As the automation industry advances toward digital transformation, some think that proven manufacturing technologies like pneumatics may become “outdated.” However, pneumatic technologies such as control valves continue to evolve, incorporating sensors, industrial network interfaces, wireless technology, and complex digital control features that can significantly improve automation applications through access to smarter, actionable information.
Valve Control Technology Evolves
Control of pneumatic valves and monitoring of cylinder position sensors were originally achieved through discrete wiring: Each programmable logic controller (PLC) output was individually wired to a solenoid valve coil and triggered separately, and position sensors on cylinders were wired back to the PLC’s input card.
This evolved into a more practical solution with the creation of plug-in valves and manifolds. All the solenoid valve connections to the PLC input/output (I/O) cards could be achieved with a single cable.
As automation systems became more sophisticated, fieldbus (industrial network) communications connectivity became more prevalent. This meant that the PLC could not only control valves but also monitor sensors and devices, exchanging I/O data via one communication cable without needing local I/O cards. Pneumatic valve manifolds naturally began incorporating both fieldbus interfaces and I/O capability to provide complete pneumatic valve packages that were more versatile and engineered to be integrated easily with smarter, more sophisticated automation platforms.
Electropneumatic Control Optimizes Pressure Regulation
Advances in valve technology, performance, and versatility took a major step forward with the integration of electropneumatic control capabilities into the valve manifold. As seen with valve manifolds, strides were also made with proportional regulators. New technologies allowed these devices to be controlled more accurately using digital signals and also allowed the integration of fieldbus connectivity, optimizing force and pressure requirements for the production system.
This advanced level of combining both directional and pressure control elevates the value and versatility of pneumatics for a wide range of automation applications and allows for greater, more precise, and optimized control in the manufacturing process.
For example, Emerson’s AVENTICS™ electropneumatic control is used in welding systems for automated manufacturing of engine starters. Here, a pre-mounted armature is transported on workpiece pallets, aligned for position detection, and brought into position for welding by pneumatically driven grippers. After welding, additional grippers return the armatures to workpiece pallets that transport them to the next production step.
Enhanced Process Monitoring and Control Offer New OpportunitiesElectropneumatic pressure regulators, combined with an advanced valve manifold with integrated fieldbus communication, optimize the diffusion welding processes with dynamically controlled pressure that can be precisely tailored to the application. At the same time, intelligence built into the manifold monitors and documents all the valve’s functions, controlling the grippers for an enhanced level of quality control and process tracking.
One of the key goals of digital transformation in manufacturing is to gather actionable information that allows for more sophisticated and optimized control of every single step in a production process. The intelligence built into pneumatic valve systems provides new opportunities for that kind of monitoring and control. For a valve rated to provide a proper operating life of 120 million cycles, at 100 million cycles, a well-designed predictive maintenance system can capture and use that data to either conduct an inspection and maintenance action or implement an automated purchasing request for a replacement device before the unit actually fails.
As pneumatic components become more intelligent, they’re generating additional data points including diagnostics, usage statistics, and lifetime data across the production systems where they’re used. This data is most valuable when used to manage production systems more efficiently, control energy consumption, and maximize uptime.
However, all this data from intelligent devices and subsystems has the potential to overwhelm the machine control network and affect control performance. Some pneumatics component manufacturers like Emerson are offering smart pneumatic monitoring “gateways” or “hubs” that aggregate and organize pneumatic performance data and deliver it through separate parallel pathways to plant management systems. These hubs can be independent of the process control architecture, using OPC UA, MQTT, HTTP, or email pathways to deliver alerts and both system- and device-level performance data.
The benefits of critical diagnostics information or key commissioning capabilities can become difficult to realize when a pneumatic valve system is mounted high in the air or deep inside a machine. For example, Emerson’s AVENTICS Wireless Auto Recovery Module (ARM) Clip provides easy access to the robust diagnostics and commissioning features of the AVENTICS Series G3 fieldbus platform via a mobile website that can be used on devices with Wi-Fi capability without an app.
Pneumatic valve systems designed for digital transformation now incorporate features and technology that provide a new level of precision control for pneumatic-driven actuators and applications.
Due to more advanced electronics within valve system control modules, designers can now incorporate proportional-integral-derivative (PID) controllers for pneumatic positioning applications that automatically apply accurate and responsive correction to a control function.
With these high-tech pneumatic capabilities, not only is it possible to provide more precise system end-point motion accuracy but in conjunction with the PLC, it’s also possible to switch from position control to force control in real time and fine-tune motion sequences for very high levels of automation, product throughput, reliability, and repeatability.
Smarter Pneumatic Valves for the Digital Transformation Era
Pneumatic valves have been steadily evolving to help OEMs and end users make full use of pneumatic technology in their automation systems. In addition, many pneumatics technology providers have substantially upgraded their online configuration and ordering tools to make it both efficient and easy to get the components machine builders need on short turnarounds.
These tools simplify what was once a time-consuming process of ordering multiple elements that make up the valve system — sub-bases, mountings, and electronics as well as the valves themselves — to purchase a complete assembly. Now, these online configurators make it easy to order a valve assembly by selecting the fieldbus interfaces, integrated I/O modules, and other features, complete with CAD drawings as part of the package without needing to know part numbers or system nuances. These tools enable both OEMs and end users to get a complete configuration in a condensed and more reliable purchasing process.
Leveraging the power of both electronics and modular, cutting-edge technology, pneumatic valves as part of a complete intelligent pneumatics motion and control platform provide a proven, cost-effective, and versatile technology option for a wide range of digital transformation initiatives for automation and manufacturing applications.
This article was written by Marchelle Forish, Product Marketing Manager, Valves and Valve Systems for Fluid and Motion Control at Emerson, Florham Park, NJ. For more information, visit here .