Pendulum Platform

Hardware and software of a 1-DoF pendulum (2022)

For preliminary algorithm verification, we developed a pendulum platform in 2022. It has only one actuated joint equipped a (brushless DC electric) BLDC motor (GYEMS L5010) and a 50:1 harmonic reducer. The point mass at the tip weighs 0.565kg (overall 0.74kg).

Project members:

  • Mechanics: Terry Cavan Chan, Xinyu Jia.
  • Electronics & Software & Algorithm: Xinyu Jia.
Pendulum plaform.

The platform allows us to roughly evaluate the actual performance of selected motors, including power, torque, and sensor accuracy.

Check motor torque constant (roughly).
Free-space tracking, zero gravity mode, and max payload test (from left to right).

In addition, we use the platform to validate our new ideas. For example, several digital filters are implemented for comparison (code).

Comparative simulation of digital filters.

Novel disturbance observers, such as our Unknown System Dynamics Estimator (USDE), are also first validated on the pendulum and then deployed on a multi-joint robotic manipulator.

Step signal. PD (left) and USDE-PD (right).
Sine signal. PD (left) and USDE-PD (right).