Design And Research Of A New-type Optical Scheme Towards Measuring The Position And Orientation Of An Aerial Target

Measuring the position and orientation of aerial target is one of the most significant research branches in modern metrology domains.Specifically,photoelectric detection measuring strategy,with distinct advantages of long working distance,real-time measurement,high precision and strong anti-interference ability,holds great potentials in diverse scientific and industrial applications.In this dissertation,I propose and demonstrate a newly-designed airborne scanning and positioning optical system,which aims at accurately acquiring the position and orientation of aerial target using photoelectric detection.In the primary scheme,measuring the azimuth and elevation angles is implemented by means of dual-channel laser scanning with vertical coaxially,and finding the target distance is performed through time-of-flight detection method.Additionally,the total measurement errors are probably originated from quality of laser beam,rotation speed error,scanning eccentricity error and many more,which is provided and discussed in detail.Attempts to eliminate the existed measurement errors are also reported and demonstrated.Designing the main modules of the optical system,including linear flattening laser emitter,laser receiver and reverse reflector,is successfully accomplished.According to the essential requirements for laser emitter,originated from the master and slave optical systems,design of the laser beam shaping is carried out.The unidirectional divergence angle and uniformity of the shaped laser beam are less than±0.05°and greater than98%,respectively.Meanwhile,the shaped laser beam has a divergence angle of 30~o and an uniformity greater than 98%in other direction.Adding various useful optical elements in the scheme,such as beam splitter and prism,I further optimize the structure with shaped laser to fulfill the operation demands.In the receiving lens,a commercial avalanche photodiode(APD),with 4 mm diameter of active area,is employed to detect the scanning light.The receiving lens consists of 4 pieces of optical elements,containing 2 aspheric lenses,which has the field of view of±37.5~o and F-number of0.57.I analyze the tolerance and stray light,and in turn investigate the impact from sunlight incident on the receiver and some possible solutions.Moreover,the corner cube prism is utilized as a reverse reflector,and it has simulation features of 21 mm size and two-row distribution with 7.5~o and 22.5~o inclined angle for each row.Furthermore,the master and slave of optical systems are both elaborately designed.On the basis of the assembly requirements from transmitting module,the receiving module and reflecting module,the corresponding mechanical structure and overall structure of each module are designed,and the assembly process of each part is briefly explained.The overall size of the mainframe isΦ103 mm×65 mm,and the dimension of the slave modality isΦ116 mm×39 mm,which meets the imperative requirements of miniaturization and lightweight design in airborne regime.