HMIs embrace the future, deliver performance

Human-machine interface (HMI) technologies have paved the way for some of industrial automation’s most beneficial applications, used to gain access to critical information.

By Maria Hansson, Kontron February 13, 2014

Advancements in human-machine interface (HMI) technologies have paved the way for some of industrial automation’s most beneficial applications, used to gain access to critical information. Competition is fierce in industrial markets, and demands continue for HMI improvements as users seek to capitalize on the added connectivity options and real-time data to improve factory line monitoring, control, and productivity. 

Processes and controls have indeed progressed; however, the manual monitoring and control of a wide variety of machines and equipment at a plant remains a difficult and time-consuming task for workers and still may not provide the desired accuracy. Further, there is a tangible need for factory automation to evolve from fragmented information and multiple platforms to systems that offer a single access point performing complex, real-time calculations. 

The new generation of HMIs offers multi-touch technology, ruggedized systems, a wide range of interface options, and long product lifetime, and enables a single access point solution that connects different areas of the factory floor. Today’s HMIs are enhancing production control and offer increased computing performance for complex and detailed data analysis. By improving the precision and accuracy of equipment operation, workers can thoroughly evaluate the entire production line for adjustments to productivity and quality. 

The centralized systems

Earlier generations of HMIs were primarily used as displays, and were effective as the principal point of contact to connect users and systems. Individual displays were connected to one or several computers, which in turn connected to a data acquisition system, controls, and an industrial network. 

Drawbacks include complex and costly cabling and a large system footprint due to multiple components. This created a greater number of potential failure points and constrained systems that required more physical space on the factory floor. Most importantly, implementations were more complex, ultimately reducing reliability while increasing maintenance and overall cost of ownership. 

HMIs have evolved dramatically in recent years, and now fulfill demands for easy operation with a design inspired by consumer devices. Screens similar to smartphones and tablets offer the familiar design and function of a consumer device, but perform to the demanding requirements of industrial deployment. Scrolling, dragging, rotating, and enlarging screen content by the touch of the operator are expected features of consumer devices, and the same intuitive operation and user-friendly interfaces are now available in HMIs that offer up to eight simultaneous touch points. 

Function and quality are important, but because ease of use is a primary issue to operators, it had to become a primary issue for OEMs as well. With software menus replacing buttons and switches, the operation is made easier. An additional, and unexpected, advantage is that new employees become familiar with production processes much more quickly, reducing the learning curve for factory floor training. New touchpanel systems also offer the added benefit of on-site training through audio and video link. 

HMIs have embraced a wide range of functions, such as visualization, control, and data processing, which were historically executed on decentralized platforms. Due to I/O and network cards getting smaller and large PCI cards being replaced by Mini PCIe and PCIe cards, it is now possible to fit larger displays into a slimmer CPU box with maintained capabilities as well as adding features such as camera or RF interfaces while maintaining the size of the system. HMI systems simplify factory floor operations and eliminate the extreme maintenance demands of separate system components. These advantages help make the manufacturing line more efficient and allow companies to respond and make rapid changes to production as the market demand fluctuates.

Maintaining performance 

Even though users may expect touchpanel PCs and HMIs to work like a consumer device, actual deployment in harsh industrial environments presents a much greater challenge—with extreme performance demands on productivity, quality, and energy-efficiency. Sophisticated data management such as “shop floor analytics” and “smart manufacturing” require efficiency at every step of the production process—and high processing power HMIs provide a building block to achieve these goals. 

The high resolution screens must be suitable for daylight environments and be validated for rugged, long-term performance. Screens in 16:9 (widescreen) format are commonly offered next to the 4:3 format. To protect the sensitive technology of the touchscreen, HMIs feature robust and scratch-proof glass panels that are easy to clean and resist dust, moisture, and liquid. HMI designs for applications such as industrial automation and medical are extremely hygienic—buttons and keyboards are minimized and construction is free of joints and grooves that trap dust and dirt. 

Touchpanels must operate in industrial temperatures that can range from 0 C to 50 C, much higher than are typical in consumer computing. Reliable, non-stop performance is required and systems must be proven rugged, mandating validation for shock and vibration, and electromagnetic compatibility (EMC). Extended supply lines and product lifecycle management are essential, as most industrial systems operate non-stop for seven years or more before being replaced. Standards-based solutions are required, protecting those long-term investments and saving development costs for custom designs. OEM and manufacturing relationships add value here, sharing expertise, development teams, and a well-defined product portfolio.

Converged control and display 

Controlling sophisticated technology with human touch is an effective way of operating systems and applications. New trends of operation include gesture control and voice recognition. Integrating HMIs with control systems is proving valuable in simplifying implementation and increasing reliability.

Reaction time and attention span, ability to multi-task, inclination for visual versus audio cues—these and many other human characteristics are inherent to safely operate industrial systems. HMIs play a critical role in capitalizing on these factors in industrial design, enabling expertly designed controls that reduce errors and ensure the most intuitive and functional link between man and machine. 

Machine control, visualization, and data processing via one centralized platform are more user-friendly than ever, courtesy of modern HMIs, which readily integrate all these different tasks to form a useful trend in industrial automation. 

For designers, the concept of control and visualization on the same system reduces costs, eliminates complicated maintenance, increases reliability and safety, and establishes a new and more competitive path for streamlined and integrated industrial computing systems.

Maria Hansson is with the Industrial and Medical Business Line at Kontron. She can be reached at maria.hansson@kontron.com.