Dynamic Visual Servoing for a Quadrotor Using a Virtual Camera

2017 ◽  
Vol 05 (01) ◽  
pp. 1-17 ◽  
Author(s):  
Geoff Fink ◽  
Hui Xie ◽  
Alan F. Lynch ◽  
Martin Jagersand
Keyword(s):  
Visual Servoing ◽  
Closed Loop ◽  
Field Of View ◽  
Visual Features ◽  
Control Law ◽  
Asymptotically Stable ◽  
Globally Asymptotically Stable ◽  
Virtual Camera ◽  
Aerial Vehicle ◽  
Planar Target

This paper presents a dynamic image-based visual servoing (IBVS) control law for a quadrotor unmanned aerial vehicle (UAV) equipped with a single fixed on-board camera. The motion control problem is to regulate the relative position and yaw of the vehicle to a moving planar target located within the camera’s field of view. The control law is termed dynamic as it’s based on the dynamics of the vehicle. To simplify the kinematics and dynamics, the control law relies on the notion of a virtual camera and image moments as visual features. The convergence of the closed-loop is proven to be globally asymptotically stable for a horizontal target. In the case of nonhorizontal targets, we modify the control using a homography decomposition. Experimental and simulation results demonstrate the control law’s performance.

Dynamic IBVS of a rotary wing UAV using line features

Robotica ◽  
2014 ◽  
Vol 34 (9) ◽  
pp. 2009-2026 ◽  
Author(s):  
Hui Xie ◽  
Alan F. Lynch ◽  
Martin Jagersand
Keyword(s):  
Visual Servoing ◽  
Depth Estimation ◽  
Image Features ◽  
Interaction Matrix ◽  
Globally Asymptotically Stable ◽  
Virtual Camera ◽  
Control Objective ◽  
Aerial Vehicle ◽  
Inspection Tasks ◽  
Rotary Wing

SUMMARYIn this paper we propose a dynamic image-based visual servoing (IBVS) control for a rotary wing unmanned aerial vehicle (UAV) which directly accounts for the vehicle's underactuated dynamic model. The motion control objective is to follow parallel lines and is motivated by power line inspection tasks where the UAV's relative position and orientation to the lines are controlled. The design is based on a virtual camera whose motion follows the onboard physical camera but which is constrained to point downwards independent of the vehicle's roll and pitch angles. A set of image features is proposed for the lines projected into the virtual camera frame. These features are chosen to simplify the interaction matrix which in turn leads to a simpler IBVS control design which is globally asymptotically stable. The proposed scheme is adaptive and therefore does not require depth estimation. Simulation results are presented to illustrate the performance of the proposed control and its robustness to calibration parameter error.

scholarly journals Adaptive 3D Distance-Based Formation Control of Multiagent Systems with Unknown Leader Velocity and Coplanar Initial Positions

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Xuejing Lan ◽  
Wenbiao Xu ◽  
Yun-Shan Wei
Keyword(s):  
Theoretical Analysis ◽  
Multiagent Systems ◽  
Relative Position ◽  
Formation Control ◽  
Control Law ◽  
Asymptotically Stable ◽  
Coordinate Systems ◽  
Lyapunov Theorem ◽  
Globally Asymptotically Stable ◽  
3 Dimensional

This paper considers the distributed 3-dimensional (3D) distance-based formation control of multiagent systems, where the agents are connected based on an acyclic minimally structural persistent (AMSP) graph. A parameter is designed according to the desired formation shape and is used to solve the problem that there are two formation shapes satisfying the same distance requirements. The unknown moving velocity of the leader agent is estimated adaptively by the followers requiring only the relative position measurements with respect to their local coordinate systems. In addition, the proposed formation controller provides a new way for the agent to leave the initial coplanar location. The 3D formation control law is globally asymptotically stable and has been demonstrated based on the Lyapunov theorem. Finally, two numerical simulations are presented to support the theoretical analysis.

