Gun Launched Micro Air Vehicle Research Articles

Conception and Manufacturing of a Projectile-Drone Hybrid System

The French-German Research Institute of Saint Louis proposed an innovative concept of a microair vehicle (MAV). The gun-launched MAV (GLMAV) is a new and original type of discreet and robust miniature hybrid system of about 1 kg for a very quick observation mission by air. The GLMAV in a projectile configuration is launched by a portable dedicated tube weighing less than 10 kg. After a ballistic flight, the GLMAV is transformed into a miniature drone with automatic deployment of coaxial counter-rotating rotors. The GLMAV in drone configuration is slowed down to be able to execute hovering or/and maneuvering flights. In few seconds, aerial observation down and forward can begin in order to capture information, because it is equipped with an embarked vision system with real-time image transmission. This paper is first focused on the conception of the launcher and of the platform in order to incorporate all the features coming from multiple disciplines. This hybrid system conception is linked to an iterative process between all fields of research such as aerodynamics, interior and exterior ballistics, mechanics, electronics, optronics and signal transmission, guidance, navigation, and control. All theoretical studies presented in this paper have then converged toward the manufacturing of the dedicated ballistic launcher and of the GLMAV platform. The latter is now ready for the autopilot implementation in the near future.

Interior Ballistics Simulation of the Two Chambers GLMAV Launcher

AbstractThe concept of a gun launched micro air vehicle (GLMAV) is currently studied at ISL. A micro air vehicle (MAV) packaged in a projectile is launched using the energy delivered by a portable weapon. When it reaches the apogee the projectile is transformed in such a way that the MAV becomes operational over the zone to be observed. A light projectile of 80 mm caliber has to be launched with low velocity: 57 or 100 m s−1. To achieve these velocities a very low pressure in the tube is needed. Hence the GLMAV launcher is designed as a two chambers system. Propellants and igniters are enclosed in a small high‐pressure canister, which is connected to the tube with the projectile (low pressure chamber) by vent holes. The charge consists of two propellants in partially separated volumes; the fast burning GB propellant ignites the slow burning L1 propellant. The interior ballistics of the GLMAV launcher is solved by the zero dimensional model STANAG 4367 with an extension for the two chambers system. Calculated pressures in the high and low pressure chamber and the muzzle velocities are compared with ISL measurements. Although the used theoretical model cannot describe correctly all specific features of the GLMAV launcher, the differences between the calculated and measured maximum values are up to 10 %.

Prediction of aerodynamic performances of a gun launched micro air vehicle

The study deals with the prediction of the aerodynamic performances of the gun launched micro air vehicle (GLMAV) platform by using the ANSYS CFX code. The validation of the numerical simulation on a micro two-bladed rotor was carried out in 2012 by the comparison of the computed thrust and torque with the measured ones and by using the experience gained from all previous computational investigations. After that, also in 2012, the computation of aerodynamic performances of a first version of the two coaxial counter-rotating rotors of the GLMAV was carried out for the hovering flight. Now, the goal of this paper consists in determining the rotation speeds of the rotors which allows a second version of the GLMAV platform to be slowed down from the rotor deployment phase up to the hovering flight. The power of each brushless motor which should be embedded in the platform is also determined from the results of the computation.

Control of a Gun-Launched MAV for Scene Observation

The focus of this paper is on the presentation of a hybrid projectile/MAV concept, namely the Gun-Launched Micro Air Vehicle (GLMAV), with a particular attention on the control strategy used for the hovering flight. The main objective of this concept is the remote observation of hazardous or inaccessible environments, especially for the protection of citizens and vital infrastructures and networks. Prior to its principal use as a standard MAV with two bladed coaxial counter-rotating rotors, the MAV is packaged as a projectile that is launched with the energy delivered by a portable weapon.The first part of the paper gives a description of the GLMAV concept as well as a complete nonlinear mathematical model for hover and near-hover flight. The second part of the paper emphases on nonlinear control strategies for the hover and near-hover flight, particularly backstepping control. The effectiveness of the proposed approaches is illustrated and discussed with some simulations and experimental results.

Aerodynamic Performance of a Gun Launched Micro Air Vehicle

The study deals with the prediction of the aerodynamic performance of the Gun Launched Micro Air Vehicle (GLMAV) platform by using the ANSYS CFX code. A first step consisted of the validation of the numerical simulation on a two-bladed rotor, which has a diameter of 0.20 m. This micro-rotor model is the perfect reproduction at a scale of 1:10 of the rotor bench that ISL had studied in the nineties. The validation was made by the comparison of the computed thrust and torque with the measured ones. These results proved the ability of the ANSYS CFX code to predict the flow field around MAV rotors and gave us confidence for further computations. The second step consisted of an analysis of the grid convergence for the single rotor of the GLMAV platform. Finally, by using the experience gained from all previous computational investigations, the computation of aerodynamic performance of the two coaxial 0.25-m diameter counter-rotating rotors of the GLMAV was carried out in hover flight.

The Transition Phase of a Gun-Launched Micro Air Vehicle

The present paper addresses the transition stage of a Gun-Launched Micro Air Vehicle (GLMAV) whose main goal is to rapidly position a rotorcraft MAV over a high-risk scene (Prison riots, blind zones: e.g. over-the-hill, etc.). The development of this robotic platform is part of an overall ongoing project (GLMAV) headed by the St. Louis French-German Research Institute (ISL). The vehicle is launched at a distance of 500 m and a height of 100 m, where the GLMAV will collect and transmit visual information from the scene. Issues raising from the use of the gun-based launching technique are discussed in detail. A control strategy is proposed to overcome such problems and to stabilize the GLMAV. High-fidelity simulations, covering ballistic and transition phases, validate the control policy adopted to face the MAV gun-launching problem.

Aerodynamic Modelling and Experimental Identification of a Coaxial-Rotor UAV

A comprehensive design of a Gun Launched Micro Air Vehicle (GLMAV) is presented. The GLMAV rotorcraft is a new Micro Air Vehicle (MAV) concept using two-bladed coaxial contra-rotating rotors and a ...

Time-Varying Observers for Launched Unmanned Aerial Vehicle⋆

AbstractIn this contribution we investigate the problem of linear velocity estimation of a Gun Launched Micro Air Vehicle (GLMAV), which is a new Micro Air Vehicle (MAV) concept, intended for outdoor flight, and using two-bladed coaxial contra-rotating rotors. The linear velocity estimation is realized using a simple time-varying Luenberger-like observer, and only using partial measurmements of an Inertial Management Unit (IMU). Simple conditions of the observation-error-asymptotic-stability are given in terms of physical variables of the GLMAV. The reduced-order observer stability analysis is realized through the Lyapunov approach and the Barbalat's lemma. Simulations results show the effectiveness of the estimation technique applied to the presented GLMAV model, identified from experimental results.