Conceptual Cab Suspension System for a Self-propelled Agricultural Machine-Part 2: Operator Comfort Optimisation

Vibration exposure of self-propelled machinery drivers is an important risk factor for low back pain disorders. In order to reduce the health risks and the discomfort to the driver and to enable the driver to work at a faster pace, it is important to isolate the driver from the machine vibrations as much as possible. Suspension systems play an important role in this comfort and health improvement. In a previous paper (Part 1: Development of a Linear Mathematical Model), a linear model of a conceptual cab suspension was derived and validated. In this study the model damping values are optimised using standard comfort parameter. The combination of comfort parameters and power spectra interpretation allows the determination of the appropriate damping values for each specific situation. The optimal value on a road profile differs substantially from that on a field profile. Lowering the stiffness value and therefore the eigenfrequency of the suspension system would provide even better vibration attenuation performance because of the lower required damping and the avoidance of the eigenfrequency being positioned in the frequency range most excited with road profiles.