Nonlinear dynamic image-based visual servoing of a quadrotor

2015 ◽  
Vol 3 (1) ◽  
pp. 1-21 ◽  
Author(s):  
Geoff Fink ◽  
Hui Xie ◽  
Alan F. Lynch ◽  
Martin Jagersand
Keyword(s):  
Visual Servoing ◽  
Lateral Position ◽  
Control Law ◽  
Stationary Target ◽  
Dynamic Image ◽  
Change Of State ◽  
Dependent Change ◽  
Exponentially Stable ◽  
Aerial Vehicle ◽  
Error Dynamics

This paper proposes a dynamic image-based visual servoing (IBVS) control law for a quadrotor unmanned aerial vehicle (UAV) equipped with a single fixed on-board camera facing downward. The motion control problem is to regulate the relative lateral position of the vehicle to a stationary target located on the ground. The control law is termed dynamic as it is based on the dynamics and kinematics of the vehicle. The proposed design uses a nonlinear input-dependent change of state coordinates and its error dynamics are proven to be locally exponentially stable with an estimate provided for the region of attraction. Experimental and simulation results demonstrate the method's ease of on-board implementation, performance, and robustness. The simulation and experimental results include a comparison with an established dynamic IBVS method. This comparison shows the proposed method can provide similar performance with the benefit of reduced complexity.

Active Compressor Surge Control Using Piston Actuation

2011 ◽  
Author(s):  
Nur Uddin ◽  
Jan Tommy Gravdahl
Keyword(s):  
Feedback Control ◽  
Closed Loop ◽  
Linear Feedback ◽  
Control Law ◽  
Asymptotically Stable ◽  
Nonlinear Feedback Control ◽  
Nonlinear Feedback ◽  
Closed Loop System ◽  
Linear Feedback Control ◽  
Surge Control

A novel approach to active surge control in compressors using piston actuation is presented. Two control laws are compared in order to evaluate the feasibility of implementing the concept. The first control law is a nonlinear feedback control derived by using backstepping and the second one is a linear feedback control derived by analyzing the eigenvalues of the linearized system around the operating point. The nonlinear feedback control law makes the closed loop system globally asymptotically stable (GAS) and uses full states feedback. The linear feedback control is only using feedback from plenum pressure and piston velocity and the removal of the mass flow feedback is advantageous for implementation. The closed loop system with the linear feedback control is locally asymptotically stable around the operating point. Simulations show that both controllers are capable of stabilizing surge.

Further results on adaptive state feedback stabilization for a class of stochastic feedforward nonlinear systems with time delays

2018 ◽  
Vol 41 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Xiaoyan Qin ◽  
Huifang Min
Keyword(s):  
Nonlinear Systems ◽  
Time Delays ◽  
State Feedback ◽  
Closed Loop ◽  
Feedback Stabilization ◽  
Asymptotically Stable ◽  
Closed Loop System ◽  
Transformation Technique ◽  
Globally Asymptotically Stable ◽  
Feedforward Nonlinear Systems

This paper further discusses the state feedback stabilization for stochastic high-order feedforward nonlinear systems with input time delay. By constructing the appropriate Lyapunov–Krasovskii functional, and using the variable transformation technique and the homogeneous domination idea, a state feedback controller is designed to ensure that the closed-loop system will be globally asymptotically stable in probability. Finally, an example is given to verify the effectiveness of the obtained analytical results.

scholarly journals Visual Servoing of a Moving Target by an Unmanned Aerial Vehicle

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5708
Author(s):  
Ching-Wen Chen ◽  
Hsin-Ai Hung ◽  
Po-Hung Yang ◽  
Teng-Hu Cheng
Keyword(s):  
Visual Servoing ◽  
Feature Vector ◽  
Field Of View ◽  
Control Input ◽  
Predictive Controller ◽  
Aerial Vehicle ◽  
Position And Orientation ◽  
Rotational Motions ◽  
And Performance ◽  
Traditional Image

