Measurements and simulation on the comfort of forklifts

In order to determine the influence of some parameters of a forklift such as the road profile, the tyre characteristics, the riding comfort, etc., measurements carried out on a forklift with different tyres and seats were evaluated using different standards and methods. In addition, a simulation model was developed and used to investigate the influence of these parameters. Simulations and test run results showed good agreement. The comparison of the results obtained with several methods of comfort evaluation and a series of tests showed that they nearly all resulted in the same classification. However, the results obtained with different methods could not always be compared among themselves. Solid tyres were found to be more comfortable than pneumatic ones because of their high damping. The negative influence of higher stiffness was smaller than the positive influence of higher damping. The simulations pointed out that for a global general investigation about comfort, the influence of the horizontal tyre stiffness and damping can be neglected. Also the seat characteristics could be linearized. When the stability of the forklift has to be investigated, the horizontal forces must also be considered.