inertial measurement unit “imu” (analog devices adis16350)
DESCRIPTION
P09233 2008-3 & 4. Airframe Measurements Group Measurements Box. Special Thanks to. &. Project Background: - PowerPoint PPT PresentationTRANSCRIPT
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 mmGPS (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 cmAirspeed (Eagle Tree Airspeed Micro Sensor)
- Range: 2 MPH to 350 MPH ± 1 MPH- Weight: 7 Grams- Dimensions: 28 mm x 16 mm x 10 mmAltimeter (Zlog)
- Range: 0 to 10000 ft ± 1 ft- Weight: 8 Grams- Dimensions: 40 mm x 23.4 mm x 9.4 mmMeasurement 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 inPitot Tube Mounting Design- Allows for quick sensor removal and
replacement- Dimension: Contained between
outermost 2 wing tip ribsUltrasonic Sensor (Maxbotix LV-EZ0)
- Range: 0 to 255 inches- Dimensions: 21.1 mm x 19.9 mm x 16.4 mm
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.
Objectives/Scope:- Measure real time position of test platform- Measure real time flight parameters- Ensure measurements are
accurate and reliable
Visit our wed page for more information and documentation:https://edge.rit.edu/content/P09233/public/Home
AIRFRAME MEASUREMENTS GROUPMEASUREMENTS BOX
Group MembersMichael 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
P092332008-3
& 4
Eagle Tree Velocity Sensor
GPS Zlog Altitude Sensor
Microcontroller Ultrasonic Altitude Sensor
The altimeters where tested against a calibrated pressure sensor to show their accuracy, based on repeatability and accuracy, the ZLOG altimeter was chosen.
GPS data was collected on a drive around the outer loop of RIT to shows it’s accuracy.
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.
IMUInertia Measurement Unit
Pitot Static Tube Mounting
Complete Measurements “BOX”
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Sp
ee
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Data Collection Event
Pitot Static Tube vs. Anemometer (Automobile Test)
Airspeed SensorAnamometer
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.
Box inside Airframe A
Measurement Box in Airframe A
and sensor mounted in the wing tip, both can be removed and replaced without complete wing disassembly.
Velocity Sensor
Pitot Tube
Pitot Tube Mount
Sensor and MCU Integration
Special Thanks to
&
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Alti
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Data Collect Event
Vacuum Chamber Simulated Altitudes
Zlog
Eagle Tree
Pressure Sensor
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Alti
tude
(Ft)
Data Collect Event
Vacuum Chamber Simulated Altitudes
Zlog
Eagle Tree
Pressure Sensor
MCU
BEC
PCGPS
Pitot Static Tube
Altimeter
IMU
JTAG
Altimeter Control
GPS Control
IMU Control
Serial
Serial
SPI
ADC
14.4V 5V
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Additional Electronics
Initialize MCU Peripherals.
SPI Initialized.UART0 and
UART1 Initialized.
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.
Initialize timers and setup
interrupt service routines.
The timers and ISRs are used to control the recording rate of the sensors.
Initialize the GPS.
GPSCommands 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.
AltimeterAn ASCII ‘L’ is sent through the UART to toggle the state of the Altimeter between on and off.
Initialize the SD Card.
SD CardCommands 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.
IMUThe 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.
Continuously Read GPS, Altimeter and IMU. Calculate speed, relative position and
heading from IMU.
Has timer reached 0.
Record Data from sensors to SD Card.
Yes
No
Enter while loop forever.
Initialize the Altimeter.
Initialize the IMU.