Extended Modeling of Vertical Axis Motion Dynamics of VTOL Vehicle

2015 ◽  
Vol 789-790 ◽  
pp. 883-888 ◽  
Author(s):  
Wojciech Janusz ◽  
Roman Czyba ◽  
Grzegorz Szafrański ◽  
Michał Niezabitowski
Keyword(s):  
Vehicle Dynamics ◽  
High Performance ◽  
Vertical Axis ◽  
Open Loop ◽  
Indirect Measurements ◽  
Parameter Estimations ◽  
Landing Platform ◽  
Standard Configuration ◽  
Aerial Vehicle ◽  
Practical Model

Development of a reliable high-performance multirotor unmanned aerial vehicle (UAV) requires an accurate and practical model of the vehicle dynamics. This paper describes the process and results of the dynamic modeling of an unmanned aerial platform known as quadrotor. To model a vehicle dynamics, elementary physical and aerodynamical principles has been employed. Parameter estimations, from a UAV design have been obtained through direct and indirect measurements. In addition to standard configuration of VTOL (Vertical Take-Off and Landing) platform, the amortized landing gear, modeled as spring-damper system, has been added. The resulting model has been implemented in a simulation environment under MATLABs toolbox, SIMULINK. Some numerical results are presented to illustrate response of the open loop system to specific commands.

Analysis of the Lubrication Regimes at the Small End and Big End of a Connecting Rod of a High Performance Motorbike Engine

2012 ◽  
Author(s):  
Luca Bertocchi ◽  
Matteo Giacopini ◽  
Daniele Dini
Keyword(s):  
Rotational Speed ◽  
High Speed ◽  
High Performance ◽  
Hydrodynamic Lubrication ◽  
Vertical Axis ◽  
Connecting Rod ◽  
Lubrication Regimes ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
Squeeze Effect

In the present paper, the algorithm proposed by Giacopini et. al. [1], based on a mass-conserving formulation of the Reynolds equation using the concept of complementarity is suitably extended to include the effects of compressibility, piezoviscosity and shear-thinning on the lubricant properties. This improved algorithm is employed to analyse the performance of the lubricated small end and big end bearings of a connecting rod of a high performance motorbike engine. The application of the algorithm proposed to both the small end and the big end of a con-rod is challenging because of the different causes that sustain the hydrodynamic lubrication in the two cases. In the con-rod big end, the fluid film is mainly generated by the relative high speed rotation between the rod and the crankshaft. The relative speed between the two races forms a wedge of fluid that assures appropriate lubrication and avoids undesired direct contacts. On the contrary, at the con-rod small end the relative rotational speed is low and a complete rotation between the mating surfaces does not occurs since the con-rod only oscillates around its vertical axis. Thus, at every revolution of the crankshaft, there are two different moments in which the relative rotational speed between the con-rod and the piston pin is null. Therefore, the dominant effect in the lubrication is the squeeze caused by the high loads transmitted through the piston pin. In particular both combustion forces and inertial forces contribute to the squeeze effect. This work shows how the formulation developed by the authors is capable of predicting the performance of journal bearings in the unsteady regime, where cavitation and reformation occur several times. Moreover, the effects of the pressure and the shear rate on the density and on the viscosity of the lubricant are taken into account.

Direct Longitudinal Force Feedback for High-Performance Vehicle Dynamics Control Systems

2021 ◽  
Author(s):  
Giorgio Riva ◽  
Luca Mozzarelli ◽  
Matteo Corno ◽  
Simone Formentin ◽  
Sergio M. Savaresi
Keyword(s):  
Model Predictive Control ◽  
Control Systems ◽  
Predictive Control ◽  
Vehicle Dynamics ◽  
High Performance ◽  
Force Feedback ◽  
Longitudinal Force ◽  
Spiral Path ◽  
Comparable Performance ◽  
Vehicle Dynamics Control

Abstract State of the art vehicle dynamics control systems do not exploit tire road forces information, even though the vehicle behaviour is ultimately determined by the tire road interaction. Recent technological improvements allow to accurately measure and estimate these variables, making it possible to introduce such knowledge inside a control system. In this paper, a vehicle dynamics control architecture based on a direct longitudinal tire force feedback is proposed. The scheme is made by a nested architecture composed by an outer Model Predictive Control algorithm, written in spatial coordinates, and an inner longitudinal force feedback controller. The latter is composed by four classical Proportional-Integral controllers in anti-windup configuration, endowed with a suitably designed gain switching logic to cope with possible unfeasible references provided by the outer loop, avoiding instability. The proposed scheme is tested in simulation in a challenging scenario where the tracking of a spiral path on a slippery surface and the timing performance are handled simultaneously by the controller. The performance is compared with that of an inner slip-based controller, sharing the same outer Model Predictive Control loop. The results show comparable performance in presence of unfeasible force references, while higher robustness is achieved with respect to friction curve uncertainties.

