Productivity Gains with Smart Robotic Tooling
Published on : Saturday 08-08-2020
By : Editorial Team
Will Healy III elaborates upon how to improve efficiency, flexibility and visibility with IO-Link on grippers, end-effectors and tooling.
Manufacturers around the world are buying industrial robots at an incredible pace. In the most recent report from Tractia & Statista published in April 2020, “the global market for robots is expected to grow at a compound annual growth rate (CAGR) of around 26 per cent to reach just under 210 billion US dollars by 2025.” But are we gaining everything we can to capitalise on this investment when the robots are applied? Robot utilisation is a key metric for realising return-on- investment (RoI). By adding smart devices around and on the robot, we can improve efficiencies, add flexibility, and expand visibility in our robot implementations. To maximise robot utilisation and secure a real RoI there are key actions to follow beyond only enabling a robot; these are: implementing smart grippers, embracing the open automation standard IO-Link, and expanding end-effector application possibilities.
Using pneumatic & electric smart grippers
In traditional pneumatic gripper applications, sensors are often not utilised. Proper function is assumed, i.e., the jaw opened and closed properly based on the signal sent to the air valve. This can cause unnecessary collisions or process failures due to stuck/worn mechanical components, leaks in the pneumatic lines, or small variations in the process cycle. Adding sensors to the grippers (Figure 1), creates a closed loop and minimal discrete feedback, like open or closed jaw, is provided. With the addition of smart sensors, we can monitor exact gripper jaw position and provide application diagnostics improving the capabilities of the robot end-effector. And finally, gripper intelligence features are expanded even further with electric grippers, giving precise control over the motion profile of the tool and providing detailed condition data on the equipment. Regularly for smart sensors and smart grippers, these commands and the data are handled via IO-Link communication, which allows for process data, parameter data, and event data to be shared with the PLC and monitored via the Industrial Internet of Things (IIoT) connections. By utilising IO-Link, both electric and pneumatic grippers can be enabled with intelligence to improve robot implementations.
Why do I care about IO-Link?
IO-Link is an open standard (IEC 61131-9), is more than ten years old, and is supported by close to 300 component suppliers in manufacturing, providing more than 70 automation technologies (Figure 2). It works in a point-to-point architecture utilising a central master with sub-devices that connect directly to the master, very similar to the way USB works in the PC environment. It was designed to be easy to integrate, simple to support, and fast to implement into manufacturing processes. Using standard cordsets and 24VDC power, IO-Link has been applied as a retrofit on current machines and designed into the newest robotic work cells. Available devices include pneumatic valve manifolds, grippers, smart sensors, I/O hubs, safety I/O, vacuum generators and more. Machine builders and equipment OEMs find that IO-Link saves them dramatically on engineering, building and the commissioning of new machines. Manufacturers find value in the flexibility and diagnostic capabilities of the devices, making it easier to troubleshoot problems and recover more quickly from downtime. With the ability to pre-program device parameters, troublesome complex-device setup can be automated, reducing new machine build times and reducing part replacement times during device failure on the production line. IO-Link devices are IIoT ready, enabling Industry 4.0 projects and smart factory applications.
Part quality, inspection, delicate part handling & measurement
Some of the most common applications like bin-picking, part stacking, or blank de-stacking make assumptions about the part being handled. But the first assumption many people make is that the robot is holding a part. Without sensor verification that the part is in place, how can it be guaranteed that the process is running without defect? And a second assumption that the correct part was loaded into the machine by the operator can cause hundreds of part defects if continued without verification. It is vital that the right part is loaded into the equipment every time, and as many parts look very similar manual inspection isn’t always accurate. A gripper is an excellent place to gauge and inspect parts as it is physically touching the part (Figure 3). This is done by utilising an analog position measurement sensor to determine the distance change of the gripper jaw (Figure 4). In addition to this, the position measurement sensor also can provide feedback for tactile gripping applications when handling delicate or precise parts. By utilising position sensing for inspection and handling of the part, we can improve part quality and reduce production defects.
