Laser Welding System for EV Batteries Hits Top Speed in Production Using PC Control and OPC UA
The BLS 500 from Manz AG uses flexible automation tech from Beckhoff to deliver highly precise and efficient production of lithium-ion battery modules for the electromobility sector
The electric vehicle (EV) market keeps accelerating, and it doesn’t brake for inefficient manufacturing processes. Producing lithium-ion battery systems, for example, demands solutions that balance high throughput and precision with flexibility for rapid market changes. So Manz AG designed the Battery Laser System (BLS) 500 laser welding system specifically to rise to this challenge.
The BLS 500 allows individual battery cells to be contacted with extreme precision so the individual cells form reliable EV battery modules. To ensure high efficiency, Manz developed a graphical programming tool and a virtual commissioning tool in-house and leveraged fast PC-based control technology and system-integrated OPC UA communication from Beckhoff.
Based in the German city of Reutlingen, Manz is a global, high-tech engineering company that focuses on production solutions for electromobility, battery production, electronics, energy and medical technology. The company’s portfolio ranges from customized single machines for laboratory production or pilot and small series production to standard systems and turnkey lines for mass production.
With such a broad portfolio, Manz has particularly high requirements regarding the flexibility and performance of their automation technology. This is clear in the production equipment for lithium-ion battery cells, battery systems and capacitors, to name but a few examples.
Customizable laser platform accelerates battery cell contacting
A prime example of Manz’s capabilities is the new BLS 500. The machine provides a flexible platform for the various laser processes used in manufacturing lithium-ion batteries. Starting from a standardized machine base, it can operate individually as a single system where the workpiece is loaded manually or as part of an integrated production line to achieve high-precision laser welding, along with laser cutting and drilling or partial material removal.
In one BLS 500 application, a battery module consisting of round battery cells is inserted into the machine manually in a laboratory scenario, but otherwise this is an automated process. The individual cells are then welded to the contacting elements by laser. As a graphical programming tool, the Smart Laser Assistant uses the CAD data of the underlying battery module to create the associated recipe. That is, it determines the optimum path calculation for all welding points and the appropriate laser power in each case.
This approach offers clear application advantages, according to Stephan Lausterer, Head of Software Core Design and Product Development at Manz. “Our programming tool makes it much easier to adapt the BLS 500 to diverse applications, for example, to different cell types and module formats,” Lausterer explains, adding that the result can then be conveniently examined in Manz’s virtual commissioning tool.
“Commissioning is accelerated and simplified by the fact that using the model, the control program can be tested in detail and realistically in advance, i.e., before the machine has actually been mechanically assembled,” Lausterer says. “In addition, high precision is achieved by using image processing to compare the CAD data of the battery pack with real-life data and to take any offset values into account during the welding process. In all these aspects, we benefit from the TwinCAT control software with its convenient and powerful OPC UA integration.”
PC-based automation drives EV battery production forward
The importance of high-performance and, above all, flexible control technology has also increased significantly at Manz in recent years. This emphasis ultimately led to the partnership with Beckhoff, which has resulted in many successful projects over the past decade.
“Originally, Manz developed its own control technology; however, this became increasingly difficult due to the growing relevance of electronics in mechanical engineering and the exceptionally fast innovation cycles in this field. We therefore went in search of a suitable specialist as a new control supplier,” Lausterer says. “In a corresponding benchmark, PC-based control proved to be the optimal solution, in particular due to the PC-based concept and the flexible, open, and finely scalable system architecture. In addition, there was the innovative strength of Beckhoff – a factor that we regarded highly even back then.”
Tilman Plaß, automotive industry manager at Beckhoff, adds the following from an automation perspective: “The high requirements of the Manz systems can be met very well with PC-based control. These requirements include the short cycle times that can be achieved with our control technology as well as a logic that covers all processes throughout the application, an aspect that promotes speed especially during format changeovers. The comprehensive functionality of TwinCAT up to OPC UA communication results in further advantages – and on both sides. For example, as a very early user of TwinCAT 3, Manz was able to provide us with important user feedback as part of our partnership.”
A C6030 ultra-compact Industrial PC (IPC) serves as the control hardware core of the BLS 500. “The C6030 is ideally suited to applications like this with limited installation space,” Lausterer says. “In addition, the computer equipped with an Intel® Core™ i7 CPU provides sufficient computing power for both machine control and visualization. This also holds true for future requirements, especially since Beckhoff is gradually integrating powerful new processor generations and – with the C6032 – also has a compact device variant with more interfaces in its portfolio.”
Such a versatile industrial PC also makes sense for Manz from another perspective, Lausterer explains: “Purchasing and warehousing are significantly simplified as a result. The same applies to the entire test tool chain for hardware and software, something which is hugely important to us at Manz. Accordingly, all the software is tested on virtual machines as well as on the real hardware.”
All in all, the TwinCAT automation software meets Manz’s requirements very well. “Among other things, we benefit from the integration of TwinCAT into Microsoft Visual Studio®. Our software team also includes high-level language programmers,” Lausterer says. “Added to this is the overall high level of flexibility, for example with the editors for the respective programming languages and through the variety of functions up to Safety Editor, TwinCAT Scope and TwinCAT HMI. In our view, this level of integration is a unique selling point of TwinCAT.”
In addition, motion control can be programmed and simulated very conveniently in C++ and with the TwinCAT 3 NC PTP, NC I and Kinematic Transformation packages. It can then run as a TwinCAT Component Object Module (TcCOM) in the real-time context. In addition, the TcCOM concept makes it easier to reuse program code and provide exceptional intellectual property protection.
OPC UA drives secure and continuous higher-level communication
Beyond fast EtherCAT communication at the field level, Manz relies on data exchange via OPC UA throughout the BLS 500. The TwinCAT 3 function OPC UA (TF6100) enables these capabilities. It offers functionalities that include the transmission of camera images to the HMI, integration into higher-level systems and cross-control communication.
The virtual commissioning tool also exchanges data with the TwinCAT controller via OPC UA. “The scope of OPC UA communication is very impressive,” Plaß says. “Manz recognized the advantages of standardized, secure and vendor-independent communication early on and uses the TwinCAT OPC UA server and client at a considerable scale and with high performance.”
These capabilities make the TwinCAT OPC UA solution indispensable, Lausterer notes: “Almost all external communication runs via OPC UA, both for our Industry 4.0 products and for customer applications. For third-party components that do not support OPC UA, we can use the TwinCAT 3 function TCP/IP (TF6310) or XML Server (TF6421). All these options demonstrate the high level of system openness offered by PC-based control.”
In addition to manufacturer independence, IT security is an important aspect for Manz. Here, OPC UA offers the clear advantage that the corresponding security mechanisms are already integrated into the communication stacks, so the necessary security capabilities are built-in right out of the box. Lausterer expects this topic will become increasingly important in the future – and not just in battery and EV manufacturing applications.
Another benefit is that Beckhoff as an early adopter has already implemented an OPC UA client on the control side at a very early stage, according to Plaß. “All the way back in 2014, Beckhoff had already presented an application scenario of TwinCAT 3 using the SOA (service-oriented architecture) PLC,” he explains. “This concept combines logic functions and OPC UA services for data-consistent, secure and standardized communication.”
Ready to recharge your battery and EV manufacturing systems with powerful industrial automation tech? Contact your local Beckhoff sales engineer today.
Jörg Rottkord, global automotive industry manager, Beckhoff Automation