A symmetry criterion is designed according to the irradiance distribution characteristic of White Light Interference (WLI). A zero Optical Path Difference (OPD) location algorithm is presented based on the symmetry criterion and discreteness of sample. The location algorithm consists of two steps: 1) Using the symmetry criterion and its variation trend to search and locate the measurement sub-peak around the maximal value in the data, which is the closest to the zero OPD; 2) Using fitting method to further locate the zero OPD and peak value based on the located sub-peak in the step 1. The location validity can also be evaluated by the symmetry criterion. The experiment of data processing and algorithm comparison shows that this location algorithm has advantage of discriminating and pick up zero OPD, which can meet the measurement need of the high precision WLI instrument.

The optical images from lunar rover could be used to reconstruct the lunar terrain spatial configuration. The products include 3D point cloud and digital orthophoto map, etc. While the images matching algorithm accuracy is closely related to the reconstruction’s accuracy and reliability, an improved dynamic programming matching method is required. Considering bidirectional constraints of row and column simultaneously and adding the dynamic seed point strategy, this algorithm can get global optimal solution with the advantages of high efficiency and stability. Compared with the result from others methods and the ground laser data, experimental results demonstrate that the method has a high accuracy and capability to meet the demand of lunar rover positioning and navigation exploration project.

A new method of horizontal tank tilt ratio based on cloud data by laser scanning is presented. Horizontal tank can be supposed as approximate cylinder. The equation of the cylinder axis can be gotten by fitting the cloud data. First, pretreatment method based on the curvature algorithm and the symmetry principle was presented to separate line segments and arc segments from single layer data. The interference of attachment points had been excluded through linear least squares fitting in order to get some stable cylindrical fitting parameters. Then, Levenberg-Marquardt nonlinear least-squares method was applied for fitting to get cylinder parametric equation. Finally, horizontal tank tilt ratio was obtained by exactly calculating. Compared with manual measurement, experimental results show that this method has fast computing speed and strong robustness, and angle deviation was less than 0.01 degrees.

In order to measure the curves of distance and output voltage for eddy current sensor, a speckle correlation method is proposed. Firstly, the linear interval is measured by the displacement platform with precision of 5um. Secondly, congestion sampling is taken out in the linear interval, the speckle pattern under different distance is captured by the micro-imaging system and more precision curves are obtained with displacement calculated by the speckle correlation method. The precision of measurement is analyzed and the influence of speckle size on measurement is also discussed. The micro-imaging system with magnification of 64.5 is designed by combining an objective with 40 magnifications and a reading microscope with 20 magnifications. The experimental object is the 40 chromium and the results show that the proposed system can achieve high precision calibration for eddy current sensor with 0.09 μm precision and more precision can be obtained by changing the magnification of the imaging system.

The concentric circle is taken as target mark. The target parallel to the rudder shaft is fixed on the rudder face. Based on monocular vision, a method for measuring object position and orientation is designed to obtain its angular displacement. Take the diameter parallel to the imaging-plane as a characteristic diameter, and take the diameter perpendicular to the characteristic diameter as an auxiliary characteristic diameter. It is proved that the auxiliary characteristic diameter’s image and two elliptic centers and the projected center are collinear. Based on the invariance of cross ratio, the projected center can be found. Through digital image processing, these characteristic diameter images and their preimages can be obtained. Thus, the relative position and orientation of the concentric circle and its angular displacement can be derived. Simulating test results: measuring range ±85° and RMS error less than 0.04° when Gaussian noise level is 2 pixels. Proposed method has strong ability to resist noise. Measurement errors caused by the target-plane deviating from the rudder-axis direction may be corrected. By this method, the angular displacements of rudder can be calibrated.

Polarization sensitive mechanism of the POL-neuron model of desert ant (Cataglyphis) offers the basis for the study on bionic polarization navigation. Referring to the angle ambiguity error of the existing signal processing method of POL-neuron model, a new angle method is proposed based on high-order polynomial fitting after analyzing the working principle of the model. According to the relationship between navigation direction and the rotation angle of reference axis, so the effective angle range can be increased from [-45°, 45°] to [0°, 180°] linearly. Finally, the corresponding experiment is also done to test the performance of this new angle method using a 4-channel polarized light navigation sensor in real skies. The result demonstrates that this method can solve the angle ambiguity error of POL-neuron model effectively, and improve the angle range dramatically.

In order to solve the problem of segmentation and location of moving object in moving scenes, an algorithm of segmentation and location of moving object in moving scenes with the fusion of background compensation and mean shift is proposed. Firstly, frame-difference method is used to get difference image based on moving scenes compensation. Then, multiple feature descriptors of nonzero pixels in difference image are established and mean shift algorithm is adopted to deal with the nonzero pixels. Lastly, segmentation and location of moving object is done with the nonzero pixels gotten from mean shift clustering. The results indicate that this method can realize moving object detection accurately.

