In order to realize real-time auto-focusing for theodolite, lens-apart method was designed with the corresponding math
model built and analyzed. An Object beam splitted after the first image surface of the theodolite traveled through two
dialyte lens and then was imaged on CCD. The distance between two spots when exactly focused was set as the
calibration value, and the relationship between defocus distance and spot offset was given. The influence of tracking
center shift and divergence angle etc. on focusing accuracy was analyzed. Compared with the traditional focusing
method, this scheme has a higher accuracy, faster calculation, higher tolerance for environment temperature and a
simpler construction. The experiment result exhibited a resolution higher than 0.056mm, which shows a bright
engineering application prospect for this method.
Proc. SPIE. 7160, 2008 International Conference on Optical Instruments and Technology: Optoelectronic Measurement Technology and Applications
KEYWORDS: Information fusion, Digital signal processing, Sensors, Computing systems, Field programmable gate arrays, Computer programming, Computer simulations, Electronic filtering, Filtering (signal processing), Data fusion
To solve the real-time and reliability problem of tracking servo-control system in optoelectronic theodolite, a multisensors
parallel processing system was proposed. Misdistances of three different wavebands were imported into system,
and then prediction was done in DSP1 to get the actual position information. Data fusion was accomplished in PPGA
imported by multi channel buffer serial port. The compound position information was used to control the theodolite. The
results were compared with external guide data in DSP2 to implement correction of above calculation, and then were
imported to epistemic machine through PXI interface. The simulation experiment of each calculation unit showed that
this system could solve the real-time problem of feature level data fusion. The simulation result showed that the system
can satisfy the real-time requirement with 1.25ms in theodolite with three imaging systems, while sampling frequency of
photoelectric encoder was 800 Hz.
A method for small three-dimensional (3D) angle measurement based on auto-collimation and moire fringe is proposed
and analyzed. A right-angle prism is used as the indicator of angle change. The inclined plane indicates the pitch and
yaw angles and roll angle in indicated by the rib which is the intersection of two right-angle sides. Pitch and yaw angles
measurement are implemented by auto-collimation based on reticule and roll angle measurement is measured based on
moire fringe. Roll angle measurement is separated from pitch and yaw by using two light sources with different
frequencies. Any small change of pitch and roll angles will induce the shift of the reticule image after reflecting by
inclined plane. And any small roll angle will induce a change in moire fringe width that is generated by scale grating
image which is reflected by the prism and index grating. The math model of this method is built up and error analysis is
presented. The theoretical calculation results show that the proposed method is feasible and can achieve high accuracy.
Measurement of the features of infrared radiation is very important for the precaution and discrimination of missiles, and relevant research is worthy in military application. The measurement of target's surface temperature is the foundation of infrared radiation characteristics measurement. The principle and configuration of target's surface temperature measurement system based on colorimetry is introduced, the measurement model is deduced and the processes of temperature measurement are presented. Least-square method and back-propagation neural network method are both used to deal with the demarcating data. Compared with the least-square method, Back-propagation neural network has more advantages, such as high precision, good applicability and so on.