Graphical representation of interconnected subsystems.
Block diagrams interconnect subsystems with summing junctions and pickoff points; rules reduce them: series G₁G₂, parallel G₁+G₂, feedback G/(1±GH). They show signal flow and the structure of controllers and communication systems.
A cruise-control loop has plant, controller, sensor and summing junction blocks.
Block diagrams show how subsystems connect, which makes complex systems easier to understand and to reduce to a single transfer function.
Graphical representation of interconnected subsystems.
Block diagrams show how subsystems connect, which makes complex systems easier to understand and to reduce to a single transfer function.
A point where signals are added or subtracted, which is where error is formed in a feedback loop.
Combine blocks in series by multiplication, in parallel by addition, and feedback loops by the closed-loop formula.
Typical applications include drawing a feedback loop with a plant, sensor and controller, reducing a multi-loop system to one transfer function for analysis and showing how a measurement noise enters a control system.
Study "Poles and zeros" first (topic 19 of 101 in Signals, Control & Comms). It covers the groundwork this topic builds on.
Unity feedback. Moving blocks across junctions. Closed-loop transfer function.
A cruise-control loop has plant, controller, sensor and summing junction blocks.
The next topic is "Signal flow graphs and Mason's rule", which builds directly on this one.
It is classed as Beginner in Signals, Control & Comms (topic 20 of 101). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.