Nonlinear algorithms for automotive engine control

Abstract

Nonlinear automotive engine control methods that would enhance shift quality are discussed. In the course of a typical automotive transmission upshift, there is an extreme decrease in the transmission's output torque during the torque-phase of the shift. This is due to the torque being transferred from a high to a low gear ratio. In the speed phase, due to inertial effects and the negative slope of the friction coefficient, the output torque rises and peaks when the shift ends, changing engine speed. Modulating engine torque can smooth these output torque transients. The sliding-mode control method is used, and a solution to the multivariable control problem (i.e. coordinated throttle and spark control) is presented. A speed-control approach is used, and relationships between speeds and desired torque (or acceleration) trajectories are discussed. >