Abstract:
A system and method of tracking location and orientation of power tools utilized in the assembly and maintenance of complex systems is disclosed. The system can facilitate collaboration between maintenance and alert maintenance personnel to complete complex system activities.

Description:
TECHNICAL FIELD 
   The disclosure generally relates to complex systems, and more particularly to collaborative assembly and maintenance of complex systems using a power tool. 
   BACKGROUND 
   Complex systems are composed of interconnected parts that as a whole exhibit one or more properties or behavior not obvious from the properties of the individual parts. For example, aircraft are complex systems with many parts and critical dependencies that require proper maintenance. Mechanical parts workers perform various tasks involving the disassembly, inspection, repair, assembly, and maintenance of mechanical parts of aircraft components according to detailed maintenance and repair procedures. The work typically includes visual and dimensional examination of parts and complex components such as wings, fuel valves, rotor blades, compressor blades, and oil pumps for obvious defects such as nicks, scratches, leaks, or corrosion, or for worn, bent, or broken parts; replacing or reworking damaged parts; and performing tests for operability of moving parts. Failure of examination can lead to significant damage and loss of life. 
   As there are many similar complex systems with critical safety requirements, there exists a need for a collaborative assembly and maintenance system that can track mechanical work precisely while being economically cost effective. 
   SUMMARY 
   A system and method of tracking location and orientation of power tools utilized in the assembly and maintenance of complex systems is disclosed. The system can facilitate collaboration between maintenance and alert maintenance personnel to complete complex system activities. 
   Various aspects of the system relate to identifying a next operation location for the power tool and monitoring performance of the tool during pre-defined tasks. 
   For example, according to one aspect, a system for collaborative assembly and maintenance of complex systems includes a network, a power tool operatively coupled to the network, the power tool comprising a sensor to sense operational characteristics associated with the tool and a job task, the operational characteristics including location and performance information, and a computer operatively coupled to the network, the computer arranged to receive the operational characteristics and to provide a next operation location for the power tool. 
   In one embodiment, the sensor of the system is at least one of a single axis accelerometer, a multiple axis accelerometer, an analog accelerometer, a digital accelerometer, a rotational speed sensor, an angular speed sensor, and a laser ring gyroscope. 
   Typically the network is a wireless network. Example networks that can be used with the system include a 802.11-compliant network, Bluetooth network, cellular digital packet data (CDPD) network, high speed circuit switched data (HSCSD) network, packet data cellular (PDC-P) network, general packet radio service (GPRS) network, 1x radio transmission technology (1xRTT) network, IrDA network, multichannel multipoint distribution service (MMDS) network, local multipoint distribution service (LMDS) network, and worldwide interoperability for microwave access (WiMAX) network. 
   In one embodiment, the power tool is a fastener, such as a power screw driver. In another embodiment, the power tool is an electrostatic discharge (ESD) simulator. Advantageously, the power tool includes a display to display the instructions. For example, the instructions can include location information for positioning the tool. 
   The computer of the system includes a display device to display a job status associated with the tool and stores the job status in a task status data store. The computer also can provide instructions to control the power tool by accessing a task design data store. In one embodiment, the computer provides the instructions on a display of the power tool. In another embodiment, the instructions are provided on a heads-up display. In yet another embodiment, the instructions are provided on a wristwatch-type display worn by a user of the power tool. 
   In another aspect, a power tool for use with a complex system includes a sensor to sense operational characteristics associated with the tool being applied to a task, the operational characteristics comprising at least one of tool location and tool performance, and a display arranged to provide an operational instruction for the tool in response to the operational characteristics. 
   In one embodiment, the power tool also includes a communication port to receive the operational instruction from a computer and to send the operational characteristics to the computer on completion of the task. The communication port is at least one of a serial port, USB port, and a wireless transmitter/receiver port. 
   In yet another aspect, a method of providing reliable assembly and maintenance of complex systems includes sensing an operational characteristic associated with operation of a power tool, the operational characteristics comprising location and performance information associated with use of the tool, and tracking use of the power tool based on the operational characteristic. 
