With wearable devices increasingly being used on the assembly line, it’s definitely time to update the old expression that ‘What you wear says a lot about you.’ A more appropriate thing for manufacturers to now say about their assembly line workers is, ‘What you wear tells us a lot about your productivity.’ The wearable devices that provide this crucial data include smartwatches, wristbands, gloves and head-mounted Google Glass.

For the last several years, workers at AGCO Corp. have used Google Glass and the Glass Enterprise Edition to follow instructions so their hands are free to assemble tractors and crop applicators. This approach has led to a 25 percent reduction in production time, fewer defects and the ability to train staff 300 percent faster, notes Peggy Gulick, director of business process improvement at AGCO.

The technology enables assemblers to scan a machine’s serial number to instantly bring up a manual, photo or video they may need to build a tractor. In addition, employees can use voice commands to take notes and leave them for the next shift worker. This allows for a more seamless transfer and increases productivity.

Assemblers at Boeing, General Electric and Volkswagen also use Glass Enterprise, and all the companies have noted similar levels of increased productivity. They also like that the device allows co-workers to instantly connect to share a live video stream, or collaborate and troubleshoot in real time.

Within Glass Enterprise are tiny sensors that continually capture worker-performance data, which is crucial to optimizing an IIoT-enabled assembly line. Equally important, however, is data that quantifies the productivity of machines and can be used to predict when they require maintenance.

To obtain this information, some companies use rugged mobile devices like tablets and handheld computers, while others rely on stationary technologies such as smart sensors and cloud-connected controllers. In every case, though, the goal is the same: Being able to access this data whenever they want from wherever they are.

Key Component

Many components are needed to develop an IIoT-enabled assembly line. But, none are more important than sensors—be they simple or smart, hidden or visible.

Simple sensors either detect the presence of something or trigger a function related to assembly, testing, inspection or shipping. Data from this detection or function is interpreted into a usable format, then sent to and stored in a connected electronic device (PLC, PC, etc.). Smart sensors, in contrast, have the ability to perform multiple tasks, store all related data and send it to one or more connected machines, or an offsite storage cloud.

Wearable and mobile devices contain built-in sensors, as do various assembly machines. These sensors capture and continuously stream extensive data related to force, temperature, pressure, motion detection, proximity and other factors.

One major benefit of operating equipment with built-in IIoT-specific sensors is they can perform self-diagnostics, thereby helping manufacturers maximize machine uptime. The sensors do this by automatically alerting an operator when a part isn’t working right, where a potential problem is, and what is wrong, or is about to go wrong.

As for visible sensors, they can be seen at various locations along the assembly line, usually next to or integrated with automated systems. These sensors perform functions as diverse as detecting or measuring parts, verifying an assembly or that a cylinder has actuated, and counting finished assemblies.

“There’s always a desire by manufacturers to have more data to make better-informed decisions, and smart sensors definitely meet that need,” says Roger Altendorf, product marketing manager for position sensors at Baumer Ltd. “These sensors primarily help predict equipment maintenance, but they’re also proving beneficial for assembly applications.”

Altendorf cites three examples at an IIoT-enabled automotive assembly plant to prove his point. On one line, many of these sensors are used to validate the size, color and thickness of floor mats for each vehicle produced. Other sensors are used at the start of another line to confirm that each fuse is the correct color. And at the end of that line, yet more smart sensors validate that a robot has placed each color of fuse in the correct location within a fuse box.

All Baumer smart sensors made since 2010 feature the IO-Link interface, which quickly transmits measured values and parameter data (i.e., measuring ranges and switchable distances) in both communications directions. This interface allows a connection between the sensor and an IO-Link master via a three- or four-wire standard cable, and transmits digital signals loss-free without any need for conversion.

Recently, Baumer introduced its series of miniature O200 photoelectric sensors. These sensors are designed for complex detection tasks, such as detecting transparent and reflective objects. One model operates as a through-beam sensor, and another model features SmartReflect, which provides a reflectorless light barrier. Two other sensors in the series are retro-reflective. The remaining three work as diffuse sensors with background suppression.

Altendorf says that electronics manufacturers often use these sensors to validate the assembly of circuit boards in electronic devices, fuse blocks with blind spots, and glass covers on cell phones. The sensors are also ideal for positioning grippers and reliably detecting small shiny or transparent objects in assembly and handling applications.

Baumer IR 18 inductive proximity sensors are suitable for both distance measurement and object detection of metal targets. Their measurement signal is unaffected by the color and shape of an object, and they have a range of up to 15 millimeters.

