Demo shows how secondary encoders can enhance cobots
3 February 2025 
On its stand at the recent SPS exhibition in Germany, the encoder-maker Heidenhain was demonstrating how secondary encoders can not only improve the accuracy of cobots (collaborative robots) but also provide collision monitoring without needing additional torque sensors. By watching a force gauge, visitors could see how the robot stayed within defined force thresholds and could switch off automatically when the exerted force exceeded 100Nm – a critical limit for collisions between cobots and humans.
Heidenhain argues that cobot manufacturers can improve the absolute position accuracy of their robots significantly by adding an accurate angle encoder on each robot axis. Mounted downstream from the gear system, these secondary encoders measure the actual position of each robot joint.
The modular encoders, with scale drums or measuring ring and separate scanners, are ideal for large shaft diameters and challenging installations.
Modular devices that can serve as secondary encoders include the robust WMRA inductive angle encoder from Heidenhain’s AMO brand, and the new MCR 16 angle encoder from the RSF brand, which provides optical scanning with improved signal quality for measuring absolute positions on large-diameter axes.
In another demonstration, Heidenhain was showing how three different encoders on a measuring arm can transmit position, sensor and monitoring data over just four wires with a cycle time of 30µs using the EnDat 3 data interface in bus operation. The benefits include reduced cabling, functional safety and extensive diagnostics.
Heidenhain: LinkedIn
