Toward Relative Mass With a Pulley-Based Differential Transmission

In the well-known electromechanical analogy that converts between electrical and mechanical system representations, mass is the dual of a grounded capacitor. Consequently, any electrical circuit that contains ungrounded capacitors, such as a filter, does not have a mechanical equivalent. A new mechanical system element representing a pulley-based differential transmission is proposed, which, when connected to a mass, is shown to simulate a capacitor in the general case. This new differential mass model provides an additional conceptual framework to model complex mechanical systems such as robotic manipulators.