A mobile orientation sensor designed for tracking an object angular motion. Low cost, small dimensions, low power consumption, casing made of special plastic and an ability to operate within a wide temperature range makes  MAHRS-3D a perfect instrument for the purposes of determination and tracking the angular motion of objects, such as: humans, Head Mounted Displays, robots, positioning devices.

Operation of  MAHRS-3D is based on the integration of nine inertial sensing elements: three three-axis accelerometer, gyro, and magnetometer units. A sensor-embedded DSP designed for processing sensing element output allows tracking of angular motion for an object within a full angle range of 360 deg. Orientation update rate - 500Hz.  

Option for changing dynamic characteristics of Kalman filter and angular sensitivity. Software for elimination of magnetic deviations and course updating.

 

 MAHRS-3D is a small-scale angular orientation sensor. Operation within a full angle range of 360 deg in all three axes, low power consumption, integration of nine miniature inertial sensing elements by processing with an adaptive Kalman filter, algorithm for elimination of magnetic deviation and course updates. 

               Land Vehicle Control             

               Remotely Operated Vehicles

               Avionics System

               Platform Stabilization

               Robotics

 

 

Specification

 

 

 

 

 

 

 

                   

 

 

 

 

 

              1. Connection of the mini AHRS.

 

Fig1-1. MAHRS-3D connectors view. MAHRS-3D sensors have two 4-pin connectors, contacts of which are connected in parallel (1-1, 2-2, 3-3, 4-4)

 

Table 1-1. Pins layout: 

 

 

              2. Communications protocol.

              2.1. Physical level:

Standard:  TIA/EIA?485A (half-duplex)

BaudRate:  1 Mbps

ByteSize: 8 bits

StopBits: 1 bit

Parity:  No

 

The communications protocol is optimized to work with16-bit words. Each word consists of two bytes, the first byte is the least significant one, and the second one is the most significant one.

 

Table 2-1. Protocol transport level data:

 

 

 

If the pause between byte in packet is bigger than 10uS this packet will be ignored by sensor.

 

 

 

 

              2.3.Output data packets.

              2.3.1. Data in the Raw Data mode.

In this mode data is output without any processing, directly from the ADC.

 

Table 2-2. Raw data packet:

 

 

* Cntr is incremented each time the data packet is transferred; it can be used to control continuity of the sensor data stream.  

 

              2.3.2. Quaternion data. 

 

Table 2-3. Quaternion data packet: