The Austrian company Flux GmbH was founded with the aim of developing encoders and measuring systems based on new technologies that offer higher performance and flexibility than commercially available encoders. The GMI effect (Giant Magnetic Impedance) is a well-known physical phenomenon, but until now it has not been used for position determination. With Servotecnica, Flux has a competent partner for market development, application technology and sales.
The Flux founding team consists of experienced engineers who have decades of experience in the development and manufacture of encoders and measuring devices based on various physical principles. With GMI technology, they exploit the properties of the Giant Magnetic Impedance effect. This states that a GMI material changes its impedance when exposed to an external magnetic field. This has an effect on the so-called skin effect, which is caused by applying an alternating current in the GMI material. This allows a signal to be generated depending on the position between the sensor (GMI film) and the external magnetic field (measuring tape). Transferred into a practical encoder, this principle offers enormous added value for users and OEMs.
Advantages over previous absolute encoders
The GMI technology differs from previous measuring principles in that, among other things, no position hysteresis effects can be observed. In addition, the measuring principle works in a larger operating range and offers an excellent signal-to-noise ratio. This results in comparatively large mounting tolerances in combination with high resolution over the entire working range. In addition, the actual sensor technology is so compact that the encoder can be integrated even in the tightest installation spaces, for example in cobot joints. Furthermore, the frameless design of the encoder means that no additional parasitic friction is introduced into the system. Encapsulated systems, on the other hand, are usually much heavier and introduce additional static and rolling friction into the rotary axis.
Features of a holistic real-time encoder
The GMI encoder works holistically. This means that the sensor scans the measuring tape over the entire 360° of a revolution. In contrast to point scanning, the GMI encoder is therefore very robust against inaccuracies such as eccentricities or an offset between the sensor and the scale tape. As a real-time encoder, it also provides an initial position that is not dependent on a calculation time. The encoder is ready to transmit the current position to the controller immediately and without time uncertainty (jitter) with every position request. A real-time encoder from Flux thus offers the same accuracy at low and at very high speeds. This makes the encoders particularly suitable for applications that require speed or torque control.
Areas of application for Flux encoders
They can also be used as load and motor encoders for all kinds of robotic applications, such as compact and slim cobots. Equally practical are their advantages in slip ring and motor applications, for example in brushless DC motors or stepper motors. Here Servotecnica can benefit from the development cooperation. Machine tools or so-called "gimbals", which are intended to keep the moving camera steady in camera mounts and drones, are also optimal areas of application. The first market-ready versions of the FLUX encoders are already available on the market and are being used successfully in applications for position, speed and torque control.