Kirill S. Ovchinnikov

Robot navigation for monitoring unsteady environmental boundaries without field gradient estimation

A non-holonomic Dubins-car like robot should detect, locate, and track the boundary of an a priori unknown dynamic environmental scalar field. The field is measured by an on-board sensor in a point-wise fashion at the robots location. The focus is on unsteady boundaries that arbitrarily evolve over time, and, e.g., may change shapes and sizes. We present a sliding mode control method for localizing and tracking such boundaries: the robot is steered to the boundary and circulates in its close proximity afterwards. The proposed control algorithm does not require estimation of the spatial gradient of the field and is non-demanding with respect to both computation and motion. Its mathematically rigorous justification is provided. The effectiveness of the proposed guidance law is confirmed by computer simulations and experiments with a real wheeled robot.

Cooperative surveillance of unknown environmental boundaries by multiple nonholonomic robots

Several anonymous Dubins-car like mobile robots travel in a planar environment that hosts a scalar field, like the level of radiation or concentration of a contaminant. The objective is to co-operatively detect and localize the boundary of the set where the field value exceeds a certain threshold. The robots suffer from deficits of competence, communication, perception, and maneuverability: they do not know the field profile a priory, are not aware of the team size, cannot communicate with and recognize one another, can measure only the value of the field at the current location, are subjected to nonholonomic constraints, and are able to move along paths of only limited curvatures. We propose a new decentralized navigation strategy that drives all robots to the desired environmental boundary, with subsequent stable circulation along it. This strategy is based on an autonomous control of every robot, prevents collisions between them and ultimately ensures their pseudo-uniform distribution over the boundary to better utilize the resources of the team for representatively portraying the boundary. Furthermore, the proposed control scheme does not employ gradient estimation, which typically needs ineffective concentration of robots into tight clusters, and is non-demanding with respect to both computation and motion. Its mathematically rigorous justification is provided. The effectiveness of the proposed guidance law is confirmed by computer simulations and real-world experiments. We consider several anonymous non-communicating Dubins-car like robots in a plane.Every robot has a point-wise access to the value of an unknown environmental field.A new decentralized navigation strategy is proposed.All robots are driven to the isoline where the field assumes a pre-specified value.Inter-robots collisions and getting into clusters are excluded.

Decentralized multi-agent tracking of unknown environmental level sets by a team of nonholonomic robots

We consider a team of nonholonomic Dubins-car like robots traveling forward over paths with bounded curvatures in a planar region supporting an unknown scalar field. Every robot measures the field value at its location and has no communication facilities; the robots are anonymous to one another. The objective is to detect and localize the level set where the unknown field assumes a given value. We present a new distributed navigation and guidance strategy that ensures convergence of all robots to the desired level set and its subsequent display via stable circulation of the robots along this set. Moreover, this strategy prevents collisions between the robots and ultimately provides their sub-uniform distribution over the level set, so that the entire team effectively and representatively portrays this set. The proposed control strategy does not employ gradient estimation, which typically needs ineffective concentration of robots into tight clusters, and is non-demanding with respect to both computation and motion. Its mathematically rigorous justification is provided. The effectiveness of the proposed guidance law is confirmed by computer simulations and real-world experiments.

Self-deployment of mobile robotic networks: an algorithm for decentralized sweep boundary coverage

Several non-holonomic Dubins-car-like robots travel over paths with bounded curvatures in a plane that contains an a priori unknown region. The robots are anonymous to one another and do not use communication facilities. Any of them has access to the current minimum distance to the region and can determine the relative positions and orientations of the other robots within a finite and given visibility range. We present a distributed navigation and guidance strategy under which every robot autonomously converges to the desired minimum distance to the region with always respecting a given safety margin, the robots do not collide with one another and do not get into clusters, and the entire team ultimately sweeps over the respective equidistant curve at a speed exceeding a given threshold, thus forming a kind of a sweeping barrier at the perimeter of the region. Moreover, this strategy provides effective sub-uniform distribution of the robots over the equidistant curve. Mathematically rigorous justification of the proposed strategy is offered; its effectiveness is confirmed by extensive computer simulations and experiments with real wheeled robots.

Low-Cost Robotic Set-Up for Pursuit Problems

Abstract In the paper two robotic set-ups illustrating pursuing problems are presented. Both set ups are made of LEGO Mindstorms NXT set and use advance programming tools. Using the presented set ups allows teachers to include low cost robotic projects into science and engineering education.