INDUSTRY ISSUE
IMPROVE AND REDUCE DRIVER FATIGUE WITH
GOOD SEATING DESIGN
O
ne important issue in driving seat design to reduce fatigue risk is the provision of correctly designed seating and the training of drivers to adjust and use the seating correctly. The two areas in which good seat design can assist are: • Correct body support and ergonomic design to reduce muscle fatigue and reduced transmission of vibration • Good design will provide comfort and reduced fatigue.
ERGONOMIC DESIGN The accepted minimum design standard which is used by all major commercial seating manufacturers for the automotive industries is to achieve an optimal position
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POWERTORQUE March/April 2022
and support for the range of driver sizes from the 5th percentile female to the 95th percentile male. In practice, all good quality seat designs will exceed this standard by providing adjustments beyond the specified range. As a minimum, adjustments must be provided for height, horizontal position and backrest recline angle. In addition, cushion slope and length adjustment and a well designed adjustable lumbar support will help to provide the best possible support for the seated driver. Incorporation of lap-sash seat belts completely within the seat is also an important factor in assisting driver comfort and safety in modern trucks and all major European manufacturers, and all Australian manufacturers, now fit this type of seat as original equipment in heavy trucks.
In the areas of cushion shape and hardness there are unavoidable compromises. For example, foam hardness which provides optimum support for an 80kg driver may feel too hard for a 50kg driver and too soft for a 130kg driver but obviously a standard must be selected. Foam shape design also requires compromise. Computerised pressure mapping systems are used by companies such as ISRI to develop the optimum foam pad shape. These systems work by determining the shape which produces the most equal pressure distribution and minimises the peaks of pressure on the seated body for a wide range of body shapes and sizes. However, personal preferences for pad shape and hardness will still determine whether a driver feels comfortable.
