Research And Design Of Industrial Robot Controller Based On EtherCAT

In order to meet a variety of manufacturing process, the openness requirement of industrial robot controller system have become increasingly. Controller system is required to support various types of input and output, different configurations, and a variety of control tasks; allows the increase or decrease of functional modules, making it easier to integrate and extend. The other hand, most industrial robots used in arc welding, assembly, cutting, contour tracking accuracy and algorithms repetitive demanding field, controller system needs to have strong real-time. Some complex tasks only by a single robot has been difficult to accomplish, you need a multi-robot system to a certain degree of coordination and cooperation to complete together,so distributed control is the development direction of the industrial robot controller system.In this paper,considering the current controller’s shortage in openness, real-time and distributed,through research and analysis on the controller structure, this paper addresses a architecture of industrial robot controller based on the Real-Time industrial Ethernet Fieldbus EtherCAT. To make the controller with higher reliability and stability, the system uses the embedded microprocessor ARM (advanced RISC machines) as the core hardware, and the system’s software is based on the strong real-time kernel:μC/OS-Ⅱ,divided the robot operation to multi tasks and complete by priority scheduling.The system uses hierarchical structure and modular design concept,communicate with EtherCAT protocol, to complete an basic industrial robot communication platform.This controller system completed a ethernet communication performance test based on a6-axis welding robot body, which can simultaneously control6axis simultaneous movement, communication servo cycle within2ms, the EtherCAT synchronization between the slaves accuracy of256ns, between master and slave using simple synchronization algorithm, frame loss rate is less than1/100000, it has meet the basic requirements of the industrial robot communication, the latter will gradually improve its performance and implementation of upper layer application software, and strive to achieve practical application level.