A new generation of smart actuator offers increased intellect, simplicity, and economy. This next generation of the original actuators – a longtime staple in automation – are being used for several applications, including factory automation, robotics, and material handling.
By integrating electronics within the actuator housing, smart actuators enable switching, synchronization, and networking to be managed automatically, based on signals from a common external source such as a programmable logic controller (PLC) or other control unit.
Participation in more complex automation schemes becomes feasible, and a more compact system footprint simplifies operation and lowers cost of ownership.
Electromechanical actuators already provide advantages over fluid-driven actuators in heavy-duty precision applications by delivering absolute position feedback, but have traditionally done so with external potentiometers, encoders, limit switches, and controls.
Integrating the components into the actuator provides additional benefits, enabling absolute analog or digital position feedback at every point in the stroke.
To provide analog position feedback, potentiometers simulated in the internal electronics send voltage signals that alert users of the absolute analog position, speed, and direction of the drive from beginning to end of stroke. They also remember that position so if power is lost, there is no need to return to a home position and reset the device.
Digital position readings can come from an integrated Hall Effect encoder, which provides a single-pulse-train digital signal to measure incremental position and speed. This improves control by indicating actual position changes and speeds.
Smarter Monitoring, Diagnostics, and Maintenance
In addition to returning real-time position data to the user, the network can monitor and report temperature, current, speed, voltage, load, and other variables, enabling advanced condition monitoring, diagnostics, and error handling. Feedback can arrive up to 10 times per second, as the actuator constantly tests itself. If it detects a problem, such as surpassing a temperature threshold, the actuator can stop mid-stroke or finish its programmed move, either fully retracted or extended, and send an error flag to the computer — all in fractions of a second.
With integrated electronics, such functionality is available to the end user on demand; via the network, it is potentially sharable in support of external troubleshooting. Once problems are identified, the plug-and-play capability gained by integrated standards simplifies repair and replacement. Where replacing a problematic hydraulic actuator might require a service call from the manufacturer for hours or even days of disassembly, reassembly, system bleeding, and testing, a smart actuator can be replaced in less than 20 minutes.
The Next Generation
Given their computational and communications capabilities, smart actuators will likely be increasingly integrated with other similarly enhanced sensors, data acquisition devices, and production equipment, as well as other actuators. Today, they are fully ready to participate in the emerging Industrial Internet of Things (IIoT) in which every device not only has intelligence and networking capability, but also an Internet address and the ability to share and subscribe to information sources.
And the IIoT is part of an even broader industrial revolution, in which computational, communications, and physical domains increasingly interact without human command. Known as cyber-physical systems, or Industry 4.0, this promises new levels of efficiency, economy, and safety.