Abstract:
An automated wire testing system includes adapter modules that couple a wire harness under test with an interface test adapter. The interface test adapter (ITA) is coupled to or integrated with an automated wire testing machine. The ITA has a panel into which a standardized connector can be plugged in any of a number of positions. Stimulus/response paths originating at test points on the wire testing machine are distributed over a larger number of contacts on the panel connectors to provide flexibility. Adapter modules for any wire harness can readily be built using the standardized connector.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to automated test equipment and, more specifically, to wire testing systems and methods. 
   2. Description of the Related Art 
   Automated test equipment (ATE) is computer-controlled equipment that tests electronic devices for functionality or performance. One category of ATE includes automated wire testing machines for testing cables, wire harnesses and other complex wired assemblies. Wire testing machines are also variously referred to in the art to which the invention relates as wire testers and wire analyzers. 
   The term “wire harness” or “wiring harness” is commonly used to refer to an assembly comprising a bundle of electrical cables with electrical connectors at their ends. Some wire harnesses, such as those used in aircraft, ships, mass transit vehicles and other large vehicles, can be quite large and complex, comprising many individual cables of various lengths, with various types of connectors. Each cable may have many individual wires bundled together that terminate in a connector having a corresponding number of contact pins or receptacles (sockets). The connectors themselves can be quite complex, such as the cylindrical connectors commonly used in military and aerospace vehicles, which typically have from a dozen to well over 100 contacts housed in cylindrical shell with a male or female bayonet or threaded coupling mechanism. Wire harnesses can have myriad network-like topologies, as may be needed to route signals throughout a vehicle or other large system, with branches and sub-branches of various lengths terminating in connectors at various locations. 
   As illustrated in  FIG. 1 , testing a typical wire harness  100  presents several challenges. The front panel of a wire testing machine  102  typically has a number of tester interface connectors  104 , which may be all of the same type or of several different types. Nevertheless, the connectors of the wire harness to be tested (i.e., the “unit-under-test” or “UUT”  100 ) may be of still another type that cannot be mated with those of the wire testing machine  102 . Also, a wire harness having a combination of some very long cables  106 , perhaps extending on the order of ten meters or more, and some much shorter cables  108 , is generally unwieldy, making it inconvenient to have all of the connectors  110  of all of the cables plugged into the wire testing machine  102  simultaneously. For these reasons, personnel charged with testing a wire harness typically construct one or more adapter cables  112 . An adapter cable  112  will have a connector  114  at one end that mates with a connector  110  on the UUT  100  and a connector  116  at the other end that mates with a tester interface connector  104  on the wire testing machine  102 . Each adapter cable  112  can be made as long or as short as may be convenient to extend between the wire testing machine  102  and the point along the length of the UUT  100  at which the corresponding connector  110  is found. The set of one or more adapter cables  112  is specifically designed for the testing of a corresponding wire harness  100  and generally cannot be used to test other wire harnesses having other structures or topologies. Thus, a manufacturer that produces, for example, 25 different wire harnesses, may have 25 corresponding sets of adapter cables  112  for testing them on the manufacturer&#39;s wire testing machine  102 . 
   It would be desirable to test complex wire harnesses on a wire testing machine without having to construct, store and use equally complex, cumbersome an d specialized adapter cables. The present invention addresses these problems and deficiencies and others in the manner described below. 
   SUMMARY OF THE INVENTION 
   The present invention relates to a system and method for testing a wire harness or similar wired assembly using an apparatus that performs automated wire testing and a plurality of adapter modules. In some embodiments of the invention, the apparatus can comprise a conventional automated wire testing machine in combination with an interface test adapter (ITA) or alternatively, in other embodiments, it can comprise an integrated device or machine that performs the functions of both the automated wire testing machine and the interface test adapter. 
   In some embodiments of the invention in which the ITA and wire testing machine are separate elements, the ITA can be mechanically mateable with or mountable on the front panel of the wire testing machine. In other such embodiments, cables can connect the ITA to the wire testing machine. The wire testing machine has a group of connectors on its front panel to which testing personnel would conventionally connect the wire harness to be tested, either directly or using adapter cables. When coupled to the wire testing machine, the wire harness is referred to as the unit-under-test (UUT). The connectors on the front panel of the wire testing machine can be referred to as tester interface connectors, and each has a plurality of contacts or test points. As described below, the present invention obviates the conventional use of complex, cumbersome and specialized adapter cables for connecting the UUT to the tester interface connectors. 
