Parallel parameter synthesis from hybrid logic HUCTL formulas
Samuel Pastva
advisor: Luboš Brim
Physical reality is becoming increasingly digital.
physical (continuous) components
digital (discrete) components
interactions
interactions
Cyber-physical systems
Cyber-physical systems are used at global scale in safety critical applications.
Wrong assumptions about a cyber-physical system can cost lives! (and millions of dollars)
Problem: System's behaviour can change with parameters.
Friction
Wind speed
Traction control on/off
Turbocharger on/off
Emission avoiding on/off
Fuel efficiency
In continuous systems small (smooth) change in parameters usually produces a small change in behaviour.
Problem: Usually
Bifurcation: Big (qualitative) change of behaviour
Behaviour patterns:
Stability ➔
➔ Oscillation ➔
➔ Stability
HUCTL: Logic for behavioural pattern specification
Stable equilibrium
Cycle (oscillation)
Unstable equilibrium
General attractor
\textbf {bind \textrm{s}: AX \textrm{s}}
\textbf{bind} \text{s}: \textbf{EX}\ \text{s}\ \land\ \neg\textbf{AX}\ s
\textbf{bind} \text{s}: \textbf{AF}\ \text{s}\ \land\ \neg\textbf{AX}\ s
\textbf{bind} \text{s}: \textbf{AG EF}\ \text{s}
Behavioural patterns
(HUCTL)
Parameter Synthesis
Pattern validity regions
Parameter Synthesis: given a family of systems, find the ones which satisfy given specification.
(If breaks are engaged, the car slows down.)
Semi-symbolic Parameter Synthesis Algorithm [1]
- Explicit state space, symbolic parameters
- Allows parallel and distributed computation
- Parameter representation using SMT formulae
- Works with both discrete systems and abstractions of continuous systems.
[1] Parallel SMT-based parameter synthesis with application to piecewise multi-affine systems
N. Beneš, L. Brim, M. Demko, S. Pastva, D. Šafránek, ATVA 2015
PITHYA: Parameter Investigation Tool [2]
- Implementation with focus on dynamical systems used in systems biology.
- Collaboration with Faculty of Sciences and Faculty of Medicine on case studies [3, 4].
[4] High-Performance Symbolic Parameter Synthesis of Biological Models: A Case Study
M. Demko, N. Beneš, L. Brim, S. Pastva, D. Šafránek, CMSB 2016
[5] Toward Modelling and Analysis of Transient and Sustained Behaviour of Signalling Pathways
M. Hajnal, D. Šafránek, M. Demko, S. Pastva, P. Krejčí, L. Brim, HSB 2016
[3] Pithya: A Parallel Tool for Parameter Synthesis of Piecewise Multi-affine Dynamical Systems
N. Beneš, L. Brim, M. Demko, S. Pastva, D. Šafránek, CAV 2017
Interested? Contact us at sybila.fi.muni.cz
Parallel parameter synthesis from HUCTL (12min)
By Samuel Pastva
