Abstract:
A system remotely collects test data from a test platform using platform attached sensors. Identification chips, each having a unique identification code, are each paired with an associated sensor to form sensor/chip pairs. At least one patch panel having a plurality of connections is positioned approximate to the platform. Connections are communicatively linked to each of the sensor/chip pairs. A computer system is communicatively linked to additional patch panel connections. The identification of selected sensors is queried by a computer command to the patch panels, and a group of sensors for a given test is identified and selected. Test data from each of the selected sensors is transferred through the patch panels to the computer system for collation and generation of a test setup compatible with a data acquisition system. Test setup information is downloaded to the data acquisition system in preparation for the next test.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates in general to data acquisition and more specifically to a system and method to selectively identify and collect data from one or more specific test devices.  
         BACKGROUND OF THE INVENTION  
         [0002]    Test laboratories need to monitor several hundred (up to several thousand) strain gages and other test devices during structural qualification of aircraft, launch vehicles, or other types of structures. A data acquisition system is commonly used to collect and collate test data. To ensure proper data collection, the connection between each strain gage or device and the data acquisition system needs to be verified. This end-to-end verification requires significant amounts of schedule time and labor during the test critical path. The verification typically involves reading labels on strain gage cables, de-mating or shorting connectors, or shorting strain gages and observing information in the data acquisition system.  
           [0003]    The disadvantage of individually reading labels on cables, de-mating or shorting connectors, or shorting strain gages to determine proper connections for the strain gages is amplified when many thousands of strain gages are used. Modern aircraft installations can require up to approximately 8,000 strain gages for structural testing. The time and labor to change out individual cables for specific individual tests requires verification of the connection at both the strain gage end and data acquisition end of the individual cable channels. Where selected quantities of the strain gages are required for individual tests, each channel (i.e. strain gage to data acquisition system connection) is typically shorted at one end of the cable and verified by an operator at the opposite end of the cable. Large amounts of test time as well as delays in construction and delivery schedule can result from the verification process for each of the channels required for an individual test.  
           [0004]    It is therefore desirable to provide a system which can be remotely controlled, which can automatically identify individual strain gages or devices for an individual test, and which eliminates the need for testing each channel for continuity prior to a test.  
         SUMMARY OF THE INVENTION  
         [0005]    According to a preferred embodiment of the present invention a system is provided to remotely collect test setup data from a mobile platform. A platform can range from one strain gage on a simple test coupon, to several hundred strain gages on a component test, or to several thousand strain gages on a major test. The system includes a plurality of identification chips each having a unique identification code are individually paired with one of the sensors to form a plurality of sensor/chip pairs. A data acquisition system is linked to alternate ones of the connections of the patch panel.  
           [0006]    The identification chips that are each associated with one of the sensors are provided with unique identification codes each having a multiple bit code formatted for digital transmission. By reading the identification code of the identification chips at the patch panel, the proper channel for each of the sensors connected to that patch panel can be identified. A remotely located computer can then signal a shunt resistor to close in the patch panel to select an individual channel to identify which path exists between a known sensor (identified by its identification code), through the patch panel into the data acquisition system. Light emitting diodes are also placed adjacent to each of the sensors and the connections on the patch panel such that a visual indication is provided at the patch panel and at the sensor to manually identify the location of the channel connector on the patch panel for an individual sensor.  
           [0007]    A computer is connected to the patch panel to provide individual commands to the patch panel for identifying or selecting individual channels for test purposes. A network capable application processor is placed between the computer and the patch panel to decode the computer commands for direct use by the patch panel. The computer can be remotely located from the patch panel and the patch panel controlled via a network connection between the computer and the network capable application processor. Each patch panel is individually controlled within the panel by a field programmable gate array module. Multiple patch panels can be networked and controlled by the computer.  
