Tracking by Deblatting

Objects moving at high speed along complex trajectories often appear in videos, especially videos of sports. Such objects travel a considerable distance during exposure time of a single frame, and therefore, their position in the frame is not well defined. They appear as semi-transparent streaks due to the motion blur and cannot be reliably tracked by general trackers. We propose a novel approach called Tracking by Deblatting based on the observation that motion blur is directly related to the intra-frame trajectory of an object. Blur is estimated by solving two intertwined inverse problems, blind deblurring and image matting, which we call deblatting. By postprocessing, non-causal Tracking by Deblatting estimates continuous, complete, and accurate object trajectories for the whole sequence. Tracked objects are precisely localized with higher temporal resolution than by conventional trackers. Energy minimization by dynamic programming is used to detect abrupt changes of motion, called bounces. High-order polynomials are then fitted to smooth trajectory segments between bounces. The output is a continuous trajectory function that assigns location for every real-valued time stamp from zero to the number of frames. The proposed algorithm was evaluated on a newly created dataset of videos from a high-speed camera using a novel Trajectory-IoU metric that generalizes the traditional Intersection over Union and measures the accuracy of the intra-frame trajectory. The proposed method outperforms the baselines both in recall and trajectory accuracy. Additionally, we show that from the trajectory function precise physical calculations are possible, such as radius, gravity, and sub-frame object velocity. Velocity estimation is compared to the high-speed camera measurements and radars. Results show high performance of the proposed method in terms of Trajectory-IoU, recall, and velocity estimation.

Research on manipulator grasping method based on vision

Aiming at the problem that the manipulator cannot grasp the object accurately when the robot changes the position and pose of the object in the process of static grasping, a set of manipulator grasping method research based on vision is proposed. Firstly, a set of camera detection and robot grasping system model is built. Secondly, each coordinate system is created for the grasping system, and the transformation relation between each coordinate system, matrix model and the quantity that needs to be calibrated are introduced in detail. Thirdly, the trajectory function from the image coordinate system to the coordinates of the manipulator is obtained through the direct linear method calibration experiment. Finally, the experimental platform for camera detection and manipulator grasping objects based on xavis was built, and the grasping success rate of the experimental platform was tested. The experimental results show that the grasping error rate of the experimental platform is within the control range. Therefore, the manipulator grasping method based on vision is of reference significance for engineering applications.

Evaluation of a Multi-Vehicle Merging Strategy Under Different Lateral Maneuvers in the Presence of Sudden Braking

The ability for multiple vehicles to merge into an ongoing platoon is an important task in the field of intelligent transportation system (ITS). For such task, first a strategy is required to include a set of rules and actions which allows the incoming vehicles to join the platoon, and second; a safe lateral trajectory generator which always ensures the safety of lateral maneuver in terms of lateral acceleration. In this paper we evaluated the multi-vehicle merging strategy using different lateral trajectory functions under sudden breaking. Simulation results show that for merging task, a switching function is necessary to switch from an adaptive lateral function to a constant lateral trajectory function in case of sudden decelerations.

The Orbital Error Analysis and Study of Space Vehicle Active Phase

In this paper we solve the three-dimensional coordinate that the satellite is relative to the geocentric coordinate under certain conditions, making use of the satellite orbit standard trajectory differential equations. By means of the method of tri-parametric equation fitting, we confirm the three-dimensional trajectory function of target flying object to geocentric coordinate in double satellites observation conditions, and analyze theoretical errors.