   The method can include transmitting an instruction to the power tool based on the operational characteristic, the instruction comprising a next operation for the tool. The sensing of the operational characteristic can include utilizing an accelerometer. The method can also include transmitting the operational characteristic wirelessly. 
   In one embodiment, the method of controlling use of the tool includes generating an instruction for operation of the power tool, and displaying the instruction on a display unit of the power tool. The method also can include tracking a location coordinate associated with the power tool. In yet another embodiment, the method can include comparing the operational characteristic to a threshold value, and controlling the power tool based on the comparison. 
   Several benefits can be derived from the present system and techniques. For example, the system can improve reliability of complex systems by monitoring completion of maintenance. The system can also facilitate coordination of various workers by keeping track of work completed and remaining. The system and techniques can also provide repair records for risk assessment/accident analysis as well as identify overlooked repair operations. 
   In addition, the system and techniques provide a portable user interface and can set tool performance characteristics that can reduce mistakes leading to further damage, reduce training requirements of workers, as well as accelerate repair times to complex systems by eliminating wasted tool movement. 
   For example, in the context of a vehicular rescue operation, the power tool of the system can be utilized to exploit design knowledge of a vehicle to assist rescuers in safely dismantling the vehicle to extricate victims of the accident. 
   Advantageously, the system can support multiple power tools and can interact with multiple systems. For example, in an assembly line context, a product under assembly can be temporarily configured with a sensor. The system can then track location information of the product and calculate relative positions for operations on the product. 
   Additional features and advantages will be readily apparent from the following detailed description, the accompanying drawings and the claims. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the disclosure. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  illustrates a block diagram of a system for collaborative assembly and maintenance of complex systems. 
       FIG. 2  illustrates an example of a graphical user interface to display operational task status. 
       FIG. 3  illustrates an example of a graphical user interface to display operational tasks. 
       FIGS. 4A-C  are flow charts of an example method to calibrate a power tool included in the system of  FIG. 1 . 
   

   Like reference symbols in the various drawings indicate like elements. 
   DETAILED DESCRIPTION 
   Referring now to  FIG. 1 , an example system  10  for tracking location and orientation of a power tool  20  that can be utilized in the assembly and maintenance of a complex system is disclosed. 
   As used herein, the phrase “power tool” refers to any electrical or battery operated drill, hammer, screw driver, fastener device that joins or affixes two or more objects together, static electricity discharge devices, such as electro-static discharge (ESD) simulators, and pneumatic and hydraulic tools, such as an impact wench and hydraulic jack, respectively. 
   As used herein, the phrase “complex system” refers to a plurality of interconnected parts that as a whole exhibit one or more properties not obvious from the properties of the individual parts. For example, aircraft are considered a complex system as aircraft are capable of sustained air travel and include various parts, such as flaps, wing tips, strut and attach fittings, engines, ribs, etc. 
   As used herein, the phrase “operational characteristics” refers to tool location, orientation and performance information associated with use of a power tool. 
   As used herein, the phrase “an operation instruction” refers to a step in a pre-defined system procedure. The system procedure can include either an assembly or repair procedure. 
   As used herein, the term “sensor” refers to a single axis accelerometer, a multiple axis accelerometer, an analog accelerometer, a digital accelerometer, a rotational speed sensor, an angular speed sensor, and/or a laser ring gyroscope. 
   As used herein, the term “computer” refers to an electronic, digital machine that responds to a specific set of instructions in a well-defined manner and can execute a prerecorded list of instructions. 
   As used herein, the term “network” refers to one or more communication paths linking electronic devices. 
   As used herein, the phrase “operatively coupled” refers to a wired or wireless connection. 
   As used herein, the phrase “head-up display” refers to any display device that presents data without obscuring the user&#39;s view. 
