Investigation of different module structures of motion-controller for multi-axis systems

Kurzfassung

The development of mechatronic multi-axis systems such as robots presents engineers with complex tasks. Especially the hardware design and the development of a control strategy is complicated. To overcome these challenges, an approach of two different Ethernet-for-ControlAutomation-Technology (EtherCAT) based motion-controller drive nodes with real-time development interface is presented and examined in this thesis. A modular hardware approach is used to adapt to single-drive and multi-drive nodes and different motor types. Within the nodes, the low-level Serial Peripheral Interface (SPI) bus is used. Each motion-controller node is equipped with a speciffcally developed SPI data protocol and control loop. While the control loop of the single-drive node is completely implemented in MATLAB/Simulink, the multi-drive node has a divided control algorithm. Besides, the read-in of sensor data is changed to fit the hardware and software structure of each EtherCAT node. Commissioning has shown that the implemented differential SPI bus leads to loss of the last two Bit per data package. The testing and investigation of the two different motion-controller are documented with oscilloscope measurements and pictures. It has been shown that synchronization of the EtherCAT communication is necessary to ensure cyclic data transmission. The analysis has also shown that the division of the speciffcally developed SPI data protocols and control loops lead to identical behavior. As a result, the single-drive and multi-drive node can be implemented into complex mechatronic multi-axis use cases.