Xuanping Cai

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This paper presents an effective algorithm for calibrating the extrinsic parameters between a camera and a laser range finder whose trace is invisible. On the basis of an analysis of three possible features, we propose to design a right-angled triangular checkerboard and to employ the invisible intersection points of the laser range finder's slice plane(More)
Internet-based teleoperation is becoming an important research field in robotics. Most of existing works employed the wired Internet or wireless local area network to transmit signals, which largely limited the movement of the robots. This paper presented a teleoperation project based upon mobile communication networks. Using mobile networks as the wireless(More)
In this paper we propose a new method of detecting moving objects from a moving camera based on SIFT(The Scale Invariant Feature Transform) features matching and dynamic background modeling. Firstly, feature points are extracted by SIFT algorithm to compute the affine transformation parameters of camera motion, and guided by RANSAC to remove the outliers.(More)
This paper presents an effective and efficient face normalization method based on eyes location. The face is first rapidly detected based on boosted cascade of simple Haar-like features. Then, the algorithm detects the position of pupils in the face image using the geometric relation between the face and the eyes. Finally, the algorithm normalizes the(More)
This paper copes with the problem of identifying the attitude dynamics of a small scale helicopter using the frequency sweep technology based on the flight data collected near the hovering condition. The frequency domain responses of a helicopter in the lateral, longitudinal and yaw channels are analysed by the partial coherence method, and the transfer(More)
Corner detection has been shown to be extremely useful in many computer vision applications. In this paper, an improved SUSAN corner detector is proposed and its performance is compared with Harris and SUSAN corner detection. The method adopts an adaptive multi-threshold strategy based on local brightness rather than one threshold for the whole image, and(More)
This paper presents a fully distributed algorithm for target tracking using a mobile sensor network. It tries to maintain the target being visible to the mobile network all the time while consuming as little motion energy as possible. Meanwhile the network connectivity is maintained. At every time, only the nodes around the target are activated while other(More)
Mobile ad-hoc networks are characterized by self-organization, rapid deployment and fault tolerance, however of limited communication range and frequent topology change. For a multi-robot formation supported by mobile ad-hoc networks, when the robots change their formation to avoid obstacles or for other purposes, a robot may easily lose its wireless(More)
The problem of multi-robot cooperative localization based on relative bearings is researched in this paper. Relative bearings of different robots are fused with motions to improve the localization accuracy of robots. We analyse the situations about relative positions of the robots and their motion trajectories. Some relative positions and motion(More)
Traditionally, the problem of stereo matching has been addressed either by a sparse feature-based approach or a dense area-based approach. This technique still suffers from a lack in accuracy or long computation time needed to match stereo images. In this paper, we employ color segments on scan lines of stereo images as primitives for matching, and(More)