Aktiv lastbilsstol för bättre förarergonomi och hälsa
The project concerns a predevelopment work for Scania AB, a leading manufacturer of heavytrucks, and was performed as a master thesis work for the program Design and ProductDevelopment at KTH. The purpose of this work was to examine how the work situation of truckdrivers, especially long-haulage drivers, can be improved with respect to prolonged sedentaryoccupation. Mental fatigue and under-stimulation due to low cognitive load during long drivescan be major risk factors for traffic accidents. Physical strain injuries to both the skeleton andmuscles are common for this working group and minimal opportunity for daily exercise alsoincreases the risk of developing blood clots in the legs, which can have serious consequences forthe driver's health.An extensive background study, both theoretical and exploratory, was performed to identify thedrivers' concerns and comfort needs. Various treatments such as massage and active sitting wereinvestigated and existing products within the area studied. The background study resulted in adefinition of the product that would be developed: an active seat that stimulates the muscles andspine during driving.From early on it was observed that the product development work would need to focus oncreating functional models to test various concepts. Theoretical analyses were not an option asthe underlying theory considers physical effects that could not be simulated. A matrix withheight-adjustable cells that change the seat contour in different patterns, and thus physicallyaffect the body, was defined. A pneumatic system with air bags that are filled and emptied indifferent ways proved to be the most applicable technology, both for constructing a model andfor future implementation in the truck. The model was developed from being manuallycontrolled to computer-controlled. Iterative testing was performed during the development andongoing changes of the airbag placement in the chair as well as the movement patterns weremade. A final concept was developed which was assessed by quantitative user tests in a test hall,with positive results. This consists of two airbag systems, one in the backrest and one in the seatpart, having five different movements that influence the body in different ways.As the developed concept was limited to only functional models, further development and testingare required for a fully developed and implementable system. The positive results of the usertests indicate that the concept is a good start to a further development work and the drivers'responses show that there is a market for the product.