14.30-15.30h: "Dynamic Optimization in Engineering - Algorithms and Applications"
Prof. Dr. Moritz Diehl (ESAT K.U.Leuven, COE Optimization in Engineering)
Aim of the talk is to illustrate how challenging application problems in
engineering can solved by help of dynamic optimization, i.e.,
solution of optimization problems with underlying dynamic system models
in form of ordinary or partial differential equations.
In order to exploit the full potential of dynamic optimization in
engineering applications, specialized algorithms and approximation
methods are needed. We argue that the best methods are very different from
the "black-box approach" that just uses a good ODE/PDE simulation routine
within good optimization routine. If both simulation and optimization are
carried out together in all-at-once approaches, often orders of magnitude
in efficiency can be realized and previously untreatable problems become
solvable.
We will present three recent applications along with the underlying
dynamic optimization algorithms:
a) robust open-loop control of an exothermic chemical reactor that shall
avoid runaways (including experiments)
b) nonlinear model predictive control (NMPC) of a distillation column
(including experiments)
c) periodic optimal control of tethered airfoils for a novel way of
large scale wind power generation (so far only computer simulations)
15.30-16.00h: coffee break
16.00-16.45h: "An Online Active Set Strategy for Fast Parametric Quadratic Programming and Application to Predictive Engine Control"
Hans Joachim Ferreau (Univ. Heidelberg)
Nearly all algorithms for model predictive control (MPC) rely on solving
convex quadratic programs in real-time. In this talk, we develop a
specially tailored online active set strategy for the fast solution of
parametric quadratic programs arising in MPC. Our
strategy exploits solution information of the previous quadratic program
(QP) under the assumption that the set of active constraints does not
change much from one QP to the next. Furthermore, we present a
modification where the CPU time is limited in order to make it suitable
for strict real-time applications. An efficient implementation of the
proposed online active set strategy is described and its performance is
demonstrated with two challenging test examples. One of these was
designed
for controlling a real-world Diesel engine with sampling times of a few
milliseconds. In these examples, our strategy turns out to be an order of
magnitude faster than a standard active set QP solver.
16.45-17.30h: "Optimization of industrial robot trajectories subject to real physical limitations"
Matthieu Guilbert (INRIA, Grenoble)
The optimization of robot trajectories usually considers bounds on motor
accelerations, velocities or torques, but that does not really reflect the
real physical limitations of a robot. We will therefore focus here on the
optimization of robot trajectories subject to real physical limitations
such as temperature limitations. We also want to point out
that industrial robots are often integrated in robotic cells which are
usually difficult or even impossible to model.
We propose therefore to decompose the optimization into two levels: the
first algorithm is based on models and a discretization of the velocity
profile, and the second one is based on velocity and torque measures on
the robot and on derivative free algorithm. The proposed algorithm gives
good numerical and experimental results on complex real world
robotic applications.
Two OPTEC professors have been awarded three "Gouden Krijtjes", the yearly teaching awards given by the organization of engineering students (vtk). Prof. Lombaert was awarded the prize for the best course in civil engineering, and Prof. Diehl the prizes for the best professor and the best course in mathematical engineering (where he teaches numerical optimization). They received these awards at the yearly "proffentap" where experienced students taught them how to draft beer professionally.
