Objetive: The transient sucking process was analyzed since the value of negative pressure plays an important role in robot’s safety

locomotion ability

parameter selection of mechanism and power. Method: A mathematical model of the transient sucking process was made and analyzed with bond graph theory since studying the process is key to improve the performance of the wall climbing robot. Firstly

the suction system is analyzed and designed keeping in mind requirements of a wall climbing robot with the Computational Fluid Dynamics (CFD) tool. Secondly

by reasonable assumptions and fluid dynamics theory

parameters of the sealing system are equivalent to rigidity and damp by bond graph theory. Then

the relationship between the negative pressure generated by the fan and the motor’s input voltage is simplified to a first-order expression. Result: Simulation result shows the transient process of a wall climbing robot’s negative pressure generating dynamic process is a first-order expression. Conclusion: At last

a bond graph model was made

and simulations by 20sim software and experiments were carried out to confirm its validity.