Evaluation of a Test Rig to Determine the Need For Human Operators in Ergonomic Testing of Pistol Grip Power Tools

Sammanfattning: Handheld power tools are found in many different manufacturing processes, everywhere from miniature screw joints in cell phones to safety-critical joints in automotive vehicles. The tools are often used for many consecutive hours which emphasizes the need for good ergonomics to ensure the safety of the operators. This master thesis, conducted in collaboration with Atlas Copco Industrial Technique AB, aims to develop a test rig and investigate whether or not it can accurately represent a human operator and  replace the need for humans in ergonomic testing of pistol grip power tools. The project focus was to evaluate the test rig's accuracy using two common tightening strategies on two different joint stiffness levels. A test rig was developed and data were gathered. The gathered data were compared and evaluated with reference data from human operators.The results of the study indicate that it is feasible to replace human operators with the test rig depending on the required accuracy. The most likely strategy to replace human operators with the test rig is Quick Step, where hard joints were marginally more accurately represented than soft joints. The research also gives valuable insights in how a test rig can be used to digitally replicate human operators and potentially be a standardized way of evaluating the ergonomics of handheld power tools.