One common assembly line use of UR18 sensors is verifying the presence and correct depth of several screws in engine clutches and manifolds. Another is verifying that a gripper’s open position is correct so it can efficiently grab screws or bolts with heads as small as 10 millimeters in diameter. A third is confirming that tubs in clothes washers are properly positioned.

FUTEK Advanced Sensor Technology Inc. has made sensors for more than 30 years, with an emphasis on sensors that measure force and torque. The company also makes custom sensors, plus electronics and software. It serves an array of industries, but specializes in medical- and aerospace-related applications. For example, two models of their sensors—the QLA295 and QMA118—are currently operating on the Mars Rover Curiosity.

All of their sensors can be offered as USB compatible, including when the application involves complex integration, notes John Vargas, sales director at FUTEK. The sensors’ connector cable has a USB port at the end that connects to a PLC, PC, assembly equipment or mobile device that can store and analyze all sensor performance data. The goal of this design is to simplify end-users’ integration concerns.

FUTEK often customizes standard IIoT requirements to meet those of select customers. To meet manufacturers’ future IIoT needs, however, FUTEK is planning to release a series of Bluetooth-enabled rotary torque sensors this fall. Data from these sensors will be immediately available on all compatible mobile devices.

“The sensors will provide live feedback on various assembly processes,” notes Vargas. “When tied to a stepper motor or actuator, for example, the sensor will confirm if the unit has reached proper torque. It knows what can wrong if the torque isn’t reached, and it can inform a technician what action to take to repair faulty parts, like over-worn bearings.”

Worn at Work

Research by the IMARC Group estimates that the global industrial wearable devices market reached a value of $1.5 billion in 2017. This market includes devices used in manufacturing and logistics, as well as healthcare and lifestyle applications. IMARC projects the market value to exceed $2.6 billion by 2023, expanding at a compound annual growth rate of 9.6 percent from 2018 to 2023.

Manufacturers in all industries are happy to contribute to this growing market, and each wearable device supplier is ready to serve it in a niche way. Tempe, AZ-based GoX Labs, for instance, offers three products to optimize assembly worker productivity by improving safety and wellness.

GoX Labs is a spinoff of GoX Studio, which was co-founded in 2007 by Joseph Hitt and Bruce Floersheim. Both men are service-disabled Army officers who have taught at the U.S. Military Academy and become recognized experts in the field of wearable robotics. In addition, Hitt is the executive director of the Wearable Robotics Association, and Floersheim is its director of operations.

GoX Studio introduced the Ergo Lite smartwatch in 2015 to help workers who do overhead assembly monitor their maximum oxygen volume (VO₂) level, heart rate, steps, cadence and rate of perceived exertion. When any of these factors reach an unsafe level, the watch vibrates, meaning the worker should take a short break.

“Sensors in the watch constantly provide haptic feedback and send data to the cloud, which, in turn, sends data back to an artificial intelligence algorithm in the watch,” explains Benjamin Bronson, chief marketing officer at GoX Labs. “This algorithm sorts through data and automatically triggers a vibration if the data signals a dangerous level of any factor being monitored, but especially VO₂.”

In 2017, the company developed the Ergo system that combines the smartwatch and a motion pad worn on the collar. Within this pad are five sensors that produce data related to fatigue, force, form, fitness and the environment as the worker performs bending and lifting. The pad also communicates with the smartwatch to let it know when the person has an unsafe level of VO₂. Last year, GoX introduced Ergo Pro, which adds patented smart insoles that measure force for balance and weight lifted.

“The Ergo and Ergo Pro systems can benefit any worker on the line who repeatedly does lifting and bending,” explains Bronson. “The systems accurately record and transmit data measuring the degree and rate of movement. Bending and lifting slowly at the proper angle is OK, but performing either action too quickly or bent at the wrong angle is bad.”

Aware of worker privacy concerns, GoX and end-users make sure that an onsite health administrator is the only person with access to all performance data for each individual. However, plant managers and administrators are allowed to regularly check aggregate data and look for worker productivity problems based on a specific task, work shift or workstation.

Each worker can check his or her complete individual data on the watch. The health administrator and plant personnel are required to login into the GoX website to view the data available to them, although this can be done on mobile devices or a stationary computer.

Bronson says manufacturers in a wide range of industries are using one or more Ergo systems. These include automotive, appliance, electronics, shipbuilding, aerospace and national defense.

