LINEAR TWIIST Contactless Linear Position Transducer

2023 NED Innovation Award Winner

Improving machine designs and performance, TWIIST is a contactless linear position transducer in the Hall effect category that processes position data along with other process variables such as temperature, velocity, acceleration, and tilt angle due to its unique helical magnetoelectronic design.

TWIIST’s compact, air-tight design has a steel barrel with a diameter of 5/8 in. (16 mm), and it comes with a choice of two types of connection points, ball joints for swivel connections, and rod ends with eyes for pivot connections. Available in full-scale (FS) strokes from 50 to 900 mm, it has a typical linearity of 0.15% FS and a typical repeatability of 0.05% FS. It can operate in a temperature range from -40 to 185°F (-40 to 85°C). With an IP67 environmental protection rating, it offers complete protection against dust and airborne particles, as well as protection against water and other liquids when submerged up to 39 in. (1 m) deep.

TWIIST provides hydraulic and pneumatic cylinder feedback control, bending rolls parallelism control in metalworking machines, control of abrasive wheel positioning in marble and stone processing machines, and mechanical dancer position control feedback in packaging and labeling machines.

Currently, there are 3 models in the TWIIST product line: The LM-L (IO-Link), LM-C (CANopen), and LS-A. The LM-L (IO-Link) and LM-C (CANopen) transmit measurements digitally up to 1,000x/s. The LS-A has a mono-variable analog output (current, voltage, or ratiometric), as well as the redundant ratiometric version to support safety applications.

The TWIIST lends itself to an unlimited number of applications for mobile and industrial hydraulic systems. For example, when steering a vehicle using spatial inclination and acceleration, the TWIIST verifies, at each millisecond, if the ground is stable under the construction equipment and can alert the operator if there's a danger of unstable ground. All of this is directly on the steering axis, without any mechanical interference, or worse, mechanical play.

This transducer allows engineers to measure with just a single device as well as the ability to correlate the evolution of measurements over time. Depending on the machine, the application, and the goals of the engineer, the TWIIST can enable self-diagnosis, self-correction, and machine learning, including predictive maintenance.

This patented technology results from a decade-long partnership between Gefran’s internal R&D department and the University of Brescia’s engineering department in Brescia, Italy.