Many control system architectures have seen improvements in speed and accuracy after adopting network solutions. While there's much discussion about network solutions for machine control, many companies remain hesitant to adopt these approaches. So, learn from your competitors and see how four machine manufacturers are using the latest motion bus technology to advance the design of new machine equipment, controlling its motion, logic operations, human-machine interfaces (HMIs), and inter-factory communication. Ethernet Leads the Way in Edge Trimming Machines Early fieldbus network solutions sometimes couldn't provide the machining capabilities required by complex, precision machine tools. Therefore, when Günter Redeker, Electrical Design Director at IMA (www.ima.de/eng), considered redesigning their Novimat edge trimming machine pilot project, he decided to take an alternative approach, using the latest PC technology. A New Machine Concept This new edge trimming machine is a high-performance system for edge trimming of wood chipboard or lightweight building materials. The Novimat Concept consists of modules and configurable machining units capable of grinding and trimming, chamfering, finishing, and leveling. This machine tool uses a continuous trajectory control method to precisely monitor and control the position of the workpiece, and can process multiple workpieces simultaneously. Application: Used in furniture manufacturing at IMA Klessmann GmbH as a dedicated trimming machine and machining center. Engineering Challenges: High-precision machining volume; complex machine tool system architecture with thousands of I/O ports and over one hundred axes. Control Method: Ethernet fieldbus control of 12 axes and integrated I/O ports, eliminating the need for a PC fieldbus card. System Overview: ● EtherCAT technology machine tool control network ● 12 axes and 30 signal paths per machine module ● Ethernet-based I/O ports and servo drives replace the traditional fieldbus ● Continuous path control ● Auxiliary CAN-based drive using an EtherCAT/CAN gateway new control platform When redesigning Novimat, IMA used Beckhoff's (www.beckhoffautomation.com) real-time Ethernet technology (EtherCAT) for control and automation. IMA's previous woodworking machine tools used a Beckhoff PC controller. This controller employs a DOS operating system, fiber optic bus automation technology, and PC-based display and control. Each machine unit has a bus terminal I/O station coupled via the fiber optic bus, while the servo drive module performs actual machining via a PROFIBUS fieldbus and communicates with the actuators via a CAN bus. Redeker explained that they switched to the new platform because the machine setup was extremely complex, with thousands of I/Os and over a hundred axes. He said, "Previously, to control these machine tools via a fieldbus system, we used a four-core fiber optic bus to collect or transmit large amounts of data at a single sampling rate required by the machine tool. This was the only way to meet the requirements." According to Redeker, the controller requires significant computing power to process this large amount of data. It not only downloads data from the fiber optic bus to memory and then back to the fiber optic bus, but also categorizes the input/output data according to the process graph. With the EtherCAT solution, he said, "The DMA controller controls the direct transfer of data between the Ethernet interface and memory, which has greatly improved our system." Another advantage of this new system is its ability to perform continuous trajectory control. Continuous trajectory control can track workpieces within a machine tool, achieving precise control along the path or synchronizing parts on a high-speed machine. The workpiece passes through the machine tool at a speed of 60 meters per minute, corresponding to a movement of 1 millimeter per millisecond, with potential associated deviations. If the continuous trajectory control time is 2 milliseconds, then completing a 60-meter machine will result in a 2-millimeter deviation, a result that is inaccurate, especially given the increasingly stringent precision requirements of machine tools today. Redeker refers to this value as the borderline value. [align=center]Providing integrated EtherCAT, Profibus, and CANopen communication protocols in the control system architecture[/align] The Novimat Concept is a single-sided, automated trimming system. As material passes through the machine tool, it performs single-sided trimming, edge trimming, and finishing. It envisions the potential of fully implementing EtherCAT technology on the machine tool, thus leveraging the latest and most powerful industrial computer technology. Currently, large production lines require two computers: one for the user interface and the other for real-time control. Redeker added, "Hopefully, in the future, these systems will only require a single computer. Also, if only one fieldbus can be used, engineering and maintenance will be much simpler." Integrated modeling, simulation, and control. In cylindrical coordinate measuring machines, automating the centering of the bearing rings with the rotating spindle involves detecting and executing the action. However, when the target accuracy is 1-2 micrometers, given bearings of different sizes and weights, and the parts may have oil on them, while also adapting to system friction, such machine tools are outstanding. A Unified Solution "Although this is a simple system, there are still many things you don't know in this application," says Dr. Thomas Kurfess, director of the International Center for Automotive Research at Clemson University. "Achieving control accuracy of 1 micrometer with a PID controller is difficult, largely due to the presence of friction. But now, it can be done using a standard motion control platform." The Novimat Concept is a single-sided, automated straight-line sealing system designed for finishing seams, edges, and corners. A collaboration between Timken (www.timken.com) and National Instruments (www.ni.com), Kurfess and his team reduced the workload of skilled workers in automated systems. Kurfess said, "The key technology that enables us to complete modeling, simulation, and control in one step lies in cutting-edge software tools. Previously, we could model and simulate a system with a certain function, but subsequent control wouldn't happen. You might ask, 'Why not?' The answer is to update your model." [align=center]High-Quality Automated Linear Edge Banding Machine Achieves Networked Motion Control[/align] Requires Efficiency Designing an effective control system to automate the manual centering process aims to reduce the cycle time required for centering. Compared to manual operation, the automated system requires only 15% of the manual measurement time. This automated control system consists of a linear slider and a precision spindle with an air bearing, which improves motion accuracy and smooths the motion. An LVDT displacement sensor is mounted on the linear slider as a measuring device, driving the bearing ring together with a fixed push rod contact. An effective control system automates the bearing centering process, significantly reducing the centering