Pointing Stability Of Light-Beam In Vibration Environment And Its Key Techniques Of Opto-Mechatronics

With the extension of application fields of optical systems, optical equipments that combine numerous research achievements, such as high-energy laser systems for long-distance propagating, space optical communication systems, high-precision laser processing equipments and high-precision measuring instruments, have 'walked' from laboratories to engineering environments. However, all kinds of dynamic disturbances, such as surrounding temperature changes, atmosphere turbulence, fog and dust, and mechanical vibration caused by various sources, may influence the performance of the systems, which prevent the optical techniques from going into practice. Based on the key techniques of vehicle-borne mobile optical systems, this dissertation investigates the quaternion method of light-beam propagation in misaligned optical systems, the light-beam automatic alignment techniques in multi-platform systems and the light-beam stabilizing techniques in vibration environment. The main works include:1. According to the Rodrigues-Hamilton parameterized quaternion, the concepts of standard quaternion and inverse operator of rotation transform of quaternion are introduced. The quaternion representations of refraction and reflection laws are deduced. This work established the basic theories for the computation of spatial light-beam propagation.2. The computational flows of the light-beam propagating in coaxial diffraction optical system, coaxial refraction optical system and optical systems with flat mirrors using quaternion method are provided. Based on the computational flows, a general software is developed by using VC++ 6.0 and OpenGL. This software is used to simulate a two-stage beam expander system, and the results are reasonable.3. Based on the theory of mechanical vibration, the computational method of misaligned position and pose of lens (or mirror) are derived, as well as the quaternion method of light-beam propagating in misaligned optical systems. A general software is developed by using VC++ 6.0 and OpenGL, which is used to analyze a two-stage beam expander system mounted on an optical platform. The results of the time domain dynamic response of the light-beam are obtained.4. Considering the light-beam stability control in bad vibration environment, a fast steering mirror (FSM) of large rotation range and large aperture is designed, which is driven by PZT actuator whose output displacement is amplified by two-stage displacement amplifier based on elliptical flexure hinge. The design equations of elliptical flexure hinge are provided.The cutout of elliptical hinge is optimized by using the particle swarm algorithm with nonlinearly decreasing weight strategies proposed in this chapter. Based on the pseudo-rigid-body-model (PRBM) method, the two-stage displacement amplifier is optimized by using the particle swarm algorithm with crowd avoidance strategy. A dynamic simulation of the FSM is completed by using software ADAMS, and the optimization results are proved reasonable.5. Based on the separate design idea of large optical systems, a scheme of light-beam automatic alignment between platforms. Based on the piezoelectricity theory and PRBM, the electromechanical dynamic model of the FSM is built. The light-beam automatic alignment of a two-platform optical system is simulated, and reasonable results are obtained.6. Aiming at pointing direction instability of light-beam in long-distance transmission, a scheme of pointing direction stabilizing control is presented. An experimental model is established, and the results show that the scheme is feasible.