When explosive ordnance disposal specialists are out in the field, they must be able to rely on every movement of their equipment. The telemax PRO remote-controlled precision manipulator from Telerob is one of the most important tools for this purpose—compact, capable of climbing, and equipped with a 7-axis manipulator. To ensure it can move safely over stairs, obstacles, and uneven terrain, reliable position feedback is essential. This is where Novotechnik’s multiturn sensors come into play.
Why Multiturn Sensors Are Essential for Mobile Applications
In many mobile and industrial applications, conventional multiturn solutions such as gearboxes, potentiometers, or optical encoders are not ideal: they often require a constant power supply, have moving parts that are subject to wear, or are simply too large for compact designs.
The magnetic multiturn sensors of the RSM-2800 series therefore deliberately rely on a different principle:
- non-contact measurement
- absolute position data without a reference run
- Revolution counting even when the power is off
- no gearbox, no backup battery
This is made possible by the GMR (giant magnetoresistance) effect —a technology that, despite its precision, is extremely robust and resistant to harsh environments.
With a measurable range of 2 to 16 revolutions, a typical linearity deviation of less than 0.05%, and a total resolution of up to 18 bits via digital interfaces, these sensors are ideally suited for demanding robotics applications.
Seamlessly integrated: Multiturn sensors in the telemax PRO
The telemax PRO is designed for applications where a matter of millimeters can mean the difference between success and failure. The robot:
- can climb slopes up to 45°
- climbs over obstacles 500 mm high
- can move loads of up to 20 kg
- remains agile thanks to the high-speed version, which can reach up to 10 km/h
Its movements—from opening a suitcase to navigating through narrow rows of seats—are highly complex and must be precisely controllable. That is why each of the four drive axles is equipped with a multiturn sensor from the RSM-2800 series.
Since there is limited space in the compact chassis, the sensors were not mounted directly on the axle but instead on a small intermediate gear to save space. As a result, one rotation of the wheel drive corresponds to six rotations of the sensor —perfect for high-resolution position detection.
According to Telerob, this combination of precision and compact design was one of the key reasons for choosing the RSM-2800.
Storing rotation counts without power using the GMR effect
The core of the sensor consists of microstructured magnetic layers. The GMR effect causes the electrical resistance to change depending on the magnetic orientation—making it ideal for continuously measuring and storing revolutions, even when no power is supplied.
The benefits:
- The position value is retained even during a power outage
- No battery, no wear parts
- Output via, for example, SSI, SPI, or an analog interface
This means the sensor is ready for use as soon as the telemax PRO is turned back on.
Built for tough conditions
Out in the field, conditions can get wet, cold, or rough—but that’s no problem for the telemax PRO’s sensor drive. The RSM-2800 meets IP67 standards as standard, withstands shocks and vibrations, and operates reliably in fluctuating temperatures.
Additional benefits:
- high-quality, heat-resistant plastic housing
- Backlash-free quick-connect coupling for fast installation
- shielded, potted cable or M12 connector
- Easy adjustment via slotted holes
