markings  68  and to provide a motor position signal indicative of the position of the movable portion  46  of the linear motor  42  relative to the stationary portion  44 .  
         [0029]     The apparatus  40  also includes a controller  74 . The controller  74  is operatively connected to the motor drive electronics  58  and controls the motor drive electronics. Thus, the controller  74  controls the linear motor  42 . In an exemplary embodiment of the invention, the controller  74  is a personal computer. The controller  74  runs a program for controlling the motor drive electronics  58  to provide desired performance of the linear motor  42 . For example, the controller  74  may control the motor drive electronics  58  for causing the movable portion  46  of the linear motor  42  to move to the right, as viewed in  FIG. 1 , at a desired rate. The rate may be a constant velocity, a constant acceleration, or a variable velocity/acceleration type movement. The controller  74  also controls the motor drive electronics  58  to stop the movable portion  46  of the linear motor  42  at a location adjacent to, but spaced apart from, the instrument panel  22  of the vehicle  10 .  
         [0030]     The controller  74  is provided with an input  76  through which data may be entered into the controller. The input  76  may be a keyboard, a drive unit, or any other type of input for inputting data into the controller  74 .  
         [0031]     A recording device  80  of the apparatus  40  is operatively connected to the motor drive electronics  58 . The recording device  80  may be any type of data collection device. In an exemplary embodiment of the invention, the recording device  80  is a personal computer. The recording device  80  receives the motor position signal provided from the motor position sensor  64 . As set forth above, the motor position signal from the motor position sensor  64  is provided to the motor drive electronics  58  as a commutation control feedback. In additional to using the data provided in the motor position signal for controlling commutation of the linear motor  42 , the motor drive electronics  58  also outputs the motor position signal to the recording device  80 . The recording device  80  records the data provided in the received motor position signals.  
         [0032]     As an alternative to providing the recording device  80  with the motor position signal from the motor position sensor  64  via the motor drive electronics  58 , the motor position sensor  64  may be directly connected to the recording device  80 . As an additional alternative, a second motor position sensor may be provided for supplying the recording device  80  with a signal indicative of the position of the movable portion  46  of the linear motor  42  relative to the stationary portion  44 .  
         [0033]     As shown in  FIG. 2 , during testing of the occupant position sensing system  12 , the controller  16  of the occupant position sensing system  12  is operatively connected to the recording device  80 . A cable  84  may be used to connect the output  30  of the controller  16  to the recording device  80 . The controller  16  provides a signal indicative of the determined occupant position to the recording device  80 . The recording device  80  records the determined occupant position information provided by the controller  16 .  
         [0034]     As shown in  FIG. 1 , the apparatus  40  also includes a test dummy  90 .  FIG. 1  illustrates the test dummy  90  as including a head and torso only. The test dummy  90 , however, may have configurations other than that illustrated in  FIG. 1 . The test dummy  90  is fixedly mounted to the movable portion  46  of the linear motor  42 . As the movable portion  46  of the linear motor  42  moves relative to the stationary portion  44 , the test dummy  90  moves with the movable portion  46 .  
         [0035]     The test dummy  90  meets the intent of Federal Motor Vehicle Safety Standard 208, but is much lighter in weight than a standard anthropomorphic test dummy. In an exemplary embodiment of the present invention, the test dummy  90  is formed from a light weight foam material that is covered with an outer skin that may be sensed with the sensor element  14  of the occupant position sensing system  12 . For example, when the sensor element  14  is an ultrasonic sensor, the outer skin of the test dummy  90  may need to be adapted to reflect ultrasonic signals in a manner similar to human skin. The test dummy  90  also includes a lightweight mounting tube, such as an aluminum mounting tube. The outer skin of the test dummy  90  may be constructed of parts from anthropomorphic test dummy constructed in accordance with 49 C.F.R. Part 572 (particularly, sections 572.140 and 572.141), as published in the Federal Register, Mar. 22, 2000 and which is incorporated herein by reference in its entirety.  
         [0036]     The use of a light weight test dummy  90  reduces the mass of the assembly of the movable portion  46  of the linear motor  42  and the test dummy  90 . As a result of the reduced mass, the momentum of the assembly of the movable portion  46  and the test dummy  90  is reduced during testing and the ability to stop the assembly prior to the test dummy contacting the instrument panel  22  is increased. During testing of the occupant position sensing system  12 , contact between the test dummy  90  and the instrument panel  22  will generally result in damage to the instrument panel. By increasing the ability to stop the assembly of the movable portion  46  and the test dummy  90  prior to the test dummy contacting the instrument panel, the likelihood of damaging the instrument panel  22  of the vehicle  10  during testing of the occupant position sensing system  12  is reduced.  