   The ITA has a panel and a second group of connectors, each of which is mounted on the panel. Each contact of each connector of the first group (i.e., the group to which the wire testing machine is connected) is electrically coupled with a contact of a connector of this second group, and at least some of the contacts of the connectors of the first group are coupled to more than one contact of the connectors of the second group (mounted in the ITA panel). Thus, in operation, the test points of the wire testing machine can be electrically coupled to more than one contact of the ITA panel connectors, thereby distributing stimulus signals generated by the wire testing machine and response signals to be received by the wire testing machine over a greater number of ITA panel contacts. This distribution of signals or signal pathways from a smaller number of test points or contacts at the wire testing machine to a larger number of contacts at the ITA panel enhances test configuration flexibility, as will become apparent from the detailed description below. 
   The term “panel” in this context refers to the area or region in which the connectors of the second group are arranged. The connectors of the second group are all of the same type as each other and are mounted on the panel in a uniform arrangement. Each adapter module has a connector that is of the same type as the connectors of the second group and are thus mateable with each other. The term “uniform” in this context means that the adapter module connectors that mate with the ITA connectors all mate in the same manner, both electrically and mechanically. To ensure uniform mechanical mating, they all have the same mechanical interface. For example, in an exemplary embodiment, the electrical contacts of each ITA panel connector can be arrayed in a rectangular arrangement of N×M contacts, and the connectors themselves arrayed in a rectangular arrangement of P×Q connectors, with each connector immediately adjacent another connector, thereby defining a rectangular array or field of (N)(P)×(M)(Q) contacts. The mechanism may include guide pins, rails or similar structures. The mating connector of each adapter module can be plugged into or otherwise mated with any ITA panel connector in the array because, in this embodiment, each such adapter module connector has the same rectangular array of mating contacts and the same mechanical mating mechanism as every ITA panel connector. In other words, the ITA panel connectors and mating adapter module connectors are made to conform to some suitable standard to provide uniformity. 
   Each adapter module also has a second connector that is mateable with a connector of the wire harness or UUT. A cable or other suitable electrical pathway couples this second connector with the first connector that plugs into one or more of the ITA panel connectors as described above. In some embodiments of the invention, the signal pathways represented by the wire testing machine Tester interface connectors can be uniformly distributed or distributed in a suitable pattern over some or all of the area of the ITA panel so as to enhance test configuration flexibility. For example, a test point on the wire testing machine can be coupled to every third contact in a rectangular array of ITA panel connectors or to one contact of each connector, thereby making the pathway available to an adapter module regardless of where on the panel it is plugged into. For convenience, each location on the panel into which an adapter module can be plugged may be referred to as a “zone,” and the zones numbered or otherwise labeled with suitable indicia on the panel. 
   A manufacturer of ITAs in accordance with the present invention can provide its customers with kits that comprise connectors conforming to the selected standard so that the customer can quickly and easily build adapter modules to test any desired wire harness. To build an adapter cable, a user need only obtain a connector of a type present in the UUT and couple it with a cable or other suitable electrical pathway to one of the standard connectors provided in the kit. Unlike a conventional adapter cable, which may comprise a complex network of interconnected connectors of different types, an adapter module of the present invention comprises one standard connector coupled with one connector mateable with a connector of the UUT. This arrangement and standardization enables re-use of the adapter cable when the user needs to test a different wire harness that has the same type of connector as previously tested wire harness. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a wire testing machine, wire harness, and adapter cables in accordance with the prior art. 
       FIG. 2  is a perspective view of the wire testing machine and wire harness of  FIG. 1  used with an interface test adapter and adapter modules in accordance with an embodiment of the present invention. 
       FIG. 3  is a front elevational view of the panel of the interface test adapter of  FIG. 2 . 
       FIG. 4  is a perspective view of the wire testing machine and wire harness of  FIG. 1  used with an interface test adapter (ITA) and adapter modules in accordance with an alternative embodiment of the invention, in which the ITA mounts on the wire testing machine. 
       FIG. 5  is a perspective view of the wire testing machine and wire harness of  FIG. 1  used with an interface test adapter and adapter modules in accordance with another alternative embodiment of the invention, in which a testing apparatus integrates the wire testing machine and ITA functionality. 
       FIG. 6  is a generalized schematic diagram of the system of  FIG. 2 . 
       FIG. 7  is a perspective view of an ITA in accordance with still another alternative embodiment of the invention, in which the ITA panel connectors are of the same type but mate with user-replaceable connectors of different types. 
       FIG. 8  is a front elevational view of one type of user-replaceable connector for the ITA of  FIG. 7 . 
