System and method of controlling a vehicle steer-by-wire system applying multivariable decoupling control

摘要

The present invention involves a method of controlling a vehicle steer-by-wire system having two independent road wheels. In one embodiment, the method comprises providing a steering wheel control sub-system to generate road wheel reference angles and to produce steering feel for a vehicle driver. The method further includes providing a road wheel control sub-system including a multivariable road wheel controlled plant and a multivariable-road wheel controller for controlling actual road wheel angles to track to road wheel reference angles within a servo control system structure having road wheel angular position feedback and road wheel angular rate feedback loops. Moreover, the method includes implementing the multivariable road wheel controller to control tracking of the actual left and right wheel angles with the left and right road wheel reference angles, respectively. The method further includes decoupling the left and right road wheel angles with the multivariable road wheel controller in the road wheel servo control system. The multivariable road wheel controller controls the left and road wheel angle based only on the left road wheel reference angle independent of the right road wheel reference angle. Also, the multivariable road wheel controller controls the right road wheel angle based only on the right road wheel reference angle independent of the left road wheel reference angle.