Mingxia Shen

An automatic splitting method for the adhesive piglets’ gray scale image based on the ellipse shape feature

Abstract The average weight of piglets in lactation can be monitored automatically by piglets’ average weight monitoring systems which are designed based on wireless multimedia sensor networks. Piglets counting in an automatic manner for piglets images is the foundation of these systems. Adhesive piglets may exist in an image due to the social character of piglets, which challenges the image splitting and automatic piglets counting. This paper proposes a segmentation algorithm for adhesive piglets images based on ellipse fitting method. Firstly, ellipse fitting is implemented for a large number of images which have one piglet. Parameters range of ellipses fitted by images with a single piglet on different age is extracted. Secondly, contours of connected components in an adhesive piglets image are extracted. Each contour is segmented based on concave points. Ellipse fitting is implemented for each contour segment. Finally, 5 rules for ellipse merging are put forwarded, which are used to merge anomalous ellipses. After ellipse merging, the number of ellipses equals the number of piglets. The proposed algorithm is applied to adhesive piglets images in Matlab R2012b and the experimental results show that the counting accuracy exceeds 86% when the number of piglets is less than 7. The algorithm provides the foundation for the piglets’ average weight monitoring systems.

Design of a Wireless Sensor Network for Farmland Monitoring

Farmland monitoring is of great significance in precision agriculture. In this paper, we design a wireless sensor network to monitor farmland information, including air temperature and humidity, light intensity, soil moisture, soil PH value, and the growth of crops. We carry out an experiment in the cornfield of Hongzehu farm. It shows that the monitoring system is effective.

Feedback stabilization of unstable periodic orbits for chaotic passive compass-like biped robot

Unstable periodic orbits of the chaotic passive compass-like biped robot which is an typically impulsive dynamical system are stabilized by using energy-shaping control. Because of impossibly instantaneous regulation of the angular and angular velocity of the passive compass-like biped robot, energy damping control with reference energy calculated by using impulsive control is supposed. Sufficient conditions under which the impulsive dynamical system is feedback stabilized are given. Simulation results verify the method.

Finite time control of a boiler-turbine system

Feedback stabilization of boiler-turbine system is discussed by using finite time control technique. First, boiler-turbine system is state feedback linearized. Then, by virtue of finite time control technique, series controllers and parallel controllers are designed respectively to stabilize boiler-turbine system. The closed-loop system exhibits faster convergence, better robustness and disturbance rejection properties. Simulations are employed to verify the proposed method.