1Design and Navigation Control of an Advanced Level CANSAT
Mansur ÇELEBİ, Serdar AY
Department of Aerospace Engineering, Turkish Air Force
Academy 34149, Yeşilyurt, Istanbul, Turkey

Mohammed Khalil IBRAHIM
Aerospace Engineering Department, Faculty ofEngineering, Cairo University, Giza 12613, Egypt

Mustafa Emre AYDEMİRDepartment of Electronics Engineering, Turkish Air Force
Academy 34149, Yeşilyurt, Istanbul, Turkey

Messaoud BENSAADA
Technical Space Center, Algeria
01 Avenue de la Palestine BP13 31200
Arzew Oran, Algeria

Lewis Hennedige Jayathu Dimuthu Kumara FERNANDO
Arthur C. Clarke Institute for Modern Technologies,
Katubedda, Moratuwa, Sri Lanka

Hiroaki AKIYAMA, Shusaku YAMAURA
Institute for Education on Space,
Wakayama University, 640-8510, Japan

ABSTRACT: This paper presents design and navigation control of an advanced level comeback CanSat
which is going to be launched to an altitude of about 400 m using an amateur rocket from ground level. TheCanSat uses advanced and ultra-light microcontroller, pressure and temperature sensors, 3-axis
accelerometer, 3-axis gyro, camera, GPS, IR distance measuring sensor, and RF communication module tocommunicate with the ground station PC. Three actuators are considered in this work for flight and groundsegments control. They are the motor driven propeller, elevator and rudder. For the flight segment,
parachute and attitude control are used to control the CanSat descent rate, attitude and heading. For theground segment control; both the propeller and the rear landing gear of the CanSat is used for heading
toward a predefined location on the ground. The rear landing gear is connected to the rudder rotational axis.
An indigenous navigation control and electronic circuit design with the test results also are presented in thispaper.
KEYWORDS CanSat, Satellite, Rocket, Launch, Navigation Control Algorithm
I. INTRODUCTION:
A CanSat design is considered a fundamental teachingtool for introduction to satellite design anddevelopment. Therefore, it is of great importance tounderstand and experience the whole process ofdesign, test, launch and recovery of CanSat. CanSat
consists of many disciplines including electronic circuitdesign, control, aerodynamics, atmospheric physics,communication, programming, etc. A basic CanSat
consists of a Microcontroller, Accelerometer, Pressureand Temperature Sensors, Camera, Structure andParachute, as shown in Fig.1.

Fig. 2 CanSat packaging inside the rocket just before thelaunch

Fig. 1 Basic CanSat hardware
Figure 2 shows the CanSat fitted inside an amateur rocket.

978-1-4244-9616-7/11/$26.00 ©2011 IEEE

In the advanced level CanSat, the mission is tolaunch and land the CanSat to a predefined target
point. Furthermore, CanSat will be sending telemetry
data to the ground station. The telemetry data consistsof accelerations, angular velocities, GPS data,pressure and temperature as well as the actuators
status. In addition to an ultra-light microcontroller,
pressure
andtemperaturesensors;
3-axisaccelerometer, 3-axis gyro, camera, GPS, IR distancemeasuring sensor, RF communication module tocommunicate with the ground station PC and threeactuators were used for flight and ground segments752

2control. These are the motor driven propeller, elevatorand rudder servos.

a. For stable descend, theprepared using an umbrella
upper head of the parachutee was cut to create a holeat the top in order to allow air to pass through it.

II. ADVANCED LEVEL CANSATT DESIGN
After the rocket is launched to an altitude
aof 400 m
and successful release of the CanSa
at from the rocket
the landing of CanSat, toward a predefinedptargetpoint on the ground, is started. Th
he landing of theadvanced level CanSat includes tw
wo segments asshown in Fig. 3. The first segme
ent is the flightsegment in which a parachute iss deployed. The
parachute will generate the lift and requiredr
descendrate. A motor driven propeller and servo controlled
rudder and elevator are employed to navigate theTwill be used
CanSat during the flight segment. Theyfor both attitude control and headding toward thetarget. Parachute will be released ju
ust before touchdown using the releasing mechanism (servo) at
about 300-600 mm above the ground. Afterown, the groundparachute releasing and touch-do
segment starts. In this segment both the motor driven
er will be used topropeller and servo controlled rudde
navigate the CanSat toward the target.
tThe rear
landing gear is controlled using the sames
mechanismof the rudder which will enable directional control ofhase.
the CanSat in the ground segment pho advanced level CanSat
Fig.4. Conceptual design ofetric characteristics
Table 1 Geome
Length [mm]Component/assembly
Main landing gear diameter
70
Rear landing gear diameter
35
Horizontal tail span
200
Horizontal tail chord
100
Vertical tail chord
100
Vertical tail span
100
Overall length of the CanSat
400