Production flexibility, format change & part identification
In addition to quality inspection, by measuring the part, we can identify the part and make automation changes on-the-fly based upon this information, creating much higher levels of flexibility and making it possible for in-process format change. With one piece of equipment and the utilisation of smart sensors on pneumatic grippers or smart electric grippers, more product can be produced. With higher efficiencies manufacturers can realise significant productivity gains.
“The benefit of the gripper in this application is the flexibility to pick a wide variety of parts on the fly because of the ability to use IO-Link recipes. Delicate or elastic parts can also be gripped due to the positional accuracy and control provided by an IO-Link servo gripper,” said Russell Tyler, sales manager system technology, Zimmer Group US, Inc (Figure 5). “The high flexibility of a Servo IO-Link gripper can be further enhanced by automatic quick-change jaws with varying geometries.” (Figure 6)
Improved productivity with smart pneumatics
As pneumatic air and vacuum systems have been an integral part of automation projects of the past, these systems can also benefit from gains in intelligence moving forward. Smart vacuum generators can provide feedback on the operation of the system; for example, if cups are starting to wear or fail, the smart devices can be used to provide estimates on remaining service life through predictive maintenance calculations. Key components like process sensors, variable regulators, pneumatic grippers, and pneumatic valve manifolds are available with IO-Link technology at a reasonable price. More importantly, these devices dramatically simplify integration, installation, and maintenance with built-in diagnostics and parameterisation tools. By utilising smart pneumatics, we substantially reduce wiring complexity in new installations and expedite downtime repairs.
Easier I/O and connectivity on robotic end-Effectors
However, most people avoid adding these types of smart technologies to end-effectors due to cable management issues or the effort to put high-flex Ethernet or many conductors into the robot dress pack. With IO-Link and its use of standard conductors for communication, integrators and machine builders have been able to install already available conductors in the arm or use lower-cost high-flex sensor cables to communicate with IO-Link smart devices on the end of arm tooling (EoAT). Smart I/O hubs allow for standard sensors to be used with simplified wiring and on large tooling, valve manifolds can be mounted and controlled on the EoAT (Figure 7). If tool change is needed for the application, non-contact wireless connectivity can send power and signal across an airgap, increasing application capabilities and functionality.
Capture data & control automation
The final point of value for robotic smart manufacturing is that IO-Link is set up to support IIoT applications. This is important as predictive maintenance and big-data applications are only possible if we have the capabilities of collecting data from devices in, around and close to the production. As we look to gain more visibility into our processes, the ability to reach deep into your production systems will provide major new insights. By integrating IIoT-ready IO-Link devices into robotic automation applications, we can capture data for future analytics projects while not interrupting the control of the automation processes (Figure 8).
Manufacturers big and small have gained impressive intelligence at the robot’s end-effector using IO-Link electric grippers, smart pneumatics and tooling enabled with IO-Link sensors. As you look to your next robotic automation project, consider how you could gain some of the benefits discussed like reduced integration efforts, improved part quality, enhanced production flexibility, more process visibility, and increased application capabilities of EoAT. To realise all the benefits of an industrial robot system and earn productivity gains in machine tending, assembly and material handling applications, smart grippers, smart sensors, and smart tooling (enabled by IO-Link) are a necessary part of your next smart factory project.
(Balluff Worldwide is headquartered in Stuttgart Germany, has subsidiaries and representatives in more than 60 countries with strong presence in India with sales offices in Chennai, Bangalore and Ahmedabad, a warehouse in Mumbai and headquarters in Pune.)
Will Healy III, Industry Strategy Manager, Balluff Worldwide, has been an integral member of the Balluff Worldwide team for more than 14 years and is currently the industry strategy manager responsible for leading global project teams, helping customers solve problems and evangelising about the power of manufacturing automation. Will is enthusiastic about smart manufacturing, IIoT technology and STEM workforce development. A Purdue University mechanical engineer who loves to share his passion for automation, Will is a board member for the Advanced Manufacturing Industry Partnership (AMIP) in Cincinnati and is active with multiple university advisory boards and associations. He brings energy to dry subjects and speaks from personal experience about the industrial revolution, managing culture change in organisations, bridging the manufacturing skills-gap, and creating value through automation. @WillAutomate