         [0037]     To test the occupant position sensing system  12  of the vehicle  10 , the linear motor  42 , along with the test dummy  90  fixed to the movable portion  46 , is mounted within the vehicle  10 . In the exemplary embodiment of  FIG. 1 , the vehicle seat (not shown) at the location to be tested is removed and the linear motor  42  is positioned in the vehicle in the position previously occupied by the removed vehicle seat. For example, when testing the occupant position sensing system  12  for detecting an occupant of the passenger seat of the vehicle  10 , the passenger seat is removed and the linear motor  42  is positioned in the vehicle at the location of the removed passenger seat.  
         [0038]     For increasing the accuracy of the test, portions of the apparatus  40 , other than the test dummy  90 , which are located within the vehicle  10  may be coated with a paint or other type of coating having a low reflectivity so that the portions are not sensed by the occupant position sensing system  12 .  
         [0039]     When the linear motor  42  is positioned in the vehicle  10 , the stationary portion  44  of the linear motor  42  is leveled and is secured relative to the vehicle  10  to prevent relative movement between the stationary portion and the vehicle. The apparatus  40  is then calibrated so as to be able to provide information regarding the relative position between the test dummy  90  and the fixed reference. To calibrate the apparatus  40 , the movable portion  46  of the linear motor  42  is moved slowly to the right, as viewed in  FIG. 1 , relative to the stationary portion  44  until the test dummy  90  comes into contact with the instrument panel  22 , which includes the deployment door  24  of the air bag module  20 . When the test dummy  90  is in contact with the instrument panel  22 , the motor position signal from the motor position sensor  64  is analyzed to determine the relative position between the movable portion  46  and the stationary portion  44  of the electric motor  42 . The determined relative position is used as a baseline or reference position for the apparatus  40 .  
         [0040]     During testing of the occupant position sensing system  12  of the vehicle  10 , the test dummy  90  is positioned in the desired initial position, to the left as shown in  FIG. 1 . To place the test dummy  90  in the desired initial position, the linear motor  42  is controlled to move the movable portion  46  to a location relative to the stationary portion  44  for placing the test dummy  90  at the desired initial position. For example, if the desired initial position of the test dummy is 500 millimeters away from the instrument panel  22 , the movable portion  46  of the linear motor  42  is moved to a position 500 millimeters away from the determined baseline position.  
         [0041]     After the test dummy  90  is positioned in the desired initial position, the linear motor  42  is controlled to move the test dummy  90  relative to the instrument panel  22  in accordance with the event to be simulated, such as a vehicle braking. The controller  74  via the motor drive electronics  58  controls the linear motor  42  to provide various accelerations and velocities of the test dummy  90  so as to simulate occupant movement during various types and severities of crash events. For example, the linear motor  42  may be controlled to move the test dummy  90  to simulate pre-crash braking.  
         [0042]     The linear motor  42  also is controlled to stop the movement of the test dummy  90  prior to the test dummy contacting the instrument panel  22 . Thus, the apparatus  40  enables testing of the occupant position sensing system  12  of the vehicle  10  without damaging any portion of the vehicle  10 . As a result, the apparatus  40  enables the testing of the occupant position sensing system  12  to be repeated under various conditions.  
         [0043]     During the movement of the test dummy  90  relative to the instrument panel  22 , the motor position sensor  64  provides signals to the recording device  80  indicative of the relative position between the test dummy  90  and the baseline position. The controller  16  of the occupant position sensing system  12  also provides signals to the recording device  80  indicative of the determined occupant position. The recording device  80  records the data received from both the motor position sensor  64  and the occupant position sensing system  12 .  
         [0044]     The recording device  80  enables the determined occupant positions from the occupant position sensing system  12  at particular points in time to be compared to the positions indicated by the motor position signals from the motor position sensor  64  at the same points in time. As a result, the ability of the occupant position sensing system  12  to detect the occupant entering the zone  26  can be determined. The recording device  80  also enables the results of the test to be plotted. For example, plots of position versus time as well as velocity versus time and acceleration versus time may be generated from the recorded position data.  
         [0045]      FIG. 4  schematically illustrates an apparatus  40   a  constructed in accordance with a second exemplary embodiment of the present invention. The apparatus  40   a  of  FIG. 4  is mounted in a vehicle  10   a  for testing the occupant position sensing system  12   a  of the vehicle. Structures of  FIG. 4  that are the same as or similar to those described with reference to the apparatus  40  of  FIG. 1  are numbered with the same reference numbers as used in  FIGS. 1-3  with the addition of the suffix “a”. Also, for brevity of the present invention, those structures of the apparatus  40   a  of  FIG. 4  that have already been described in detail with reference to  FIGS. 1-3  will not be described again with reference to  FIG. 4 .  
