23 Jul 2024


£100 encoder is an absolute rival

£100 encoder is an absolute rival

The technology developer Cambridge Consultants has come up with a novel, low-cost absolute positioning system (shown below) which, it says, could be used in applications where traditional linear encoders are too costly, too fragile or not accurate enough.

The technology, originally developed to solve the measuring problems of a CCL client, uses a compact optical head to read a digital scale that has been laser-marked onto the surface of a rod. As the read head moves along the rod, light from a pair of LEDs is reflected off the marked surface and the signals are interpreted using powerful DSP (digital signal processing) technology.

Dr Robert Jones, the CCL engineer who developed the technology, says that it can achieve a resolution of 1-5 microns and operate at speeds of up to 3m/s over lengths of up to 50m. He claims that the system can tolerate dirt and oil on the scale and can work with a signal-to-noise ratio of -5dB.

The client for whom CCL developed the positioning system previously used a magnetostrictive technology, which required holes to be drilled into the shaft being measured.

Jones says that most of the technology for the encoder system is commercially available off-the-shelf so that it could cost as little as £100 in volume production.