Youtube user blogger45 uploaded a new video on his channel. He made a balancing pendulum that swings with a fan motor. A webcam "watches" a mark on the shaft of the pendulum. The motor is controlled with an Arduino, using PWM pulses through a H-bridge. This latest version powers the motor through 2 brushes on each side of the 2-pieces metallic shaft of the pendulum. The swing up algorithm uses a PID in feed-forward to control the energy, and when the angle is within 0.2 rads of the vertical axis, another PID loop controlls the angle of the pendulum. Visit his channel for more.