SISO Calculator vs ControlsLab

SISO Calculator was built to help practicing engineers and students get an intuitive sense of System Dynamics and Controls. The interface is focused so you can quickly interact with controllers and plants to see immediately how time and frequency interact and how controllers behave.

ControlsLab is a professional-grade system dynamics and controls simulator designed for engineering students, educators, and practicing engineers. Simulate a mass-spring-damper system in real time. Adjust parameters with intuitive sliders and instantly see how the system responds - no coding required, no MATLAB license needed. FREE FEATURES SYSTEM SIMULATION - Mass, damping, and spring parameter control - Step, ramp, parabolic, and sinusoidal inputs - Adjustable initial conditions x(0) and dx(0) - Input signal overlay on time response plot VISUALIZATION - Live time-domain response plot - S-plane pole visualization - System stability classification - Overdamped, underdamped, critically damped detection ANALYSIS MODES - Open-loop mode: plant driven directly by input - Closed-loop mode: negative feedback with configurable setpoint PRO FEATURES - $4.99 One-time purchase, no subscription PID CONTROLLER - Full negative feedback implementation - P, PI, PD, and PID controller types - Live Kp, Ki, Kd gain tuning with instant response - Adjustable reference setpoint FREQUENCY DOMAIN - Bode plot: magnitude (dB) and phase (degrees) - Logarithmic frequency axis - Natural frequency, damping ratio, and bandwidth readouts WHO IS THIS FOR? - Undergraduate engineering students studying dynamic systems and feedback control - Graduate students reviewing control theory - Professors and educators demonstrating system behavior in lectures - Practicing engineers doing quick back-of-envelope system analysis - Anyone curious about how control systems work ControlsLab turns abstract differential equations into visual, interactive experiences. Move a slider and watch poles migrate across the S-plane. Toggle a controller and see overshoot disappear in real time. No prior programming experience required.