Performance on an Adaptive Automated Team Tracking Task with Human and Computer Teammates

1997 ◽  
Vol 41 (1) ◽  
pp. 551-555 ◽  
Author(s):  
Kristin Krahl ◽  
Mark W. Scerbo
Keyword(s):  
Adaptive Systems ◽  
High Performance ◽  
Vertical Axis ◽  
Tracking Task ◽  
Superior Performance ◽  
Performance Skills ◽  
Group Assignment ◽  
Pursuit Tracking ◽  
Human Participants ◽  
High Level

The present study examined team performance on an adaptive pursuit tracking task with human-human and human-computer teams. The participants were randomly assigned to one of three team conditions where their partner was either a computer novice, computer expert, or human. Participants began the experiment with control over either the horizontal or vertical axis, but had the option of taking control of their teammate's axis if they achieved superior performance on the previous trial. A control condition was also run where a single participant controlled both axes. Performance was assessed by RMSE scores over 100 trials. The results showed that performance along the horizontal axis improved over the session regardless of the experimental condition, but the degree of improvement was dependent upon group assignment. Individuals working alone or paired with an expert computer maintained a high level of performance throughout the experiment. Those paired with a computer-novice or another human performed poorly initially, but eventually reached the level of those in the other conditions. The results showed that team training can be as effective as individual training, but that the quality of training is moderated by the skill level of one's teammate. Moreover, these findings suggest that task partitioning of high performance skills between a human and a computer is not only possible but may be considered a viable option in the design of adaptive systems.

scholarly journals Improvement in energy conversion for unmanned aerial vehicle charging pad

2020 ◽  
Vol 17 (2) ◽  
pp. 767
Author(s):  
M. R. AL-Obaidi ◽  
M. A. Mustafa ◽  
W.Z.W. Hassan ◽  
N. Azis ◽  
A. H. Sabry ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Design Methodology ◽  
Font Size ◽  
Contact Charging ◽  
Charging Station ◽  
Ground Station ◽  
Landing Platform ◽  
Aerial Vehicle ◽  
Fully Automatic ◽  
Software And Hardware

<span style="font-size: 9pt; font-family: 'Times New Roman', serif;">An efficient charging station is a necessity for Unmanned Aerial Vehicle (UAV) systems. However, if that implementation adds more complexity and onboard weight, then that exercise becomes a burden rather than a benefit since UAV's engineers aim to improve efficiency by reducing the energy consumed by the software and hardware of the complete aeronautical system. This article recommends a fully automatic contact charging station for UAVs, which can charge UAVs and thus resolve flight endurance restrictions of the UAV. The ground station consists of square copper plates that are positively and negatively polarized successively in a chessboard with particular sizes to guarantee electric contact at the landing. The design methodology used with the loading station takes into account the differences in UAV orientation once the platform has landed. In addition, this innovation uses independent charging after touchdown. Thus, this technology relaxes common flight times and help to enhance general mission times. This paper presents a unique charging platform in a “chessboard” configuration, which is devised as an interconnecting interface to facilitate the charging process and overcome inaccuracies with the landing. The solution devised in this research requires few components and presents two power source options (solar &amp; mains power). Additionally, this work presents, to the best of our knowledge, a uniquely innovative recharging landing platform, which incidentally requires no additional software or changes to the UAV’s onboard software settings</span><span style="font-size: 9pt; font-family: Arial, sans-serif;">.</span>

scholarly journals MATHEMATICAL MODELLING OF THE UNMANNED AERIAL VEHICLE DYNAMICS

2018 ◽  
pp. 37-44
Author(s):  
V. Y. Stepanov
Keyword(s):  
Mathematical Model ◽  
Mathematical Modelling ◽  
Unmanned Aerial Vehicle ◽  
Vehicle Dynamics ◽  
Point Of View ◽  
Dynamics Analysis ◽  
Aerial Vehicle ◽  
Main Components ◽  
Controlled Object

The article gives a classification of the main components of unmanned aerial vehicle (UAV) systems, gives the areas in which the application of UAVs is actual in practice today. Further, the UAV is considered in more detail from the point of view of its flight dynamics analysis, the equation necessary for creating a mathematical model, as well as the model of an ordinary dynamic system as a non-stationary nonlinear controlled object, is given. Next, a description of the developed software for modeling and a description of program algorithm are given. Finally, a conclusion describes the necessary directions for further scientific researches.

scholarly journals A Precise and GNSS-Free Landing System on Moving Platforms for Rotary-Wing UAVs

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 886 ◽  
Author(s):  
Francisco Alarcón ◽  
Manuel García ◽  
Ivan Maza ◽  
Antidio Viguria ◽  
Aníbal Ollero
Keyword(s):  
Relative Position ◽  
Unmanned Helicopter ◽  
Landing Position ◽  
Moving Platforms ◽  
Landing Platform ◽  
Aerial Vehicle ◽  
The Stability ◽  
Novel Concept ◽  
High Level ◽  
Rotary Wing

This article presents a precise landing system that allows rotary-wing UAVs to approach and land safely on moving platforms, without using GNSS at any stage of the landing maneuver, and with a centimeter level accuracy and high level of robustness. This system implements a novel concept where the relative position and velocity between the aerial vehicle and the landing platform are calculated from the angles of a cable that physically connects the UAV and the landing platform. The use of a cable also incorporates a number of extra benefits, such as increasing the precision in the control of the UAV altitude. It also facilitates centering the UAV right on top of the expected landing position, and increases the stability of the UAV just after contacting the landing platform. The system was implemented in an unmanned helicopter and many tests were carried out under different conditions for measuring the accuracy and the robustness of the proposed solution. Results show that the developed system allowed landing with centimeter accuracy by using only local sensors and that the helicopter could follow the landing platform in multiple trajectories at different velocities.

