John Deere Uses Simulation to Dramatically Improve Tractor Comfort

John Deere engineers made extensive use of multibody simulation to develop a new electronically controlled hydraulic cab suspension that dramatically improves operator comfort in the field and on the road. Up to now, cab suspension systems have used coil springs or air cushions with high natural frequencies that do little to dampen vertical oscillations in the critical 2.3 Hz range. Deere engineers used multibody simulation in the concept phase of the new design to determine that reducing the natural frequency of the cab to 1 Hz would isolate the operator from the dominant excitations. This called for a static spring deflection of 60 mm that in turn required a load leveling system to achieve sufficient spring travel under different loading conditions.