Stateflow

Exploring a Real-World Stateflow Application

The modeling of a fault-tolerant fuel control system demonstrates how Simulink and Stateflow can be used to efficiently model hybrid systems containing both continuous dynamics and complex logical behavior.

Simulink elements model behavior based on a given sample time. Each loop of its block diagram is assigned an increment of sample time. Stateflow execution makes no consideration for sample time. Internally, its application might take many cycles of execution, which are assumed to take place during the sample time assigned in Simulink.

The model described represents a fuel control system for a gasoline engine. This robust control system reacts to the detection of individual sensor failures and is dynamically reconfigured for uninterrupted operation. This section describes how Stateflow is used to implement supervisory logic control system to deal with the sensor failures and contains the following topics:

• Overview of the "fuel rate controller" Model -- Gives you a top-down look at the fuel rate controller demo model along with an introduction to the Simulink logic of the fuel rate controller model and how failures are simulated.
• Control Logic of the "fuel rate controller" Model -- Introduces you to the control logic Stateflow diagram of the fuel rate controller model and its response mechanisms for system failure.
• Simulating the "fuel rate controller" Model -- Takes you step by step through the simulation of the fuel rate controller model focusing on Stateflow simulation in which you can witness state changes in response to simulated failures.

Stateflow Hierarchy of Objects

Overview of the "fuel rate controller" Model