Components

Fig. 3 Landing segments of advancced level
CanSatA. Airframe Design:
Steel can is used as a fuselage. Insiide this fuselage,
all components are included and/or attached
ato it. All
onboard sensors, electronics and com
mputer are placed
inside the can. Batteries and paarachute releasemechanism are also placed inside thee can. Parachute,Motor driven propeller, landing gears, elevator anda attched to therudder, GPS, communicaton module arecan as shown in Fig.4. Th
he geometricalcharactereistiscs of the CanSat arre presented inTable.1. All CanSat componets andd its weight arelisted in Table.2. The geometric constraint
cof theCanSat is to fit inside a cylinderical compartementcof
400 mm length and 100 mm diameter.. The total weightof the CanSat should not exceed 1 kg which is themaximum payload of the rocket.
o plastic sheet
Elevator and rudder are made ofreinforced by flexible thin steel strip
ps. Main landing
gears are also made of plastic sheet, flexible thin steel
e parachute wasstrips and patch tape sandwich. The753

Microcontroller
2-axisGyroscope3-axis
Accelerometer
PressureSensor
GPS Module
Radio Module
Thermometer
SD CardModuleMicro SD Card
2GB
Servo Motor
CameraMotor
Motor Drive
propeller
Landing Gears
Frame
Li-Po Battery
Wiring Board
3V battery
9V battery

Total Weight

Table 2 We
eight estimation
Approximate
Type
Weight [g]mbed NXP LPC1768LPR530AL

101L
MMA7361L

1SCP-1000

2GT-720FXbee Pro
LM35DZ
MSC-MOD1015
411

DNF-TSD22048

4

GWSMICR
RO/2BBMG/J
FS-MD20035
1345
10106015010020545532

3B. Electronic System Design:
As a microcontroller an Mbed miccrocontroller wasemployed. I/O pin layout and interfacces are shown inFig. 5 [1]. Extensive engineering and testing of all theelectronics were done before the final layout, as shownc
connectionin Fig. 6. Figure 7 shows the final circuit
diagram and Fig. 8 shows resultiing main boardconnected to GPS, communication moodule and the LiPo battery.
Fig. 8 Onboaard electronics

erfacesFig.5 I/O pin layout and inte•

After separation fromm the rocket; the CanSat isstabilized by controlling roll and pitch angles
and this is realized by actuating both theor with/without the motor
rudder and elevato
driven propeller.

•For the orientation of the CanSat using thed propeller, detection of therudder, elevator anddirection of the Ca
anSat is implemented by
calculating the angle between the vector
position and velocityy vector as shown in Fig.9.
The calculations off the radius of the circle
described by the CanSat
Caround the target
allows us to determmine the distance between
the target and the Ca
anSat, and given by:

R = Δx 2 + Δy 2
Position vector =( a1 = x(t ) − x(0) , a2 = y (t ) − y (0) )Velocity vector =( b1 = x (t ) − x(t − 1) , b2 = y (t ) − y (t − 1) )ΔtFig. 6 Development of the onboarrd electronics

Δtnd outer product gives:
The inner product ana1 .b1 + a2 .b2
For θ ∈ ⎡− π , π ⎤ : cosθ =⎢⎣ 2 2 ⎥⎦2a1 + a22 . b12 + b22
a1.b2 − a2 .b1For θ ∈ ⎡ π , − π ⎤ : sin θ =⎢⎣ 222 ⎥⎦a1 + a22 . b12 + b22

Fig. 7 Schematic of electronic circuit
C. Navigation Control Algorithm:
To ensure stability of the CanSat and its orientation
towards the target, two control algoriithms have beendeveloped; one for stabilization of the CanSat during
flight segment and one for its orientation toward theTalgorithm oftarget during the ground segment. The
flight control operates as follows:

Fig. 9 Orienta
ation of CanSat
Thus the control algorith
hm for stabilization andorientation of the CanSat aree shown in Fig. 10 and Fig
11, respectively.

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4Fig. 12 Simulation of the control algorithm
E. Firmware Development:
The firmware development of the many sensors canbe implemented easily by using ready-made codesfrom mbed cookbook. The present firmware
development includes:

Fig. 10 Control algorithm; stabilization algorithm

●
●
●
●
●
●

Controlling of propeller Motor
Controlling of elevators and rudder driving
motorsAccessing GPS data
Interfacing Gyro, Acceleration, Pressure andTemperature Sensors
Data Transmission using XBee Modules
Controlling and navigation

Firmware developed in classes and libraries as shownin Fig. 13.

