State charts for modeling control logic
A state chart is a representation of an event-driven (reactive) system. In an event-driven system, the system makes a transition from one state (mode) to another, if the condition defining the change is true.
For example, you can use a state chart to represent the automatic transmission of a car. The transmission has these operating states: park, reverse, neutral, drive, and low. As the driver shifts from one position to another, the system makes a transition from one state to another, for example, from park to reverse.
State charts are used to model complex logic including:
- Scheduling a sequence of tasks or steps for a system
- Defining fault detection, isolation, and recovery logic
- Supervising how to switch between different modes of operation
You can create state charts with Stateflow software and integrate them into a Simulink model. These state charts provide additional capabilities beyond traditional finite state machines, including:
- Modeling hierarchical states for large-scale systems
- Adding flow graphs to define complex decision logic
- Defining orthogonal states to represent systems with parallelism
State chart, modeled in Stateflow, showing state hierarchy. Inner states are substates (children) of the outer state (called a superstate or parent).
Aerospace and Defense Applications
See also: control logic, finite state machine, state diagram, control systems, embedded systems, state chart videos