Semi-autonomous unmanned ground vehicle control system

Author(s):  
Jonathan Anderson ◽  
Dah-Jye Lee ◽  
Robert Schoenberger ◽  
Zhaoyi Wei ◽  
James Archibald
2010 ◽  
Vol 2010.5 (0) ◽  
pp. _59225-1_-_59225-8_
Author(s):  
Jong Seok Lee ◽  
Jae Yi Oh ◽  
Yeo Giel Yoon ◽  
Ju Yong Kang ◽  
Won Gun Kim ◽  
...  

2015 ◽  
Vol 220-221 ◽  
pp. 774-780 ◽  
Author(s):  
Eduardo Corral ◽  
Gennady Aryassov ◽  
Jesús Meneses

The aim of this work is to improve the navigation capabilities of an off-road unmanned ground vehicle (UGV) by optimizing the angles between its legs and its body (its configuration angles), as the vehicle travels by a particular track profile. We present a numerical program based on a quasi-static half vehicle model. For a profile entered by the user, the program will be able to calculate how the angles between the legs and the body must vary along the trajectory, so that to maintain the torque on the wheels as constant as possible. Results may be helpful in vehicle control tasks, in particular when passing obstacles efficiently.First of all, some considerations concerning the nomenclature and geometry of the vehicle are presented. Then, the kinematics of the vehicle is exposed starting from the function that defines the profile. We focus on the position and/or trajectories of remarkable points to be employed later. From the kinematics, the quasi-static model is developed and the equations to calculate the forces and torques involved are presented. The algorithm basically calculates the position along the track and the angles between the legs and the body and then, by using the previous equations, finds the optimal values of those angles that satisfy a given condition (as equal to normal forces, torque constancy, minimum torque, etc.)As results, we present the configuration angles that equal to the normal forces on the wheels when the vehicle ascends a ramp, depending on the slope. We also present the optimal configuration angles variation required for the vehicle to pass over a step obstacle. And for a complex profile how the torque changes in function of the angles between the legs.


Robotica ◽  
2021 ◽  
pp. 1-19
Author(s):  
Ali Ghasemi ◽  
Farhad Parivash ◽  
Serajeddin Ebrahimian

Abstract This research deals with the autonomous landing maneuver of a quadrotor unmanned aerial vehicle (UAV) on an unmanned ground vehicle (UGV). It is assumed that the UGV moves independently, and there is no communication and collaboration between the two vehicles. This paper aims at the design of a closed-loop vision-based control system for quadrotor UAV to perform autonomous landing maneuvers in the possible minimum time despite the wind-induced disturbance force. In this way, a fractional-order fuzzy proportional-integral-derivative controller is introduced for the nonlinear under-actuated system of a quadrotor. Also, a feedback linearization term is included in the control law to compensate model nonlinearities. A supervisory control algorithm is proposed as an autonomous landing path generator to perform fast, smooth, and accurate landings. On the other hand, a compound AprilTag fiducial marker is employed as the target of a vision positioning system, enabling high precision relative positioning in the range between 10 and 350 cm height. A software-in-the-loop simulation testbed is realized on the windows platform. Numerical simulations with the proposed control system are carried out, while the quadrotor system is exposed to different disturbance conditions and actuator dynamics with saturated thrust output are considered.


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