Abstract According to the development of industry, conventional surveillance system has not already satisfied by the demand today. The combination application of the CCD camera and image analysis technology in personal computer could enhance the functionality and more and more get a lot of attraction on it. Therefore, CCD camera is gradually popular in people live and industry application. However, CCD camera depends on the process ability of personal computer very much. Furthermore, it can¡¦t work well independently on the application. Based on these problems, this paper proposes an effective monitoring technique to establish an image servo module through using the embedding Ethernet controller with CMOS image sensor. The ¡§image servo module¡¨ can execute independently the designate image monitor work. Eventually, an ¡§Internet-based remote visual monitoring system¡¨ was built by integrating ¡§image servo module¡¨ and ¡§database service system¡¨ to widely promote the application on surveillance system. From the experiment system, user can use the IE explore or Netscape to supervise the internet-based image monitor system from web-server. In addition, a real-time monitor system based on VB program tool was also developed for any computer to monitor or setup the remote image server module to achieve the designated work. The transfer speed of Internet image server system is 7~8 frames/s. Keywords¡Gimage servo module, Internet-based remote visual monitoring systems

The brightness variance, caused by relative velocity of the camera and environment in a sequence of images, is called optical flow. The advantage of the optical-flow-based visual servo method is that feature of the object dose not need to be known in advance. Therefore, it can be applied for positioning and tracking implement tasks. The purpose of this thesis is to implement the image servo technique and the sliding-mode control method to track an unknown image pattern in three dimensional motion. The goal of tracking is to maintain identical image captured by the camera based on the relative movement calculated from the optical flow.

A monocular visual servo system for a target with variable shape has been developed in this paper. It consists of two parts: an image-processing unit and a servo control unit. For the image-processing unit, the motion between the target and image center is determined by a template match approach. The image is grabbed by the camera equipped on a Pan-Tilt robot and the robot is controlled to track the target by maintaining the target on the image center. However, the template needs to be updated when the target deforms. For the servo control unit, the movement is estimated by the Kalman filter technique to enhance the tracking performance of the visual servo system.

This thesis presents a robust real-time active tracking system with a pan-tilt camera. The proposed visual servo framework is able to track a deformed object and maintain the target always inside the field of view. For the image processing, an efficient template matching and searching method using the mean-shift theory is developed. The robustness is achieved by appending the ratio histogram, a kernel function, and the template update to the framework when the target is deformed. Then the pan-tilt unit turns towards the target and keeps the target inside the field of view of the camera by feeding back the position information to a Kalman filter. Experimental results show that the presented scheme works successfully when the target is vague or concealed or deformed. The visual tracking task can also be accomplished even when a similar object crosses over the target. In addition, the refreshing rate can be up to 60 frames per second.

The optical flow has been one of the common approaches for image tracking. Its advantage is that no prior knowledge for image features is required. Since movement information can be obtained based on brightness data only, this method is suitable for tracking tasks of unknown objects. Besides, insects are always masters in chasing and catching preys in the natural world due to their unique compound eye structure. If the edge of the compound eye can be applied to tracking of moving objects, it is highly expected that the tracking performance will be greatly improved. Conventional images are built on a Cartesian reference system, which is quite different from the hexagonal framework for the compound eye of insects. This thesis explores the distinction of the hexagonal image framework by incorporating the hexagonal concept into the optical flow technology. Consequently, the reason behind why the compound eye is good at tracking moving objects can be revealed. According to simulation results for test images with different features, the hexagonal optical flow method appears to be superior to the traditional optical flow method in the Cartesian reference system.

This thesis presents a visual servo control scheme for a ball-and-plate system with a maze. The maze built on the plate forms obstacles for the ball and increases variety and complexity of its environment. The ball-and-plate system is a two degrees-of-freedom robotic wrist with an acrylic plate attached as the end effector. By using image processing techniques, the ball¡¦s position is acquired from the visual feedback, which was implemented with a webcam and a personal computer. A fuzzy controller, which provides dexterity of the robotic wrist, is designed to decide the slope angles of the plate to guide the ball to a designated target spot. Using the method of distance transform, the path planning based on the current position of the ball is conducted to find the shortest path toward the target spot. Besides, a relaxed path, appears to be more suitable for actual applications, is provided by the obstacle¡¦s expansion approach. Experimental results show that the presented control framework successfully leads the ball to pass through the maze and arrive at target spot. The visual servo control scheme works effectively in both stabilization and tracking control. Based on this preliminary achievement, further improvement and deeper exploration on related research topics can be carried on in the future.

Zugl.: Aachen, Techn. Hochsch., Diss., 2006.

Thesis (D. Min.)--Logos Evangelical Seminary, 2008. / Vita. Includes bibliographical references (leaves 231-239).

Automatic control is used to operate all kinds of processes: everything from temperature in houses to the control of robots. The course in automatic control in Uppsala University includes laboratory experiments where students conduct tests on a wheel controlled by a, so called, PID-controller which is one of the most widely used control mechanisms. This is a prime opportunity for students to get practical experience of working with PID-regulators and test how different parameters influence results. That system has been improved in this project as there were previously several issues with the system. The system was buggy and one of the tasks where the students are to test the systems’ reaction to oscillating input signals was cancelled because that feature had not been implemented yet. These issues were successfully fixed in this project and all tasks are now doable. Another problem was (and is still to some degree) that a lot of measurement noise occurs when measuring speed. This in turn causes the part of the controller that is sensitive to noise (the derivative part, for those familiar with PID-controllers) to function poorly. Some improvement has been made to this by using low-pass filtering for control purposes and the least square method for display purposes, but the signal is still noisy. The key to solving this issue lies in implementing an algorithm that can precisely estimate the speed without distorting any other information, or alternatively buy sensors with higher precision.

The text of this master´s thesis deals with designing universal control unit for simple robots. In the first part of the thesis there is a list of robotics competitions which are organized to popularize robotics. The next part describes construction and individual components of simple robots used in these competitions. The third part includes description of parts used on this unit and its whole scheme together with its circuit board layout and mounting. The fourth part deals with construction of simple demo-robot with this control unit. The last part describes the software designing for the unit and checking its functionality.