All 6 units covered in depth — open/closed loop, transfer functions, stability analysis, root locus, Bode plots, and compensators — with GATE PYQs for every topic.
Control systems is the study of how to make a dynamic system behave the way we want — keeping a motor at the right speed, a drone level, or a voltage regulated despite disturbances. The whole subject rests on one elegant idea: feedback, where we measure the output, compare it to a target, and use the error to drive the system back on course.
We start from the mathematical model — the transfer function, which captures how a system responds in the Laplace domain — and build up to the tools that tell you whether a design is stable and how it behaves over time. Stability is the heart of the subject: a controller that overshoots or oscillates forever is useless, so engineers lean on the Routh–Hurwitz criterion, the root locus, and Bode plots to guarantee well-behaved responses.
These ideas are not just academic. The same feedback mathematics governs phase-locked loops on a chip, voltage regulators, and the servo loops in robotics and aerospace — including the kind of landing-control problem you can feel in our interactive booster-landing lab. Master the stability tools here and the rest of the subject falls into place.