Path-Tracking Control of Stochastic Quadrotor Aircraft in Three-Dimensional Space

Author(s):  
K. D. Do

Despite the fact that environmental loads (forces and moments) induced by wind on quadrotor vertical take-off and landing (VTOL) aircraft consist of both deterministic and stochastic components, all existing works on controlling the aircraft either ignore these loads or treat them as deterministic. This ignorance or treatment deteriorates the control performance in a practical implementation. This paper presents a constructive design of controllers for a quadrotor aircraft to track a reference path in three-dimensional (3D) space under both deterministic and stochastic disturbances. A combination of Euler angles and unit-quaternion for the attitude representation of the aircraft is used to result in an effective control design, and to achieve path-tracking control results. Weak and strong nonlinear Lyapunov functions are introduced to overcome difficulties caused by underactuation and Hessian terms induced by stochastic differentiation rule. To overcome the inherent underactuation of the aircraft, the roll and pitch angles of the aircraft are considered as immediate controls. Potential projection functions are introduced to design estimates of the deterministic components and covariances of the stochastic components. Simulations illustrate the results.

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Chuanfeng Wang

Curve-tracking control is challenging and fundamental in many robotic applications for an autonomous agent to follow a desired path. In this paper, we consider a particle, representing a fully actuated autonomous robot, moving at unit speed under steering control in the three-dimensional (3D) space. We develop a feedback control law that enables the particle to track any smooth curve in the 3D space. Representing the 3D curve in the natural Frenet frame, we construct the control law under which the moving direction of the particle will be aligned with the tangent direction of the desired curve and the distance between the particle and the desired curve will converge to zero. We demonstrate the effectiveness of the proposed 3D curve-tracking control law in simulations.


Robotica ◽  
2017 ◽  
Vol 36 (3) ◽  
pp. 374-394 ◽  
Author(s):  
Khoshnam Shojaei

SUMMARYMost of the previous works on the motion control of autonomous underwater vehicles (AUVs) assume that (i) the vehicle actuators are able to tolerate every level of the control signals, and (ii) the vehicle is equipped with the velocity sensors in all degrees of freedom. These assumptions are not desirable in practice. Toward this end, this paper addresses the trajectory tracking control of the underactuated AUVs with the limited torque, without the velocity measurements and under environmental disturbances in a three-dimensional space. At first, a variable transformation is introduced which helps us to derive a second-order dynamic model for underactuated AUVs. Then, a saturated tracking controller is proposed by employing the saturation functions to bound the closed-loop error variables. This technique reduces the risk of the actuators saturation by decreasing the amplitude of the generated control signals. In addition, a nonlinear saturated observer is introduced to remove the velocity sensors from the control system. The proposed controller copes with the uncertain vehicle parameters, and constant or time-varying environmental disturbances induced by the waves and ocean currents. Lyapunov's direct method is used to show the semi-global uniform ultimate boundedness of the tracking and state estimation errors. Finally, some simulation results illustrate the effectiveness of the proposed controller.


2020 ◽  
Vol 29 (14) ◽  
pp. 2050229 ◽  
Author(s):  
Palanisamy Ramasamy ◽  
Vijayakumar Krishnasamy

In this paper, a three-dimensional Space Vector Modulation (3D SVM) is implemented for minimization of Common-Mode Voltage (CMV) of five-level Neutral Point Clamped (NPC) inverter. The 3D SVM control includes all merits of 2D SVM and provides better control compared to other PWM strategies. The switching state vectors are selected based on the nearest vector Switching State Vector (NSV); it selects the switching vectors which are having the minimum CMV level. It leads to minimization of the bearing voltage and protection of the drive from the damage; also this system reduces the total harmonic distortion. The switching time is calculated by reference vector identification with large and small subcubes tracking and prisms tracking in 3D cubic region. The CMV level with 3D SVM scheme is compared with other PWM methods. The simulation and hardware results are verified using Matlab Simulink and FPGA processor.


2017 ◽  
Vol 14 (4) ◽  
pp. 126-137
Author(s):  
A. A. Komrakov

This article describes the process of visualization of data obtained in the course of a scientific experiment or test process of complex technical systems using modern methods of creating images and video based on volumetric models of objects in three-dimensional space. The main stages of the process of developing integrated systems for data acquisition and visualization are considered, as well as analysis of such systems using the tools of queuing theory. An example of the practical implementation of the proposed approaches is given.


Author(s):  
Marek Borowiec ◽  
Marcin Bochenski ◽  
Grzegorz Litak ◽  
Andrzej Teter

AbstractIn the paper, a new 3D energy harvesting system is provided. This work discussed the Lagrange approach to derive the differential equations of motion in the case of energy harvesting systems. An electromechanical system consists of a mechanical resonator, a piezoelectric transducer and electrical circuit with the load resistor. A flexible slender rod clamped at the bottom and loaded by the tip mass is proposed as the resonator. Moving in the 3D space, it enables the system to avoid the gravitational potential barrier of the straight vertical shape in case of buckling. This paper investigates the response of the rod deflection and the root mean square power output of selected vibration mode shapes with an attached tip mass.


2011 ◽  
Vol 179-180 ◽  
pp. 1322-1326
Author(s):  
Ru Ting Xia

The aim of the present experiment was to investigate visual attentional allocation of top-down and bottom-up cues in three-dimensional (3D) space. Near and far stimuli were used by a 3D attention measurement apparatus. Two experiments were conducted in order to examine top-down and bottom-up controls of visual attention. In the experiment 1, the cue about the location of a target by means of location information. In the experiment 2, color cue by brief change of color at target locations was presented. Observers were required to judge whether the target presented nearer than fixation point or further than it. The results in experiment 1 and experiment 2 show that both location and color cue have the effect on reaction time, and that shift of attention were faster from far to near than the reverse. These findings suggest that (1) attention in 3D space might be operated with both location and color controls included the depth information, (2) the shift of visual attention in 3D space has an asymmetric characteristic in depth.


2019 ◽  
Vol 8 (2) ◽  
pp. 78
Author(s):  
Magda Pluta ◽  
Bartosz Mitka

This paper describes the algorithm of the view factor (V-factor). It is based on an analysis of visibility, taking into account the attractiveness of the observed elements in a three-dimensional space. The results of the V-factor analysis provide input for the decision-making process when selecting the most advantageous planning scenario so that the harmony of landscape and ecological balance can be maintained. The V-factor indicator can be successfully used in the process of spatial planning, in particular, at the stage of determining the parameters of new buildings and lines of sight between planned buildings. The purpose of the indicator is to determine the numerical values for observation points, thus facilitating a comparative assessment of the attractiveness of view available from the special points in space. The analysis uses a 3D space model that includes an integrated existing and planning state designed on the basis of planning scenarios. The V-factor analysis takes into account the distance of the observation point from the observed object, vertical and horizontal angles of observation, and the aesthetic value of the observed object. As a result, an average value of the V-factor indicator was obtained for each planning scenario, which facilitated the determination of the more beneficial one in terms of the attractiveness of view.


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