ABSTRACT This paper presents a new Omni-Directional Tilt Sensor (ODTS), which consists of the LED light, transparent cone-shaped closed container, mercury, camera, embedded systems and so on. The volume of the mercury in the container is equal to half of the container’s. When the detected surface is horizontal, the shape of mercury in the image captured by the camera is a black disc since the mercury is lightproof. When the detected surface tilts, the mercury flows and the mercury surface always maintains horizontally due to the gravity force of the earth. At this time, some area of the transparent cone-shaped closed container is not shaded by mercury and the border of the mercury’s shape in the captured image is a half circle and a half ellipse. Thus there is a translucent crescent-shaped area in the image. With analyzing this area by the specific algorithm based on machine vision, the tilt angle and directional angle can be obtained. The experimental results show that the ODTS proposed has some advantages, such as simple maintenance, high precision, wide range, low cost, real-time, reliability and high visualization.
Cite this paper
nullY. Tang and C. Chen, "Design of Omni-Directional Tilt Sensor Based on Machine Vision," Journal of Sensor Technology, Vol. 1 No. 4, 2011, pp. 108-115. doi: 10.4236/jst.2011.14015.
 C.-T. Wang, E.-H. Yang, J.-G. Zhang, Y.-X. Ma, B. Zhang, “The Omni-Directional Electronic Level Structure and Measuring Analysis Principle,” Journal of Scientific Instrument, Vol. 27, No. 2, 2006, pp. 183-185.
 J.-F. Liu and M.-Y. Li, “The Principle Analytics of Gravity Sensor Level Measuring Instrument,” Sensors and Instrumentation, Vol. 24, No. 7, 2008, pp. 159-160.
 Y. Wu, Y.-H. Song and W.-J. Su, “The Research of Liquid Pendulum Tilt Sensor,” Coal Mine and Machinery, No. 6, 2004, pp. 31-32.
 Y. Lin, L.-H. Pu and F.-X. Zhang, “The Structure Principle of the Omni-Directional Gas Pendulum Tilt Sensor,” Electronic Components and Materials, Vol. 25, No. 5, 2006, pp. 19-22.
 J.-H. Zhou, J.-Z. Wu and M.-Q. Xu, “The Micro Tilt Sensors of Image-Based Identification,” Automation, Vol. 27, No. 11, 2006, pp. 39-44.
 B.-O. Guan, H.-Y. Tam and S.-Y. Liu, “Temperature- Independent Fiber Bragg Grating Tilt Sensor,” IEEE Photonics Technology Letters, Vol. 16, No. 1, January 2004, pp. 244-226. doi:10.1109/LPT.2003.820101
 F. Hua, I. Reading and Z. P. Fang, “Novel Opical Sensor for Precise Tilt Angle Measurement,” Control, Automation, Robotics and Vision, 2006.ICARCV’06. 9th International Conference, Singapore, 5-8 December 2006, pp. 1-4.
 H.-Q. Liu, “Circle Detection Based on Hough Transform,” Master’s Thesis, Northeastern University, Shenyang, 2005, pp. 34-38.