       FIG. 9  is a front elevational view of another type of user-replaceable connector for the ITA of  FIG. 7 . 
       FIG. 10  is a front elevational view of an ITA in accordance with still another alternative embodiment of the invention, in which the ITA mounts to the front panel of the wire testing machine with an adjustable mounting mechanism. 
   

   DETAILED DESCRIPTION 
   As illustrated in  FIG. 2 , a testing apparatus comprises an interface test adapter (ITA)  200  and a plurality of adapter modules  202 . In the illustrated embodiment of the invention, this testing apparatus couples or interfaces the wire harness unit-under-test (U UT)  100  with a conventional wire testing machine  102 . Such automated wire testing machines  102 , which include all of the switching and control electronics (not shown for purposes of clarity) needed to perform automated tests upon wire harnesses, are well-known in the art, commercially available from a number of sources, and therefore not described in further detail herein (in this patent specification). 
   ITA  200  includes a first group of connectors  204  that can be plugged into or otherwise mated or connected to (as indicated by dashed line) connectors  104  of the same type on the front panel of wire testing machine  102 . As used herein, the term “type” with reference to a connector refers to the electrical and mechanical configuration of the connector, and only connectors of the same type can be mated. Although most electrical connectors are also typically referred to as either male or female or as plugs or jacks, these designations are not especially relevant to the present invention. For example, in some embodiments of the invention connectors  104  can be male and connectors  204  can be female, and in other embodiments connectors  204  can be male and connectors  104  can be female. For purposes of convenience, the terms “plug,” “jack,” “plugs into,” “is plugged into,” etc., are similarly used synonymously and interchangeably and without regard to gender herein unless the context clearly dictates otherwise. In preparation for using the testing apparatus to test UUT  100 , the user plugs connectors  204  into the corresponding connectors  104 . 
   ITA  200  also includes a second group of connectors  206  mounted on a panel  208 . In further preparation for using the testing apparatus to test UUT  100 , the user plugs one or more adapter modules  202  into connectors  206 . In the illustrated embodiment, panel  208  is a rectangular connector block in which connectors  206  comprise rectangular arrays of contacts  210 . Nevertheless, in other embodiments of the invention it can have other suitable configurations. Each adapter module  202  has a first connector  212  that is mateable with any of connectors  206  on panel  208 . Connectors  212  are all of the same type as each other, i.e., the have the same electrical and mechanical interfaces. With further reference to  FIG. 3 , panel  208  includes mating mechanical interface that allows any of connectors  212  to be plugged into it at any location at which a connector  206  is present. Each connector  206  can be labeled with a “zone” number (not shown for purposes of clarity) or other suitable indicia on panel  208  for convenience of reference. Although in the illustrated embodiment the mechanical interface comprises guide rails  214  distributed along the upper and lower edges of panel  208 , with mating guide channels (not shown for purposes of clarity) in connectors  212 , in other embodiments the mechanical interface can be of any other suitable type, such as guide posts with mating apertures, etc. (The configuration shown in  FIGS. 2–3 , in which one such connector  212  is plugged into the leftmost two connectors  206  (e.g., of “Zone  1 ” and “Zone  2 ”), and three more connectors  212  are plugged into the connectors  206  of Zones  4 ,  5  and  7 , respectively, with the connectors  206  of Zones  3  and  6  remaining unconnected, is intended merely to be illustrative of one of many such possible configurations.) A suitable retaining mechanism (not shown for purposes of clarity) such as one in which a connector  212  snaps into place when plugged into panel  208  can also be included to inhibit inadvertent removal. Connectors  212  and  206  can have any suitable structure that provides good electrical and mechanical connection. For example, each contact of each connector  212  can have a spring-loaded probe (not shown for purposes of clarity). Note that a connector  212  can span more than one connector  206 , as exemplified by the leftmost connector  212  shown in  FIGS. 2–3 . That is, a single connector  212  can make contact with the electrical contacts of two or more adjacent connectors  206  in panel  208 . 
   Each adapter module  202  further comprises a second connector  216  that is coupled with the corresponding connector  212  via a suitable cable or bundle of wires. Each connector  216  is selected to be of the same type as one of the connectors  110  of UUT  100  so that it can be mated to that connector  110 . In further preparation for using the testing apparatus to test UUT  100 , the user plugs each connector  110  into a mating connector  216  of one of adapter modules  212 . 
