Principles And Design Of Virtual Angle Gauge Via Smartphone

With the popularity of application of smartphone in the forestry industry and the rising of quantity and capability of smartphone, there are more apps for measureing heightgage and range uses. In this circumstance, this article combined with angle gauge measurement theory and the principle of convex lens, researched the algorithm and developed the application by using lens and acceleration sensor, and gave out a virtual angle gauge with automatic slope correction based on smartphone that can take place of angle gauge products.This article took the method of prototype method and experiment method, combined the rod gauge structure principle and convex lens imaging principle, determined the equivalent counting rules of model of rod gauge in the convex lens imaging system, and then determined the real image measurement in image plane to equivalent rod gauge. By using the JAVA language, the program was developed in Android system to determined the parameters so that the real image in the image plane was visible. In the upper of camera preview screen, outlined the gap for counting. On the other hand, the value from the acceleration sensor can be concluded correction paramteer in different slope gradient, and then used the parameters to correct the original gap directly in order to achieve the automatic leveling function.In this study we accomplished the virtual gauge by using a Meizu MX3 smartphone, and selected fifty trees in Beijing Olympic Park randomly to take as the sample experiment. Taking the method of gauge controlled measuring, measured by virtual gauge of smart phone and gauge alternately,testing the accuracy of critical tree. The experiment show that, the average relative error of virtual gauge by using smart phone is 4.85%, higher than gauge by 0.27 percentage, the accuracy is almost the same. But compared with the gauge, the virtual gauge of smartphone has more information elements and coule develop stronger. Compared with the special electronic angle gauge, the virtual gauge of smartphone has a lower cost, but has a better portability and other advantages. This study made a meaningful attempt for the realization of virtual gauge function in smartphone.