Multi-Body Systems Modeling, Analysis And Implementation Of Interventional Diagnostic Micro-Robots

Vascular interventional robot has been become a hot scientific research topic currently at home and abroad with the development of Biotechnology Engineering, MEMS and its processing technology. Human lumen is a complex pipeline system, not only in geometry but also there are biological flow field inside it. The force situation of the vascular interventional robot is very complex.Because vascular interventional robot will run in humen lumen that so special envorement that it must be absolute security and reliability. Under the presupposition, to integrate functional modules in the limited of size constraints as much as possible and ensure flexibility of movement, it is particularly important for designing and controlling on the base of the mechanical model. The typical operating environment, the mathematical model of the arteries and digestive tract, is built where the robot will run, and is simulated as a numerical model. Then based on this multi-body dynamics, the kinematics and dynamics theory of the interventional robot are studyed based under constraints of pipe geometry and the envorement of flow field. The paper's findings have great reference value in researching on underwater robots and pipe robot which will be operated in liquid field.There are many factors caused complex in analysing the dynamic problems, such as no fixed base, coupling motion of intervention robot with the motion of the liquid in humen lumen, the size limited of humen lumen, the more varies of pose, e.t. Expressing robot pose is cited the euler quaternions which solve the singularity of the numerical model well. All positions and orientations of the robot form a Lie group. Using Lie group and Lie algebra to describe multi-mechanical system is very convenient. Lie algebra is the essence of motion screw. Introduction of screw theory and spatial operator algebra theory lead that it a unified simple form in the calculation of the motion parameters. Intervention robot is simplified as a single typical six-dimensional space mobility in this paper, and it's kinematics and dynamics model of running in the blood flow. Then robot is simulated in the three-dimensional dust running along the palnning path, that provides a basis for designing structure and controlling motion. The liquid force on robot in the specific environment is calculated by CFD software and the force is substituted in the dynamic model as the form of load. This simplifies the dynamic model and not losing the essence of the problem. This method is extended to use in the more complex topology system on the basis of single typical body dynamics.For more general interventional robotic systems, assuming that the system contains not only the body, also contains flexible body, and maybe either chained system and tree-type multi-body systems. This paper analyzes the structure and motion characteristics of the open-chain topology multi-section creeping robot, and uses the theory Huston lower body array method to describe the system topology. Then according to the judgment on differentiating rigid or flexible body, using space operator algebraic (SOA) method, establish a commen dynamics model of the chain and common tree creeping robot, and carry on some experiments to verify the results. The paper further develops the theoretical system of spatial operator algebras and describes the high-efficiency modeling of the general dynamics of active interventional multi-body system by use of spatial operator. Hinges are defined as active hinge and passive hinge respectively, according to driving types of hinge in the system. Responding to the types of hinge, the recursion of hinge's inertia, general acceleration and general active force, and redundant force of the system are performed in the order that from the top of the system to the base and from the base to the top respectively. Through the three methods of recursion mentioned above, the paper has set up the general recursion dynamics modeling of the active interventional robot system and achieved high computation efficiency of O(n). This arithmetic can be applied to the recursion of backward, forward and compounded dynamics of pipe and underwater robots (excluding rigid and flexible multi-body system and drive-lack system). Using the dynamic model established before, the paper analyzes the multi-section creeping interventional robot.Research group have manufactured the squirm and nomadic robots, according to the bionic principle. Studying the drive mechanism of the robot, realized the recognition of the robot's dynamic parameters on the simulated platform that has been established, and finally get the data value of the driving force and the resistance of the flow field, etc. On this basis, the paper has developed a special simulation program with symbol software of Mathematica and conducted a simulation research on the typical interventional assignment. And finally, the paper has got the driving force information related to the robots and the motion information of the joints and verified the theory and methods claimed in the paper.