Detection of weak targets in heavy ground clutter is one of key issues for Foreign Object Debris (FOD) surveillance radar on runways. Because of “Shelf-shielding” effect, traditional CFAR detection algorithms cannot effectively detect targets in multiple target environments. A method of trimmed-mean clutter-map CFAR detection is proposed. First, multiple targets echo model of Frequency Modulation Continue Wave (FMCW) radar based on the scenarios of airport runways and characteristics of radar system is established. Then, the largest samples in referencing cells are removed and mean of remaining samples is the clutter-level estimation. To obtain a stable detection threshold to detect targets, the clutter-map cells are updated scan-by-scan. At last, further analysis of main factors which affects detection performance of this algorithm is studied.

In order to solve the imaging position error of the short focal length wide field of view infrared theodolite, which is caused by optical, mechanical, alignment and other factors in the actual production process, this article used the idea of partition processing that the image is divided into multiple zones, and then least squares linear processing is performed in each zone. We can obtain the desired fit parameters, which can be used to validate the calculation on the back of the validation data. Results of the experiment show that this method can improve the full-field measurement accuracy.

A new general modeling method for bridge based on the OpenFlight model is proposed by analyzing and simplifying the structure of bridge, making the girder-type bridge, suspension bridge, arch bridge and cable bridge a general model structure. Aiming at heat characteristics of box girder, cable, railing and other typical part of bridge, the computational model for infrared radiation characteristics is built by considering a variety of natural factors, which can be simulated through image gray information. Moreover, a general software system is developed. Experimental results show that the method can effectively simulate the infrared radiation characteristics of bridge at any time, any geographical position and any meteorological environment.

To reduce the loss of image details caused by traditional median filter, an adaptive median filter algorithm is proposed based on multi-stage noise detection. According to the spatial correlation of pixels, the proposed algorithm detected the types of noise progressively. First, it detected the single noise pixel by counting the number of pixels that had similar values in filter window. Then it extended the filter window in adjacent space to detect the two pixels noise, and added constraints to detect the three or above adjacent pixels noise. Finally, the noise pixel was replaced with the median. In addition, the proposed algorithm can adjust the threshold of pixel spatial correlation discrimination adaptively to meet the processing of different distribution noises. Compared with other median filters, experimental results show that the proposed algorithm can remove noises effectively with maintaining the detail information of the original image.

Stereoscopic image quality assessment is an effective way to evaluate the performance of stereoscopic video system. However, how to utilize human visual characteristics in quality assessment is still an unsolved issue. In this paper, an objective stereoscopic image quality assessment method is proposed based on perceptual significance. Firstly, by analyzing the effects of visual saliency and distortion on perceptual quality, we construct perceptual significance model of stereoscopic images. Then, we separate the stereoscopic image into four types of regions: salient distortion region, salient non-distortion region, non-salient distortion region and non-salient non-distortion region, and evaluate them independently. Finally, all evaluation results are integrated into an overall score. Experimental results show that the proposed method can achieve higher consistency with the subjective assessment of stereoscopic images and effectively reflect human visual system.

Normalized Cross Correlation (NCC) algorithm is one popular image matching algorithm based on the intensity correlation, but its application is limited because of high computational complexity and long computing time. Therefore, a normalized cross correlation image matching algorithm based on adaptive step size is proposed. According to the normalized cross correlation coefficient, the step size is chosen adaptively which can increase the matching speed obviously. The normalized cross correlation coefficient is improved to increase the differential degree of step size thresholds. So the selection precision of adaptive step size is boosted evidently. At the same time, the matching time and the matching speed are allocated reasonably. Experiment results indicate that the matching time of the proposed algorithm is reduced to 10%~50% compared with the traditional NCC algorithm without loss of precision.

Differentiating angular displacement and displacement at manipulator’s end-effector directly, analysis formulas of angular velocity, linear velocity, angular acceleration and acceleration are given in this paper. According to these formulas, two iterative programs about velocity and acceleration at end-effector is given as well as. Since it is not necessary to count transform matrix from frame {n-1} to {0} in iterative program, the algorithms become simpler and thereby can be used to enhance the property of real-time in manipulator control.

A high precision closed-loop control positioning system taking the DMC2210 card as a control core is designed, which uses linear encoder as feed-back component to realize the precise positioning of indexing movement. The analysis and optimization pointing to the phenomenon of workbench’s overshoot is carried out in two parts. One part, the relation between stepping motor’s deceleration and ruling precision is analyzed, and then the phenomenon of workbench’s overshoot is optimized preliminarily by the stepwise deceleration’s style. The other part, the influence of spring’s stiffness on workbench’s overshoot problem is analyzed and simulated. After the change for spring with stronger stiffness, the index error caused by workbench’s overshoot phenomenon is improved largely. After the improvements, extensive tests on ruling gratings with density of 79 g/mm are carried out. Experimental results indicate that the precision of the indexing movement at ruling echelle with 79 g/mm is controlled in 5nm.We select one of the better data (the indexing movement’s precision is 2.887 nm) after our improvement to compare with one of the better data (the indexing movement’s precision is 7.759 nm) in the previous tests. The result shows that the ruling engine’s indexing precision is significantly improved.