The Mechanism Research Of Two Novel Parallel Multi-dimensional Vibraton Isolation Platforms

Electromechanical equipments often suffer from the impact of adverse factors such asvibration and friction when they work in abominable dynamic environment. Unfortunatelythis may cause failure even destruction of equipments. Sophisticated optoelectronicdevices are especially sensitive to vibration. For example, in the process of aerialphotography, since the vibration influence the stability of the visual axis of the aerialcamera, this greatly affects the imaging precision. Another example is that vibration ofteninfluences the target tracking of the seeker in the flight of missile. Vibration isolationprocessing is in urgent need for those equipments that are sensitive to vibration. Toaddress this problem, we use parallel mechanism in the field of multi-dimensionalvibration isolation which based on the mass-spring system of vibration isolation principlein this paper. Multi-dimensional vibration isolation platforms based on two kinds ofparallel mechanisms are researched and analyzed, and vibration isolation effect of theplatforms are evaluated.As one of the branches of mechanisms, parallel mechanisms have been applied inmany aspects because of the characteristics such as high precision, high stiffness etc.Parallel mechanisms can be used as a multi-dimensional vibration isolation platformbecause of its essential characteristics of multi-dimensional movement. Multi-dimensionalvibration isolation platform based on parallel mechanism has many advantages comparedwith traditional multi-dimensional vibration isolation platforms. Meanwhile they also havesome unsatisfactory respects. Two mechanisms applied in the multi-dimensional vibrationisolation platform are discussed; meanwhile kinematics and dynamics of the twomechanisms are researched, too.(1) A6-DOF and a3-DOF mechanisms are proposed, both the branches of the twomechanisms have the closed-loop substructure. The freedom, workspace, inversekinematics and stiffness of the6-DOF mechanism is analyzed. For the3-DOF mechanism,the freedom and kinematics character are analysed based on the influence coefficient ofthe mechanisms. The input election is addressed on the global performance index. Finally the singularity is researched.(2) Mathematical modeling was carried out based on parallel mechanism theory, thevibration isolation of the system is analyzed by differential equation of motion of themechanisms, and the force transfer rates and natural frequencies of vibration isolationplatforms are calculated.(3) Kinematics and dynamics characteristics and vibration isolation performance ofthe multi-dimensional vibration isolation platform are verified by software simulation.Each mode of the vibration of the platofrms are calculated.In this paper, two parallel mechanisms applied in multidimensional platform areresearched. This will have the certain theoretical reference value to research kinematicsand dynamics of parallel mechanism applied in multi-dimensional vibration isolationplatform.