This report presents a method of controlling an unmanned ground vehicel (UGV) by employing hybrid control theory. The linear dynamics of the UGV near a straight path conform to modern linear quadratic regulator theory. Two different methods for regulation of the UGV on a straight track are analyzed. The first method employs the steering angle as an input, while the second employs the derivative...

In this paper we have presented a study on vision based autonomous driving of a four-wheel-drive platform for agricultural applications. The developed driving platform can be autonomously driven on any path pattern. The key contributions to this paper are development of unique navigation pattern to train the mobile robot to follow any kind of path pattern. We have demonstrated how speed, camera...

Dynamic soaring is a technique used the sea bird the Albatross. This technique allows for the bird to stay in the air for extended periods of time with very little effort. Dynamic soaring utilizes the wind gradient on the surface of the ocean to maintain its airspeed. A similar technique is used by RC glider pilots to achieve high speeds by using the shear wind layer on the leeward side of moun...

This paper presents a method for formation flight and collision avoidance of multiple UAVs. Due to the shortcomings such as collision avoidance caused by UAV's high-speed and unstructured environments, this paper proposes a modified tentacle algorithm to ensure the high performance of collision avoidance. Different from the conventional tentacle algorithm which uses inverse derivation, the modi...

This paper presents a computationally-fast inverse dynamics model based on unit quaternion orientation representation for use in the generation of unmanned aircraft trajectories when the flight envelope may include all flight path orientations, a necessary attribute for aerobatics or unmanned air-to-air combat vehicles. The model removes the inherent singularities in Euler-angle attitude repres...

A new set of higher-order analytic solutions is introduced for the critical cases of: (a) ballistic skip trajectories with initial speed greater than the circular orbital speed (supercircular case); (b) shallow ballistic entry with entry speed less than the circular orbital speed (subcircular case); and (c) shallow ballistic entry from low circular orbits (circular case). Both non-circular case...

In this paper, kinetic and kinematic modeling of a 4 wheel steering vehicle is done and its movement is controlled in an optimal way using Linear Quadratic Regulator (LQR). The results are compared with the same control of two-wheel steering case and the advantages are analyzed. In 4 wheel steering vehicles which are nowadays more applicable the number of controlling actuators are more than the...

This paper presents a study of a minimum time-to-climb trajectory analysis for aircraft flying in a twodimensional altitude dependent wind field. The time optimal control problem possesses a singular control structure when the lift coefficient is taken as a control variable. A singular arc analysis is performed to obtain an optimal control solution on the singular arc. Using a time-scale separa...