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Imaging and Localisation Package for a Martian Balloon Based
Aerobot
Dave Barnes, Andy Shaw, Phil Summers
Roger Ward, Mark Woods, Malcolm Evans
Gerhard Paar, Mark Sims
ESA Contract No. 17400/03/NL/CH
Contents
• ILP overview
• Balloon gondola hardware
• Balloon localisation
• Balloon simulator
• The way forward
Imaging and Localisation Package
• The package will allow optimal acquisition of images to reconstruct accurate models of the surface of the explored planet, and accurate localisation of the balloon with respect to the Martian surface. The ILP by means of aerobot mounted cameras and computer vision techniques will: a) acquire and store images of the surface at various resolutions, b) construct and update a 3D model (DEM) of the surface, (cont..)
Imaging and Localisation Package
• c) constantly estimate the position (latitude, longitude and altitude) of the aerobot as well as its motion with respect to the surface, and d) decide on the base of the communications budget, of the morphology of the surface and of the information content of the images, which images at which resolution/compression need to be transmitted to Earth.
Contents
• ILP overview
• Balloon gondola hardware
• Balloon localisation
• Balloon simulator
• The way forward
Hardware Overview
• Balloon envelope
• Propulsion system
• Altimeter
• Camera
• On-board processor
• Mock terrain
Balloon Lift
• A 1830 mm ( 6 ft) diameter balloon will produce a total lift of 3 kg
• PVDC envelope mass =1 kg– Gondola mass = 2 kg
• Mylar envelope mass = 0.3 kg– Gondola mass = 2.7 kg
HardwareOverview
Firewire interface (IEEE1394), supplies power (12V), allows 400Mbps, raw data. 30fps @ 640x480
RS232 serial interface, 2Hz, accuracy of 1.5mm
Allows communication to a base PC at 11Mbps and allows simulation of the comms window.
Supplies power to the whole system 14.8V 5850mAh
Small PC running a P4M 2.4Ghz, 512Mb RAM, 20Gb HDD, requires +5V @ 4.2A, +12V @ 4.85A Total 35W
Contents
• ILP overview
• Balloon gondola hardware
• Balloon localisation
• Balloon simulator
• The way forward
Localisation Approach
To maintain localisation accuracyover large aerobot flight distances,our ILP approach augments a relativelocalisation method with an additionalglobal localisation approach.
Contents
• ILP overview
• Balloon gondola hardware
• Balloon localisation
• Balloon simulator
• The way forward
Balloon Simulator Overview
ILP MartianBalloon
Simulator
Terrain Data:MOLA, MOC,
THEMIS
MartianMeteorology:ESA MCDB
& CFD
BalloonAerodynamics
Model
GondolaInstrumentation
Modele.g. Camera
Balloon Simulator Overview
ILP MartianBalloon
Simulator
Terrain Data:MOLA, MOC,
THEMIS
MartianMeteorology:ESA MCDB
& CFD
BalloonAerodynamics
Model
GondolaInstrumentation
Modele.g. Camera
Contents
• ILP overview
• Balloon gondola hardware
• Balloon localisation
• Balloon simulator
• The way forward
Tethered Martian Balloon Study
• Martian Atmospheric Parameters?– Location, Temperature, Pressure, Wind Speeds
• Balloon Envelope Parameters?– Material, Density, Thickness, Permeability
• Balloon Tether Parameters?– Material, Density, Young’s Modulus, Balloon Altitude (500m)
• Rover (or Lander) Related Parameters?– Winch Mass (incl. electronics), Gas Storage
• Science Instrument Mass?– Instruments, Power, Communications, Electronics (1kg)