Planning for charging in transport missions is vital when commercial long-haul vehicles are to be electrified. In this planning, accurate range prediction is essential so the trucks reach their destinations as planned. The rolling resistance significantly influences truck energy consumption, often considered a simple constant or a function of vehicle speed only. This is, however, a gross simplification, especially as the tire temperature has a significant impact. At 80 km/h, a cold tire can have three times higher rolling resistance than a warm tire.A temperature-dependent rolling resistance model is proposed. The model is based on thermal networks for the temperature at four places around the tire. The model is tuned and validated using rolling resistance, tire shoulder, and tire apex temperature measurements with a truck in a climate wind tunnel with ambient temperatures ranging from -30 to 25 °C at an 80 km/h constant speed. Dynamic tire simulations were conducted using a heat transfer model, considering road, ambient, shoulder, and apex temperatures. The simulation results were compared with measured data for ambient, shoulder, and apex temperatures, and the model captures both time constants and stationary levels. The resulting model can predict the dynamics of the rolling resistance and will, therefore, give a more accurate prediction when tires are cold and warming up. Driving range simulations of a long haulage battery-electric truck have also been conducted demonstrating how the range changes with varying ambient temperatures as well as the influence a snapshot consumption has on range estimation.

Cylinder air-charge is one of the most important parts of the torque control in a gasoline engine, due to the necessity to keep a stoichiometric air-fuel ratio, for the three-way catalyst to work efficiently. Throttle and phasing of the camshafts are actuators that have a big effect on the cylinder air-charge, this results in a cross-coupling between the actuators. One approach to handle the cross-coupling that occurs with multiple actuators is to use model predictive control (MPC), that handles the cross-coupling through the use of models and optimization. Models that support computation of gradients and hessians are desirable for use in MPC.To support the model design experimental data of cylinder pressure, from an inline four-cylinder engine with dual independent cam phasing, supported by gas exchange simulation, the effects from variable valve timing on the cylinder air-charge are investigated during the valve overlap period. The analysis highlights the effect of a phase described using the path of the least resistance as having an inhibiting effect on the backflow of residual gases during the overlap period. Making the flow reversal over the exhaust valves an important event to keep track of the residual gases.From the analysis of the effects on air-charge, a model is developed and proposed for the volumetric efficiency, the engine’s ability to fill the cylinders with fresh air. The model structure is derived using partial volumes, and it fits into the Mean Value Engine Model (MVEM) framework, making it is especially useful for control design. The model is validated against stationary measurements and the results show that the proposed model captures the important behaviors and changes in the air-charge related to the variable valve timing. Making it suitable for usage in an MPC framework.

The strive towards cleaner and more efficient combustion engines, driven by legislation and cost, introduces new configurations, as exhaust gas recirculation, turbocharging, and variable valve timing, to name a few. Beside all the positive effects on the emissions and fuel consumption, they all affect the air-charge system, which increases the cross-couplings within the air-path control, making it an even more complex system to control. As the SI engine uses a three-way catalytic converter, which enforces a condition of stoichiometric combustion, the amount of air flow and fuel flow are connected. This means that the air flow has a direct impact on the driveability of the engine, through the torque. 

As configurations are constantly improved or added, a component and model-based methodology is chosen in the thesis, as it would bring flexibility and the possibility to reuse previous developments. As it enables the engineers to keep down the development cost and at the same time bring along knowledge of the systems through the model's descriptions.

The air-charge system's task is to supply the combustion chamber with the correct air mass flow, in the most energy efficient way. To be precise in the control of the air mass flow, the actuators are also constantly developed and becoming both faster and more precise. One example of this is in the first part of the thesis, where an electric servo controller for the wastegate actuation is implemented and compared against the more traditionally used actuator, controlled through a pressure difference over a membrane. As the focus for the air-charge system is the control of mass flows, how these flows can be represented by compact models is also investigated in the thesis, as compact models are beneficial for control from a computation time perspective. In the last part of the thesis a simulation study for controlling the intake manifold pressure, with a constraint on intake manifold temperature, using the throttle as actuator is investigated. Lastly, an implementation of a model predictive controller acting as a reference governor, for the throttle and intake cam phasing, in an engine test cell is demonstrated. As the controller only acts as a reference governor it makes it possible for an engineer to develop the actuator controllers independently if a closed loop model of the actuator system is supplied to the controller. The coordination, of the two actuators, is solved by letting the intake cam phasing depend on the intake manifold pressure, that is a state.

Knocking is an unwanted behavior that is affected by the intake manifold temperature. This paper demonstrates through simulation how nonlinear Model Predictive Control design could be used as a reference governor for the control of the throttle position, with a soft constraint on intake manifold temperature. The implementation is able to suppress the peak temperature during an acceleration by slowing down the pressure build-up. Because of the usually slow dynamics of the temperature sensors, the paper proposes an Extended Kalman Filter implementation that uses a transient detection to decide whether to rely on the sensor feedback or the model. Copyright (C) 2021 The Authors.