Assembly task verification system and method

• US 8,200,354 B2
• Filed: 04/21/2006
• Issued: 06/12/2012
• Est. Priority Date: 04/21/2006
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Freeman, Philip L., Shepherd, Thomas E., Zuver, Christopher K
• Primary Examiner(s): Patel, Ramesh
• Assistant Examiner(s): Norton, Jennifer L.
• Application Number:
  US11/408,754
• Publication Number:
  US 20070265942A1
• Time in Patent Office: 2,244 Days
• Field of Search: 700/245, 700/258, 700/259, 700/114, 700/254, 318/568.11, 318/568.12, 318/568.13, 901/30, 901/41, 901/42, 901/47, 382/152
• US Class Current: 700/114
• CPC Class Codes: G05B 19/402 characterised by control arrangements for positioning, e.g. centring a tool relative to a hole in the workpiece, additional detection means to correct position G05B19/19 takes precedence
• CPC Class Codes: G06Q 10/08 Logistics, e.g. warehousing, loading or distribution; Inventory or stock management
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders
• CPC Class Codes: Y10S 901/30 End effector
• CPC Class Codes: Y10S 901/41 Tool
• CPC Class Codes: Y10S 901/42 Welding
• CPC Class Codes: Y10S 901/47 Optical

Abstract

A method for verifying completion of a task is provided. In various embodiments, the method includes obtaining location coordinates of at least one location sensor within a work cell. The at least one sensor is affixed to a tool used to operate on a feature of a structure to be assembled, fabricated or inspected. The method additionally includes, generating a virtual object locus based on the location coordinates of the at least one location sensor. The virtual object locus corresponds to a computerized schematic of the structure to be assembled and represents of all possible locations of an object end of the tool within the work cell. The method further includes, identifying one of a plurality of candidate features as the most likely to be the feature operated on by the tool. The identification is based on a probability calculation for each of the candidate features that each respective candidate feature is the feature operated on by the tool.

Claims

1. A method for verifying completion of a task, said method comprising:

obtaining location coordinates of at least one location sensor within a work cell, utilizing an indoor global position system to provide three-dimension coordinates of the at least one location sensor,

wherein the at least one location sensor is affixed to a tool used to operate on a feature of a structure to be assembled;

generating a virtual object locus based on the location coordinates of the at least one location sensor upon generation of an event signal by the tool that indicates completion of a task by the tool,

the virtual object locus corresponding to a computerized schematic of the structure to be assembled and representative of all possible locations of an object end of the tool within the work cell;

generating a plurality of lines of action vectors extending through the object end of the tool;

identifying one of a plurality of candidate features as the most likely to be the feature operated on by the tool based by using the virtual object locus and the plurality of lines of action vectors in performing a probability calculation for each one of the candidate features that each said candidate feature is the feature operated on by the tool;

identifying a specific candidate feature, out of a plurality of candidate features, as a most likely one of the plurality of candidate features operated on by the tool, by performing a probability calculation that includes comparing each candidate feature with each virtual object locus point and angle line of action vector of the virtual locus, to obtain a distance and angle of the each candidate feature to each point in the virtual object locus, wherein the distance and angle are used to determine the probability of the object end of the tool and orientation that matches each candidate feature; and

designating a given one of the candidate features as the specific candidate feature that has a highest probability value of all of the plurality of candidate features above a predetermined probability threshold as the most likely one of the plurality of candidate features operated on by the tool at the time the event was generated.

2. The method of claim 1, wherein obtaining location coordinates of the at least one location sensor within a work cell comprises calibrating the at least one location sensor to have known coordinates relative to the object end of the tool.

3. The method of claim 1, wherein generating a virtual object locus comprises calibrating the structure to have a known location, placement and orientation within the work cell.

4. The method of claim 1, wherein the candidate features include a select set of all the features indicated by the computerized schematic.