Networking Machine Tools with the Internet of Things

Two trends have recently shaped the machine tool market: First, the number of axes used in machining is rapidly increasing as shops order machine tools that are nothing less than complex production plants with integrated, multi-tasking horizontal and vertical networking for large-series production. Second, compact – but highly precise – machine tools are winning market share, especially in emerging countries. With the latest generation of the IndraMotion MTX CNC system, Bosch Rexroth Corporation (Charlotte, NC) meets both of these trends with significant increases in performance and additional software functions for higher productivity that is scalable to the needs in both hardware and software.

In its highest configuration, IndraMotion MTX now controls up to 250 axes in 60 independent NC channels using one control hardware. This system is already designed for the requirements of Industry 4.0, with open interfaces into the world of the Internet of Things (IoT), multi-touch operating devices and simulation programs. By means of a multicore processor, the system achieves minimal cycle times, even with a maximum number of axes, and replaces additional controls that were previously necessary in complex rotary transfer machines. This means machine tool manufacturers can also economically automate complicated systems, especially since a PLC in accordance with IEC 61131-3 is integrated for automation in all variants. With pre-defined technology functions for turning, milling, drilling, grinding, punching and jet cutting, this system is suitable for universal use.

On the other end of the performance scale, the compact IndraMotion MTX micro CNC system also takes on the job of 5-axis machining of components. Therefore, end users can fulfill precision requirements, for example those of the automobile industry, with minimal investment costs. The IndraMotion MTX system family already fulfills all of the prerequisites for horizontal and vertical networking with an integrated OPC UA webserver and the Open Core Interface technology. This can also be seen in the latest generation of control devices. The multi-touch HMI transfers the user-friendly operation of smartphones and tablets to the CNC control system and shortens training time with additional information.

Scalable simulation software provides the opportunity to test and optimize NC programs at different complexity levels, both online and offline. This software monitors collisions and offers extensive opportunities to optimize NC programs in order to reduce cycle times with higher cutting force and shorter downtimes. The free-of-charge basic version creates a 3D contour plot and a cutting removal simulation, both online and offline. In the full version, shops import the 3D models of machine tools, stock variants, clamping devices and tools, adapt them if necessary and, in doing so, receive a virtual figure of the complete machine tool and the processes.

Using IndraMotion MTX as a networkable CNC system, the first manufacturers and end users of machine tools are already starting to implement IoT applications that range from new, wireless operating devices with tailored apps to the networking of entire production lines for increased availability, productivity and energy efficiency. Industry 4.0 concepts are gradually finding their way into everyday operation among machine tool manufacturers and end users on the shop floor as they link machine tools more closely with the IoT world. To enable networking, the core of IndraMotion MTX has been opened to wider access so that machine tool manufacturers can independently create individual functions in high-level languages. In addition, the integrated OPC UA Webserver and other web technologies provide further opportunities to network machine tools horizontally and vertically.

For machining turbine blades, for example, operation and programming of the A156 5-axis machining center built by Italian manufacturer C.B Ferrari Srl (Varese, Italy) is now done completely wirelessly via smart devices. The operating concept is based on multi-touch applications and an integrated 3D simulation function. Using the Open Core Engineering platform, C.B. Ferrari developed specific apps for the control system. The IndraMotion MTX Advanced system guarantees machine tool accuracy of 0.1μm, processing speeds in the PLC of less than 0.5 milliseconds, and CNC cycle times of up to 0.25 milliseconds.

The Generic Data Server service package takes Industry 4.0 one step further by connecting machine tools with the IoT world via secure networks and analyzing the machine data for the users to improve the availability, productivity and energy efficiency of production lines. To do this, the Generic Data Server detects and monitors all relevant control, drive and sensor data using open communication interfaces, such as OPC UA or Sercos interface, and saves it in a Private Cloud. Using pre-defined methods for data analysis, the Generic Data Server guarantees conclusive Remote Condition Monitoring of the networked machines and thereby increases machine availability.

Analytical tools for the optimization of cycle times and energy consumption that are integrated into the Remote Process Monitoring indicate relationships between the NC line data and PLC signals, as well as the intelligent drives. This means end users can improve their processing times and costs, ensure that the processing quality is documented and increase energy efficiency. The Generic Data Server saves all fault messages in a logbook and allows causes and rates of faults to be traced for the entire life cycle of the machine tool so that users can systematically recognize the causes of faults and reduce downtimes in the long-term. The modular service package includes installation of the entire hardware and sensor technology, the preparation of the Smart Data analysis as well as the Remote Condition Monitoring and Remote Process Monitoring by Rexroth specialists.