“People connectivity is the next phase of IIoT, especially in manufacturing,” predicts Bronson. “Within five years, we’ll have the Internet of everything and everybody.”

Last July, Clemson University student Matthew Krugh received an honorable mention award in robotics and automation from STEM-software maker MapleSoft for his Augmented Associate wearable glove. Sponsored by the BMW Manufacturing Co., this glove is used when assembly involves one or more electrical connections.

The glove works in conjunction with an opposite-hand smartwatch and features one sound sensor between the thumb and forefinger, and another near the shoulder. There are also flexible force sensors on the thumb and first three fingers, a real-time clock, and a housing on the top of the wrist that contains a nine-axis inertial measurement unit and an integrated microcontroller.

During assembly, sensor-generated data is quickly gathered. The force sensors measure the amount of force applied by each finger to the male part being inserted into the female part. In turn, the sound sensors measure the click of the insertion.

After assembly, the sensor data is analyzed to determine if the assembly process was successful or not. This involves the microcontroller wirelessly sending data through a nearby aggregator to the cloud for process analytics, and receiving the result back before sending it to the watch. After briefly vibrating, the watch displays either a green check for pass (when the clicking sound is loud enough), or a red X for fail. All process data is stored in the cloud.

Krugh developed the glove at Clemson’s Vehicle Assembly Center, and used it on the Center’s prototype assembly line. BMW plans to soon perform assembly line trials with the glove at the automaker’s plant in Spartanburg, SC.

The Ironhand glove, from Bioservo Technologies AB, connects to a power unit that is worn like a backpack. Pressure sensors within the glove trigger servomotors within the power unit and give the wearer a more powerful grip, which is easily adjusted for each application.

The glove’s “soft extra muscle” strengthening technology merges neuroscience, mechatronics and robotics, and increases worker endurance for manual assembly tasks. All collected data can be analyzed to assess workers and classify them as a high or low ergonomic risk.

Karlsruhe, Germany-based Kinemic offers a wristband that allows users to control devices using gestures or an AirMouse by simply writing in the air. Hand and arm movements are recorded on the band, which then translates them into gestures or text. The band’s software easily integrates with Android-based and other mobile devices, allowing for their completely hands-free operation.

Another wristband designed to help assembly line workers is Ford Motor Co’s Portable Quality Assurance Device. When connected to a smartphone app, the Bluetooth-enabled device helps workers make faster and more accurate quality checks on new vehicles.

Specific quality inspection requirements for each vehicle that passes along the assembly line are displayed on the device’s touchscreen. The worker is then able to instantly follow up and approve. According to Ford, the system has reduced human error, while shortening each vehicle check by an average of seven seconds.

Ford initially used the device at its Valencia, Spain, plant in early 2016. It is now used in many other company plants as well.

In Hand, on Demand

Rugged tablets are increasingly being used on assembly lines for IIoT purposes. Last summer, Profshare Market Research released a study that estimated the devices’ global market value to be $425.3 million in 2016. The group expects that total to increase to $794.8 million by 2026, with a compound annual growth rate of 5.8 percent over the next seven years.

Other related research reports, including one by Technavio, cite two key reasons for the devices’ increasing popularity. The first is a fall in their average selling price. Another is manufacturers’ growing need for paperless, on-the-fly data management systems that store data and extract useful information using data analytics.

“When it comes to rugged mobile tablets, manufacturers are more knowledgeable than ever about the devices’ capabilities and what they can do for them on the assembly line and throughout the plant,” notes John E. Chis, vice president of sales and marketing at MobileDemand L.C. “Equally important, the collaboration between the IT and operations departments at these manufacturers has never been better, with both groups fully understanding the beneficial impact these devices have on workers and customers, as well as the quick ROI they provide.”

MobileDemand L.C. has been making rugged tablets since 2003, with its first customer being Anheuser-Busch distributor Bemiss Distributing Co. in 2004. Today, MobileDemand makes 10 tablets, including its latest model for high performance and productivity, the xTablet T1680.

Measuring 11.6 inches in diameter and featuring a Windows 10 operating system, the xTablet T1680 mounts easily on assembly equipment and forklifts. It is rugged enough to meet the MIL-STD 810G, which requires a device be fully functional after a 4-foot drop.

The tablet easily connects to a dual-band Wi-Fi plant network using Bluetooth 5.0 technology. Other features include an 8th generation Intel Core i5-8250U Processor, an 8-megapixel camera, four sensors (accelerometer, gyroscope, e-compass and light), a built-in microphone and I/O ports for USB 3.0., auxiliary devices (3.5 millimeter), power (DC barrel jack), and standard SIM and microSD cards.

