Smart Water Rocket System Group 6 Connor Phillips (EE) Kyle Moran (CE) Gabriel Fernandez (EE)

Sponsor

Space Trek's Water rocket program Space Trek is a summer camp at Kennedy Space Center for middle school, high school, and college students One of their many science experiments is a water rocket capable of launching up to 100 feet in the air Prior to launch there is a pre-flight analysis simulation that lets students adjust and test different flight parameters (water volume, air pressure, launch angle)

Water rocket contd. Once the camp attendees have their flight specifications, they move outside to a field to launch the water rockets The rocket is filled and then pressurized using a bike pump, mounted on the Launchpad, and then fired by pressing a red button When the rocket reaches the peak of its trajectory, a gyroscope activates a mechanical system to release the parachute After retrieving the rocket measurements are recorded from the on-board altimeter

Water Rocket Launch

Goals and objectives Automate the rocket launches to create a better experience for both students and staff Replace on-board altimeter with custom altimeter with wireless data transmission capabilities Allow students to use a mobile application to review the data from their launches and easily compare between groups

specifications Altimeter must be less than 10 grams and fit into the rocket without changing its center of mass Launch pad angle plate must be motorized for more precise angles Data must be transmitted wirelessly without the need to take the altimeter out of the rocket Altimeter must be water resistant in case of leakage

Block diagram

MCU Arduino Uno TI MSP430

Altimeter Pressure GPS Radar Pros: Pros: Pros: Cons: Cons: Cons: Cheap Low voltage Cons: Slightly inaccurate Pros: Accurate Cons: Expensive High power consumption Pros: Direct altitude measurement Cons: Antenna requirements

BMP-180 I2C Low Power Breakout board easily available Inexpensive Small Good Resolution

Accelerometer Triple-Axis Used to obtain velocity in a 3 dimensional space More than required

ADXL345 I2C Low Power Small Very Common

Communications Bluetooth Pros – straight forward implementation, handles data well when paired Cons – bad range, might not show data in real time, can lose data when unpaired Wi-Fi Pros – works at greater ranges than Bluetooth and won't lose data Cons – Wi-Fi connection in the launch zone isn't strong

Programming microcontroller Collect data from sensors – velocity, height and distance Sensors include a pressure sensor and accelerometer Transmit Data wirelessly to ground Ensure consistent and reliable data for comparison Essentially designing an altimeter with wireless transmissions

Mobile Application Tablet Located at launch station Accepts data from custom altimeter in rocket Organizes data by groups and inserts into database Uploads data to simple web server for later comparison Will have the option to view most recent launches for quick review

Sequence Diagram Shows flow from altimeter receiving data to transmitting back to the ground Takes into account failed packets and bad connections Will store data onboard temporarily until a good connection has been made Students will be locked from launching rocket until instructor has given permission

Class Diagram Shows relationship between different modules of the rocket and how it connects to the tablet on the launch pad Altimeter in rocket will gather data from onboard sensors and transmit wirelessly to the tablet Tablet will interpret data and fill out a database for each group and transmit that data to a remote server for later viewing from the classroom

LaunchPad Tablet Using an Android Tablet for lower cost and easy replacement More familiarity designing in Android Will be programming application in Android Studio Stretch goals include adding a lock feature to prevent launches until authorized (key switch and 4-pin code) Must be able to interact with microcontroller in the rocket

Launchpad automation The current water rocket platform involves an angle plate that is adjusted by manually loosening and tightening a knob to set a desired launch angle A stepper motor will be connected to a microcontroller and operated using an LCD with +/- to adjust the angle To power the automation a large capacity battery will be used

Automation design Space Trek has a 3D-printer on site which can be used for parts to modify current launch pad Angle plate modified to adjust angle with stepper motor System will be attached underneath each launch pad Protecting from some of the water thrust but ultimately the motors and MCU will have to be housed in a water resistant container

Stepper motor selection Stepper motors will be used to automate the launchpad because DC are generally for high rpm and servo motors are high rpm and accurate, but generally more expensive than stepper motors Servo motors require a feedback mechanism and support circuitry to drive positioning Stepper motors are low cost, slow rotating, easy to set up and control (a stepper motor is built for position control)

Selecting a Battery Stepper motors require continuous power by design Large capacity to endure all of the launches during experimentation Durable because it will be used outdoors Chose lead-acid because they are relatively cheap so that they can be replaced High capacity, reliable and long lasting

Projected Costs Component Cost Lead-Acid Battery $18 Stepper Motor (x4) $20 Arduino Uno (x2) n/a ATMega328p (x2) $8 BMP180 $4 ADXL345 $7 Bluetooth Module (x2) Li-Po Battery Misc. Mechanical Parts $30 Misc. Electronics $50 Breakout Boards $16 PCB $200 TOTAL $381

Work Distribution Launchpad Altimeter Software Connor Phillips X Gabriel Fernandez Kyle Moran

Questions?