           [0008]    Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the invention.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0010]    [0010]FIG. 1 is a diagram showing the configuration tool and a simplified portion of the present invention;  
         [0011]    [0011]FIG. 2 is a diagram showing a strain gage connected to a patch panel of the present invention;  
         [0012]    [0012]FIG. 3 is a diagram similar to FIG. 2, showing multiple patch panels networked together and the optional use of an Intranet connection; and  
         [0013]    [0013]FIG. 4 is a block diagram showing the process to extract data from a strain gage/chip pair using a patch panel of the present invention to prepare the data acquisition system for test. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0014]    The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0015]    Referring to FIG. 1, a sensor system  10  includes at least one strain gage  12  having a first lead  14 , a second lead  16 , and a third lead  18  each connected to a common terminal strip  20  (e.g., by soldering). The first lead  14  typically provides current to the strain gage  12 . The second lead  16  is the return path for the current from the strain gage  12 . The third lead  18  from the strain gage  12  is a signal lead normally fed to signal conditioning equipment (not shown), where the output is read as the strain gage  12  output. Each strain gage  12  is provided with an associated identification chip  22 . The identification chip  22  is known and includes a multi-bit, unique identification code or number which is assigned to the identification chip  22  when it is constructed. The unique identification code assigned to the identification chip  22  is a non-repeating code such that every identification chip  22  has a unique code assigned to it. The identification chip  22  can also be a memory chip such that additional data for the strain gage  12  can be identified thereon. The identification chip  22  is provided with a first identification (ID) lead  24  and a second ID lead  26 . The first ID lead  24  and the second ID lead  26  may terminate at the terminal strip  20  depending upon the design of the identification chip  22 .  
         [0016]    Both the strain gage  12  and the identification chip  22  leads are commonly connected to an interface connector  28  located close to the strain gage. From the interface connector  28 , the input and output to the strain gage  12  and the identification chip  22  are commonly provided in a short interface cable  30  connected to a configuration tool  36  during initial strain gage  12  installation and checkout. The interface cable  30  extends remotely from the position of the strain gage  12  and the identification chip  22  and terminates at a connector  32 . Each of the components including the connector  32 , the interface cable  30  and both the strain gage  12  and the identification chip  22  together form a channel  34 . Multiple channels  34  can be used depending on the number of sensors required. In a preferred embodiment, the interface connector  28  and the connector  32  are RJ-45 connectors, known in the art, however, the invention is not limited to the connector type.  
         [0017]    The connector  32  terminates at a configuration tool  36 . The configuration tool  36  provides either a data input or output point for the identification chip  22  or a collection point for data from both the strain gage  12  and the identification chip  22 . The configuration tool  36  is provided with manual connectors (not shown) for direct readout and recording of installed strain gage resistance and resistance to ground via a digital multi-meter/digital volt-meter  38 , which can be recorded by the configuration tool  36 . The configuration tool  36  can be a portable computer or similar device. Separate probes (not shown) can also be provided in the configuration tool  36  to locally read and record the data provided in the identification chip  22 , the strain gage resistance, and resistance to ground at terminal strip  20 . The strain gage  12  and the identification chip  22  are both normally connected to a platform  40  from which strain data is required. The configuration tool  36  can be positioned remote from the platform  40 , or adjacent to the platform  40 . The platform  40  can include any of a plurality of items requiring test data, including but not limited to structures, fluid systems, vehicles, and air flow devices. The one or more strain gages  12  can also be replaced by other sensor types, including, but not limited to, pressure, flow, velocity, thermocouples, and acoustic sensors.  
         [0018]    Referring now to FIG. 2, a patch panel sensor system  100  is shown. The patch panel sensor system  100  includes at least one strain gage  102  having a first lead  104 , a second lead  106 , and a third lead  108  connected to a terminal strip  110 . At least one identification chip  112  is also provided for each strain gage  102 . Each identification chip  112  includes a first ID lead  114  and a second ID lead  116 . Both the first ID lead  114  and the second ID lead  116  are also connected to the terminal strip  110 . A connector  118  joins all of the leads from the terminal strip  110  into a common assembly for routing through a cable  120 . A distal end of the cable  120  includes a connector  122 . Similar to the sensor system  10  of FIG. 1, each strain gage  102  and identification chip  112  together with the cable  120  and the connectors  118  and  122  form a channel  124 . A plurality of channels  124  can be connected into a patch panel  126 .  
         [0019]    The connectors  122  are provided on a front face of the patch panel  126 . On the rear of the patch panel  126 , a corresponding number of connectors  138  are also provided. Each connector  138  provides a throughput connector for each of the channels  124 . From each connector  138 , one of a plurality of cables  140  transfers data to a data acquisition system  142 . The patch panel  126  provides a normal, non-intrusive, three wire direct interface between each strain gage  102  and the data acquisition system  142  The patch panel  126  includes a plurality of the connectors  122  on a front face and the same number of output connectors  138  on the rear face of the patch panel. A preferred embodiment provides connectors for 32 channels of strain gages or sensors. In one embodiment of the present invention, the patch panel  126  has a width of approximately 48.3 cm (19 inches) and a height of approximately 5.1 cm (2 inches). Each of the connectors  122  and  138  are formed along a longitudinal row on the front and rear respectively, on the body of the patch panel  126 .  
