## State Diagram |

A state diagram is a model of a reactive system. The model defines a finite set of states and behaviors and how the system transitions from one state to another when certain conditions are true.

State diagrams are used to model complex logic in dynamic systems, from automatic transmissions to robotic systems to mobile phones. Examples of this complex logic include:

- 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

Building upon traditional finite state machines, state diagrams provide additional capabilities including:

- Modeling hierarchical states for large-scale systems
- Adding flow graphs to define complex decision logic
- Defining orthogonal states to represent systems with parallelism

For more information on modeling state diagrams, including these advanced techniques, see Stateflow^{®} and Simulink^{®}.

- Stateflow Overview 1:57 (Video)
- Control Logic Made Easy with Stateflow 38:30 (Webinar)
- Introduction to Stateflow for Controls Applications 22:01 (Video)
- Modeling Logic in Communications Applications, Part 1 8:20 (Video)
- Finite State Machine Concepts (Documentation)

- Fault Detection for an Aircraft Control System (Example)
- Develop Logic for a Launch Abort System 12:46 (Video)
- Spacecraft Automated Landing System 17:56 (Video)
- Requirements-Based Testing in Aircraft Control Design (AIAA Paper)

- Modeling a Fault-Tolerant Fuel Control Systems (Example)
- Automotive Powertrain Control System 17:21 (Video)
- Automatic Transmission Control (Example)
- Hybrid Electric Vehicle Modeling and Simulation 45:15 (Webinar)

*See also*: *control logic*, *finite state machine*, *control systems*, *embedded systems*, *state chart*