DT021/4 Final year project Christophe SCAYA Surveillance rocket DT021/4 Final year project Christophe SCAYA The name of my ……. 14/11/2018

Structure of discussion Aim of the project: Design a low-cost rocket for ground surveillance Design an embedded system with a set of sensors and a digitial video camera Multidisciplinary aspects: Mechanical concept Electronics Computing Blabla, this gnd surveillance is realised by an embedded blablba Main interest  multidisciplinary project Mechanical ++ : -physical study of a system -aerodynamical characteristics Electronics due to the presence of sensors 14/11/2018

Part I : The rocket Schematic from the rocket made with catia 14/11/2018

What type of rocket ? Preliminary requirements: Principle: Low-cost materials Easy to use and reuse Principle: Water initially put in a plastic bottle Pressurised air is then added A manual system triggers the flight WATER ROCKET First question : what type of rocket? The rocket must be easily product in a big scale The system allows to release the rocket from its launching system 14/11/2018

Stability of the rocket 1/2 Assume a rocket with an initial trajectory. A disturbance is added and the initial trajectory deviates from a small angle α CASE 3: the rocket returns to its initial trajectory The rocket is stable GOOD DESIGN ! CASE 1: the rocket continues to increase the deviation from its initial trajectory The rocket is unstable VERY BAD DESIGN ! CASE 2: the rocket stays on the deviated trajectory The rocket is neutral BAD DESIGN The main source of disturbance : wind We define the stability as the aptitude of the rocket to recover its initial trajectory How is it possible to obtain the stable case ? 14/11/2018

Stability of the rocket 2/2 Two points influence the stability: The Centre of mass (Cm) The Aerodynamic centre (Ac) The condition to obtain a stable rocket is to position Ac below Cm This is done by correctly shaping the fins of the rocket Due to the position of 2 physical points 14/11/2018

Recovery system Parachute is located in the nose cone of the rocket When the rocket reaches its maximal position, a small weight falls and release the cone and the parachute The parachute can open itself and slowdown the rocket 14/11/2018

Part II : Electronics 14/11/2018

Objectives Record physical values from the flight with appropriate sensors Data are analysed by a microcontroller located in the nose cone Transmit the data to the ground via an appropriate wireless system Sensors are connected to the PIC which proceed to ADC 14/11/2018

Possible type of sensors Gyroscope Measurement : inclination Interest : monitoring the inclination of the rocket due to the wind effect Price : €37.90 each (minimum order quantity of 25) Too expensive : NOT CHOSEN 14/11/2018

Possible type of sensors Pressure sensor Measurement : relative pressure Interest : monitoring the pressure inside the plastic bottle. This value can be used to deduce the force developed by the rocket in flight. Price : €13 each Implementation: very difficult to fix inside the rocket Not easily implementable : NOT CHOSEN Relative pressure compared to atmospheric pressure Type sensor not considerate but very interesting. If a new project is given to a student that shd be great to include this sensor 14/11/2018

Possible type of sensors Accelerometer Measurement : acceleration Interest : monitoring the acceleration of the rocket and then deducing both speed and position Price : about €10 each Implementation: on the main PCB All is good: CHOSEN 14/11/2018

Global implementation Receiver To the ground Max233 convert the signal PIC to comply with the RS232 standard 14/11/2018

States of the PIC Power is switched on Waiting mode: Power is switched on Ready for flight: The ready switch is pressed ; the PIC waits to detect variations in the accelerometer outputs Flight: The PIC transmits the accelerometer values via the wireless system End of flight: No variation detected from the accelerometer ; return to “ready for flight” state The main program is divided into different states 14/11/2018

Part III : Computing 14/11/2018

Data recovery Data sent using the RS232 protocol Necessary to use software HyperTerminal can be used in Windows Very simple to use Data from the rocket printed on the screen Not practical to exploit  Use another special software : RocketSOFT developped with Java 1.6 and NetBeans IDE 6.0 To get back (récupérer) the data from the serial port 14/11/2018

Demonstration 14/11/2018

Videos flight 14/11/2018

Videos flight First flight : 8th April 2008 Second flight : 10th May 2008 Other flights : 14th May 2008 Flight 1 Flight 3 Flight 4 14/11/2018

Thanks for your attention Putain c’est fini, je suis en VACANCES !!! 14/11/2018