   Users can readily build adapter modules  212  by using a kit provided by the manufacturer of ITA  200  or other source. The kit can include a supply of connectors  212 , which, as described above, are all of the same type, i.e., conform to a standard selected by the ITA manufacturer. The supply of connectors  212  can include connectors  212  of different sizes, e.g., some that mate with only one connector  206 , others that span two connectors  206 , still others that span three connectors  206 , etc. The user will generally have access to a supply of connectors  216  that mate with connectors  110  of UUT  100  because the user who is testing the wire harnesses (UUTs)  100  is generally the same party who built them. Such a user may already own or otherwise have access to a conventional wire testing machine  102 . It is thus contemplated that in using embodiments of the present invention, a company can purchase ITA  200  along with a kit for building adapter modules  202  to facilitate testing the wire harnesses the company is manufacturing. 
   To test UUT  100 , the user couples UUT  100  to wire testing machine  102  in the manner described above and then programs or otherwise configures wire testing machine  102  to perform tests of the type well-understood in the art. The manner in which wire testing machine  102  can be programmed and otherwise configured and used is also well-understood and is therefore not described herein. 
   As illustrated in  FIG. 4 , in an alternative embodiment of the invention, an ITA  200 ′ is mounted on the front panel of wire testing machine  100 . It can be mounted in a user-removable manner so that a user can install ITA  200 ′ in preparation for testing UUT  100  and remove it when testing is completed. The mounting mechanism can have any suitable structure and operate in any suitable manner. The resulting testing apparatus can be used in the same manner as described above with regard to the embodiment illustrated in  FIG. 2 . 
   As illustrated in  FIG. 5 , in another alternative embodiment of the invention, elements of ITA  200  ( FIG. 1 ) are integrated with elements of wire testing machine  100  in an integral apparatus  500 . That is, the electronic switching, control and coupling elements (not shown) that provide the testing functionality are housed together. As illustrated by the various embodiments described above, elements of the apparatus can be housed together or separately in any suitable arrangement. 
   As illustrated in  FIG. 6 , ITA  200  ( FIG. 2 ) includes, in addition to the elements described above, a number of signal routing units  600  that electrically couple or interface connectors  204  with those of panel  208 . Each signal routing unit  600  can have any suitable structure, such as a pair of inter-wired back-to-back connectors  602  into which respective connectors  604  and  606  can be plugged. The electrical signal paths on the board  602  can be configured to match or adapt ITA  200  to the configuration of any wire testing machine  102 . 
   As illustrated in  FIG. 7 , in still another form, an ITA  700  includes a number of configurable connectors  702  on its front panel. The manufacturer or user can configure each connector  702  with a selected type of connector, such as the DIN-style connector shown in  FIG. 8  or the pin array-style connector shown in  FIG. 9 . ITA  700  is otherwise functionally the same as ITA  200 , described above. Thus, in the manner described above, a user connects ITA  700  to a wire testing machine (not shown in  FIG. 7 ), connects mating adapter modules (not shown in  FIG. 7 ) to connectors  702 , and connects a UUT (also not shown in  FIG. 7 ) to the adapter modules. 
   As illustrated in  FIG. 10 , in an embodiment similar in concept to that of  FIG. 4 , some or all of the elements constituting an ITA  1000 , such as the panel  1002 , are mounted on horizontal and vertical telescoping adjustable arms,  1004  and  1006 , respectively, which are in turn mounted on the front panel of the wire testing machine  102 . The user can adjust arms  1004  and  1006  to align connectors (not shown) on the rear of ITA  1000  (not shown) with those (not shown) on the front panel of wire testing machine  102 . 
   It is to be understood that the present invention is not limited to the specific devices, methods, conditions, or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments of the invention by way of example only. For example, unless the context clearly dictates otherwise, as used in the specification and the appended claims, a reference to something using the singular article “a,” “an,” or “the” encompasses embodiments having both one and more than one, the term “or” means “either or both.” Likewise, a reference to something “on” something else also encompasses embodiments in which one is “in” the other, and conversely, a reference to something “in” something else also encompasses embodiments in which one is “on” the other. “Coupled” means connected via zero or more intermediate elements. Also, a reference to a particular numerical value includes at least that particular value. In addition, any methods or processes set forth herein are not intended to be limited to the sequence of steps set forth but also encompass other sequences, unless expressly stated otherwise. With regard to the claims, no claim is intended to invoke the sixth paragraph of 35 U.S.C. Section 112 unless it includes the term “means for” followed by a participle. 
   It will be apparent to those skilled in the art that various modifications and variations can be made to this invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover all modifications and variations of this invention that come within the scope of one or more claims and their equivalents.