Rocket Launched Glider for Near-Field Surveillance Team 7: Josh Elkind, Jesse Morzel, Alexander Reiner, Fiona Strain, Sophia Stylianos

Controls  System    

                     

We   used   an   Android   tablet   for   communication   with   the   ArduPilot   to   determine  destination   points   and   track   and   log   9light   data.   It   is   a   slightly   modi9ied   version   of  AndroPilot,  an  Android  open-­‐source  ground  station  project  for  MAVLINK  UAVs.    The  microcontroller   subsystem   is   designed   to  be   very   easy   to   switch  between  manual  and   autonomous   mode.   If   manual   mode   is   desired,   the   6   channel   receiver   will   relay  commands  from  a  human-­‐operated  remote  control  on  the  ground  to  the  microcontroller.  If   autonomous  mode   is   desired,   embedded   code   on   the  microcontroller  will   take   over  control  of  the  servos.  For  our  project,  we  used  a  modi9ied  version  of  the  ArduPilot  Mega’s  open  source  C/C++  ArduPlane  code.    By  adding  a  custom  autonomous   9light  mode,  we  were   able   to   incorporate   the   controls   system   logic   from   the  MATLAB   simulation.   This  mode  uses  primarily  rudder  control  to  navigate  to  the  desired  waypoint.  This  logic  also  allows  for  the  programming  of  obstacles  in  the  9light  path.    

   

Testing  Balloon  Drop  Tests  Using   a   helium   weather   balloon,   the   team   conducted   several   glider   drop   tests   before  integrating  the  rocket  engine.  The  goal  of   these  tests  was  to  characterize   the  glider   9light,  collect  data  used  to  verify  our  MATLAB  simulation,  and  gain  knowledge  about  the  controls  inputs  for  autonomous  9light.  Additionally,  the  tests  con9irmed  functionality  of  the  onboard  camera  system,  ArduPilot  Mega  system,  and  the  transmitters  and  receivers  for  both.    Rocket  Launch  Tests  The   integration   of   the   rocket   engine   into   the   fuselage   of   the   glider   allowed   the   team   to  perform  a  series  of  rocket  launch  tests.  The  goal  of  these  tests  was  to  verify  the  structural  integrity  of  the  glider  when  exposed  to  the  heat  from  the  rocket  engine  and  the  high  thrust  forces  of   launch.  Additionally,   the   tests  were  needed   to  con9irm   the  stability  of   the  glider  during  the  rocket   launch.  Using  an  F50  Estes  rocket  engine,   the  team  con9irmed  that  heat  shielding   tape   effectively   protected   the   foam   body   of   the   glider   and   that   carbon-­‐9iber  reinforced  wings  remained  intact  during  launch.  By  positioning  the  rocket  engine  in  such  a  way  that  the  thrust  vector  acted  through  the  center  of  gravity,  the  glider  remained  stable.  

Simulation  of  Launch  and  Flight  Controls  

Project  Overview    

The  project  addresses  the  need  for  a  low  cost  UAV  that  can  be  easily  deployed  by  military  personnel   for   near-­‐9ield   surveillance   purposes.   An   initial   rocket   launch   enables   the  unpowered  glider   to   reach  a  gliding  height  necessary   to  autonomously   9ly   to   the  desired  surveillance  area.  As  opposed   to  recorded  and  saved  video,   the  glider   transmits   its  video  feed  to  the  ground  station  in  real  time,  rendering  the  retrieval  of  the  plane  unnecessary.

Electronics      

Future  Plans    

By   utilizing   a   UAV   under   both   rocket   launch   and   gliding   conditions,  we   found   certain  inef9iciencies   that   can   be   addressed   in   the   future.   The   following     improvements   will  optimize  the  glider  for    rocket    launch    and    autonomous    9light.  Wing  Deployment  Mechanism:   In   order   to   reduce   lift   and   drag   forces   on   the   glider  during   launch,   a   wing   deployment   mechanism   should   replace   the   9ixed   wings.   This  system  would  improve  stability  throughout  the  launch,  allow  the  glider  to  reach  higher  altitudes,  and  decrease   the  potential  of   the  glider   incurring  damages.  The  wings  would  be  9lush  against  the  body  of  the  fuselage  during  launch  and  extend  once  in  9light  phase.  Ground   Station   Customization:   While   the   theory   for   navigation   based   on   obstacle  avoidance   exists   in   the   modi9ied   ArduPlane   code,   a   more   customized   ground   station  would  allow  for  in  9light  addition  of  obstacles  via  the  Google  Maps  UI.    

   Customer:  Thomas  Castner,  Faculty  Resource:  Bruce  Kothmann  

Above   is   our  MATLAB   simulation   for   the   9light   path   of   the   rocket   launched   glider.   It  shows   an   initial   launch   phase   (burn   time   highlighted   in   green)   with   a   proportional-­‐integral   controller   maintaining   a   steady   body   velocity   angle   with   the   ground.  Subsequently  a  PID  controller  affects  the  elevator  directing  it  around  cylindrical  “No-­‐9ly  zones”  towards  a  prede9ined  waypoint.  

The  above  plots  show  both  the  GPS  data  from  a  glider  drop  test  and  a  simulation  that  takes  as  an  input  the  discrete  time  series  of  control  angle  inputs.  Using  the  real  world  raw  data,  the  simulation  predicts  a  9light  path  very  similar  to  what  was  observed.  

Project  Challenges    

The  challenge  in  constructing  a  UAV  that  can  execute  both  a  rocket  launch  and  autonomous  9light  phase  is  that  these  two  modes  have  very  different  demands  on  the  vehicle.  For  rocket  launch,   high   forces   are   present   due   to   the   thrust   from   the   engine   and   the   lift   and   drag  forces  on  the  wings.  Due  to  these  forces,  the  glider  must  have  enough  structural  strength  to  ensure  that  the  wings  and  tail  survive  the  launch.  These  components  must  also  be  able  to  survive   the  heat   generated   from   the   rocket   engine.  Additionally,   the   forces   acting  on   the  glider  must   be   located   properly   to   ensure   stability   throughout   the   launch.   For   the   9light  phase,   the   glider   must   have   the   appropriate   control   surfaces   to   allow   for   continuous  control  from  the  9light  program.  These  control  surfaces  have  to  be  used  to  ensure  that  the  glider  reaches  its  designated  waypoint.  

Carbon  Fiber  Rods  

Onboard  Camera  

Launch  Pad   Rocket  Mount   Electronics  Housing