A double laser filtering approach to vibration noise rejection for hot-rolled strip flatness measurement

This paper proposes a new filtering method based on the Kalman filtering algorithm for hot-rolled strip flatness measurement system. The system involves processing slowly changing signal, which can be considered as a bounded random process, and its model parameters are completely unknown. The noise rejection strategy in double lasers can generate a compensation signal. Since the initial and accumulative error would lead to negative filter effect or even cause divergence, Kalman filter is integrated to effectively deal with the initial error and enhance convergence. In this setting, the noise rejection strategy is used as a prediction model to constitute a similar Kalman filter. The correlated error caused by measurement error is coped with by a compensation model based on the feature of correlated error to enhance the filter effect. Both theoretical analysis and simulations show that the new algorithm has a better filter effect than the traditional Kalman filtering algorithm for the system.     

Measurement of binocular disparity in polarized based stereoscopic display by using digital camera

This work presents an image displacement measurement by using a box pattern and the edge spread function analysis in the polarized based stereoscopic displays. The measurement determines to identify three factors (i.e., box size, image displacement, and spatial frequency response (SFR)) from the box patterns. The polarized based stereoscopic displays might sacrifice pixels for producing 3D images, which might produce errors in the image displacement and then affect the depth perception indirectly. Based on the measurement, the errors can be quantified by using the three factors. Owing to the light leakage distorting the edge spread function to obtain an inferior SFR, exactly how light leakage affects the edge spread function can be resolved on the basis of the SFR results, especially at a frequency (1/display pixel) of 1.9 in the case of the horizontal displacement. Light leakage also induces the error of the box height in even and odd intervals of the vertical displacements more than 2 pixels and 0.5 pixels, respectively. The image displacement measurement provides a simple and comprehensive means of evaluating the optical characteristics, disparity, and sharpness of the stereoscopic displays, via the three factors.     

Vision-based action recognition of earthmoving equipment using spatio-temporal features and support vector machine classifiers

Video recordings of earthmoving construction operations provide understandable data that can be used for benchmarking and analyzing their performance. These recordings further support project managers to take corrective actions on performance deviations and in turn improve operational efficiency. Despite these benefits, manual stopwatch studies of previously recorded videos can be labor-intensive, may suffer from biases of the observers, and are impractical after substantial period of observations. This paper presents a new computer vision based algorithm for recognizing single actions of earthmoving construction equipment. This is particularly a challenging task as equipment can be partially occluded in site video streams and usually come in wide variety of sizes and appearances. The scale and pose of the equipment actions can also significantly vary based on the camera configurations. In the proposed method, a video is initially represented as a collection of spatio-temporal visual features by extracting space–time interest points and describing each feature with a Histogram of Oriented Gradients (HOG). The algorithm automatically learns the distributions of the spatio-temporal features and action categories using a multi-class Support Vector Machine (SVM) classifier. This strategy handles noisy feature points arisen from typical dynamic backgrounds. Given a video sequence captured from a fixed camera, the multi-class SVM classifier recognizes and localizes equipment actions. For the purpose of evaluation, a new video dataset is introduced which contains 859 sequences from excavator and truck actions. This dataset contains large variations of equipment pose and scale, and has varied backgrounds and levels of occlusion. The experimental results with average accuracies of 86.33% and 98.33% show that our supervised method outperforms previous algorithms for excavator and truck action recognition. The results hold the promise for applicability of the proposed method for construction activity analysis.     

The Stability of Concentrated Thiosulphate Solutions at High Temperature. Part II. The Loss of the Sulphite

The decomposition of concentrated thiosulphate fixers at elevated temperatures occurs because the sulphite is converted into sulphate and thiosulphate in a reaction catalyzed by the thiosulphate. When the sulphate is gone the thiosulphate decomposes giving sulphur and sulphurous acid which latter is also lost by the above mechanism.     

Measuring and evaluating bitumen coverage of stones using two different digital image analysis methods

The most used pavement for paved roads in the world is asphalt. It is therefore important that the asphalt is as durable as possible to avoid expensive repairs of the roads. One important factor of the durability of the road is the adherence between the stones and the bitumen that holds the stones together. The affinity is tested by the so called rolling bottle test, where one put stones covered in bitumen in a bottle with water and let it roll on a bottle rolling machine. After a while the degree of bitumen coverage is estimated. In this paper, a method to estimate the degree of bitumen coverage using image analysis has been developed instead of the manual estimation that is used today. The presented method works for all colors of the stones and is based on the fact that bitumen reflects light much better than raw stones. A turntable that is rotated somewhat between images is used together with a light source in shape of a quarter of a circle to get as much specular reflections as possible. Then the amount of detected reflections is used to estimate the degree of bitumen coverage. To be able to compare the result with something close to ground truth, the method has been evaluated on lighter stones and compared with a second image analysis method that works well for lighter stones, and the results are promising.     

Confucian ecological vision and the Chinese eco-city

“Living in harmony with nature” is the slogan of the Chinese government’s campaign against the environmental crisis and has become the target of many mega eco-city projects which have emerged in China during the last decade. A number of papers in Chinese journals attribute this slogan to the government’s revival of the Confucian ecological vision, combined with western technology. This paper first compares the concept of nature in these mega eco-cities and the Confucian concept of tianrenheyi, the unity of Heaven and Humanity, suggesting that the human–nature relationship in eco-cities is essentially a consumer–commodity relationship, which is void of the sacredness or moral association of the human–nature relationship in the unity of Heaven and Humanity. Secondly, drawing on the theory of ecology and interconnected systems and noting that the failure of eco-city projects lies in the separation of the eco-city from the city itself, I suggest that the eco-city’s approach of taking nature as a guinea pig of technology in a “vacuum space” is quite opposite to the Confucian idea of the unity of Heaven and Humanity which emphasizes the interconnectedness of all inorganic and organic forms. In conclusion, I evoke Wang Shu’s practice of sustainable architecture to illustrate a more authentic, up-to-date interpretation of the Confucian ecological vision—investigating the relational reality, developing one’s moral nature and cultural intuition.     

Monocular-vision-based method for online measurement of pose parameters of weld stud

With the rapid development of stud welding technology, weld studs are extensively used in automobile industry. A weld stud differs from a regular stud in that it has special external features. This study develops a novel non-contact, fast, and high-precision method based on monocular vision for measuring the position and attitude parameters of a weld stud. Under this method, the measuring principle for the weld stud’s position and attitude parameters is derived and an accurate mathematical model is set up. Based on this mathematical model, a precise calibration method for the projective transformation’s corresponding relationship parameters is developed and an optimal observation condition is then introduced as the constraint into the measurement process so as to enhance the location precision. The experiment results show that the proposed method is fast and accurate, and it satisfies the requirement of online, flexible, fast, and high-precision measurement of weld studs’ pose parameters in automobile and other manufacturing industries.     

基于TRIZ理论的TFT-LCD基板玻璃视觉检测系统优化设计

采用TRIZ理论,对TFT-LCD基板玻璃视觉检测系统存在的无法反应颗粒趋势、机械定位存在质量隐患、检测兼容性差等技术瓶颈问题进行了分析解决,从而构建了一套完善的视觉检测系统,实现了兼容检测G4.5及G5 TFT-LCD基板玻璃的能力,为TFT-LCD基板玻璃产业同行解决生产中的技术问题提供了新的方法思路。