time. Application: Automating the centering process of the bearing ring on the rotating spindle in a cylindrical coordinate measuring machine. Engineering Challenges: Reduce setup time; ensure repeatability of bearing ring centering within 1.5 to 2 micrometers in highly dynamic machine tool systems. Control Approach: Use LabVIEW control design and simulation software; hardware includes a PXI/Compact PCI card and a Soft Motion driver for motion control. System Overview: ● LabVIEW Control Design Toolkit, real-time and simulation modules ● Soft Motion driver ● Measurement device: LVDT displacement sensor ● Kalman filter for raw data processing Design Challenges The designers used NI's LabVIEW Control Design Toolkit to design and analyze high-order loops in the system and could programmatically apply a custom Kalman filter to the output of the noise measurement device. Kurfess said, "LabVIEW's greatness lies in its signal processing and sampling, not its control capabilities." However, the current LabVIEW for real-time objects based on DSPs and FPGAs allows you to rethink your control approach. Time segmentation and software prioritization expand our scope. Ten years ago, we selected a sample and processed it; afterwards, we did some work on its analog output for control. Previously, software speed depended on the computer, and performance guarantees were limited. With the new real-time control, performance guarantees are now possible, and software priorities can be set. [align=center]The system successfully achieved repeatability accuracy of 1.5-2 micrometers under varying frictional forces caused by factors such as bearing size, weight, and lubrication.[/align] Kurfess added that the use of Soft Motion in this application makes the system hardware completely transparent, seamless, and easy to program. He said, "The real-time controller runs in software, and all you need to do is convert the Soft Motion to change the object. You can change it to run the program directly on the DSP instead of having to run it on a computer." [align=center]The control system uses NI's software motion control technology[/align] Electronically powered axis driven post-press equipment Is centralized control, object-oriented software, digital networking and tight coupling, and composite coordinate servo control the secret to Goss International's success in the next-generation Pacesetter? This is the solution for the 1100 printing roller press. The new machine tool design abandons the traditional power axis approach, replacing it with advanced networked control that ensures tight synchronization between servo mechanisms and high-speed I/O ports anywhere on the network. [align=center]The control system automatically centers the bearing rings, saving the number of centering operations.[/align] Engineering Challenges According to Dr. Atef T. Massoud, a senior engineer at Goss, he believes that achieving centralized control and coordinating a large number of axes in the system using a single position reference is the most significant engineering challenge. What comes after the Pacesetter? The 1100 is a modular machine tool whose assembly can be changed as needed to adapt to high-volume production requirements. It can use six to forty feed ports, with a rated speed of 2000 pieces per hour and a maximum of 45 axes. However, using the same motion control method, another Goss post-press processing machine can support 94 axes. In this application, Goss selected SynqNet networking and eXMP controllers from MEI/Danaher Motion (www.motioneng.com). Goss also chose 1kW Digiflex SynqNet Drives from Advanced Motion Controls (www.amc.com); the motors were from Baldor (www.baldor.com). The drives were custom-made by AMC and included additional I/O ports. Application: Goss International's next-generation web offset printing post-press processing equipment. Engineering Challenges: Achieving high-performance, electronic drive shaft and cam system using centralized control, digital networking, and tightly coupled, multi-axis servo control. Control Method: The SynqNet control platform is used to close the core position control loop, enabling control of up to 94 axes while maintaining strict synchronization between the system's servo axes and high-speed I/O ports. System Overview: ● Each eXMP SynqNet controller can control more than 20 servo motor axes ● Red Hat Linux management process scheduling and application attribute configuration ● Servo systems replace master-slave, gear, and coupling transmission systems in mechanical communication with the upper layer. They offer high-performance, dynamic systems with dynamic adjustment capabilities. Utilizing MEI's Motion Programming Interface (MPI), centralized control is achieved through C programming. Massoud explains that they used "object-oriented design principles" to implement the multi-threaded software structure required by the machine tool and to extend the large number of servo axes. He says, "Implementing centralized control of the system was a challenge for us. We had to design an eXMP controller to control all the objects while specifying instructions for 20 axes." A significant feature of MEI's Motion Programming Interface (MPI) is its ability to reuse motion program code on the control platform. Massoud explains that in this application, they defined a set of equations representing the machine tool's state and instructions, enabling each axis in the system to execute them. Each axis can only process its own data and can only execute a pre-defined set of control equations. Massoud said, "We can separate different axes running on the same CPU because each axis can only process its own data." The object-oriented approach allows for the reuse of program code and its data processing methods, making it convenient to program the system in C and maintaining a large number of axes in the system. Massoud explained that, for example, he created homing/synchronization sequences, which any axis could then use. However, if axis 10 is using the homing sequence equations, it can only process its own data. Once the equations are designed, they can be used by any servo axis in the system. [align=center]In the new post-press equipment, virtual sorting replaces traditional mechanical sorting, and a high degree of synchronization is achieved between the system's servo motors and high-speed I/O interfaces via Ethernet communication .[/align] Another challenge in this application is how to communicate the status of each axis with the upper-level controller or PLC. On the production line, when the drive shaft system becomes servo-controlled, do some of the original components still remain on the Pacesetter? One of the components retained from the previous design is the PLC, used to control the machine tool's logic performance. By using Ethernet for communication between the PLC and the eXMP controller, the computational burden on the PLC can be reduced as communication bandwidth and transmission speed increase. Additionally, complete diagnostic information can be communicated and displayed on an HMI with a touchscreen at the feed inlet. [align=center]The modular design of the Pacesetter 1100 can accept 6-40 branch stations from anywhere to meet production needs[/align]