Navsight Solution
– Hardware Manual
NAVSIGHTHM.1.5
2.1. System
The following diagram shows the basic organization of the Navsight solution. Internal GNSS receiver is
optional.
The RS-485 link between IMU and processing unit allows secure and long distance communication
(e.g. 50 m).
2.2. IMU
The IMU is the main component that will drive the overall system performance. Several IMU configurations
are proposed to address different applications requirements.
2.2.1. Ekinox IMU
Ekinox IMU has been designed to deliver an exceptional performance in a very compact and cost effective
package. Ekinox IMU integrates low noise gyroscopes. The integrated accelerometers are ultra low noise and
highly efficient in vibrating environments due to a low Vibration Rectification Error. Sensor specifications
are listed below.
2.2.1.1. Accelerometers
A2
A3
Remarks
Full scale (
g
)
± 8
± 14
Velocity Random Walk (µ
g
/√hz)
7
40
Allan variance – @ 25°C
In run bias instability (µ
g
)
2
10
Allan variance – @ 25°C
Vibration Rectification Error (µ
g
/
g
²)
<200
<50
VRE – 20 Hz – 2 kHz
Bandwidth (Hz)
433
433
Attenuation of 3 dB
Orthogonality (°)
< 0.02
< 0.02
Over temperature range
9/73
Figure 2.2: Navsight simplified block diagram
Sensors sampling &
Calibration
Coning & Sculling
integrals @ 1 kHz
EKF and output
@ 200 Hz
IMU
Processing Unit
3 Axis
Gyroscopes
3 Axis
Accelerometers
CAN
RS-232/422
GNSS*
Aiding Equipment
»
Dual Antenna GPS, GPS/GNSS, RTK
»
Odometer, DVL
ETHERNET
RS-485