   As shown in the  FIG. 1  example, the system  10  includes a wireless network  14 , at least one power tool  20  operatively coupled to the wireless network  14  through a wireless access point router  12 , and a computer  40  operatively coupled to the network  14  and in communication with the power tool  20 . The computer  40  is configured to receive operational characteristics of the power tool  20  and to provide a next location for the power tool  20  to be utilized in accomplishing a job task. Although only one power tool  20  is shown in  FIG. 1 , the present disclosure is not limited to one power tool and can include a multitude of varied power tools that are capable of communicating using wired or wireless protocols. 
   The computer  40  is an electronic device that includes a central processor unit (CPU)  42 , random access memory (RAM)  44 , an input-output control module  46 , and non-volatile memory  50 , all of which are interconnected via a bus line  48  and controlled by the CPU  42 . In one exemplary embodiment, the non-volatile memory  50  of the device  40  is configured to include a task-design module  52  and task-status module  54  that operate to send and receive messages over the network  14  to the power tool  20 . Details of the task-design module  52  and task-status module  54  are discussed below. 
   The task-design data store  56  and task-status data store  58  provide storage for one or more data items representative of a complex system task. In one embodiment, the data stores  56 ,  58  are relational databases. In another embodiment, the data stores  56 ,  58  are established on a directory server, such as a Lightweight Directory Access Protocol (LDAP) server. In other embodiments, the data stores  56 ,  58  are a configured area in memory  50  of the computer  40 . 
   The wireless network  14  can include an 802.11-compliant network, Bluetooth network, cellular digital packet data (CDPD) network, high speed circuit switched data (HSCSD) network, packet data cellular (PDC-P) network, general packet radio service (GPRS) network, 1x radio transmission technology (1xRTT) network, IrDA network, multichannel multipoint distribution service (MMDS) network, local multipoint distribution service (LMDS) network, worldwide interoperability for microwave access (WiMAX) network, and/or any other network that communicates using a wireless protocol. 
   As shown in  FIG. 1 , the power tool  20  can be a hand held rotary driver. While the following description is provided with reference to a rotary driver, it is readily understood that the broader aspects of this disclosure are applicable to other types of power tools, including drills, static electricity discharge devices, such as electro-static discharge (ESD) simulators, hammers, as well as pneumatic and hydraulic tools, such as an impact wench and hydraulic jack, respectively. 
   For example, in one exemplary embodiment, the power tool  20  includes a spindle  28  (i.e., a rotary shaft) drivably coupled to an electric motor  22 . A drive shaft  24  of the motor  22  is connected via a gear  26  to the other end of the spindle  28 . These components are enclosed within a housing  25  of the tool  20 . Operation of the tool  20  is controlled through the use an operator actuated switch  35  included in the handle of the tool that regulates current flow from a power supply  34  to the motor  22 . The power supply  34  can be direct current (D.C.) power, alternate current (A.C.), or a combination of both. 
   The power tool  20  is further configured with a controller  32  for setting operational characteristics of the tool in response to instructions received from the computer  40 . For example, torque conditions for the tool  20  are received by the computer and can be set by the controller  32 . In another embodiment, when the angular velocity of the tool meets a threshold value, the controller can cut power to the motor  22 . In yet another embodiment, where the tool  20  is an electro-static discharge device, the amount of static-electric charge to be discharged is received from the computer  40  and set by the controller  32 . 
   As shown in the  FIG. 1  example, the tool is configured with a sensor  30  that is in communication with the controller  32 . The sensor  30  is used to sense operational characteristics associated with the tool. For example, tool location and orientation are sensed by the sensor  30  and relayed to the controller  32 . In another embodiment, location and performance information of the tool  20  are relayed by the sensor  30  to the controller  32 . 
   The sensor  30  is an analog multi-axis accelerometer that is used to measure the location and orientation of the power tool as the tool is being applied to a particular job task. Other types of sensors, such as angular speed sensors, digital accelerometers, laser ring gyroscopes, etc., are also within the scope of this disclosure. In addition, for different power tools, it is envisioned that the sensor  30  may be disposed in a different location than shown in  FIG. 1  and/or configured to detect motion along one or more axis. 
