AHRS-II-P

The Inertial Labs Attitude and Heading Reference Systems, AHRS-II is the next generation of enhanced, highperformance strapdown systems that determines absolute orientation (Heading, Pitch and Roll) for any device on which it is mounted. Orientation is determined with high accuracy for both motionless and dynamic applications.

The Inertial Labs AHRS-II-P utilizes Tactical-grade IMU: 3-axes each of precision accelerometers & gyroscopes and Ultra High precision, gyro-compensated, embedded Fluxgate Compass to provide accurate Heading/Yaw, Pitch and Roll of the device under measure.

Integration of gyroscopes’ output provides high frequency, real-time measurement of the device rotation about all three rotational axes. Accelerometers and Fluxgate magnetometer measure absolute Pitch, Roll and magnetic Azimuth at AHRS initial alignment as well as providing ongoing corrections to gyroscopes during operation.

KEY FEATURES AND FUNCTIONALITY

• State-of-the-art Kalman Filter based algorithms for different dynamic motions of UAV, Aircrafts, Helicopters, Vessels, Ships, ROV, UUV, Robots, UGV, AGV, Gimbals and Antennas
• Highly accurate, sensitive, and temperature stable Fluxgate magnetometers (in-house technology)
• Input from External GNSS Receiver;
• 0.6 deg Gyro-Stabilized Heading and 0.08 deg Pitch & Roll Dynamic Accuracy over operational temperature range
• 1 deg/hr gyroscopes Bias in-run stability
• 5 μg accelerometers Bias in-run stability
• Suitable for Primary Attitude Reference and as Motion Control System for marine applications
• Embedded 2D and 3D magnetic calibration on hard and soft iron
• RS-232, RS-422, and CAN 2.0 interfaces
• Full temperature calibration of all sensing elements
• Up to 200 Hz data update rate (AHRS) and 2000 Hz data rate (IMU)
• Compact design. Environmentally sealed (IP67)

One of the key elements to the success of Inertial Labs AHRS-II is its use of Inertial Labs 8mm Fluxgate Magnetometers, which have distinct advantages over commonly used magneto-inductive or magneto-resistive magnetometers. In operation over time and temperature fluxgate magnetometers have superior stability and repeatability. In terms of sensitivity, fluxgate magnetometers provide up to two orders of magnitude increased sensitivity.

In addition to the performance advantages, unlike the chip-level magnetometer technology, fluxgate magnetometer technology has been depended on for over 70 years to provide an accurate reference to North. It remains the most reliable magnetic sensor technology for determining an object’s heading.

AHRS-II-P key specifications summary

Heading static accuracy:  0.3 deg
Heading dynamic accuracy: 0.6 deg (gyro magnetic)
Heading dynamic accuracy: 0.1 deg (with GNSS input)
Pitch & Roll static accuracy: 0.05 deg
Pitch & Roll dynamic accuracy: 0.08 deg
Gyroscopes Bias in-run stability: 1 deg/hr
Accelerometers Bias in-run stability: 0.005 mg