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GPS/INS Test and Verification Facility

GPS/INS Test and Verification Facility . The inner rotational axe in the climate chamber . Rotary table ACUTRONIC AC3347

Inertial sensors (rotational speed and acceleration sensors) are – on their own or in combination – the basis of many navigation systems. Before implementing such measurement devices it is necessary to test the functionality and quality of the sensor technology when combined with the entire navigation system. The GPS/INS facility was set up at DLR Bremen in 2009 to test and verify in-house devices. The facility is also available for external users and a DIN ISO certification is being prepared.
The facility consists of a Spirent GSS7700 GPS-simulator connected to an ACUTRONIC AC3347 rotation table to test GPS-supported inertial navigation systems, as well as other precision measurement devices for 3D coordinate evaluation and optical direction measurement.
The rotation table stimulates inertial sensors which can be calibrated by setting profiles of rotational speed. An integrated thermal chamber allows testing under defined temperature conditions and verification of temperature dependences in the sensor technology.
In addition to 30 electrical supply and signal lines, the rotation table’s inner platform offers a port for the GPS-antenna signal, provided via the GPS-simulator. Using the real time capable data interface SCRAMNet+ via a dSPACE-system, the rotation table can be embedded into hardware-in-the-loop testing.

Possible Services

• Inner calibration of rotational speed sensors within a thermal chamber, determination of offset, scale factor, noise, drift, rotational speed limits, dynamic and their temperature dependence
• Alignment measurements between several rotational speed sensors or for optical / mechanical references (case or mirror)
• Testing and calibrating of GPS-receivers
• Flight path simulation for rotational speed sensors and GPS-receivers using pre-set trajectories
• Hardware-in-the-loop tests via a real time capable dSPACE-system
• Thermal testing between -50°C and +80°C
• Calibration of angle and inclination of the measurement system

GPS-Simulator Spirent GSS 7700

• 4-32 channels
• GPS L1 supports C/A + P Code + M-Noise
• GPS L2 supports C/A or p Code + L2C + M-Noise
• GPS L5 supports L5 I and L5 Q
• Complete flexibility through SimGEN software
• Real time remote control and simulated flight path for hardware-in-the-loop
• Output of different RF signal L1/L2
• Interference of up to 16 channels on L1 band

Rotary Table ACUTRONIC AC3347

• Continuing rotation around three axes with max. 1000°/s
• Max. rotational speed acceleration between 400 and 30000°/s²
• Orthogonality errors of each axis <3 arc seconds
• Rotational speed solution 0.0001°/s
• Temperature stabilization through climate chamber with CO2 cooling between -50°C and +80°C
• Connection over SCRAMNet+ to the real time simulation platform dSPACE
• 450m diameter of inner rotary plate
• 15kg specific test object weight
• GPS antenna line and other electric connections on the rotary plate