Development of a Computerized Model for Evaluation of Manual Insertion of Flexible Hoses in Automobile Assembly

Abstract

The purpose of this work was to develop a protocol and a related computer application, herein called the Hose Insertion Program, which predicts human insertion capability for flexible hoses as a function of worker, hose, and task factors. The protocol is based on previous studies of hand strength, posture, friction, and hand clearance, and provides the logic for the program's algorithms. To demonstrate and evaluate the program, seven different hose insertions were selected from an automobile assembly plant. After modeling the whole body forces capable using human modeling software, raw data from these insertions and the output from the human modeling software were entered into the Hose Insertion Program. Because assembly operators were observed performing these insertions, it was hypothesized that the program output would indicate that the “insertion force capable” would be greater than “insertion force required” for both whole body and coupling force for the gender and approximated size/strength percentiles observed at the plant. Such an output would mean that the program accurately predicted that these operators were able to perform the hose insertion. For whole body push forces modeled in human modeling software and then entered into the Hose Insertion Program, all 7 outputs were accurate in stating that the operators were capable of performing the task. Of the 7 “insertion force capable” output opportunities for coupling forces related to the observed insertion operations, all 7 outputs were accurate in stating that the operators were capable of performing the task.