Generation of isocomfort working area based on psychophysical evaluation

For efficient operations, vital hand controls must be easily controlled by the operator from his or her normal working position. The primary working area based on operator's working comfort was developed to serve as a design guideline to the workplace design or the control panel layout. Six males and four females participated in the experiment in which working comfort was measured for a level control with respect to the frontal and sagittal distances from the body center and the slope of a work table. The response surface methodology using a central composite design was employed to develop a prediction model for perceived working comfort. The concept of the proposed working area is a significant extension to the conventional working area such as Farley's or Squires' curves. It is shown that the distance to a control instrument and the slope of a work table have a quadratic effect to working comfort. It is noticeable that comfortable working area also exists outside the conventional working area. The result of the response surface analysis also indicated that a little slope of about 15° for a work table improved working comfort.