         [0046]     The apparatus  40   a  of  FIG. 4  is identical to the apparatus  40  of  FIG. 1  with the exception that the test dummy  90   a  is not mounted directly to the movable portion  46   a  of the linear motor  42   a.  Instead, in the exemplary embodiment of  FIG. 4 , the test dummy  90   a  is mounted on an end of a long rod  96   a  that is fixed to the movable member  46   a  of the linear motor  42   a.    
         [0047]     The apparatus  40   a  of  FIG. 4  enables the vehicle seat  98  associated with the position of the vehicle  10   a  to be tested to remain in place in the vehicle during the testing of the occupant position sensing system  12   a.  As a result, a more realistic test of the occupant position sensing system  12   a  is performed since background structure of the vehicle  10   a  is not removed during the test, particularly, since some occupant position sensing systems may use the background structure as part of the evaluation criteria.  
         [0048]     The apparatus  40   a  of  FIG. 4  operates in the same manner as the apparatus  40  of  FIG. 1  for testing the occupant position sensing system  12   a  of the vehicle  10   a.  To position the test dummy  90   a  in front of the seat  98  at the location of the vehicle  10   a  to be tested, a hole  100  is formed in the backrest portion of the seat  98  associated with that vehicle location and the rod  96 , to which the test dummy  90   a  is attached, is extended through the hole. An end of the rod  96  opposite the test dummy  90   a  is secured to the movable portion  46   a  of the linear motor  42   a.    FIG. 4  illustrates two clamps  102  for securing the end of the rod  96  to the movable portion  46   a  of the linear motor  42   a.    
         [0049]      FIG. 5  schematically illustrates an apparatus  40   b  constructed in accordance with a third exemplary embodiment of the present invention. The apparatus  40   b  of  FIG. 5  is mounted in a vehicle  10   b  for testing the occupant position sensing system  12   b  of the vehicle. Structures of  FIG. 5  that are the same as or similar to those described with reference to the apparatus  40  of  FIG. 1  are numbered with the same reference numbers as used in  FIGS. 1-3  with the addition of the suffix “b”. Also, for brevity of the present invention, those structures of the apparatus  40   b  of  FIG. 5  that have already been described in detail with reference to  FIGS. 1-3  will not be described again with reference to  FIG. 5 .  
         [0050]     In  FIG. 5 , the sensor element  14   b  of the occupant position sensing system  12   b  is mounted in the instrument panel  22   b  in a location above the air bag module  20   b.  As with the embodiments of  FIGS. 1 and 4 , the sensor element  14   b  may be located at any location in the vehicle for sensing the position of an occupant, such as the overhead area.  
         [0051]     The apparatus  40   b  of  FIG. 5  is identical to the apparatus  40  of  FIG. 1  with the exception that the apparatus  40   b  includes a support structure  110  that enables the linear motor  42   b  to be positioned in front of a backrest portion  112  of a seat  114  of the vehicle  10   b.  The support structure  110  of  FIG. 5  includes legs  120 ,  122 , and  124  that enable the linear motor  42   b  to be positioned on or above a cushion portion  116  of the seat  114 .  
         [0052]     The legs  120 ,  122 , and  124  extend between the stationary portion  44   b  of the linear motor  42   b  and structure of the vehicle  10   b,  such as the floor  128  of the vehicle. Preferably, two of the legs, shown in  FIG. 5  as legs  120  and  124 , are located at opposite ends of the stationary portion  44   b  of the linear motor  42   b.  The legs  120 ,  122 , and  124  may be adapted to telescope so that the length of each leg may be adjusted. One vehicle arrangement might include two legs at the front of the stationary portion  44   b  of the linear motor  42   b  and the rear of the stationary portion being supported by the cushion portion  116  of the seat  112 . Spacer blocks may be used for leveling the stationary portion  44   b  of the linear motor  42   b.  The legs  120 ,  122 , and  124  also may include structure for securing the legs to the vehicle  10   b,  such as feet that may be fixed to the floor  128  of the vehicle.  
         [0053]     The apparatus  40   b  of  FIG. 5  operates in the same manner as the apparatus  40  of  FIG. 1  for testing the occupant position sensing system  12   b  of the vehicle  10   b.  Like the apparatus  40   a  of  FIG. 4 , the apparatus  40   b  of  FIG. 5  enables the vehicle seat  114  associated with the position of the vehicle  10   b  to be tested to remain in place in the vehicle during the testing of the occupant position sensing system  12   b . As a result, a more realistic test of the occupant position sensing system  12   b  is performed since background structure of the vehicle  10   b  is not removed during the test.  
