Automation technologies continue convergence across platforms, offering simulation and greater motion control capabilities for CNCs
The roots of computer numerical control technology stretch all the way back to the 1950s, but the technology remains highly relevant for machinery to this day. The options for modern CNCs continue to increase, providing an even wider toolset for all industries that need this level of control. Advances in different cutting head types covering everything from metal to fabric to foods, along with faster control hardware and software, allow engineers to complete more accurate cuts in less time. The widely established benefits of CNC include greater throughput and precision, fewer rejects and less finishing.
As higher performance options for cutting heads and multi-axis servo systems emerged, CNC applications have forced software platforms to step up. More complex application demands placed on plasma, waterjet and laser cutters, plus routers and blades, push conventional CNC software to its limits and leaves controls engineers seeking more flexible options. Many have chosen to standardize on PC-based control platforms that integrate CNC, motion control and PLC on the same platform. This is due in large part to the higher processing capabilities of multipurpose industrial PCs (IPCs) which immediately help increase CNC performance and precision by eliminating previously separate hardware devices. Simply removing multiple devices that previously had to communicate with each other directly improves cycle times.
Today’s PC-based control platforms also offer easy integration of simulation and CAD software in the same engineering environment. For example, MATLAB®/Simulink® can link directly with TwinCAT 3 automation software to incorporate existing CAD and CNC models for faster machine design. It also can help speed the development of prototype parts in ways that are very cost-effective.
The overall machine design can also be adapted to suit changes in part prototyping, which simply was not possible in the recent past. System-integrated motion design software can push this proactive machine design even further by expanding the range of tools for easier specification of required motor and drive equipment, precisely matching them to all mechanical components in the machine.
Cheat the axis – deflection
Even the best-designed machine must be refined and optimized based on real-world conditions observed after commissioning. Especially in CNC applications, these conditions vary widely depending on the industry, application and material type. In cutting applications you can see blade deflections that may require system adjustments for different speeds and different materials. This requires a real-time software that can read data from advanced sensors – which were not common in the past. In a simple sense this is called ‘cheating’ an axis by using look ahead and monitoring of real-time sensors. It allows engineers to work around or work with blade deflection to increase cut performance. Creating an effective algorithm to cheat the axis in CNC applications can eliminate the deflection, which can increase throughput without sacrificing accuracy. This adds further efficiencies and cost-savings by minimizing raw material waste and scrap.
Regardless of the application type, advanced CNCs can leverage 3D CAD models and visualize cutting imperfections so engineers can quickly correct them in software. The TwinCAT CNC library can run an interpolation to compare axes and calculate the best vectors based on spline control and the exact dimensions of a finished part. With this information, simulation software can determine the optimal part cutting paths using data insights from the observed trajectory of the axis and its defined velocities. Using simulation for CNC design can enhance existing operations with familiar workpiece materials, but it can also provide invaluable benefits when working with new and prototype materials. This ensures greater success when deploying and commissioning machines in any industry.
CNC meets IoT in industrial automation technology
Unsurprisingly, this level of CNC refinement generates significant amounts of data that must be managed. Fortunately, PC-based control architectures offer advantages here too through hardware, software and networking standards that are ready for implementing higher level databases, SQL servers, IoT concepts and cloud services today. Whether managing data onsite or off, this does not require the addition of another layer of controls technology as the new functionality is added in standard software. One IPC can easily multitask CNC and IoT duties on one CPU without adding a special gateway or managed switch.
Cloud communication is easily implemented directly on IPCs via accepted standards such as MQTT, AMQP and OPC UA. In the context of PC-based control, the IoT programming is handled in the same engineering environment used to program the CNC, PLC, robotics, machine safety and more. Multipurpose PC control ecosystems also help multipurpose engineers develop their skills and blur the line between who’s a CNC programmer, versus a PLC programmer or an IoT programmer.
However, you don’t need to crunch code to push data to the cloud. Simple IoT bus couplers have been introduced that establish cloud communication via a simple configuration page instead of programming. This approach to IoT and cloud is especially good for retrofit applications because it is possible to harness machine data from older CNC machines that may have a legacy fieldbus such as DeviceNet or PROFIBUS. This fuels analytics and dashboards with actionable information that can be viewed on premises or globally by manufacturers or the CNC machine builders that serve them.
CNCs learn new tricks
While CNCs were introduced over a half century ago, many modern systems have kept pace with major automation technology developments to this day. The advent of PC-based control technology for CNC applications has only accelerated these developments. The convergence of previously separate hardware and software platforms multiplies efficiencies that can be measured from design and programming to commissioning and runtime. In the beginning stages of CNC machine design, simulation in the TwinCAT engineering environment provides the fastest possible development times with the fewest possible errors and redesigns. Simulation also speeds up time to market and installation by weeding out the most time-consuming surprises previously discovered during the commissioning stage.
PC-based control platforms that consolidate machine control functions boost performance and accuracy while easily adding the latest features such as cloud connectivity throughout the entire lifecycle of a CNC. Enabled by industrial PC hardware and software, CNCs will remain open for future automation and motion control advancements, whether we already see them on the horizon or not.
Are you interested in using simulation and PC-based automation to enhance your CNC machines? Contact your local Beckhoff sales engineer today.
Matt Prellwitz is the Drive Technology Product Manager for Beckhoff Automation LLC.
A version of this article previously appeared in Control Engineering.