telephone icon

Call +44 (0) 1342 717102


Willow Technologies New Fiber Optic Gyro Simplifies Measurement of Dynamics of High- performance Vehicles


FOG-IMU Developed Specifically for Vehicle Dynamics Testing

Willow Technologies today introduced the VG600AA series, a solid-state sensor subsystem designed by Crossbow Technology Inc.,  specifically for demanding automotive dynamics testing. The unit simplifies the measurement of high-performance vehicle dynamics by hooking into the serial port of any standard PC or laptop.

The VG600AA's embedded software provides navigation frame acceleration data for easy analysis which allows test engineers to evaluate the performance of their vehicles quickly by minimizing their test setup time.  The VG600AA has proved a more reliable system than traditional spinning mass gyros and runs off a 10 -15Vdc power supply for easy hook up to automotive power. The unit is easy to set up and is ideal for auto manufacturers and their suppliers for use in proving ground testing.

Utilizes Latest Solid-state Technology

The VG600AA utilizes the latest in silicon micro machined (MEMS) technology and proprietary digital signal processing  (DSP) algorithms.  It is a highly reliable replacement for older mechanical vertical gyros. While mechanical sensors have a MTBF (meantime between failure) as low as 500 hours, the VG600AA has much higher reliability with a MTBF of over 50,000 hours, with no moving parts to wear out.

The VG600AA consists of three fiber-optic rate sensors, a three-axis accelerometer, a temperature sensor, a 16-bit analog-to-digital converter, a high-performance DSP and EEPROM, all packaged in one small (6" x 5" x 4") aluminum housing. The fiber optic gyros used in the VG600AA provide several advantages over other gyro sensors including high  bandwidth, small size, light weight, geometric flexibility, inherent immunity to electromagnetic interference (EMI) and corrosion resistance.

The principle behind the use of fiber optics is that by measuring changes in the light exiting the optical fiber, the property of the environment that caused the change in light can also be measured. In highly dynamic environments or in applications that require high accuracy, the VG600AA provides a better result than Coriolis sensor-based IMUs. Fiber optic gyros provide angular rate and rotation sensing for applications that require great accuracy over long measurement periods, making them ideal for use in automotive testing.

Proprietary Software Eases Testing

With its DSP technology, proprietary algorithms, and embedded software, the VG600AA provides a complete solution. Sophisticated DSP software calculates instantaneous angle from the rate sensors and uses the accelerometers to correct for drift and to provide a gravity reference, resulting in functionality equivalent to the traditional mechanical vertical gyro. The VG600AA provides stabilized roll and pitch output with an instantaneous initial erection rate compared to the traditional spin-up of several minutes.

The embedded software provides instant navigation frame acceleration data for easy analysis. This specially designed software in the VG600AA provides the data in a way that is easily understood and much more useful for automotive testing. This minimizes test setup time and lets test engineers quickly evaluate the performance of their vehicles.

A Complete Solution

Several manufacturers offer parts of the sensor solution, such as the MEMS ICs and individual FOG rate sensors. The  Crossbow unit integrates these components into a subsystem that is complete with algorithms programmed into the firmware. The VG600AA is packaged in an aluminum housing measuring 6" x 5" x 4" and weighing 50 oz.

Willow Technologies Ltd. Unit 3 Borers Yard, Borers Arms Road, Copthorne, West Sussex, RH10 3LH, UK

Tel: +44 (0) 1342 717102, Fax: +44 (0) 1342 717014, Email: