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Sliding Mode Controller Reaching Law & Chattering Calculator

Sliding Mode Control (SMC) is a robust variable-structure control technique that drives system state trajectories onto a predefined sliding surface.

Initial position displacement error.

Initial velocity state derivative.

Defines sliding surface dynamics eigenvalue.

Discontinuous control gain (s_dot = -K * sgn(s)).

Saturation function layer width to suppress chattering.

What Is the Sliding Mode Controller Reaching Law & Chattering Calculator?

Sliding mode control drives system states to a switching surface s = 0 and keeps them there using high-frequency discontinuous feedback.

How Does the Sliding Mode Controller Reaching Law & Chattering Calculator Work?

The reaching phase drives s(0) to zero in finite time t_reach = |s(0)| / K; on the surface, system dynamics are completely invariant to matched disturbances.

Sliding Mode Controller Reaching Law & Chattering Calculator Formula & Variables

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

s = c x_1 + x_2, quad dot{s} = -K operatorname{sgn}(s), quad t_{ ext{reach}} = rac{|s(0)|}{K}

Constant-rate reaching law dynamics and reaching time to sliding manifold.

How to Use the Sliding Mode Controller Reaching Law & Chattering Calculator

  1. Input initial states (x1, x2), sliding surface coefficient c, switching gain K, and boundary layer thickness phi.

Step-by-Step Example Calculation

Inverted Pendulum Sliding Mode Regulation

Input Values:

initialStateX1:2
initialStateX2:-1
slidingCoeffC:3
switchingGainK:5
boundaryLayerThicknessPhi:0.15
Worked Steps: Initial sliding variable s(0) = 5.0, Reaching time = 1.00 s, Chattering suppressed within boundary layer phi = 0.15.

Understanding Your Result

Displays reaching time in seconds, initial sliding variable s(0), and boundary layer smoothing parameter.

Factors That Affect the Result

  • Higher switching gain K speeds reaching but exacerbates physical actuator chattering; boundary layers smooth chattering into quasi-sliding.

When Should You Use This Calculator?

  • Electric motor drives, robotics manipulators, aerospace flight control, and power inverters subject to parameter uncertainty.

Assumptions & Limitations

  • Assumes matched disturbances satisfy bounds within switching gain K.

Frequently Asked Questions

Calculation Accuracy & Reference Note

Standard Slotine & Li variable structure control formulation.

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