Dynamic analysis of Scissor Lift mechanism through bond graph modeling

This paper describes the implementation of general multibody system dynamics on Scissor lift Mechanism (i.e. four bar parallel mechanism) within a bond graph modeling framework. Scissor lifting mechanism is the first choice for automobiles and industries for elevation work. The system has a one degree of freedom. There are several procedures for deriving dynamic equations of rigid bodies in classical mechanics (i.e. Classic Newton-D'Alembert, Newton-Euler, Lagrange, Hamilton, kanes to name a few). But these are labor-intensive for large and complicated systems thereby error prone. Here the multibody dynamics model of the mechanism is developed in bond graph formalism because it offers flexibility for modeling of closed loop kinematic systems without any causal conflicts and control laws can be included. In this work, the mechanism is modeled and simulated in order to evaluate several application-specific requirements such as dynamics, position accuracy etc. The proposed multibody dynamics model of the mechanism offers an accurate and fast method to analyze the dynamics of the mechanism knowing that there is no such work available for scissor lifts. The simulation gives a clear idea about motor torque sizing for different link lengths of the mechanism over a linear displacement.