Structural sketch is to draw its working schematic diagram, such as guide rod mechanism and cam mechanism with structural symbols. The mathematical model is, for example, how to calculate the transmission ratio and transmission power between pulley transmission and gear transmission of input mechanism motor, and list the calculation formula and solution process. This is a mathematical model.

That is, the process and conduction mode of motion transmission from power source mechanism (such as motor) to working mechanism are calculated by using the principle formulas of power transmission, power transmission, speed and ship speed of mathematical model.