One countertop maker uses the tablet to improve quality control by ensuring exact measurements when cutting rigid materials. Workers at steel mills also use stored measurement data to consistently ensure exact cutting and slitting of steel slabs.

“Automotive, appliance and plastics manufacturers regularly use rugged tablets,” notes Mark Boyer, senior technical support manager at MobileDemand. “One latter customer mounts a 10-inch tablet at the front of each assembly line in a plant where totes, laundry baskets and garbage cans are produced. The tablets carefully monitor the uptime and downtime of each line, and feed this information to an 80-inch display panel positioned near the plant’s ceiling rafter for all to see.”

MobileDemand introduced its first-ever handheld device, the A680, earlier this year. It features a 6-inch display, an Android 8.1 EnterpriseReady OS platform, a Media Tek MT8735b Quad Core engine for high efficiency, and various apps.

The device is lightweight (0.84 pound), rated IP65 for sealing protection from water and dust, and connects to a dual-band Wi-Fi plant network via Bluetooth 4.0. It also comes with an integrated bar code reader and is Google Mobile Services certified.

Per Holmberg, CEO of JLT Mobile Computers, says the company sees an increasing demand for Android-operating-system models within many of its core segments, including warehouse logistics, transportation, ports, mining and agriculture markets. This trend led the company to launch three new units last October: the 5-inch MH1005A rugged handheld, and 7-inch MT1007A and 10-inch MT2010A rugged tablets.

All devices are powered by ARM Cortex-A53 octa-core 1.3-gigahertz processors, and come with bright-sunlight-viewable displays and a capacitive multitouch screen. Front and rear integrated cameras are standard, along with a near-field communication reader for capturing data. 1D and 2D bar code readers are optional.

For maximum productivity, the units include Wi-Fi, Bluetooth, GPS and mobile broadband, and provide full-shift battery life. They are IP65 dustproof and water resistant, capable of operating in temperatures of -10 to 50 C, and meet MIL-STD-810G requirements for durability.

More Specialized Control

Machines, robots, PLCs and sensors are ever present in manufacturing facilities worldwide. The problem is, they typically use different communication protocols and run independently. An industrial IIoT controller can overcome these communications barriers by enabling supervisory control and data acquisition (Big SCADA) of all factory operations, along with data analytics using the plant’s cloud computing network.

OEMs in various industries integrate the ex700 series of HMI-controllers from Exor America Inc. in assembly machines to enhance their data gathering, storage and analysis capabilities. Users include manufacturers that produce equipment for food and beverage packaging, and machines that make HVAC systems, metal parts, industrial freezers and even chicken incubators, according to Matt Durbin, engineering manager at Exor America. He says the HMI-controllers can also be retrofit on older equipment to make them IIoT compatible.

The units feature an external touch screen that measures up to 21.5 inches in diameter with a resolution up to 1,920 by 1,080 pixels. Displayed on the screen are various types of real-time, machine performance data. A built-in VNC function allows the HMI screen data to be mirrored on tablets, Android-based smartphones and other portable devices for immediate tracking by engineers and managers.

There are five models in the series (ex705, ex707, ex710, ex715 and ex721), all of which offer three ports for networking, and can function as a cloud Gateway via an OPC UA Server. Connectivity is secured with Corvina, an open virtual private network, and full network separation.

The HMI-controllers also run JMobile software and have a powerful browser with industry standard Web engines. CODESYS V3 is optional software that enables the HMI-controller to function as a master PLC, and send and receive data over Ethernet using major protocols. Also optional are plug-in modules for fieldbus systems, more I/O and other controllers.

“These controllers offer an all-in-one solution, by optimizing worker control, machine control and cloud control,” notes Durbin. “They serve as an access point to collect assembly line data from machine sensors, and push this data on to the storage cloud.”

The NX1 controller from Omron Automation features multicore technology that executes machine control tasks while collecting and sending synchronized data from sensors, servomotors and other devices to a host IT system. Only 66 millimeters wide, the controller houses EtherNet/IP, EtherCAT and OPC UA ports—the latter being specifically designed for IIoT applications.

All three ports enable data usage at production sites and provide an intuitive, secure connection to host IT systems. Production information is directly stored in databases, eliminating the need for a PC or middleware, ensuring real-time traceability of all products and improving quality control.

The controller provides control of I/O and motion on up to 12 axes, and within a 1-millisecond cycle time.