   As shown in  FIG. 1 , the power tool  20  includes a transmit-receive device  33  that is in communication with the controller  32  and the computer  40 . For example, in one exemplary embodiment, the transmit-receive device  33  is arranged to wirelessly transmit operational characteristics received by the controller  32  from the sensor  30  to the computer  40  and to receive instructions from the computer  40  concerning a next operation location for the power tool. The instructions are included in a graphical user interface that includes operating settings for the power tool  20 , such as torque setting, discharge amount, and holding time. 
   The sensor  30  wirelessly transmits operational characteristics of the tool  20  to the computer  40 . An example of the graphical user interface provided to the tool  20  from the computer  40  is discussed in connection with  FIG. 3 . 
   During tool  20  operation, operational characteristics, such as angular rotation, rotation rate, and static-electric discharge, are monitored by the controller  32  based on one or more signals received from the sensor  30 . When the rotational rate of the tool  20  exceeds a threshold value received from the computer  40 , this can indicate completion of a particular job task. For example, a certain number of rotations for a rotary driver or an amount or time of electrical discharge associated with operation of an ESD simulator can indicate that a certain task is complete. It will be appreciated by one skilled in the art that various sensor signals may be used to determine the completion of a particular task. 
   The task-design module  52  provides instructions to the power tool that contain choices an operator of the tool should make to accomplish a particular task with the tool  20 . As shown in  FIG. 1 , the task-design module  52  is in communication with the task-design data store  56  that includes data for pre-defined tasks relating to complex systems. For example, in one embodiment, the task-design data store  56  includes all relevant part and task information associated with a designated repair procedure for aircraft maintenance. In another embodiment, the task-design data store  56  includes all relevant part and task information for assembling an aircraft. The task-design module  52  receives operational characteristics from the power tool  20  and can provide a next location for the power tool  20  to be utilized. 
   For example, a repair scenario for an aircraft can operate as follows. First, the aircraft is parked and chocked, and the power tool  20  is calibrated by placing the tool at one or more fixed positions on the airframe. The task-design module  52  then selects the designated repair procedure from the design data store  56 , such as replacing a leading edge flap. The power tool  20  then indicates where to attach lifting rigs and which fasteners to remove, indicating the torque required for each on its display. After the flap is replaced, the task-design module  52  sets the desired torque on the tool  20  and indicates on the tool&#39;s display each location where a fastener is to be placed, recording the actual tool performance for each operation in the task-status data store  58 . Advantageously, if one worker leaves at the end of a shift or on a break, the task-status data store  58  can be used to guide another worker to resume work on the next fastener. In addition, tracking tool performance, such as torque and revolutions per minute (RPM) can also detect a stripped screw or bolt that provides inadequate fastening. The system  10  can schedule remedial maintenance based on tool  20  performance. Further details of how the task-design module  52  receives the operational characteristics and provides a next location to the power tool are discussed below. 
   An exemplary method for initializing and calibrating the power tool  20  executed by the task-design module  52  is described in connection with  FIGS. 4A-C . As shown in  FIG. 4A , to begin a task, the power tool&#39;s initial location is identified. Typically, this step includes positioning the power tool at a pre-defined start location for the particular task. As shown in  FIG. 4A , the sensor can track and display X, Y, and Z coordinate positions  100  on the tool  20 . 
   Upon the user of the tool  20  selecting the actuated switch  102 , the controller  32  directs the transit-receive device  33  to transmit the initial location (0,0,0) to the task-design module  52 . Upon the task-design module  52  receiving the initial location (0,0,0), the task-design module  52  relays the initial location information to the task-status module  54  which records the same in the task status data store  58 . The task-design module  52  then provides a graphical user interface  90  to the power tool  20  to display operational tasks. 
     FIG. 4B  illustrates a method of recording position locations associated with the tool  20 . For example, as explained previously, the power tool includes a sensor  30  that tracks and displays location information  106  of the tool. Selection of the actuated switch results  108  in the controller  32  directing the transit-receive device  33  to transmit the current location (X,Y,Z) to the task-design module  52  which relays the same to the task-status module  54  for recordation  110  in the task status data store  58 . 
