Node localization using mobile robots in delay-tolerant sensor networks

We present a novel scheme for node localization in a Delay-Tolerant Sensor Network (DTN). In a DTN, sensor devices are often organized in network clusters that may be mutually disconnected. Some mobile robots may be used to collect data from the network clusters. The key idea in our scheme is to use this robot to perform location estimation for the sensor nodes it passes based on the signal strength of the radio messages received from them. Thus, we eliminate the processing constraints of static sensor nodes and the need for static reference beacons. Our mathematical contribution is the use of a Robust Extended Kalman Filter (REKF)-based state estimator to solve the localization. Compared to the standard extended Kalman filter, REKF is computationally efficient and also more robust. Finally, we have implemented our localization scheme on a hybrid sensor network test bed and show that it can achieve node localization accuracy within 1m in a large indoor setting.

Terminal approach navigation for autonomous robots in a sensory network

In this paper we present a technique based on precision guidance approach for the sensor delivery and reception problem between two mobile robots. A slave robot is employed to collect sensors and slack them on a tray carried by the mobile master robot. We define the terminal attitude of the slave robot with respect to the master and present a LQR control approach to solving the problem of achieving a desired terminal approach angle necessary for the appropriate sensor delivery. The approach criteria is defined in terms of both minimizing the miss distance and controlling the slave robot's body attitude with respect to the master robot at the terminal point.

So flat, so cute! Robots, superflatness and asian architectural futures

Many depictions of urban futures have a distinctly Asian flavour. There have been numerous visions of highly technological futures whose environments extrapolate present societies into futures technically, culturally and politically dominated by China or Japan, Such futures are portrayed as both exciting and threatening, to the point that the Japanese academic and cultural critic Toshiya Ueno used the term ‘Techno-Orientalism’ to describe the phenomenon. Nevertheless, whether Western interest is Orientalist or not, Asian architects are also increasingly looking to their own contemporary and future cultures for inspiration. This paper will discuss two manifestations of this. The first is Thai architect Sumet Jumsai’s Bank of Asia. Unlike contemporaneous English hightech buildings, with their coldly mechanistic representation of ducts and struts, Jumsai’s Bank of Asia, takes on the anthropomorphic character of Japanese scifi robots. It is endearing, friendly, even cute. The second example is what might be termed superflat architecture, from the term coined by the artist Takashi Murakami to describe an aesthetic of intrinsic flatness, eliminating depth in favour of skin and surface. The emergence of Techno-Cute and Superflat architecture suggest contemporary Asian architectural sensibilities that neither derive their aesthetic qualities solely from tradition nor from Western Modernism or Postmodernism.

Simulation of underwater robots using MS Robot Studio©

One stage in designing the control for underwater robot swarms is to confirm the control algorithms via simulation. To perform the simulation Microsoftpsilas Robotic Studiocopy was chosen. The problem with this simulator and others like it is that it is set up for land-based robots only. This paper explores one possible way to get around this limitation. This solution cannot only work for underwater vehicles but aerial vehicles as well.

Cooperative hunting by distributed mobile robots based on local interaction

This paper proposes a distributed control approach called local interactions with local coordinate systems (LILCS)to multirobot hunting tasks in unknown environments, where a team of mobile robots hunts a target called evader, which will actively try to escape with a safety strategy. This robust approach can cope with accumulative errors of wheels and imperfect communication networks. Computer simulations show the validity of the proposed approach.

Formation of networked mobile robots

This thesis presents a novel approach for controlling a robotic swarm to generate a geometric pattern described by a given contour, and a suitable communication scheme which enables the robots to communicate with each other as an all-to-all network.

Mobility and vision for mobile robots in non-deterministic, competitive environments

Develops an award winning design for an omnidirectional mobile robot that is both lightweight and extremely maneuverable. Two methods of robot vision, one using rotating lasers and a second using color video cameras were also developed and the merits of both explored.

A robust set-valued state estimation approach to the problem of vision based SLAM for mobile robots

The problem of visual simultaneous localization and mapping (SLAM) is examined in this paper using ideas and algorithms from robust control and estimation theory. Using a stereo-vision based sensor, a nonlinear measurement model is derived which leads to nonlinear measurements of the landmark coordinates along with optical flow based measurements of the relative robot-landmark velocity. Using a novel analytical measurement transformation, the nonlinear SLAM problem is converted into the linear filter is guaranteed stable and the ALAM state estimation error is bounded within an ellipsoidal set. No similar results are available for the commonly employed extended Kalman filter which is known to exhibit divergent and inconsistency characteristics in practice.

Optimization-based formation of autonomous mobile robots

The formation of autonomous mobile robots to an arbitrary geometric pattern in a distributed fashion is a fundamental problem in formation control. This paper presents a new asynchronous, memoryless (oblivious) algorithm to the formation problem via distributed optimization techniques. The optimization minimizes an appropriately defined difference function between the current robot distribution and the target geometric pattern. The optimization processes are performed independently by individual robots in their local coordinate systems. A movement strategy derived from the results of the distributed optimizations guarantees that every movement makes the current robot configuration approaches the target geometric pattern until the final pattern is reached.

Consensus control for a system of underwater swarm robots

The control of a swarm of underwater robots requires both a control algorithm and a communication system. Unfortunately, underwater communications is difficult at the best of times and so large time delays and minimal information is a concern. The control system must be able to handle a large number of robots without a master control, i.e., a decentralized control approach. This paper describes Consensus control as a way to decentralize. Consensus control allows each robot to know the final goal and then to decide, based on the position of the other robots, its best move to help achieve the goal.