         [0054]     By enabling testing of occupant position sensing systems without damaging the vehicle in which the occupant position sensing system is located, the apparatus of the present invention makes it economically feasible to perform test under various environmental conditions. For example, the occupant position sensing system may be tested under varying amounts of ambient light, with the test dummies donned with various types of clothing, etc.  
         [0055]     From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. For example, the motor position sensor may be a LVDT (linear voltage differential transformer). Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.  
         [0056]     For purposes of full disclosure, sections 572.140 and 572.141 of 49 C.F.R. Part 572, as published in the Federal Register, Mar. 22, 2000 are reproduced below:  
         [heading-0057]     Subpart P-3-Year-Old Child Crash, Test Dummy, Alpha Version  
         [heading-0058]     § 572.140 Incorporation by Reference.  
         [0059]     (a) The following materials are hereby incorporated in this subpart P by reference: 
        (1) A drawings and specifications package entitled “Parts List and Drawings, Subpart P Hybrid III 3-year-old child crash test,dummy, (H-1113C, Alpha version) February 2000”, incorporated by reference in § 572.141 and consisting of 
            (i) Drawing No. 210-1000, Head Assembly, incorporated by reference in §§ 572.141, 572.142, 572.144, 572.145, and 572.146;     (ii) Drawing No. 210-2001, Neck Assembly, incorporated by reference in §§ 572.141, 572.143, 572.144, 572.145, and 572.146;     (iii) Drawing No. TE-208-000, Headform, incorporated by reference in §§ 572.141, and 572.143;     (iv) Drawing No. 210-3000, Upper/Lower Torso Assembly, incorporated by reference in §§ 572.141, 572.144, 72.145, and 572.146;     (v) Drawing No. 210-5000-1(L), -2(R), Leg Assembly, incorporated by reference in §§ 572.141, 572.144, 572.145 as part of a complete dummy assembly;     (vi) Drawing No. 210-6000-1(L), -2(R), Arm Assembly, incorporated by reference in §§ 572.141, 572.144, and 572.145 as part of the complete dummy assembly;    
            (2) A procedures manual entitled “Procedures for Assembly, Disassembly and Inspection (PADI), Subpart P, Hybrid III 3-year-old Child Crash Test Dummy, (H-1113C, Alpha Version) February 2000”, incorporated by reference in § 572.141;     (3) SAE Recommended Practice J211/1, Rev. Mar 95 “Instrumentation for Impact Tests-Part 1-Electronic Instrumentation”, incorporated by reference in § 572.146;     (4) SAE J1733 1994-12 “Sign Convention for Vehicle Crash Testing” incorporated by reference in § 572.146.     (5) The Director of the Federal Register approved those materials incorporated by reference in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51.     Copies of the materials may be inspected at NHTSA&#39;s Docket Section, 400 Seventh Street SW, room 5109, Washington, D.C., or at the Office of the Federal Register, 800 North Capitol Street, NW, Suite 700, Washington, D.C.        
 
         [0072]     (b) The incorporated materials are available as follows: 
        (1) The drawings and specifications package referred to in paragraph (a)(1) of this section and the PAD1 document referred to in paragraph (a)(2) of this section are available from Reprographic Technologies, 9000 Virginia Manor Road, Beltsville, Md. 20705 (301) 419-5070.     (2) The SAE materials referred to in paragraphs (a)(3) and (a)(4) of this section are available from the Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, Pa. 15096. 
 
 § 572.141 General Description 
       
 
         [0076]     (a) The Hybrid III 3-year-old child dummy is described by the following materials: 
        (1) Technical drawings and specifications package 210-0000 (refer to § 572.140(a)(1)), the titles of which are listed in Table A of this section;     (2) Procedures for Assembly, Disassembly and Inspection document (PADI) (refer to § 572.140 (a) (2)).        
 
         [0079]     (b) The dummy is made up of the component assemblies set out in the following Table A of this section:  
                           TABLE A                                   Component assembly   Drawing No.                           Head Assembly   21O-1000           Neck Assembly (complete)   210-2001           Upper/Lower Torso Assembly   21 O-3000           Leg Assembly   210-5000-               1 (L), −2(R)           Arm Assembly   210-6000-               1 (L), −203)                      
 
         [0080]     (c) Adjacent segments are joined in a manner such that except for contacts existing under static conditions, there is no contact between metallic elements throughout the range of motion or under simulated crash impact conditions.  
         [0081]     (d) The structural properties of the dummy are such that the dummy conforms to this part in every respect only before use in any test similar to those specified in Standard 208,  Occupant Crash Protection,  and Standard 213,  Child Restraint Systems.