Posted to News on 30th Jan 2008, 20:44
Motion simulators designed for precision test applications
Aerotech's new ARMS series rotary motion simulators provide highly accurate angular rates, acceleration and position profiles for inertial component test systems and instruments. The new simulators include a choice of slip ring assemblies and rotary unions for interfacing with the unit under test (UUT) and are supplied with matched servo drives, motion controls and GUI motion design software. Users are able to generate or download complex rotary motion profiles and execute them with a velocity stability to 0.0001 per cent over 360 degrees for direct loads up to 170kg. The range is aimed at dynamic in-process testing of gyroscopes, MEMS sensors, accelerometers and other rate table applications requiring ultra-precise rotational profiling for use on avionics equipment, automobiles, and other ground-based vehicles and inertial platforms.
ARMS motion simulators are available in three basic models with nominal width and tabletop diameter of 146, 196 and 260mm. Each model includes a choice of two stack heights to accommodate Aerotech's high-torque S-series ironless and slotless direct-drive servomotors with peak torque from 11.7-146Nm. With no motor cogging, absolutely no torque ripple and zero backlash, the S-series allows smooth and precise speed control and peak acceleration in excess of 20,000 degrees per second.
Directly-coupled high-resolution rotary encoders and Aerotech's MXH series multipliers provide a selectable angular resolution within the range of 0.02 arc sec to 4 arc sec with a calibrated accuracy to within +/-5 arc sec and positional repeatability to +/-1 arc second.
High-precision rotary stages
ARMS motion simulators are based upon Aerotech's high-precision rotary stage technology as used in a wide range of high-throughput applications across manufacturing production, inspection and research markets. Dual large-diameter bearings provide impressive wobble and moment stiffness specifications and the low-inertia design allows acceleration and speed performance that is said to be significantly higher than competing manufacturers products.
The ARMS series includes integrated motion controls featuring DSP-based drives with up to 20kHz current and servo loop closure rates, ensuring the high levels of positioning performance and rate stability. The servo bandwidth value for an unloaded simulator is specified at >70Hz and the control system features a wide range of filtering and calibration features to ensure the broadest possible value. Aerotech is able to supply granite or composite machine base components and customer-specific fixturing to optimise the total system performance.
Users may directly program their own motion profiles in a standalone package or interface LabVIEW, C and .NET software. For users who have their own motion simulation programs, Aerotech's GUI motion design software accepts files with arrays of velocity, position and acceleration versus time.
To provide electrical services to the UUT, ARMS motion simulators are fitted with a choice of standard or low-noise slip ring assemblies, with the number of ways determined by the model diameter. The full range covers up to 96 ways with a current rating of up to 2A with convenient Sub-D connectors fitted to the rotating tabletop and fixed base parts of the simulator. Up to two rotary joints for air, vacuum or hydraulics may also be specified with compression fittings supplied. To complete the straightforward commissioning of the ARMS series, motor power and feedback connectors are also fitted and mating cable assemblies supplied to order.
Each ARMS tabletop has a black anodised finish and a 62 Rockwell hardness coating; also included are engraved markings and a matrix of metric threaded holes (imperial versions are also available). The fixed platform also includes ample though-holes and T slots in the base and sides. Each model includes a clear aperture (either 8 or 25mm diameter) which is used for the rotary joint and some slip ring variants, therefore for certain applications the aperture may be available for the customer's own services.
