Design & Control of Autonomous Underwater Vehicle SEA 1.0 Md. Abu Shahzer, Faraz Ahmad Khan, Ali...
-
Upload
bernice-short -
Category
Documents
-
view
216 -
download
0
Transcript of Design & Control of Autonomous Underwater Vehicle SEA 1.0 Md. Abu Shahzer, Faraz Ahmad Khan, Ali...
Design & Control of Autonomous Underwater Vehicle
SEA 1.0 Md. Abu Shahzer, Faraz Ahmad Khan, Ali Shazan Gulrez, Haris Siddiqui, Jatin Varshney
Faculty Advisor: Dr. Saleem Anwar Khan
Presented by
Ali Shazan Gulrez & Jatin Varshney
Team ZHCET, Aligarh Muslim University
Present Work- Objectives
• Design Autonomous Underwater Vehicle needed for ocean observation
• Keep its weight optimum for desired operation• Design AUV less than 2 m of length and 0.5 m of diameter• Design under water vehicle such that it can bear 5 m of
water pressure• Follow the assigned path, pick and drop objects from and to
the specific bins• Design a vehicle which is self sinking to a desired level
under water and self rising to the surface, using buoyancy• Device an automatic control for the vehicle to make it
autonomous
Design
• SEA 1.0 is designed positively buoyant• Water suction makes SEA neutrally and negatively buoyant
depending on amount of water entered inside• Upward-downward motion achieved by buoyancy control• Structure designed using CAD software • Center of mass lies below center of buoyancy along Zv axis
• Couple created on displacement in x-z plane will always be restoring
• Coordinates Cb (-13.24, 0) mm and coordinates Cg (-13.24, -389.743) mm
• Position of cg adjusted so that XCG is equal to XB (adjustment done by placing dead weight suitably)
• CD = a α2 + b α + c, where, a = 5.25 rad.−2, b = -0.315 rad.−1,
c = 0.732,
z
x
α
BL
Dw + Df
T
W
u∞
XV
ZV
cb
cg
Zgb
21
2
D
DC
u A
CD
α
Hull Drag, CD versus α, at u∞ = 0.5 m/sec
• Dimensional form of governing equations of underwater vehicle dynamics in x – z plane
• Internal structure– Four PVC plates of 200 mm diameter and10 mm thickness– Six 18mm diameter holes on each plate symmetrically drilled and aligned to allow six aluminum rods of 16mm
diameter to pass through– Two stretchable plastic water pipes of 50 mm diameter attached to bars moved horizontally by a single DC servo
motor placed at the centre of the structure which expand and contract the pipes for the buoyancy changing mechanism.
– Electrical components inside: 18.5 V rechargeable batteries , two D.C. servo motors, on-board computer and extra battery as dead weight
2
2
1x-momentum: [ sin cos ] cos
2
1z-momentum: [ cos sin ] sin
2
where, and L is characteristic length
L D
L D
uu uu w C C tx z L
uw wu w C C t gu z L
Tt
21z-Moment: Z ( )( cos sin ) sin
2gb L D
I Au C C T B
• External components– Main Pressure Hull: PVC material. – Front cap hollow with converging end, 300mm in length and 200mm in
diameter (front and rear portion for water suction)– Hydro-dynamically designed to reduce wave resistance and friction drag– Main delta wing with two more delta wing attached at extreme left and
right corners of the main pressure hull to provide stability– Two six strap-on BTD150 thrusters each mounted on the rear side of
the AUV– Thrusters provide power for forward movement as well as differential
control used for turning while in stationary position– Robotic arm of Aluminum for collecting and dropping objects attached– Navigation sensors (for sensing the motion of the vehicle), Mission
sensors (for sensing the operating environment and mission events), and Depth sensor.
– Two small CMOS-color camera
CAD Design of SEA
Partially Assembled model of SEA
Simulation of AUV
Simulation Parameters
• Atmospheric pressure = 1bar• Temperature = 30 deg C• depth of vehicle = 2 m •Depth of sea bed =15 m •Relative velocity = 0.5 m•Negligible viscosity •Designed in ansys design modeler and meshed in ICEM CFD. • modal:- ansys – fluent (inviscid – laminar).
Electrical System Design• Provide motion control
• Provide Image Processing
• Measure the vehicle’s depth
• Discern the vehicle’s attitude
• Measure the vehicle’s Surge velocity
• Provide Regulated Power to each Component
1.66GHz On board processor
Cam Front
CamBottom
Wi-Fi module
ActuatorBoard
Workstation PC
LV-EZ1
iNEMO board
Robotic Arm Control
Wireless Communication
MC33926 through servo
Thrusters
T1
T2
Servo Motor, Depth Control
I2C L298
M1
18.5 V 5000mAh
18.5 V 5000mAh
Distribution
Block Diagram of Electrical System Design
CONTROL SYSTEM DESIGN
Computed Torque Control
MV’+D(V)V+G=T ______________(i)we assume a Linear TorqueT=AT’+B_____________________(ii)T’ is chosen based on Position & VelocityT’=-KvV-KpP__________________(iii)V’+KvV+KpP=0________________(iv)Errors are defined as e=Pd-P; e’=Vd-V; e”=Vd’-V’_______(v)Implementing PID Control T’= ___(vi)T= _______(vii)
Kp
Kpi1/s
Vd’
Kvi
1/s
Kv
M SEAP
V
D(V)V + G
Vd
Pd+
++ +
+ +
+ T
-
+ +
+ -
e
e’
PID Tracking Controller Block Diagram
PID TRACKING CONTROL
S.NOName Of
Part
SpecificationEstimated
CostDiameter(mm)
Power(kW)
Voltage(V)
Length(mm)
Torque(N-m)
Weight(kg)
RPM MaterialNumberRequired
1.Main
Pressure Hull
204 - - 824 - - PVC 1
2.Front End
Cap210 - - 288 - - PVC 1
3.Rarer End
CapPVC 1
4. Delta Wing PVC 1
5. Propeller 19.1 SEA Botix 2 1,70,000
6.Robotic
ArmNex
Robotics1 12000
7. Plates Aluminium 4
8. Rods Aluminium 6
9. Processor Intel 1 25,000
10.DC Servo
Motor5 Fatuba 2 1000
11. Camera Microsoft 1 2000
12. Atmega 640 5 Atmel 1 2500
13.iNEMO module
5STM
Electronics1 3000
14. Battery 18.5 Li-Poly 2 7000
PLAN OF ACTION
•August 2012•Designing & Body FabricatingLevel 1
•January 2013•Control Design, Buoyancy ControlLevel 2•Summer 0f 2013• Completion of AUV•Financial Assistance from AMU, Alumni Associations, private and public sector Organizations
Level 3
CONCLUSION
• Proposed design weight approximately 22 kg• Dimensions of SEA 1.0 are well within required
specification• AUV design proposed can withstand 5 m water pressure• Control mechanism proposed is suitable for SEA 1.0 to
follow the assigned path, pick and drop objects from and to the specific bins
• Vehicle design proposed is self sinking to a desired level under water and self rising to the surface, using buoyancy control mechanism
• The cost is also optimized• Simple mechanism is used for control dynamics
Thanking You all