To track moving targets undergoing unknown translational and rotational motions, a tracking controller is developed for unmanned aerial vehicles (UAVs). The main challenges are to control both the relative position and orientation between the target and the UAV to within desired values, and to guarantee that the generated control input to the UAV is feasible (i.e., below its motion capability). Moreover, the UAV is controlled to ensure that the target always remains within the field of view of the onboard camera. These control objectives were achieved by developing a nonlinear-model predictive controller, in which the future motion of the target is predicted by quadratic programming (QP). Since constraints of the feature vector and the control input are considered when solving the optimal control problem, the control inputs can be bounded and the target can remain inside the image. Three simulations were performed to compare the efficacy and performance of the developed controller with a traditional image-based visual servoing controller.

scholarly journals Remarks on input-to-state stability of collocated systems with saturated feedback

2020 ◽  
Vol 32 (3) ◽  
pp. 293-307
Author(s):  
Birgit Jacob ◽  
Felix L. Schwenninger ◽  
Lukas A. Vorberg
Keyword(s):  
Linear System ◽  
Control Systems ◽  
Additional Assumption ◽  
Closed Loop ◽  
Asymptotically Stable ◽  
Globally Asymptotically Stable ◽  
Infinite Dimensional ◽  
Collocated Control

Abstract We investigate input-to-state stability (ISS) of infinite-dimensional collocated control systems subject to saturated feedback. Here, the unsaturated closed loop is dissipative and uniformly globally asymptotically stable. Under an additional assumption on the linear system, we show ISS for the saturated one. We discuss the sharpness of the conditions in light of existing results in the literature.

Disturbance observer-based visual servoing for multirotor unmanned aerial vehicles

2018 ◽  
Vol 66 (3) ◽  
pp. 258-267 ◽  
Author(s):  
Hui Xie ◽  
Zhen He ◽  
Darryl Veitch
Keyword(s):  
Disturbance Observer ◽  
Visual Servoing ◽  
Visual Target ◽  
Feedforward Control ◽  
Field Of View ◽  
External Disturbances ◽  
Saturation Control ◽  
Controller Performance ◽  
Aerial Vehicle ◽  
Control Part

Abstract This paper presents a disturbance observer based input saturated visual servoing law for a quadrotor unmanned aerial vehicle (UAV). The controller regulates the 4D relative pose, i. e., 3D translational and yaw motion, between the vehicle and a planar horizontal visual target in an environment with external disturbances. A feedforward control is used to compensate the lumped disturbance consisting of both system uncertainties and external disturbances. The feedback control part is based on a nested saturation control, which is used to bound the orientation of the UAV and therefore helps to keep the visual target in the camera’s field of view. Simulation results are provided to demonstrate controller performance.

Position-Based Visual Servoing of a Micro-Aerial Vehicle Operating Indoor

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Hanoch Efraim ◽  
Amir Shapiro ◽  
Moshe Zohar ◽  
Gera Weiss
Keyword(s):  
Visual Servoing ◽  
3D Model ◽  
Closed Loop ◽  
Specific Problem ◽  
Three Dimensional ◽  
Adaptive Controller ◽  
Single Image ◽  
Micro Aerial Vehicle ◽  
Aerial Vehicle ◽  
Gain Scheduled

In this work, we suggest a novel solution to a very specific problem—calculating the pose (position and attitude) of a micro-aerial vehicle (MAV) operating inside corridors and in front of windows. The proposed method makes use of a single image captured by a front facing camera, of specific features whose three-dimensional (3D) model is partially known. No prior knowledge regarding the size of the corridor or the window is needed, nor is the ratio between their width and height. The position is calculated up to an unknown scale using a gain scheduled iterative algorithm. In order to compensate for the unknown scale, an adaptive controller that ensures consistent closed loop behavior is suggested. The attitude calculation can be used as is, or the results can be fused with angular velocity sensors to achieve better estimation. In this paper, the algorithm is presented and the approach is demonstrated with simulations and experiments.

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