Understanding Moving Pendulum Dynamics

Sep 24, 2024

Lecture on Dynamics of Moving Pendulum

Introduction

  • Focus on dynamics of a moving pendulum.
  • Comparison between static and moving pendulum systems.
  • Importance of understanding pendulum dynamics in various applications, including robotics and walking.

Concepts Covered

Moving Pendulum Dynamics

  • Moving pendulum as a model for walking or dancing.
    • Hip moves in motion, leg rotates simultaneously.
  • Conceptualization as a robot with a moving base and rotating arms.

Equation of Motion

  • Derived equations for pendulum dynamics:
    • Fixed Pendulum: Moment equation around a fixed point.
    • Moving Pendulum: Moment equation not applicable at the moving point O; valid around Mass Center (MC).
  • Explained why traditional moment equations are not applicable when the base is moving.

Forces and Acceleration

  • Reaction forces (Fx, Fy) and their effects on the pendulum.
  • Use of derivative principles to understand acceleration impacts.
    • Derivation of velocity and acceleration vectors with respect to time.

Application of Newton's Laws

  • Utilization of Newton's Second Law for deriving force equations in X and Y directions.
  • How to factor in the unknown forces Fx and Fy using these laws.

Linear and Nonlinear Dynamics

  • Linearization of non-linear dynamics using Taylor series.
  • Comparison of linearized and actual dynamics of the pendulum.
  • Discussion of homogeneous vs. non-homogeneous differential equations.

Practical Example and Simulation

  • Simulation of pendulum motion using MATLAB.
  • Creation of state-space equations and simulation of moving pendulum dynamics.
  • Demonstration of how variations in base motion affect pendulum dynamics.

Advanced Topics

Chaotic and Intermittent Dynamics

  • Introduction to chaotic systems and their relevance in higher-order dynamics.
  • Visualization of dynamics through phase portraits.

Control Systems

  • Brief introduction to control applications and disturbance handling in dynamic systems.
  • Future applications in control classes (M530).

Real-World Understanding

  • Analogy to human motion and dance.
  • Historical context and personal anecdotes to aid understanding.
  • Encouragement to engage with code for better practical understanding.

Conclusion

  • Emphasis on understanding dynamic systems and preparing for advanced studies in dynamics and control.
  • Encouragement to explore additional applications and simulations for deeper learning.

Note: These notes are based on a lecture discussing the dynamics of moving pendulums and their applications in both theoretical and practical frameworks. The lecture included equations, simulations, and physical analogies to real-world systems.