In the paper, we studied two local multi-robot coordination problems, namely, local gathering control and formation tracking. Firstly, a new local control strategy is proposed to address the gathering problem based on routing schemes and using only bearing measurements. The interaction graph might be directed and time varying, but the convergence is still ensured. Second, a zero steady-error formation tracking control is developed by introducing an integral component, which eliminates the steady-state error when the leaders preform uniform rectilinear motions. Last, a novel IR sensor is developed to measure relative bearing angles and distances of neighboring robots and experiments are carried out based on the developed mobile platforms with IR sensors, which demonstrate not only the success of our proposed control strategies, but also the applicability of our developed mobile platforms in the field of local multi-robot coordination.

In this paper, we propose and develop a small-scale research platform for intelligent transportation systems (ITSs). Our platform has four main parts, i.e., an arena, an indoor localization system, automated radio-controlled (RC) cars, and roadside monitoring facilities. First, to mimic traffic environments, we build an arena with a wooden floor, mock buildings, and streets. Second, to facilitate feedback control for trajectory following, an indoor localization system is set up to track the RC cars. Third, both autonomous driving RC cars and human driving RC cars are developed, based on an automated RC car design. The automated RC cars can receive control signals from a computer through an Xbee RF module and control the front and rear wheels through motors. A new control algorithm is developed to allow the RC cars to track predefined trajectories. Finally, we implement an example of roadside monitoring, which uses a fish-eye camera associated with advanced video processing for image segmentation, object identification, and tracking. Experiments are performed to demonstrate the effectiveness of the designed platform. We also discuss possible ITS research problems that can be studied in this testbed.

Wireless Multimedia Sensor Networks (WMSNs) are gaining popularity among researchers over the past few years. Knowledge of the geographic locations of the sensor nodes is very important in a WMSN. In this paper we propose a new algorithm which uses the connectivity information, the estimated distance information among the sensor nodes, as well as the vision images to find the location of the sensor nodes to enable sensor calibration. We achieve this by solving an ID association problem in the WMSN. We then generate local maps for nodes in immediate vicinity and merge them together to get a global map. We demonstrate the effectiveness of our proposed approach through computer simulation.

This paper presents a low-cost, simple automated mobile platform for 3D environmental digitization. Compared with other customized 3D digitization platforms, all parts in our platform are commercial off-the-shelf. In order to build a 3D model of a salient target, we present a new viewpoint planning method for fast 3D digitization. Within a predefined accuracy, our method can determine the minimum overlap between two consecutive scanning images to speed up the digitization process. This guarantees the next scanning image can be merged to the previous one properly. The results from both simulation and experiments show the effectiveness of our viewpoint planning method. Our tests of this mobile robot system demonstrate the feasibility of 3D digitization based on a low-cost platform.

This paper proposes an approach to modeling and evaluating the performance of communication protocols based on formal specifications. A combined extended finite state machine (EFSM) and queueing network model is presented which is more sophisticated than either technique alone. Furthermore, the model avoids the state space explosion problem which may arise by the use of reachability analysis on an EFSM. The approach is illustrated using a simple sliding window protocol written in the formal description technique Estelle.>