HYSDEL
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HYSDEL - Hybrid systems description language
HYSDEL is a high-level modeling framework for the specification of hybrid systems.
General properties
HYSDEL allows modeling a class of hybrid systems described by interconnections of linear dynamic systems, automata, if-then-else and propositional logic rules. It allows hybrid models to be formulated in a manner appealing to the application engineer. The description of a hybrid system in HYSDEL is on an abstract, descriptive level. Its first strongest point is that uses simple natural language statements to model complex relations. A compiler translates the abstract HYSDEL description to generate computational models in the form of mixed-logic dynamical (MLD) or piecewise-affine (PWA) systems. These can then be used in computations related to system optimization, verification or control synthesis - this is the second strongest point of HYSDEL.
Operational principle of HYSDEL
HYSDEL consist of three main components:
- HYSDEL source file (input)
- compiler
- mathematical model (output).
In order to obtain a proper mathematical representation of a given hybrid object, HYSDEL uses a compiler which generates MLD model. MLD model can be used consequently for control design and analysis in Multiparametric Toolbox (MPT).
HYSDEL 3.0 enhancements
Thus, the new version 3.0 includes several enhancements, in particular,
- extension of the HYSDEL syntax
- new improved compiler
- generation of higher quality models
- merging of models
- graphical modeling of hybrid systems.
The extended HYSDEL syntax can be characterized by use of variables in vectorized/matrix form, indexed access to declared variables, nested FOR loops, and structured model merging. Enhanced syntax allows now code writing in a rationalized form which is more easier to follow and revise. If we return to the previous example of a linear time-invariant model, the new HYSDEL syntax will look as follows
SYSTEM model {
INTERFACE {
STATE { REAL x(2); }
INPUT { REAL u(2); }
PARAMETER { REAL A = [1, -0.2; -0.3,0.5]; }
}
IMPLEMENTATION {
CONTINUOUS { x = A*x + u; }
}
}
Note that the size of code is reduced due to vectorized syntax. Further code reductions can obtained by defining multiple parameters.
This version of HYSDEL uses YALMIP as a compiler for MLD model generation. YALMIP is a MATLAB toolbox for rapid prototyping of optimization problems. The main motivation for using YALMIP is rapid algorithm development. The language is consistent with standard MATLAB syntax, thus making it extremely simple to use for anyone familiar with MATLAB. Another benefit of YALMIP is that it implements a large amount of modeling tricks, allowing the user to concentrate on the high-level model, while YALMIP takes care of the low-level modeling to obtain as efficient and numerically sound models as possible.
HYSDEL 3.0 offers a graphical layer of modeling which includes also model merging. The whole graphical layer is transformed to a single HYSDEL source file, and MLD model is generated. By this way the user does not have to take care about the code writing, it is done automatically.
Downloads
For more information and recent updates in HYSDEL 3.0, please contact Michal Kvasnica at [1].
