Drive and control technology for a machine to manufacture reinforcement steel mats

16. April 2019

Moving heavy loads highly dynamically

Mashtronics approaches this task using servo drives, inverter drives and a powerful machine control system from Yaskawa.

The exterior of the inconspicuous production hall of Mashtronics D.O.O. reveals nothing of the type of specialists at work inside: The Serbian mechanical engineering company develops and manufactures systems for the automated processing of wires, primarily for customers in Eastern Europe and North Africa. The company was on the quest for drive and control components that meet equally high standards in terms of precision, quality and throughput for a new machine to manufacture reinforcement steel mats. It found what it was looking for at Yaskawa. When it came to recalculating parameters such as torque and transformation ratio, the assistance provided by the Serbian Yaskawa partner Tipteh was also a decisive factor.

The automated processing of wires – be it straightening, cutting, weaving, bending or winding – is complex and places unique demands on the machines used. The Serbian company Mashtronics D.O.O. specializes in just this: The mechanical engineering company supplies systems to the whole of Eastern Europe, as well as some North African markets, from Mladenovac, some 40 km south of Belgrade. 

Founded in 1999, the company's recipe for success lies in its ability to provide sophisticated technology that meets European standards at comparatively low prices. A crucial element of this strategy is the use of powerful drive and control technology. Since 2014, Mashtronics has been working together with an experienced partner of Yaskawa in this area: The automation specialist Tipteh d.o.o. is headquartered in Ljubljana, Slovenia and has subsidiaries in several countries in South East Europe, including Serbia.

Wire processing machines are continuously being optimized to further increase their productivity – and ultimately to achieve higher prices. In this case, productivity means that the machine must ensure higher cycle rates while still ensuring the same level of – or even higher – precision. As a product, wire has two characteristic requirements: The material to be moved is very heavy. And it has to be unwound and wound up in production.

In a new steel wire cutting machine, the Mashtronics engineers have responded to these requirements using drive and control components from Yaskawa. The idea is then to also use these components in other applications, such as in wire bending machines. As part of the cooperation with the Serbian partner Tipteh, parameters such as torque and transformation ratio were also recalculated. This resulted in a clear increase in productivity compared with its predecessor model.

Sigma-5 servo drive system

The precise and rapid movement of the wire is ensured by servo drives from the Sigma-5 series, which are integrated in the complete solution using, for example, PROFINET or CANopen. The Sigma-5 servo system range from Yaskawa contains servodrives consisting of servomotors, servo amplifiers and a powerful SigmaWin+ engineering tool. The range includes rotary motors, direct drives and linear motors. The standard models guarantee both faster positioning times and high positioning accuracy of less than 1 µm. 

To help integrate the system into comprehensive automation solutions, there are – in addition to PROFINET – modular interfaces for EtherCAT, CANopen, POWERLINK and MECHATROLINK II and III. Thanks to an auto-tuning function and an automatic filter function to suppress vibration, the system continues to function quietly and with a minimum of vibration even at low speeds. Optimal operation is therefore guaranteed even for high-precision applications. At the same time, machine wear is reduced. This has a positive effect on subsequent costs.

Sigma-5 components can be started up and diagnosed quickly and easily using the user-friendly SigmaWin+ software. Manual settings and specialist technical knowledge are not required. For example using the auto-tuning algorithm, two axes can be accurately configured in high performance machines in less than two hours, instead of the normal eight.

V1000 inverter drives 

Irrespective of whether a wire is to be wound up or unwound, the control and drive technology is required to perform complex tasks. For example, the roll diameter is permanently changing, meaning that the speed and torque of the motor have to be adjusted to ensure a constant tension of the material web. In the machine designed by Mashtronics, a V1000 inverter drive is responsible for this task.

The V1000 inverter drive series from Yaskawa provides a reliable and efficient solution for the safe and accurate control of permanent magnet motors. With its highly dynamic open-loop vector control, the inverters provide the optimum choice for driving both asynchronous and permanent magnet synchronous motors in the output range from 100 W to 15 kW. 

Launched as the smallest compact inverter drive in the world, the V1000 is characterized by an extremely small footprint. In addition to its compact dimensions, it is also suitable for side-by-side installation, i.e. for mounting several devices directly alongside each other. This means that the inverter drives take up even less space in the switching cabinet. A patented hybrid cooling element made from a special alloy compensates for the reduced ventilation effect, thus preventing the inverter drives from overheating. 

An integrated dual rating function means that the inverter drives can work at 120 percent overload in normal duty mode in applications that require low overload. This means that a comparatively smaller inverter drive is able to perform the work for which a larger drive would otherwise be required. Moreover, the braking resistor unit reduces the deceleration time by around 50 percent. Finally, the V1000 allows a rapid response to changes in load and speed, thereby optimizing the machine performance.

MP2600iec machine control system

The processes in the machine are controlled by a MP2600iec control system. This module designed for 1.5-axis applications can be plugged directly into the Sigma-5 servo amplifiers. Based on PLCopen Motion, its IEC development interface ensures simple, fast, and user-friendly programming in accordance with the IEC 61131-3 standard.

The machine control system is particularly suited to independent sub-machines in modular, mechatronic machine architectures. The integration of motion control functions, PLC and drive control in one assembly enables complete sub-machines to be automated.

The MP2600iec 1.5-axis controller is part of the MP2000iec controller range, which is chiefly used in multi-axis applications. MP2600iec is used to beneficial effect in 1.5-axis applications such as winders, cross cutters, flying saws or print mark/register control, labeling and cam disks. The sub-machine that is automated using the MP2600iec motion module receives the guide value from a master encoder and synchronizes its slave axis to this guide value. The modular design means that the sub-machines can be tested and put into operation individually.

The MP2600iec motion module is suitable for communication with Ethernet I/P, Modbus TCP, OPC server and via web browser. In addition to the master encoder input, it has eight digital inputs and eight digital outputs and one analog input and one analog output. All integrated inputs and outputs can be programmed freely.

In conclusion

Machine wire processing primarily involves moving large loads precisely and at high throughputs. In a recent new development for the production of reinforcement steel mats, the Serbian mechanical engineering company Mashtronics approaches this task using servo drives, inverter drives and a powerful machine control system from Yaskawa. The result is a clear increase in productivity.