Implementation Of The Rigid-flexible Coupling Dynamic Experiment Table

Rigid-flexible coupling is hotspot in aerospace,robotics and robotics,weapons,vehicles and other areaes.Compared with theoretical research,rigid-flexible coupling experiments develop slowly limited by various factors.The single axis air bearing table produces thin film between testbed and bearing via compressing air,this thin film levitate the table off the ground,which could be used to simulate relative motion without friction.A design of the rigid-flexible coupling experiment table is based on single-axis air bearing table.This system has the characteristics of high precision,high reliability,simple operation,high efficient,and flexible extension.It can be adapt to complicated and special experimental requirement.The dissertation will be mainly presented as follows:Study background,significance of rigid-flexible coupling are summed up.Difficulties and research directions of rigid-flexible coupling are presented respectively.The operational rationale and parts for the rigid-flexible coupling experiment table are introduced.Free rotation of experiment table around the hub's center is realized.The relatively rotation in plumb direction of the hub and flexible appendage can be drived by motor.At the same time,the ratio of the beam and hub inertia can vary.A new set of measuring and control system using Compact RIO is given based on systematical design strategy,together with research cost,development period,performance index and daily maintenance.This designed system enjoys multiple channels for date gathering,control and real time monitoring.The rigid-flexible coupling experiment table software programs are coded under Lab VIEW.After completing design and construction of hardware and software in the rigid-flexible coupling experiment table,there is still a need to measure several dynamic parameters accurately.The inertia of the hub,drag coefficient,and the acceleration performance of the electromagnetic valve is measured.Strain acquisition module is calibrated.Constraint mode and free mode of the flexible beam is obtained.To verify performance of the rigid-flexible coupling experiment table,several experiment programs are designed based on it,such as the modal characteristics of hub-beam,free vibration of the system in case of different stiffness and the ratio of the flexible beam and hub inertia,dynamic experiments of the rigid-flexible coupling system and dynamic experiments of the curved beam.The hub is influenced by its vibration frequency and the first frequency of the flexible beam,while the flexible beam is also influenced by the second frequency under free vibration condition.The influence of the high order frequency can be ignored.The frequency of the hub-beam-spring system and the flexible beam increase with the increase of torsional stiffness.The frequency of the flexible beam increase with the increase of the ratio of the flexible beam and hub inertia.