   The method also can include providing playback positions. This feature is particularly advantageous to users of the tool that desire to know what tasks the tool was previously used on. As shown in  FIG. 4C , for example, the task-design module  52  first accesses stored location coordinates  112  from the task-status data store  58  and then displays the location coordinates on the tool as absolute coordinates or relative to a particular target. 
   Turning now to  FIG. 3 , an example graphical user interface  90  provided by the task-design module  52  for display on a video display  38  of the power tool  20  is shown. The interface  90  includes directional indicators  72 ,  74 ,  76  and  78  that serve to direct a user of the device to position the tool  20  in a particular location, an instruction area  84  that is utilized to indicate an objective of the task, a graphics area  86  to illustrate a particular part or item that is the subject of the task, an operational settings area  88  that displays operational characteristics that are to be applied to the tool for a particular task, a display area  80  that can provide interactive instruction to the user concerning use of the tool  20 , and a status area  82  that is utilized to indicate whether the tool is position calibrated. 
   The task-status module  54  monitors and tracks power tool  20  utilization and performance and is in communication with the task-status data store  58  to record current status of tasks completed, in progress, and to be completed. The task-status module  54  can provide a graphical user interface  50  that illustrates task status. 
   For example, referring now to  FIG. 2 , an example graphical user interface  50  provided by the task-status module  54  is shown. The user interface  50  is displayed on a display device operatively coupled to the computer  40 . For example, in one embodiment, the interface  50  is displayed on a computer monitor attached to the computer  40 . In another embodiment, the interface  50  is displayed on a remote display device operatively coupled to the computer  40 . It will be appreciated by one skilled in the art that some repair procedures may not require a precise sequence and can be processed by the present system. In addition, it will be appreciated by one skilled in the art that the present teaching of the disclosure can be applied to various tasks. For example, the present system can be utilized to provide an indication of a fastener requiring remediation, such as replacing a stripped nut and/or bolt. 
   The interface  50  includes a graphic over-view area  52  that illustrates a selected complex system to be worked upon with the tool  20  and a graphic detail-view  54  that illustrates a particular area or subassembly of the complex system that is to be worked upon by the tool  20 . In one embodiment, detail components  56  of the subassembly can also be illustrated with status graphically. For example, as shown in  FIG. 2 , four (4) of the bolts depicted have clear centers indicating that they need to be worked upon by the tool, three (3) of the bolts have shaded centers indicating that they have already been worked upon, and one (1) bolt has a blackened center indicating that it is next bolt to be worked upon. 
   As shown in  FIG. 2 , the graphical user interface  50  also includes a detail area  58  arranged in the form of a matrix that includes an operation column  60  to indicate the type of operation that is to be performed with the tool, a part column  62  that indicates a component item that is to be worked upon by the tool, a physical characteristic  64  of the component  62 , an operational characteristic  66  of the component that is to be set on the tool, and a status column  68  indicating whether or not the operation task for the component is completed or not completed. Status indicators in the status column  68  are color coded to facilitate reading of the matrix  58 . 
   It will be appreciated that various of the above-disclosed and other features and functions, or alternative thereof, may be desirably combined into many other different systems or applications. For example, in one embodiment, the power tool operates as a stand-alone tool wherein the operational instructions are downloaded from the computer to the tool prior to initiating the task. Memory of the tool stores the operational instructions locally. The tool executes the locally stored operational instructions in response to receiving operational characteristics from the tool sensor. 
   Upon completion of the task, the tool uploads to the computer operational characteristics associated with the tool being applied to the task. For example, in one embodiment, task results of applying the tool to the task are uploaded to the computer. Typically, the power tool includes a communication port that allows the tool to receive the operational instructions and send operational characteristics to the computer. The communication port can be a serial port, a Universal Serial Bus (USB) port, or a wireless transmitter/receiver port. 
   It will be appreciated that various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims. In addition, the claims can encompass embodiments in hardware, software, or a combination thereof.