Study On The Design Of The Compound Driving In-pipe Robot And Its Dynamics Characteristics

The pipe robot has been widely used in recent years, whose application is influenced by the driving performance. And yet the driving mechanism is evaluated by indexes like large driving force, long-walk distance and stable speed. Fluid driving and motor driving pipe robot are two types of the robots widely employed in today’s world. The former is characterized by large driving force, long-walk distance but poor speed stability due to poor controllability. The latter is characterized by good location performance and speed controllability but a limited energy capacity. Therefore, there is the necessity to put forward a compound driving robot that combines the merits of the two, and establish theor ies related to compound driving so as to lay the foundation and provide theoretical guidance for the application of the compound driving method. And it is of great significance to the improvement of the driving performance of the pipe robot as well as the application of it.Firstly, the mechanism design principle of the compound driving pipe robot is determined by that concerning to the compound system. The general composition, the scheme and the main performance indexes of the mechanism are decided by the characteristics of fluid driving and motor driving mechanism. And the general size of the mechanism and the compound driving concrete working principles are then further determined according to the selective design scheme, and the detailed designs of parts and components are finished based on them, including designs of the cup, the supporting structure, the flowing regulation mechanism, the selection of motor and the variable diameter mechanism. Finally, the 3-D model of the compound driving pipe robot is established, which lays a foundation for further related theoretical study.The statics characteristics of the driving mechanism are further analyzed based on the established compound driving model. The stress and strain and the modal of the pub are analyzed with finite element method. And the compound driving mechanism is applied in the liquid-filled pipe, so the complete pipe flow field model is established with CFD numerical method, and the time variant characteristics of pipe flow field parameters are obtained.The dynamics characteristics of motor-driven robot are obtained through creating virtual prototype simulation environment by simplifying the model and establishing the virtual pipe. And the complete flow dynamics characteristics of the robot’s running in pipe are analyzed based on pipe flow field model, the time variant characteristics of flow field parameters are obtained. And the interaction characteristics between the robot velocity and velocity field and the relationship between the dynamic pressure and fluid velocity are obtained by analyzing the influence of the speed qualitatively and quantitatively.Finally, fluid driving force model is established with CFD method, and the study on the compound dynamics characteristics is carried out. The fluid driving force models of different open and different fluid velocity are established, and its influential characteristics are also analyzed. Based on this, the dynamic characteristics of compound driving in low fluid velocity and open condition are analyzed. The interaction simulation analysis is further carried out, which verifies the validity of theoretical model and driving principles.