Control System Calc
PID Tuning & Bode plot
Free · Designed for iPad. Not verified for macOS.
Enter a transfer function and get PID tuning, Bode plots and step response with stability margins and performance metrics. Built-in examples, 100% offline.
Control System Calc (ControlCalc) is an engineering tool for control engineers, R&D staff and students. Enter a transfer function to perform PID tuning, frequency-domain analysis and time-domain simulation — turning textbook control theory into a pocket tool you can use anywhere. All calculations run locally on your device, no internet required.
KEY FEATURES
■ PID Tuning
Five classic tuning methods built in: Ziegler-Nichols open-loop step, Cohen-Coon, Ziegler-Nichols closed-loop ultimate, plus IMC-Lambda and AMIGO. Each method includes guidance on when to use it.
■ Closed-Loop Step Simulation
Simulate the closed-loop step response with an FOPDT model and a PID controller with derivative filtering. View the control effort u(t) to spot actuator saturation, and fine-tune parameters by hand.
■ Bode Plot & Stability Margins
Draw magnitude and phase curves on a log scale, with automatic 0 dB / −180° reference lines, gain margin, phase margin and crossover frequencies — stability at a glance.
■ Step Response & Performance Metrics
RK4 time-domain simulation that automatically computes overshoot, rise time and settling time.
■ Second-Order Designer
Back-solve system parameters from overshoot Mp / settling time ts, or from damping ratio ζ / natural frequency ωn, then push them to the step-response page in one tap.
■ Root Locus & Nyquist (Pro)
Root-locus branch tracing with the imaginary-axis stability boundary, an equal-aspect Nyquist plot with unit circle, plus pole/stability analysis for deeper insight.
THOUGHTFUL DETAILS
• Built-in library of classic example models — tap to load and go
• Draggable readouts on time-domain curves (live t / y display)
• Numeric keyboard with a Done button; input parameters persist automatically
• Simplified Chinese / English / German / Japanese, switchable in-app instantly
PRO UPGRADE (one-time purchase)
• Removes all ads
• Unlocks IMC-Lambda / AMIGO tuning methods
• Unlocks Nyquist plot, root locus and pole/stability analysis
• Unlocks CSV data export
Buy once, keep forever. Family Sharing supported.
WHO IS IT FOR
Control, electrical, mechatronics and process engineers, R&D and commissioning staff, students taking control-theory courses, and anyone who needs to quickly validate a control-system design.
DISCLAIMER
All results are provided for engineering reference only. Real-world system design and commissioning should combine field conditions with professional judgment.
Have feedback or questions? Contact us from the Settings page.
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The developer, 洋 刘, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
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Information
- Seller
- 洋 刘
- Size
- 6.6 MB
- Category
- Utilities
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - iPad
Requires iPadOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
English and 3 more
- English, German, Japanese, Simplified Chinese
- Age Rating
4+
- 4+
- Contains
Advertising
- Copyright
- © 2026 YangLiu