Automation equipment connected through open standards helps users to achieve the goals envisioned under the IoT connectivity and data analytics revolution. MTConnect and OPC are two open communication standards that enable shops to easily connect production equipment for data collection. Furthermore, MTConnect standardizes the data across equipment, a prerequisite for subsequent data analytics. Rexroth has long embraced open standards and continues this tradition with their Multi-Ethernet and Open Core Engineering Interface offerings. OPC is one of these open communication standards and is offered in Rexroth PLC, motion logic and CNC controllers. The OPC DA communication is installed in many high production systems for data communication but has been followed by the newer, faster and more universal OPC UA standard in recent years.

Thanks to this consistent support for open standards, the data in the IndraMotion MTX CNC controllers can be accessed using OPC DA under Windows and OPC UA directly from the controller. Security mechanisms are provided to the machine tool builder to control which data is accessible via OPC. To further improve ease of integration, OPC companion standards are also observed, such as the MTConnect-OPC UA companion specifications. MTConnect is a standard that provides manufacturing data in a consistent format and method – independent of the manufacturing equipment. The MTConnect Agent collects and buffers the data and sends it to the MTConnect Client software as desired. From the start, MTConnect included the Adapter function that allows it to bridge to other communication channels, one being OPC. This method is further detailed in the MTConnect-OPC UA companion specifications.

This OPC capability in both IndraMotion MTX and VIMANA from System Insights (Emeryville, CA) makes it easy to access all motion and PLC data exposed for access to the MTConnect Adapter. The MTConnect Agent then provides the data in the MTConnect format to the data collection cloud at the specific end user installation.

VIMANA, the predictive analytics platform for manufacturing intelligence, integrates with Bosch Rexroth drive and control technology to connect assets and monitor, analyze, and optimize the factory floor for improved operational performance. VIMANA expands connectivity to multi-vendor and legacy factory devices with interoperability of OPC UA and OPC DA to MTConnect. This data is then streamed to the VIMANA servers for advanced analytics generating dashboards for real-time monitoring and proactive management of operational performance. Smart alerts from enriched data communicate potential maintenance or safety problems before they occur. Bosch Rexroth’s broad automation technology portfolio integration with the VIMANA Suite enables shops to leverage machine tool data for insight into machine utilization, maintenance, safety and energy consumption.

Automation experts all agree that decentralized intelligent axes are the future in increasingly networked production environments to Industry 4.0 – provided they can communicate via open interfaces with higher-level systems. With firmware 20VRS, Rexroth further extends these capabilities in hydraulic motion control (HMC). The multi-Ethernet capability of 20VRS is extended with the POWERLINK protocol. The user can now simply select the POWERLINK protocol in software beside Sercos, PROFINET RT, Ethernet/IP and EtherCAT to reduce hardware variants and spare parts, and further enable the machine tool builder to take advantage of best-in-class HMC hydraulic axis controllers with a wide range of machine controllers and communication protocols. It is also now possible to use pure analog voltage/current feedback systems beside SSI, EnDat 2.2 and INC. Valve specific characteristics can automatically be measured and compensated to reduce startup time – especially important in machine tools with multiple hydraulic axes.

The pre-defined hydraulic functionalities encompass closed-loop position, pressure, force, and velocity control, alternating control, and open loop controlled operation. These functions were further enhanced with additional filter functions. Additional libraries for the IEC61131-3 PLC can reduce engineering and startup time when integrating custom hydraulic axis control functions. It also further standardizes the functionality and increases application diagnostics. Uniform, easy to use IndraWorks software with optimized dialogs can be used over Ethernet for offline configuration, fast commissioning, parameterization, backup, restore and diagnosis of the HMC axis controller. The user can also use an SD Card to duplicate settings, update firmware, and perform backup and restore. With decentralized intelligence and the multi-Ethernet interface of the HMC, users can easily integrate the physical advantages of hydraulics, including high power density and simple wear-free overload protection, into modern, future-proof machine tool applications.

Bosch Rexroth Corporation, 14001 South Lakes Drive, Charlotte, NC 28273, www.boschrexroth.com.