If analytics are the ‘brains’ behind Industrie 4.0 then smart sensors are the heart and lungs. They are the lifeblood of a modern smart factory; the dataflow that keeps it operating at optimal efficiency. But what differentiates a smart sensor from the common or garden variety? Well, it’s the ability that current solid state technology has given us to integrate multiple devices of different functionality onto the same substrate or wafer.
This technique of combined technologies brings multiple benefits. For instance, a mix of analog and digital circuitry allows the sensing functionality, data processing, diagnostic information, as well as configuration capabilities to coexist on a single device. Not only that, but the communication functionality can also be integrated, and this could even be a wireless transmitter if that is what the situation requires.
Having all this functionality built into the device at the substrate level gives smart sensors the power to adapt their behaviour to changing conditions. Self calibration is an example. All sensors experience some degree of drift over time due to the ageing effect on components. Smart sensors are able to self compensate for this on a continuous basis, which gives more accurate data over the lifetime of the device, and in fact, extends the lifetime of the device as well.
Self calibration aside, it is the adaptive nature of smart sensors that gives manufacturers the ability to respond to the emerging trend of customised orders. The power of the Internet gives consumers the ability to order products in a variety of colours, finishes and styles, while expecting delivery times comparable to ordering from stock. The only way for manufacturers to respond is by producing in lot sizes of one. To do this efficiently requires them to reconfigure production lines quickly, which places an extra burden on the sensors as they must be able to self-adapt to this environment of continuously changing parameters.
Specialist sensor supplier SICK Automation has taken up the challenge. The company vision is to equip future machines with a generation of sensors that can be automatically parameterised by the machine controller. When the customer order arrives, the machine is configured quickly and without intervention to produce a personalised one-off piece at the cost of a mass produced item. See ‘Smart sensors for smart factories’ for more.
Contactless energy transfer untangles a mess
Non-contact energy transfer enables the supply of energy through an air gap, which eliminates the need for supply cables to the device receiving the power. This type of inductive power transfer, now quite common in rechargeable consumer products like electric toothbrushes, is used in industrial applications to power sensors and automated guided vehicles.
In the AGV application, the big advantage is that those cumbersome drag chain systems, traditionally used to carry the power cables to the vehicle, are no longer necessary. Instead, a powered inductive loop (or series of loops) is installed along the path of the AGV which is equipped with pick-up plates that are energised in the magnetic field. The current generated is then rectified on the vehicle and converted back to an AC voltage of the amplitude and frequency required by the vehicle’s drive motors.
SEW-Eurodrive has perfected such a system under the brand name Movitrans and we feature an interesting local application story in this issue. Sasol Wax has installed a Movitrans system to power the pallet transfer trolleys that transport the wax to the exit conveyors, and ultimately the pallet wrapping machines. Getting rid of the existing messy drag chain system provided many benefits in this situation. See ‘Contactless energy transfer system at Sasol Wax’ for details.
SAIMC expands its horizons
In closure this month, congratulations to the organisers of the SAIMC gala dinner held this time at Montecasino. It was a slickly arranged affair and the dancing afterwards proved the perfect foil to an evening of automation technology and awards. For those of you who could not be there, you can read more about it on ‘SAIMC expands its horizons’.
Steven Meyer
Editor: SA Instrumentation & Control
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