Method of detecting that a tightening tool should be subjected to maintenance

A computer program product stored on a non-transitory computer-readable medium, said computer program product for detecting that a tightening tool should be subjected to maintenance, wherein said computer program product comprising computer instructions to cause a processing unit to perform the following operations:

• acquiring, from a plurality of tools, data indicating torques and corresponding rotation angles applied to a fastener during each of multiple tightening operations having been performed by the tools from an instance when the tools are fully functioning until tool maintenance is required, the applied torques being normalized with a maximum supported torque of the tools said data being acquired during normal operation of the tools;
• dividing the acquired torque data into a plurality of groups each representing torques having been applied at the corresponding rotation angles;
• determining, from the acquired data, a total rotation angle having been applied for each group since the instance when the tools were fully functioning;
• and
• computing, for each group, a measure indicating total rotation angle that can be applied by a fully functioning tool before tool maintenance is required, if the tool is operated to only apply torques corresponding to each group,
• wherein the measure being computed by computing a tool wear metric for each tool by dividing, for each group, the determined total rotation angle with the measure indicating total rotation angle that can be applied by a fully functioning tool before tool maintenance is required to create individual group metrics, and summing the created individual group metrics to 1, wherein the computed measure for each group enables subsequent computation of the tool wear metric for an individual tool to determine that maintenance is required for said individual tool.

A device configured to detect that a tightening tool should be subjected to maintenance, the device comprising a processing unit operative to cause the device to:

• acquire, from a plurality of tools, data indicating torques and corresponding rotation angles applied to a fastener during each of multiple tightening operations having been performed by the tools from an instance when the tools are fully functioning until tool maintenance is required, the applied torques being normalized with a maximum supported torque of the tools said data being acquired during normal operation of the tools;
• divide the acquired torque data into a plurality of groups each representing torques having been applied at the corresponding rotation angles;
• determine, from the acquired data, a total rotation angle having been applied for each group since the instance when the tools were fully functioning;
• and
• compute, for each group, a measure indicating total rotation angle that can be applied by a fully functioning tool before tool maintenance is required, if the tool is operated to apply torques corresponding to each group,
• wherein the measure being computed by computing a tool wear metric for each tool by dividing, for each group, the determined total rotation angle with the measure indicating total rotation angle that can be applied by a fully functioning tool before tool maintenance is required to create individual group metrics, and summing the created individual group metrics to 1, wherein the computed measure for each group enables subsequent computation of the tool wear metric for an individual tool to determine that maintenance is required for said individual tool.