Averaging, integral of special function

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SUMMARY

The discussion focuses on integrating the state equations to determine the average system behavior for the given differential equations. The equations are defined as \(\dot{x_1} = x_2\) and \(\dot{x_2} = -x_1 + 1 - 2u(0.5sat(x_2) + 0.5 - p(t))\), where \(u(s)\) is the unit step function and \(p(t)\) is a periodic function with period \(T = 1\). The average function \(f_{avg}\) is calculated using the formula \(f_{avg} = \frac{1}{T}\int_0^T f(x,t)\). The user expresses uncertainty about the correct formulation of the equations, particularly regarding the saturation function \(sat(x_2)\).

PREREQUISITES
  • Understanding of differential equations, specifically state-space representation.
  • Familiarity with periodic functions and their properties.
  • Knowledge of the unit step function and its applications in control theory.
  • Concept of averaging in dynamic systems and integral calculus.
NEXT STEPS
  • Study the properties of the saturation function \(sat(x)\) and its impact on system dynamics.
  • Learn about the application of averaging theory in control systems.
  • Explore methods for solving periodic differential equations.
  • Investigate numerical integration techniques for approximating integrals in dynamic systems.
USEFUL FOR

Students and professionals in control engineering, particularly those working with dynamic systems and differential equations. This discussion is beneficial for anyone looking to deepen their understanding of averaging techniques in system analysis.

psl86
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Homework Statement



Integrate the right hand side of the state equation to find the average system

\dot{x_1} = x_2
\dot{x_2} = -x_1 + 1 -2u(0.5sat(x_2) + 0.5 - p(t))

Homework Equations



u(s) = 0 for s<0, u(s) = 1 for s>=0
p(t) is periodic with T = 1
f_{avg} =\frac{1}{T}\int_0^Tf(x,t)

The Attempt at a Solution



\dot{x_1} = x_2
\dot{x_2} = -x1 - sat(x_2)
 
Last edited:
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Im almost 100% certain that this is suppose to end up as

x1_dot = x2
x2_dot = -x1 - sat(x2)

but I can't make the argument..
 
No one in here with a steady averaging-theory brain?
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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