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Root Locus Asymptote & Breakaway Calculator

The root locus technique plots the trajectories of closed-loop poles in the complex s-plane as scalar controller feedback gain K varies from 0 to infinity.

Location of pole 1 on real axis (e.g. 0 for integrator).

Location of pole 2 on real axis.

Location of pole 3 on real axis.

Optional real transmission zero (0 indicates no zero).

What Is the Root Locus Asymptote & Breakaway Calculator?

Root locus plots closed-loop pole migrations in the complex s-plane as feedback gain K scales from zero to infinity.

How Does the Root Locus Asymptote & Breakaway Calculator Work?

Roots begin at open-loop poles and travel toward open-loop zeros or out to infinity along asymptotes centered at sigma_a.

Root Locus Asymptote & Breakaway Calculator Formula & Variables

The core mathematical equation utilized by this calculator is expressed as:

sigma_a = rac{sum ext{Poles} - sum ext{Zeros}}{n - m}, quad phi_k = rac{(2k + 1) 180^circ}{n - m}

Evans root locus centroid and asymptote departure angle equations.

How to Use the Root Locus Asymptote & Breakaway Calculator

  1. Input real-axis pole locations and optional zero location.

Step-by-Step Example Calculation

Type-1 Third-Order System

Input Values:

p1:0
p2:-3
p3:-8
z1:0
Worked Steps: Asymptote centroid sigma_a = -3.67, radiating angles = [60°, 180°, 300°], Breakaway sigma_b = -1.28.

Understanding Your Result

Reports asymptote center of mass sigma_a, departure angles, and breakaway points.

Factors That Affect the Result

  • Relative degree (number of poles minus zeros) determines the number of radiating asymptotes.

When Should You Use This Calculator?

  • Designing lead/lag compensators, tuning proportional gains, and assessing transient damping.

Assumptions & Limitations

  • Applies to negative unity feedback SISO control systems.

Frequently Asked Questions

Calculation Accuracy & Reference Note

Standard Evans root locus geometric formulation.

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