P09233
2008-3 & 4
Special Thanks to
&
Pitot Static Tube Mounting
Project Background:
The long term goal of this project is to create, field
and implement a full system of measurement
devices that will be used to control an unmanned
aerial vehicle. This will be the first quarter that
the project is being worked on, and the primary
goal will be to implement off the shelf
measurement devices to characterize the
necessary parameters for in-flight control of an
unmanned aerial vehicle.
Problem Statement:
The project will combine several sensors to
measure the fundamental parameters of in-flight
movement to allow for a flight control system to
calculated the necessary information to sustain
flight.
and sensor mounted
in the wing tip, both
can be removed and
replaced without
complete wing
disassembly.
Pitot Tube
Group Members
Michael Skube (ME), James Hunt (ME), Joseph Peters (EE), Bill
Atkinson (ME), John Isely (ME), Heidi Morgan (EE), Kevin Li (EE)
Faculty Advisor: Dr Jason Kolodziej
Complete Measurements “BOX”
Pitot Tube Mount
Velocity Sensor
The completed measurements box fits inside the fuselage of
Airframe A (P09231). The box is attached with 4 thumb screws,
and the complete box also acts as the outer fuselage, sealing
the hole that is required to insert the box into the airframe.
Objectives/Scope:
- Measure real time position of test platform
- Measure real time flight parameters
- Ensure measurements are accurate and reliable
Measurement Box in Airframe A
Visit our wed page for more information and documentation:
https://edge.rit.edu/content/P09233/public/Home
Serial
Altimeter 5V
GPS Control
PC
JTAG
MCU
GPS
Serial
5V
IMU Control
IMU
SPI
5V
5V
Pitot Static
5V
Tube
ADC
BEC
14.4V
5V
Initialize MCU
Peripherals.
SPI Initialized.
UART0 and
UART1 Initialized.
Initialize timers
and setup
interrupt service
routines.
Initialize the GPS.
Initialize the
Altimeter.
Several Peripherals are used to interface the Microcontroller
with the sensors. The GPS and Altimeter are interfaced with
the 2 UARTS. The IMU and SD card are interfaced with the
SPI.
The timers and ISRs are used to control
the recording rate of the sensors.
GPS
Commands are sent through the UART to control the GPS.
The GPS utilizes NMEA protocol. Several types of data can
be obtained from the GPS in addition to position.
Altimeter
An ASCII ‘L’ is sent through the UART to toggle
the state of the Altimeter between on and off.
Initialize the IMU.
IMU
The IMU consists of 6 sensors. The SPI is configured to
send 2 byte length commands. The MCU controls which
sensor data is places on the MISO.
Initialize the SD
Card.
SD Card
Commands are sent through the SPI in a 6 Byte packet
which consist of a command, data and checksums. 74 Clock
pulses on the SPI along with a Logic high on the MOSI and
chip select lines places the SD Card in SPI mode.
Enter while loop
forever.
Continuously Read GPS, Altimeter and IMU.
Calculate speed, relative position and
heading from IMU.
No
Has timer
reached 0.
Yes
Eagle Tree Velocity
Sensor
Record Data from
sensors to SD Card.
GPS
Zlog Altitude Sensor
Microcontroller
Pitot Static Tube vs. Anemometer
60
(Automobile Test)
50
40
30
Speed (mph)
Altimeter Control
Inertial Measurement Unit “IMU” (Analog Devices ADIS16350)
- Tri-axis gyroscope ± 75°/s, ± 150°/s, ± 300°/s settings
- Tri-axis accelerometer ± 10 g measurement range
- 350 Hz bandwidth
- Dimensions: 23 mm x 23 mm x 23 mm
Microcontroller (AT91SAM7S256)
- Flash, 64K Bytes RAM, USB 2.0, RTT, 10 bit ADC 384 ksps
- 2x UARTs, TWI (I2C), SPI, 3x 32bit TIMERS, 4x PWM, SSC, WDT
- PDC (DMA) for all peripherals, up to 60MHz operation
- Dimensions: 80 mm x 120 mm
GPS (San Jose Navigation)
- Refresh rate: 5 Hz
- Accuracy: 3.3 m accuracy, 2.6 m accuracy with DGPS
- Dimensions: 2.6 cm x 2.6 cm x 0.6 cm
Airspeed (Eagle Tree Airspeed Micro Sensor)
- Range: 2 MPH to 350 MPH ± 1 MPH
- Weight: 7 Grams
- Dimensions: 28 mm x 16 mm x 10 mm
Altimeter (Zlog)
- Range: 0 to 10000 ft ± 1 ft
- Weight: 8 Grams
- Dimensions: 40 mm x 23.4 mm x 9.4 mm
Measurement Box Design
- Mounting positions for all sensors & includes vibration isolation
- Dimension: 3 in x 3.25 in x 3.75 in w/t base plate 6 in
Pitot Tube Mounting Design
- Allows for quick sensor removal and replacement
- Dimension: Contained between outermost 2 wing tip ribs
Ultrasonic Sensor (Maxbotix LV-EZ0)
- Range: 0 to 255 inches
- Dimensions: 21.1 mm x 19.9 mm x 16.4 mm
The Pitot Static Tube was compared against a anemometer,
measuring the velocity of a automobile, the accuracy is
reasonable given the low cost of the Pitot Static tube setup.
20
10
Airspeed Sensor
Anamometer
0
0
10
20
30
40
50
60
70
Data Collection Event
The altimeters where tested against a calibrated pressure
sensor to show their accuracy, based on repeatability and
accuracy, the ZLOG altimeter was chosen.
400
Vacuum Chamber Simulated Altitudes
350
350
Zlog
Zlog
300
300
250
Eagle
Eagle Tree
Tree
Pressure
Sensor
Pressure Sensor
250
200
Altitude
(Ft)
Altitude(Ft)
Sensor
andElectronics
MCU Integration
Additional
Box inside Airframe A
150
200
100
150
50
100
0
1
2
3
4
5
6
7
8
9
Data Collect Event
GPS data was collected
on a drive around the
outer loop of RIT to
shows it’s accuracy.
Ultrasonic Altitude
IMU
Inertia Measurement Unit
Sensor
10
11
12
13
14
15
16
17