Balance Control of Semiactive Seat Suspension with Elimination of Dynamic Jerk

The paper presents modification of the conventional balance control of semi-active suspension systems aiming at the elimination of the damping force and consequently sprung mass acceleration discontinuities (dynamic jerk). An analysis of the relationship between the relative displacement of the sprung mass and the relative velocity between the sprung and unsprung masses shows sudden damping force variations (jumps). Conventional balance control in this way introduces at zero crossings of the relative velocity across the suspension jumps in damping force and consequently sprung mass acceleration jumps. The acceleration jumps cause a significant reduction in isolation benefits of semi-active suspensions in which the conventional balance control is used. The presented modification of the conventional balance control leads to elimination of the damping force and also sprung mass acceleration jumps as is showed by the results of the numerical simulations. The results also show that the rise of the effective sprung mass acceleration value is not significant.