Theory And Experimental Research Of Rigid-Flexible Hybrid Mechanism For Manipulator And Rotor

Hybrid mechanism is widely used in various fields,because the hybrid mechanism is a complex mechanism with multiple closed-loop structures,it is a challenging study to establish its kinematics and dynamics model.In order to establish the kinematic model of complex mechanism,In this paper,the theory method of extended skew-symmetric matrix is proposed which can be used to establish the kinematics model of complex mechanism,based on this method,the general forward acceleration and the corresponding Hessian matrix are solved,and the kinematics and dynamics models of the rigid-flexible hybrid manipulator and the rigid-flexible hybrid rotor actuator mechanism are established.Theoretical research,prototype development and experimental research of rigid-flexible hybrid force sensing finger,rigid-flexible hybrid manipulator and rigid-flexible hybrid rotor actuator mechanism are carried out.The theory method of extended skew-symmetric matrix is proposed and the theoretical series formulas of extended skew-symmetric matrix is derived.Hessian matrix and general forward acceleration for several typical kinematic limbs in series-parallel hybrid mechanism are solved by the theoretical series formulas of extended skew-symmetric matrix.The results can be used to solve the kinematics and dynamics of rigid-flexible hybrid manipulator and rotor actuator mechanism.The theoretical series of formulas extended skew-symmetric matrixes is verified with a simulation mechanism for a2(RPS+SPR+UPS+SPU)-type hybrid mechanism.The rigid-flexible hybrid finger mechanism with force sensor is designed.Based on its structural properties,the equivalent mechanism is constructed and the degrees of freedom of the equivalent mechanism with constant or variable length of the flexible link are analyzed.The kinematics model of the finger mechanism is established by vector method.The position,velocity and acceleration of the fingertip in the equivalent mechanism at constant length of the flexible link is derived.The statics equations are derived by the principle of virtual work and mechanical constraint relationship.The various forces acting on the fingertip,key links and sensor at constant and variable lengths of the flexible link are solved.A rigid-flexible hybrid manipulator model consisting of a parallel mechanism with three rigid-flexible hybrid finger mechanisms is designed.The kinematics model of the manipulator grasping the object is established,and the general velocity and acceleration of each fingertip of the hybrid manipulator and the grasped moving object are solved by using the theoretical series formulas of extended skew-symmetric matrix.The corresponding composite Jacobian matrix and composite Hessian matrix are solved.A general dynamics model of this type of hybrid manipulator is established by the principle of virtual work.Taking two new parallel mechanisms and three fingers as examples,A simulation model of the hybrid manipulator is constructed to verify the correctness of the theoretical model.Experimental study of the grasping performance of the rigid-flexible hybrid manipulator prototype.Loading experiments on the finger prototype is conducted to study and analyze the flexibility,safety,load-bearing capacity,and force-sensing capability of the flexible fingers.A method to determine the mass of the grasped object based on multi-finger sensor measurements is proposed.Loaded gripping experiment on the rigid-flexible hybrid manipulator prototype is conducted to study and analyze the kinematic performance,loading capacity,self-adaptability,grasping force perception,grasping and releasing object performance of the manipulator.Two new rigid-flexible hybrid rotor actuator mechanisms for helicopters with elastic limbs is designed based on parallel mechanisms of 2SPS+UPU+SP type and 2PSS+PSR+SP type.The kinematics model of the mechanism is established by the theory method of extended skew-symmetric matrix,and dynamics model of the mechanism is established by the principle of virtual work.According to the dynamic results,the influence of the spring on the actuation forces and constrained forces of the rotor is analyzed.The parallel mechanism makes the rotor have a larger inclination and stiffness,compared with the traditional helicopter rotor structure is more simple,lightweight and safe.