Decentralized Servo Drives for Industrial Robotic Automation

Murrelektronik, a global provider of automation and installation technology, focuses on decentralized system architectures for machine builders. Traditional industrial robotic systems rely on centralized architectures, where robot controllers and servo drives are housed within a control cabinet. This conventional setup requires dedicated power and feedback connections for each motor, resulting in extensive cabling, significant installation effort, and large cabinet space requirements, which limits the flexibility of modular machine designs. To overcome these limitations, the company sought to extend decentralized automation principles into robotics, creating a practical reference for future machine designs.

Integration of decentralized motion control
In collaboration with Danfoss and autonox Robotics, Murrelektronik developed an application test case using a 6-axis industrial robot designed for material handling, assembly, dispensing, and welding. The project utilized a decentralized motion platform where the servo drives and motors are combined into a single compact unit. By mounting these integrated servo drives directly onto the robotic arm, the need for conventional cabinet-based servo installations is eliminated. A single power supply module with an integrated decentral access option board powers all the decentralized drives through daisy-chain cabling. This architecture brings control, power distribution, and input/output interfaces closer to the machine level.

Safety and precision requirements
The engineering team required a platform that offered high-precision dynamic motion control, functional safety, and open communication protocols. Advanced safe motion functions beyond basic safe torque off were necessary to ensure operator safety without compromising machine productivity. "We evaluated the market for a decentralized servo solution, and the integrated drive was an excellent fit for our concept," states Marco Bosch, Global Head of Solution Engineering at Murrelektronik. "We need advanced safe motion functions that allow us to combine flexibility, productivity, and machine safety." The selected platform utilizes silicon carbide modules for optimized thermal efficiency and supports multiple industrial communication protocols, facilitating seamless integration into the existing programmable logic controller environment.




Reduction in cabling and cabinet space
Following a six-month collaborative engineering period, the resulting architecture provided a scalable, fully operational blueprint for modular machine designs. The direct installation of servo drives on the robot structure entirely removed cabinet servo drives, reducing the control cabinet footprint by 60 percent. Furthermore, the implementation of daisy-chain wiring decreased total cable length by up to 80 percent. This reduction lowers overall cabling costs and creates a cleaner, more compact machine structure, providing system integrators and equipment manufacturers with a verified method for implementing decentralized motion control in robotic applications.

Edited by Maria Brueva, Induportals editor – adapted by AI.

www.murrelektronik.com