The drivers of flexible automation
Employing flexible automation technology now is vital for companies to sustain growth, keep a diverse range of products flowing through their lines, and minimize the downtime associated with product changeovers. Advances in industrial technology and the overall evolution of automation over the past century have been unprecedented. In that time, automation has gone from a "fixed" state to being more flexible (see Figure 1).
Fixed automation is designed to produce a single product repetitively and efficiently. This concept worked well on manufacturing floors in the past, which often produced one or a limited assortment of products in very large lot sizes with limited variability. This type of automation is beneficial because the upfront equipment cost is lower than flexible solutions. Throughput also is optimized if the machine only runs a single part. However, modularity is not usually a consideration within the original design, which means converting machinery to support multiple product configuration is often impractical financially and difficult to implement.
The next level of automation, programmable automation, is designed to accommodate some configurability after implementation. This includes the ability to write new code to perform operations with mechanical changeovers that are performed manually. The downside is that the changeover process is often very labor intensive and requires significant downtime to replace tooling and make programming changes.
The more modern approach is flexible or "soft" automation where the machine operator employs a mix of recipe control and mechanical automation that seamlessly converts one process to another at the touch of a button. This allows manufacturers to produce a wider variety of products through a single machine that is designed to adapt to address the next generation of products. Flexible equipment employs electromechanical automation that achieves positional control for quick and repeatable process changeovers. This allows a diverse range of products to flow through the line with little downtime (see Figure 2).
Once any product variability is introduced into the system, fixed automation becomes extremely ineffective from a cost standpoint. Conversely, flexible automation becomes more cost-effective as product mix increases and becomes the optimal solution once a moderate mix is achieved.
The rapid evolution of access to machine information and data management has created endless possibilities for flexible automation. The world has become much smaller and operates at a much faster pace than it did a decade ago. A constant supply of information is readily available, be it for use by machines or the humans interacting with them. The influence of robotics in industry cannot be overstated either. These factors have provided a setting that is allowing flexible automation to thrive.
The Industrial Internet of Things (IIoT) also is playing a major role in flexible automation. The IIoT describes a network of electronic devices embedded with software and sensors that provide an endless stream of information that can be used to improve flexible automation. Sensors that gather this data can be remotely accessed by virtually any machine (or person) to make real-time adjustments on the plant floor to maximize efficiency.
Industrie 4.0, a European initiative designed to encourage manufacturers to develop smarter automated factories that essentially can think and respond independently to changing dynamics on the plant floor, also is pushing advancements in flexible automation. Industrie 4.0 focuses on developing smart factories, where automated equipment is programmed to be autonomous and require minimal human intervention.
Collaborative robots, which allow for rapid repurposing and redeployment of mechanical automation, are also influencing flexible automation designs. As their name suggests, collaborative robots work in conjunction with people to perform a variety of tasks, in a manner that presents no safety risk. For instance, a collaborative robot can remove a part from a press and perform a finishing operation that would typically be performed by a person but not require the same level of machine guarding.
There is also a lot of focus on maximizing throughput and reducing downtime on production equipment contrasts with an industry increasingly trending toward high mix, low-volume manufacturing.
All of these outside influences are combining to create an environment that is helping promote flexible automation’s growth.
Leveraging existing technology
Beyond the external developments that have paved the way for the expansion of flexible automation, the continued growth of existing automation technology has opened new doors. For instance, programmable automation controllers (PACs) have combined motion and machine control in one platform. These controllers are designed to support both overall machine management and specific coordinated motion through servo-controlled actuation.
Compared with traditional fluid power, electromechanical actuation allows for more flexible positioning to accommodate new product sizes and process changes. Specific motion profiles can be created to address the needs of specific products going through the line. To realize the value of flexible automation, the system must be able to change setups between products quickly and seamlessly. To accomplish this, the actuators must have the ability to address a variety of decisions within the available workspace.
As machine builders are pushed to address unique application challenges, component scale becomes more challenging. In the past, this may have been addressed by selecting different families of automation components from one machine to the next to accommodate changes in speed, payload, or thrust. It’s also important to select reliable components to prevent premature failure.
Given the multitude of challenges that machine designers face in creating flexible automation, what can manufacturers of electromechanical components and mechanical stages do to alleviate some of these challenges? At least part of the answer is in designing scalable and configurable product platforms to address a broader range of application demands.
Mechanical stages that are scalable were designed with the specific intent of addressing the significant amount of variance in application demands, such as capacity, speed, stroke length, changes in payload or moment load, thrust, and precision. A number of automation platforms, such as articulated robotic arms, can be employed to provide this level of flexibility. Traditional robotic arms were designed as fixed implants on a plant floor with the objective of producing one output.
However, with the emergence of collaborative robots, it is easier to redeploy articulated arm systems in new applications. Linear mechanical stages can be deployed in single-axis or multi-axis orientations that offer inherent flexibility. As a single-axis stage, they are very cost-effective, but even in multi-axis configurations, typically Cartesian or gantry solutions are extremely cost-effective. Linear stages typically can achieve higher payload and precision and address a larger footprint than robot arms (see Figure 3).
Touchscreens such as human-machine interfaces (HMIs) allow for recipe control and on-the-fly adjustment from one process to another. These screens can be preprogrammed with specific buttons and alarms, allowing the operator to preview system changes and select recipes that will implement the machine changeovers needed to accommodate different products or processes. Menu control through an HMI simplifies changing stroke and motion profiles to accommodate multiple package sizes.
More technological breakthroughs are undoubtedly around the corner to support the shift toward flexible automation. Other technologies that haven’t been deployed will be crucial in furthering the shift away from fixed and programmable automation. All these technologies, coupled with an ever-increasing flow of information and an ever-decreasing tolerance for downtime, will continue to set the stage for the expansion of the flexible automation age.
Jeremy Miller, product manager, Parker Hannifin Corporation. Edited by Chris Vavra, production editor, Control Engineering, CFE Media, email@example.com.
Flexible automation will allow manufacturers more versatility in creating products while minimizing downtime.
The Industrial Internet of Things (IIoT) and Industrie 4.0 will improve flexible automation by giving manufacturers and machines more data to work through.
Existing technologies such as collaborative robots can help improve automation and make it more flexible on the plant floor.
What other developments will improve flexible automation?
See related stories about automation below.