Trends in advanced chassis control

Motorola vehicle system developers examine the state-of-the-art microprocessor and other electronics technologies driving the development of advanced braking, steering, suspension control, and collision warning/avoidance systems.

Electronically controlled chassis systems have enhanced safety enormously by optimizing the interface between tire and road surface, either in the longitudinal, lateral, or vertical directions. Antilock braking systems (ABS), four-wheel drive (4WD), and traction control systems (TCS) are three popular technologies that optimize dynamic stability in the longitudinal direction. Conventional 4WD systems typically use a transfer box with a viscous coupling that engages when a difference in the rotation speed between front and rear wheels occurs. However, newer electronically controlled systems are more efficient, according to Motorola product developers, because considerable slip is not required before the 4WD operates, and driveline torsion as well as traction and braking capacity can be better optimized.

In the vertical direction, roll stabilization and active-suspension systems can be implemented, although they are still in their infancy in terms of production applications. Sensors that detect vehicle roll can also be used for rollover protection systems as well as for roof and curtain airbags.