         [0020]    Within the patch panel  126 , a field programmable gate array module  128  is linked to each of the channels  124 . The field programmable gate array module  128  acts as a decoder and receives signals from an external source for programming to or accessing data from the identification chip  112  from each of the channels  124 . The patch panel  126  also includes a shunt resistor  130 . The shunt resistor  130  is closed across strain gage first lead  104  and second lead  106  of channels  124  by commands given through the field programmable gate array module  128 . When the shunt resistor  130  is closed across any of the channels  124 , a voltage change is observed at the data acquisition system  142 , verifying the connection between connector  138  of the patch panel  126  and the assigned input channel of the data acquisition system  142 .  
         [0021]    The patch panel  126  is also provided with a light emitting diode  132  for each of the channels  124 . The purpose of the light emitting diode  132  is to provide a visual indication of the location on a particular patch panel  126  for one of the desired channels  124 . Each channel  124  has a light emitting diode  133  connected across the first and second leads  114  and  116  of the identification chip  112 . Each light emitting diode  133  is powered via a first diode lead  134  and a second diode lead  135 . The light emitting diodes  132  and  133  for a select channel  124  will illuminate when selected by the field programmable gate array module  128 , and the patch panel  126  also displays the channel number on a channel address indicator  136 . Light emitting diodes  132  and  133  are used in part to make troubleshooting more efficient by providing a visual correlation of the patch panel input connector  122  and the corresponding strain gage on the platform  40  (shown in FIG. 1).  
         [0022]    Depending upon the number of total channels required for a test, a plurality of patch panels  126  may be used. Each patch panel  126  therefore requires an identification code to uniquely identify each individual patch panel  126 . The channel address indicator  136  in a preferred embodiment of the present invention provides a seven segment light emitting diode display to indicate a range of the channels provided by the patch panel  126 . For example, an individual patch panel  126  may indicate that a channel range for exemplary channels  33  to  64  are provided by a particular patch panel. A selector switch  137  provides a manual means of changing the channel address indicator  136  to identify the particular range of channels provided by any one of the patch panels  126 .  
         [0023]    The field programmable gate array module  128  within the patch panel  126  is directed by instructions received via a data line  144  from a network capable application processor  146 . The network capable application processor  146  includes a computer processor, an Ethernet connection, and a transducer bus controller. A network connection  148  connects the network capable application processor  146  to a computer  150 . The computer  150  provides instructions for accessing individual channels  124 , accessing any plurality of channels  124 , and instructions to close the shunt resistor  130  via the field programmable gate array module  128 . The code transmitted from the computer  150  is linked via the network capable application processor  146  to the field programmable gate array module  128 , where the code is decoded for use. The computer  150  also typically stores information including a strain gage name, a strain gage factor, a strain gage transverse sensitivity, a strain gage resistance, a strain gage type and a strain gage lot number for each strain gage. Some of this information can also be provided in an identification memory chip (not shown) if an identification memory chip is used to replace the identification chip  112 . The computer  150  can format all of the data from each of the strain gages  102  and identification chips  112  and provide a test setup for downloading to the data acquisition system.  
         [0024]    Several functions of the data acquisition system  142  are to provide excitation to the strain gages  102 , read the voltages from each of the strain gages  102 , and to convert the strain gage voltage to engineering units. When hundreds or thousands of strain gages  102  are used for a particular test, the patch panel  126  provides to an operator of the data acquisition system an indication of which particular strain gage  102  is assigned to each of the channels  124  and the corresponding input channel number on the patch panel.  
         [0025]    A data line  152  is shown in phantom in FIG. 2. The data line  152  provides another preferred embodiment of the present invention wherein the computer  150  is not used. Where a data acquisition system  142  is provided with sufficient capability, direct requests to identify individual channels  124  and to identify the code saved on individual identification chips  112  can be directed from the data acquisition system  142  through the network capable application processor  146  directly to the field programmable gate array module  128 .  
         [0026]    A plurality of patch panels  126  are used in a preferred embodiment of the present invention in order to provide the capability for configuring hundreds and up to thousands of individual strain gages  102 . The network capable application processor  146  provides the capability to network each of the plurality of patch panels  126  via a plurality of data lines  144 .  
