Control systems guides

Short, plain-English explainers for the most common frequency-domain and stability tools in control systems.

• How to Read a Bode PlotLearn how to read a Bode plot: magnitude in decibels, phase in degrees, the logarithmic frequency axis, corner frequencies, roll-off, and stability margins.
• Gain Margin and Phase Margin ExplainedWhat gain margin and phase margin mean, how to read them from a Bode plot, and why these stability margins matter when designing a feedback control system.
• The Nyquist Stability Criterion, ExplainedUnderstand the Nyquist stability criterion: how encirclements of the −1 point relate to right-half-plane poles, and the Z = N + P counting rule for closed-loop stability.
• Root Locus Rules and How to Draw OneThe main root locus construction rules: real-axis segments, asymptotes and their angles, breakaway points, and imaginary-axis crossings, with a tool to draw it.