4 research outputs found
The Isoline Tracking in Unknown Scalar Fields with Concentration Feedback
The isoline tracking of this work is concerned with the control design for a
sensing vehicle to track a desired isoline of an unknown scalar field. To this
end, we propose a simple PI-like controller for a Dubins vehicle in the
GPS-denied environments. Our key idea lies in the design of a novel sliding
surface based error in the standard PI controller. For the circular field, we
show that the P-like controller can globally regulate the vehicle to the
desired isoline with the steady-state error that can be arbitrarily reduced by
increasing the P gain, and is eliminated by the PI-like controller. For any
smoothing field, the P-like controller is able to achieve the local regulation.
Then, it is extended to the cases of a single-integrator vehicle and a
doubleintegrator vehicle, respectively. Finally, the effectiveness and
advantages of our approaches are validated via simulations on the fixed-wing
UAV and quadrotor simulators
Sensor Network Based Collision-Free Navigation and Map Building for Mobile Robots
Safe robot navigation is a fundamental research field for autonomous robots
including ground mobile robots and flying robots. The primary objective of a
safe robot navigation algorithm is to guide an autonomous robot from its
initial position to a target or along a desired path with obstacle avoidance.
With the development of information technology and sensor technology, the
implementations combining robotics with sensor network are focused on in the
recent researches. One of the relevant implementations is the sensor network
based robot navigation. Moreover, another important navigation problem of
robotics is safe area search and map building. In this report, a global
collision-free path planning algorithm for ground mobile robots in dynamic
environments is presented firstly. Considering the advantages of sensor
network, the presented path planning algorithm is developed to a sensor network
based navigation algorithm for ground mobile robots. The 2D range finder sensor
network is used in the presented method to detect static and dynamic obstacles.
The sensor network can guide each ground mobile robot in the detected safe area
to the target. Furthermore, the presented navigation algorithm is extended into
3D environments. With the measurements of the sensor network, any flying robot
in the workspace is navigated by the presented algorithm from the initial
position to the target. Moreover, in this report, another navigation problem,
safe area search and map building for ground mobile robot, is studied and two
algorithms are presented. In the first presented method, we consider a ground
mobile robot equipped with a 2D range finder sensor searching a bounded 2D area
without any collision and building a complete 2D map of the area. Furthermore,
the first presented map building algorithm is extended to another algorithm for
3D map building