25/07/20 01

New Gyroscope Family from Willow

Willow Technologies Ltd, the UK appointed distributor for Silicon Sensing Systems Ltd, now supply the recently developed CRS family of Single  Axis Silicon Vibrating Structure Gyroscopes.

The CRS family has evolved to satisfy the demand from developers of inertial systems that gyroscopes be smaller, more reliable and less  expensive.  This has resulted in a shift by gyroscope designers away from a purely mechanical approach towards solid state devices. The CRS devices are based upon the very latest manufacturing technologies with micro machined silicon components making-up the mechanics of the gyroscope.

The CRS devices work by making use of a phenomenon know as the Coriolis force – a force that is observed to act to a moving element in a rotating body. In operation, an innovative patented mechanical ring structure is made to oscillate by the application of an alternating force to the ring. When this oscillating body is placed in a rotating reference frame, the Coriolis force comes into play, producing a secondary oscillation orthogonal to the primary oscillating motion. Measuring the size of the resultant vibration provides an output signal proportional to the  rate of movement of the gyroscope.

The silicon ring used in the CRS gyroscopes is both small and light. Its low inertia means that when the structure containing the gyro is moved, the ring easily moves with it, providing very high resistance to shock (typically 200 g's 1 ms half-sine approx.).  Also, the silicon ring itself is relatively strong and very resilient, it does not fatigue in the same fashion as metal.

The gyroscope has been carefully designed so the silicon ring itself has no fundamental vibration patterns at low frequency.  All  fundamentals are high in frequency so that it is inherently insensitive to vibration and will operate in harsh environments (typically up to 2g rms 20 Hz to 2 kHz random).  The devices have an onboard Application  Specific Integrated Circuit (ASIC) which integrates the functions of the gyro control loop electronics and signal processing, providing a volts in – volts out sensor.  This approach enables techniques and technologies previously employed on earlier generations of Silicon Vibrating Structure Gyro's to be used at much lower cost.

The CRS family operate on 5VDC with an operational temperature range of –25 to +85 DegC with a typical scale factor of 12.75mV/Deg/Sec over the range +/-150deg/sec (for the CRS02-01-PS) and an MTBF of over 100000 hours conditions at 25 DegC.  Various specification and package configurations are available to suit individual customer requirements.

Applications include navigation systems, platform stabilization, remotely piloted vehicles and other related applications.