Fig. 13 Software development
Ground station software was developed using
Matlab. Real-time data from different sensors andactuators status as well as the trajectory data which ispassed on the processed GPS data can be visualizedon the ground station interface screen, as shown in theFig. 14.

Fig. 11 Control algorithm; orientation algorithm
D. Dynamic Modeling and Simulation:
Figure 12 shows the simulation results of the trajectoryof the CanSat during decent using the above
mentioned stabilization algorithm.

F. Fabrication
Fabrication of the CanSat parts and component
installations were the most time consuming process.
Each modification of the airframe should be tested andshould pass both the geometrical and weightcontractions. Figure 15 shows the fabricated parachuteattachment
plateandreleasing
mechanism.
Packaging test inside a compartment similar to that ofthe rocket is shown in Fig.16. Other fabrications

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5

include tail unit, motor-driven propelleer, rear and front
landing gears and the servos installatio
on.

Fig. 14 Ground station softwarre interface
Fig. 16 Packagin
ng of the CanSat

Fig. 17 Testing off pressure sensor

Fig. 15 Parachute releasing meechanism
G. Testing
ment of CanSat
Testing is the most curial elem
engineering each component is exxtensively tested
during the firmware development andabefore final
design review. Figures 17 and 18 show
sthe testing
results of the pressure and GPS senso
ors, respectively.
ed as follows:
Other tests which have been performe
med to decide• Parachute Tests were perform
parachute diameter, stabilizationn hole diameterand robe length for stable desccend and proper
descend rate.
• Rover Tests were performed too decide proper
angular velocity for turning in orrder avoid fallingover• Parachute Separation Mechanism tests wereble and reliable
performed to ensure sustainab
separation.
• Balloon Tests were performed to test wholeprocess as shown in Fig. 19.

Fig. 18 GP
PS Testing
H. Risk Analysis
Risk analysis was performed to identify the mostcritical element and/or patth for the whole mission.
The following issues are considered during theanalysis.

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6Fig. 20. Process plan for the construction of theCanSatIII. RESULTS, CONCLUSION
N AND LESSONS LEARNED

Fig. 19 Balloon test
1. Loading Phase:
he rocket.
a. No smooth fitting inside th
2. Launch Phase:a. Break in the hardware,b. Motor’s sudden start in the rocket due tovibration,c. No start for the recording..
3. CanSat Deployment Phase:a. No opening of the parachutebparachuteb. Motor’s sudden start before
stabilityc. No recording.
4. Navigation Phase:
hm bugs,a. Navigation control algorithb. No connection to satellites for GPS,nd stations,c. No connection with ground. Improper control of the control surfaces
and motor.
5. Landing Phase:a. Parachute not release beffore touch down,b. No landing on landing geaars.
6. Rower Back Phase:a. Non control of control surffaces and motor,
b. Bad GPS communications,c. During rovering fold down of CanSat due
to obstacles,
gorithm.
d. Bugs in the navigation alg

The first basic CanSat wasw
launched form KADA
launch site to 350m altitude in Wakayama, Japanhe wind was strong but theusing an amateur rocket. Th
launch was proceeded ass planned. Pre-launchingprocedure was executed successfully. Both thelaunching and parachute deployment was very
successful. However due sttrong wind both the rocket
and CanSat was drifted aw
way. CanSat drifted until it
became invisible by naked eye.
u
recovery and• Strong wind cause unsuccessful
this warrant to perfform simple aerodynamics
calculation to ensure
e minimum drift.
• Telemetry sensor data and GPS should
implemented
aon your CanSat• Put your name and address
thJon 11 March 2011
Due to earthquake that hit Japanand the resulting tsunami and nuclear leakage theadvanced level CanSat launcch was cancelled.
a highlighted during theThe following key factors aredevelopment process of the CanSat project.
•••••Project Management
System Engineering
Team Work
Communication
Reliability
IV. REFER
RENCES[1]

I. Systems Engineering Process
e first step in theSystem engineering planning is theSystem Engineering Process. Initiall brain storming
phase was done to develop an initia
al plan of how tobest organize and manage people, resources, andmaterials needed for the project. Tassks, sequence oftasks, and estimated time required too complete tasks
were identified to construct a WorkW
Breakdown
Structure (WBS) diagram. The follow
wing major task
and milestones are identified: Preeliminary Design
Review (PDR), Engineering Model (EM), Quality
Assurance (QA), Critical Design Revieew (CDR), Flight
Model, and the launch date. The milestones aree construction ofillustrated in the process plan for thethe CanSat as shown in Fig.20.

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mbed programming workshop for CanSat, senio
networks, inc. 2011,