e equilibrium.  For
      this reason, to actually balance the system, we'll have to switch to a
      different controller once we get near the fixed point (an idea that we'll
      discuss more in the next chapter).</p>

      <example id="pendulum_energy_shaping"><h1>Energy Shaping for the Pendulum</h1>

      <p>Take a minute to play around with the energy-shaping controller for
      swinging up the pendulum</p>

      <script>document.write(notebook_link('pend', "energy_shaping"))</script>

      <p>M