TABLE OF CONTENTS Gear shifting by engine control realizes fast gear shifts by controlling the engine instead of sliding the clutch to a torque-free state in the transmission, as described in Section 7.3. This is done by controlling the internal torque of the driveline. The topic of this section is to derive a control strategy based on a model of the transmitted torque in the transmission. There are other alternatives of internal torques that can be used as control objectives, e.g. drive-shaft torque, but this is not used here except in the final subsection. Thus, there is a detailed study of the dynamical behavior of the transmission torque, which should be zero in order to engage neutral gear. A transmission-torque controller is derived that controls the estimated transmission torque to zero while having engine controlled damping of driveline resonances. With this approach, the specific transmission-torque behavior for each gear is described and compensated for.
A model of the transmission is developed in Section 7.5.1, where the torque transmitted in the transmission is modeled as a function of the states and the control signal of the Drive-shaft model. The controller goal was stated in Section 7.3, and is formulated in mathematical terms as a gear-shift control criterion in Section 7.5.2. The control law in Section 7.5.3 minimizes the criterion. Influence from sensor location, simulations, and experiments are presented in the sections following.
There are many possible definitions of internal driveline torque. Since the goal...
