TwinCAT 3 NC I for robot-based polishing and grinding machines

June 22, 2021 8:25 pm

PC-based control technology from Beckhoff is flexible and enables convenient programming of even complex algorithms.

PMA Pacific is committed to replacing traditional manual grinding processes in the Chinese sheet metal industry with cutting-edge solutions. The company’s vision involves promoting environmentally-friendly and efficient automated polishing solutions and providing more customised sheet metal grinding solutions. This goal lent itself to abrasive belt grinding machines from Peitzmeier Maschinenbau, which incorporate the entire Beckhoff range of PC and EtherCAT-based control and drive technology – especially TwinCAT 3 NC I software.

PMA Pacific Machinery Company Limited (PMA Pacific) was founded in August 2015 and is located in the modern China-Singapore Suzhou Industrial Park. The company is the production centre, service base and sales headquarters of abrasive belt grinding machines from German company Peitzmeier Maschinenbau GmbH in the Asia-Pacific region. The product range covers standard machines and customised solutions for processing workpieces such as cases and cabinets, covers for kitchenware and parts for food and drug machinery or packaging machines.

Especially in the food and pharmaceutical industries, a finely polished, high-quality surface also means a lower risk of contamination. Manual grinding is highly labour-intensive in this respect and can also pose health risks due to the large amounts of metallic dust generated. Consistently high grinding quality and efficient grinding processes are thus only achievable by increasing the level of automation – even with smaller batches down to lot size 1. The new generation of polishing and grinding machines is ideal for this purpose. Based on PC Control and TwinCAT as well as robotic technology, they enable automated grinding, reduce labour costs and improve grinding efficiency.

Hardware architecture for high precision and dynamics

PMA Pacific already uses PC-based control in its conventional machines. Now TwinCAT automation software will also be used for the programming, teaching and operation of newly developed robot-based polishing and grinding machines. PMA Pacific General Manager, Yue Yang Zhu explains, “PC-based control technology from Beckhoff is flexible and enables convenient programming of even complex algorithms. TwinCAT offers an extensive range of functions to meet the general requirements of polishing and grinding machines. PC-based control and TwinCAT especially offer excellent real-time performance and can therefore also achieve complex motion control. The comprehensive Beckhoff product portfolio includes all the required automation components, from EtherCAT I/Os to servo drive technology through to complete control systems.” The automation system of the new abrasive belt grinding machines consists of a high-performance CX2020 Embedded PC and a CP2915 multi-touch Control Panel, as well as the powerful AX8000 multi-axis servo system and AM8000 servomotors. In addition, TwinSAFE components have been integrated into the complete system to ensure optimum machine safety.

The X-axis and Y-axis of the integrated robot adopt the gantry axis structure. The ABC axes each have a servomotor plus the Z-axis of a grinding head to construct a straight line and rotating motion with six degrees of freedom. The modular, EtherCAT-based AX8000 compact drive combines high-performance FPGA technology with multi-core ARM processors. FPGA-based control algorithms with multi-channel current control technology enable sampling and response times of less than 1 is to regulate current and speed control cycle times of as low as 16 μs – depending on the configured switching frequency. The requirements of a wide motor regulation range and highly dynamic robot actions can therefore be fulfilled optimally.