Vision-based pose estimation of a multi-rotor unmanned aerial vehicle

2019 ◽  
Vol 7 (3) ◽  
pp. 120-132
Author(s):  
Kashish Gupta ◽  
Bara Jamal Emran ◽  
Homayoun Najjaran
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Three Dimensional ◽  
Processing System ◽  
Training Procedure ◽  
Autonomous Landing ◽  
Content Type ◽  
Landing Platform ◽  
Aerial Vehicle ◽  
Autopilot Systems ◽  
Practical Implications

Purpose The purpose of this paper is to facilitate autonomous landing of a multi-rotor unmanned aerial vehicle (UAV) on a moving/tilting platform using a robust vision-based approach. Design/methodology/approach Autonomous landing of a multi-rotor UAV on a moving or tilting platform of unknown orientation in a GPS-denied and vision-compromised environment presents a challenge to common autopilot systems. The paper proposes a robust visual data processing system based on targets’ Oriented FAST and Rotated BRIEF features to estimate the UAV’s three-dimensional pose in real time. Findings The system is able to visually locate and identify the unique landing platform based on a cooperative marker with an error rate of 1° or less for all roll, pitch and yaw angles. Practical implications The proposed vision-based system aims at on-board use and increased reliability without a significant change to the computational load of the UAV. Originality/value The simplicity of the training procedure gives the process the flexibility needed to use a marker of any unknown/irregular shape or dimension. The process can be easily tweaked to respond to different cooperative markers. The on-board computationally inexpensive process can be added to off-the-shelf autopilots.

Active Aerodynamics Through Active Body Control: Modelling and Static Simulator Validation

2020 ◽  
Author(s):  
Henrique de Carvalho Pinheiro ◽  
Francesco Russo ◽  
Lorenzo Sisca ◽  
Alessandro Messana ◽  
Davide De Cupis ◽  
...  
Keyword(s):  
Fuzzy Logic ◽  
Control Strategy ◽  
Vehicle Dynamics ◽  
Fuzzy Logic Control ◽  
High Performance ◽  
Subjective Evaluation ◽  
The Body ◽  
Race Car ◽  
Logic Control ◽  
The Stability

Abstract Active aerodynamics is a growing field in the race car and high-performance vehicles segments, since each situation on the track may require different aero forces to achieve the best vehicle dynamics performance. This paper presents an active aerodynamics control system developed through the active control of the body trim. By interchanging four different setups on the suspension heights with a fuzzy logic control, relevant advantage is obtained in terms of lap time reduction. Two systems, a PID and a Feedforward logic, are studied to implement the control strategy and important differences are found in the stability of tire-ground forces benefiting the latter. Furthermore, the system was validated in a Driver-In-the-Loop (DIL) static simulator with a more realistic road conditions and important insights in terms of subjective evaluation.

Trajectory optimisation of an aerobatic air race

2009 ◽  
Vol 113 (1139) ◽  
pp. 1-8 ◽  
Author(s):  
H. van der Plas ◽  
H. G. Visser
Keyword(s):  
High Performance ◽  
Equations Of Motion ◽  
Computational Cost ◽  
Optimal Solution ◽  
Open Loop ◽  
Receding Horizon ◽  
Mass Model ◽  
Control Approach ◽  
Time Optimal ◽  
Trajectory Optimisation

Abstract This paper deals with the synthesis of optimal trajectories for aerobatic air races. A typical example of an air race event is the Red Bull Air Race World Series, where high-performance aerobatic aircraft fly a prescribed slalom course consisting of specially designed inflatable pylons, known as ‘air gates’, in the fastest possible time. The trajectory that we seek to optimise is based on such a course. The air race problem is formulated as a minimum-time optimal control problem and solved in open-loop form using a direct numerical multi-phase trajectory optimisation approach based on collocation and non-linear programming. The multiphase feature of the employed collocation algorithm is used to enable a Receding-Horizon optimisation approach, in which only a limited number of manoeuvres in sequence is considered. It is shown that the Receding-Horizon control approach provides a near-optimal solution at a significantly reduced computational cost relative to trajectory optimisation over the entire course. To avoid the path inclination singularity in the equations of motion based on Euler angles, a point-mass model formulation is used that is based on quaternions. Numerical results are presented for an Extra 300S, a purpose-designed aerobatic aircraft.

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