Rolf Pfiffner - Academia.edu (original) (raw)
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Papers by Rolf Pfiffner
Autonome Mobile Systeme, 1995
Journal of Dynamic Systems, Measurement, and Control, 2002
A new model for the dynamics of the mechanical part of a belt CVT (Continuously Variable Transmis... more A new model for the dynamics of the mechanical part of a belt CVT (Continuously Variable Transmission) is presented. The model takes into account the mass of the belt, assuming it to be uniformly distributed over its length. The model can therefore be used as a benchmark for FE models, which focus on every element of the belt or chain, as well as for much simpler models that neglect the belt mass or imply significant simplifications in the respective kinematics. Although a nonholonomic system has to be investigated, the result is surprisingly simple, i.e., an algebraic solution is provided that is not much more complicated than the solutions derived with more stringent assumptions. The equations of motion derived here are especially suitable for use in control applications.
High speed machine tooling allows one to increase productivity and product quality, but presents ... more High speed machine tooling allows one to increase productivity and product quality, but presents new challenges for the control system. To meet them, this paper proposes to review the conventional control structure, restating the control problem in terms of a constrained finite horizon optimization problem, which can be solved efficiently with a MPC-QDMC algorithm. This approach is shown to allow to enhance significantly the precision attainable with a fixed actuator choice. The model necessary for MPC is determined at best using a black box model identification
International Journal of Robust and Nonlinear Control, 2001
Control Engineering Practice, 2003
Continuously variable transmissions (CVTs) offer the potential to substantially improve the part-... more Continuously variable transmissions (CVTs) offer the potential to substantially improve the part-load fuel efficiency of spark-ignited engines. The control of CVTs has traditionally been designed using static arguments, i.e. by identifying the best efficiency points in the engine map for each constant power requirement and by following that curve using some heuristics as much as possible also in transients.In this
Autonome Mobile Systeme, 1995
Journal of Dynamic Systems, Measurement, and Control, 2002
A new model for the dynamics of the mechanical part of a belt CVT (Continuously Variable Transmis... more A new model for the dynamics of the mechanical part of a belt CVT (Continuously Variable Transmission) is presented. The model takes into account the mass of the belt, assuming it to be uniformly distributed over its length. The model can therefore be used as a benchmark for FE models, which focus on every element of the belt or chain, as well as for much simpler models that neglect the belt mass or imply significant simplifications in the respective kinematics. Although a nonholonomic system has to be investigated, the result is surprisingly simple, i.e., an algebraic solution is provided that is not much more complicated than the solutions derived with more stringent assumptions. The equations of motion derived here are especially suitable for use in control applications.
High speed machine tooling allows one to increase productivity and product quality, but presents ... more High speed machine tooling allows one to increase productivity and product quality, but presents new challenges for the control system. To meet them, this paper proposes to review the conventional control structure, restating the control problem in terms of a constrained finite horizon optimization problem, which can be solved efficiently with a MPC-QDMC algorithm. This approach is shown to allow to enhance significantly the precision attainable with a fixed actuator choice. The model necessary for MPC is determined at best using a black box model identification
International Journal of Robust and Nonlinear Control, 2001
Control Engineering Practice, 2003
Continuously variable transmissions (CVTs) offer the potential to substantially improve the part-... more Continuously variable transmissions (CVTs) offer the potential to substantially improve the part-load fuel efficiency of spark-ignited engines. The control of CVTs has traditionally been designed using static arguments, i.e. by identifying the best efficiency points in the engine map for each constant power requirement and by following that curve using some heuristics as much as possible also in transients.In this