         [0027]    Using commands from the computer  150  through the network capable application processor  146 , any individual strain gage  102  can be shunted by shunt resistor  130 , and any individual identification chip  112  can be accessed. In addition, all of the channels  124  for a given patch panel  126  or all of the channels  124  for a plurality of patch panels  126  in a given test arrangement of identification chips  112  can also be simultaneously accessed and recorded and/or displayed in near-real-time on the computer  150 . Similarly, any one channel  124 , any group of channels  124  of a particular patch panel  126 , or all of the channels  124  in a plurality of patch panels  126  in a given test arrangement can be shunted via the field programmable gate array module and the shunt resistor  130  in each patch panel  126 .  
         [0028]    Referring to FIG. 3, the arrangement of FIG. 2 is further detailed showing the interlinking of multiple patch panels  126   a  and  126   b  to the platform  40 . The platform  40  has multiple strain gages  12   a ,  12   b ,  12   c  and  12   d , each associated with an identification chip  22   a ,  22   b ,  22   c  and  22   d , respectively, and a light emitting diode  132   a ,  132   b ,  132   c  and  132   d , respectively. Commands from the computer  150  can optionally be routed through a user provided Intranet  154  to either the data acquisition system  142  via an Ethernet line  156  or to the network capable application processor  146  via an Ethernet line  158 .  
         [0029]    When all the necessary strain gages (e.g.,  12   a ,  12   b ,  12   c ,  12   d , etc.) are connected, a data system operator (not shown) can interact with the plurality of patch panels ( 126   a ,  126   b , etc.) in an automated, systematic inventory of all strain gages (or sensors) in the system. The results of the inventory can be automatically transformed into a setup file  160  in a format suitable for downloading to the data acquisition system  142  via the Intranet  154  and the Ethernet line  156 .  
         [0030]    Referring now to FIG. 4, a sequence of steps is identified to access and record all patch panel input channel numbers and associated identification chips  112  for a plurality of patch panels  126  of the present invention. This data is formatted and downloaded for use by the data acquisition system. In a step  162 , a command is input using a computer  150  to display all patch panel input channel numbers and their associated identification chip  112  numbers. In a step  164 , the command is bussed from the computer to a network capable application processor and from the network capable application processor to each patch panel. In a step  166 , the command is decoded using a field programmable gate array module in each patch panel into a format required to access the identification chips. In a step  168 , the field programmable gate array module reads the unique identification number of the identification chips  112 . In a step  170 , the unique identification numbers of identification chips  112 , and corresponding patch panel input channel numbers, are bussed from the field programmable gate array module in each patch panel to the network capable application processor, and from the network capable application processor to the computer, where the information is displayed and recorded to disk. In step  172 , the computer integrates the previously entered information about each strain gage such as a gage number, gage factor, transverse sensitivity, gage resistance, gage type and gage lot number for each strain gage, and generates a test setup in a known format for downloading to the data acquisition system. In a final step  174 , the test setup is downloaded to the data acquisition system via the Intranet to be used by the data acquisition system to acquire data on the next test.  
         [0031]    As previously noted, the computer has the relationship of the patch panel output channel numbers and the corresponding data acquisition system input channel numbers. Also, the relationship between strain gages  102  and associated identification chips is previously established during initial strain gage installation using the configuration tool as shown in FIG. 1. This allows for the logical and automatic relationship between all strain gages  102  and their corresponding data acquisition style input channels to be established. This automatically completes verification of each strain gage installation, versus the commonly known, tedious and costly, end-to-end verification of each strain gage installation.  
         [0032]    A patch panel  126  for accessing information from sensors of the present invention offers several advantages. By providing a patch panel  126  having multiple channel capability between a particular set of sensors (e.g., strain gages) and a data acquisition system  142 , it is possible using the patch panel  126  to read the information associated with the individual strain gages to correctly provide a strain gage lineup for a particular test and transmit the individual strain gage data directly to the data acquisition system  142 . Associating each strain gage or sensor with an identification chip having a unique identification number assigned to each chip provides the capability of uniquely identifying each strain gage or sensor. Providing a computer access to the patch panel permits software to be provided which can directly access the patch panel to query the particular channel location for any individual sensor or strain gage. Using a shunt resistor within the patch panel also remotely provides the capability of verifying a particular patch panel channel. Connecting to a particular data acquisition system input channel using a network capable application processor between the computer and the patch panel permits commands generated by the computer to be directly read into the patch panel. Light emitting diodes provided at both the location of each individual sensor or strain gage and the channel identification location on the patch panel provide a visual indication of a correct channel lineup between any individual sensor and the data acquisition system. The patch panel of the present invention permits existing data acquisition systems to remotely communicate with uniquely identified sensors.  
         [0033]    The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.