An INS/GPS Navigation System
with MEMS Inertial Sensors
for Small Unmanned Aerial Vehicles
56367 Masaru Naruoka
The University of Tokyo
1. Introduction and Background
2. Method
3. Numerical Simulations and Results
Introduction and Background
• Needs for a new navigation system of
small UAVs
– Small UAV
• About 1 m wingspan
• Easy operation
– Hope for Autonomy
– The existing ones = expensive, big, heavy
• What’s new? = Low cost, small, light
Method(1)
Navigation System for Small UAVs
•
Features
– Low cost
– Small
– Light
•
Unit
1. Inertial Navigation System (INS) with MEMS
inertial sensors
2. Global Positioning System (GPS)
Method (2)
INS with MEMS inertial sensors
MEMS
inertial
sensors
Low cost, small, light,
but low accuracy.
Position
Acceleration
Velocity
Angular ratio
Integrate
INS
Attitude
Method (3)
GPS and the Kalman Filter
INS
Position
Velocity
The
Kalman
Filter
Position
Velocity
Attitude
Attitude
GPS
High update ratio.
But,
high accuracy?
Position
Velocity
Numerical Simulations
• Sensor Model (1)
True
Value
• Sensor Model (2)
Not
Assumed
!
+
+
True
Value
Random
Drift
+
+
+
White
Noise
White
Noise
Ideal
More real
Results
Horizontal trajectory history
2576
Rotating
direction
Latitude [seconds]
2574
2572
True Value
under Sensor Model (1)
under Sensor Model (2)
Start
and
Goal
2570
2568
2566
2738
2740
2742
2744
2746
Longitude [seconds]
2748
2750
2752
Conclusion
• My new navigation system
– Low cost, small, light, fit for small
UAVs.
– A certain level of precision.
• Short term operation …
–good estimation.
• However, long term operation …
–Failed and error accumulation.
–Need to improve the algorithm.
Appendix (1)
Numerical Simulation Condition
• Whole simulation time = 240 sec.
• Rotating Radius = 200 meter.
• Sensor Model
– Accelerometer = ADXL202 (Analog Devices)
– Gyro = ADXRS150 (Analog Devices)
• Update Ratio
– INS = 50 Hz
– GPS = 1 Hz