Section: New Results

Model-free control

Participants : Cédric Join, Riachy Samer, Lotfi Belkoura.

After the successful implementation of model-free control [75] , [81] for several concrete situations:

• Throttle control for IC engines (with APPEDGE and PSA) [94] ;

• Stop-and-go automotive control strategy (in collaboration with the École des Mines de Paris and PSA) [72] , [114] , [115] ;

• Hydroelectrical dams modeling and control (in collaboration with EDF) [92] , [93] ;

• Shape memory actuators (collaboration with the team directed by Prof. E. Delaleau at the École Nationale des Ingénieurs de Brest [88] , [89] );

• Model-free control involves the design of the so-called "intelligent" PID controllers [75] , [82] , and a mathematical explanation via "intelligent" PID controllers of the strange ubiquity of PIDs has been developed in [74] , and the simulations confirm the superiority of the new intelligent feedback design;

• Application of model-free control method to set Delta hedging [76] ;

• Model-free control of "Planar Vertical Take-Off and Landing" (PVTOL) aircraft [108] ;

• Model-free control for power converters [103] ;

• The longitudinal control of the electrical vehicle by using model-free control technique [73] ;

• Model-free control for automatic water level regularization [93] and [92] ;

• [49] simplifies several aspects of the practical implementation of the newly introduced model-free control and of the corresponding intelligent PID controllers. Four examples with their computer simulations permit to test our techniques.

More achievements have been made in 2011, listed as follows:

• Shape Memory Alloys (SMA) are more and more integrated in engineering applications. These materials with their shape memory effect permit to simplify mechanisms and to reduce the size of actuators. Most of successful control strategies applied to SMA actuator are not often suitable for industrial applications. In [17] , an application of the new framework of model-free control to a SMA spring based actuator was proposed. This control strategy is based on new results on fast derivatives estimation of noisy signals, its main advantages are: its simplicity and its robustness. Experimental results and comparisons with PI control are exposed that demonstrate the efficiency of this new control strategy.

• The regulation of freeway traffic flow, which is a complex nonlinear system, is achieved via the newly introduced model-free control in [39] and [64] . Several computer simulations are validating our control strategy, which is easy to implement and shows good robustness properties with respect to perturbations;

• After numerous successful applications, [36] has revisited some points of model-free control. The numerical differentiation of noisy signals may be replaced by a real time parameter identification which is much simpler. The strange ubiquity of classic PIDs is explained as well as the almost universal utilization of ultra-local models of order 1.We show that even with a partially known model the utilization of an intelligent PI controller remains profitable.

• The Ph.D. work of Y. El Afou allowed for experimental results on climate control in greenhouse.