Peter Templin

An LQR torque compensator for driveline oscillation damping

This paper derives an LQR anti-jerk controller for an automotive driveline. The time derivative of the drive shaft torque, which is closely related to the vehicle jerk, is used as a virtual system output and regulated to zero. Thereby the controller does not need a reference model for generation of reference trajectories for the control law evaluation. The controller acts as a torque compensator for the drivers torque demand which the controller output asymptotically follows. The properties of the controller are discussed and the behavior is illustrated by simulation examples.

Simultaneous estimation of driveline dynamics and backlash size for control design

The ldquoShunt and shufflerdquo-phenomenon at rapid torque transients in a vehicle driveline greatly influences the drivability. A dynamic model that can describe both the traversing of the backlash and the following poorly damped oscillations is proposed. It is experimentally shown to have good predictive capability which is important for control design. The model includes backlash to avoid underestimating the oscillation amplitude after rapid large accelerator pedal movements (ldquotip-in/outrdquo). The parameter estimation results are obtained using only the existing engine torque signal and engine and vehicle speed measurements.

A Diesel Engine Model, Including Compression Brake, for Powertrain Control

A diesel engine model, designed for studying events during automated gear shifting in a heavy duty truck is presented. It will be used for developing and evaluating powertrain control strategies. The deceleration in engine speed to the new synchronous speed, during an upshift, is of special intereset. The straightforward approach is to cut fuel and wait for the engine to slow down due to friction and pumping losses. In many cases, this approach is too slow, and the engine compression brake needs to be activated. The engine model, assuming quasi-steady, bidirectional thermodynamic flow with constant specific heat capacities, is implemented using Modelica. A simple model of the hydraulic circuit that governs the activation of the compression brake mode is incorporated in the model. Problems related to the simulation of the engine brake systems are discussed. They are handled by empirical correction factors. Measurements from rapid engine speed decelerations are used for verification.

Experimental Results for a Powertrain LQR-torque Compensator with Backlash Handling

This paper extends an LQR anti-jerk torque compensator for an automotive driveline with an optimization based handling of the backlash. The time derivative of the drive shaft torque, which is closely related to the vehicle jerk, is used as a virtual system output and regulated to zero. Thereby the controller does not need a reference model for generation of reference trajectories for the control law evaluation. The properties of the controller are discussed and the behavior is illustrated by simulation examples and verified by experiments.