Where sensors were once simple analogue components with basic output, the best contemporary solutions feature mixed signal ASICs with front end signal processing, calibration for varying environmental conditions and robust bidirectional communication interfaces that embody intelligence in the sensor head itself. The knock on effect is intelligent industrial systems that are simpler to configure and maintain.
In this article, we discuss how SWINDON Silicon Systems’ expertise in mixed signal ASIC / MEMS and System on Chip (SoC) technology will benefit industry’s move towards and place itself at the heart of intelligent sensing.
Intelligent sensors in industry
From accelerometers and gyroscopes in mobile phones to the multitude of sensors in our cars that help us park more safely and ensure our tyre pressures are at optimum value, we are surrounded by applications that help us in our day to day activities making us more productive and keeping us safe.
As we experience what is possible in our everyday lives, it is inevitable that this will cross over into the industrial environment where the addition of “intelligence” brings considerable advantages in terms of increased flexibility and productivity.
Throughout industry there are a wide range of sensors being used to detect, measure and analyse changes in pressure, displacement, proximity, temperature and flow to name a few. However, many have basic output and simply provide raw data that has to be further interpreted to produce useful information. Many also require frequent manual adjustments, calibration and maintenance, both on a routine basis and when they need to be replaced.
By installing intelligent sensors these factors can be avoided, resulting in an increase in productivity.
Adding intelligence to industrial sensors
Companies such as SWINDON Silicon Systems are now working with sensor manufacturers, to apply their expertise in designing and developing customized ASIC / MEMS solutions in a variety of formats to the industrial marketplace.
Customised ASICs offer a very small form factor, highly optimised design and lowest cost solution for medium to high volume applications.
Integrating technology for a fully packaged solution
When designing an ASIC, especially with relatively simple systems, it often makes sense to integrate other parts of the circuit schematic on to the same silicon die. The resultant System on Chip (SoC) combines analogue and digital functions and adds processing power. This processing power can be in the form of an embedded microcontroller or, for simple, fixed function intelligence, a logic gate implementation.
The main driver for this level of integration in a sensor is reduced size and lower BOM cost. If we take a look at proximity sensors, for example, many of these are no bigger than your finger including sensor element and PCB sealed in a waterproof enclosure. Twenty years ago this level of integration would have been very challenging and out of the reach of most companies, now the acquisition of smart sensor technology is a reality and more accessible.
However, sometimes it is not possible to integrate all the system features into a single ASIC die – this is where a System in Package (SiP) comes into its own.
The benefit of placing a single packaged component on the PCB is maintained. ASIC die, Micro Electro Mechanical System (MEMS) devices, CCD Image Sensors, large value discrete components and other die of different process geometry or metallurgy can also be included.
Intelligent sensors “in the field”
ASICs open up the possibility of adding intelligence to sensors, and that brings new opportunities to the factory floor.
Firstly, the sensor can accommodate pre-processing of data in the sensor itself, allowing operational decisions to be made “at the edge”. This local analogue or digital signal pre-processing can improve raw data measurement as it reduces noise and allows filtered and relevant data to be sent to the centralised data collection point.
Sending measurement data in a digital form can for example improve read accuracy by being more noise immune and offer detection and correction of errors when they occur. The installer sees a drop in complexity as data is provided in a ready scaled and linearised form.
Calibration tables can be stored and applied by the sensor. These values can be loaded into memory at the time of manufacture by SWINDON or re-calibrated in the field.
More processing power in the sensor head effectively makes the computing more distributed – reducing code complexity, for example in PLCs, and even opens the possibility of closing control loops locally, thus reducing round-trip latency.
With bi-directional communication links also being integrated into industrial environments, the intelligent sensor can now hold operational parameters, provide setup or fault diagnostics, sensor head based human machine interfaces can be reduced or removed and cloud based monitoring becomes more straight forward.
Intelligent sensors lend themselves more favorably to ‘fieldbus’ arrangements where they share wiring infrastructure and changes or replacements are quick and efficient.
Conclusion – Transforming the factory environment
As companies such as SWINDON continue to apply their considerable expertise in mixed signal ASIC / MEMS, SoC and SiP technology to the industrial sector then intelligent sensing will start to transform the factory environment and we will see more versatile, cost-effective and environmentally friendly factory and production processes.
As well as adding intelligence to sensors, the commissioning of a custom mixed signal ASIC meets industry demands of higher performance and smaller size, without increasing costs.