A recent study by Ericsson found that almost two thirds of manufacturers believe their company will be at least 80 per cent automated in the next ten years. This transformation will not be possible without an industrial control system, which is the mechanism behind automated machine independence and motion. Here, Richard Mount, Director of Sales at ASIC design and supply company Swindon Silicon Systems, explains how Application Specific Integrated Circuits (ASICs) can help your industrial control system stand out from the crowd.
The devices used in industrial control system technology benefit virtually every industrial sector, including manufacturing, transportation, energy and water treatment. Despite their apparent diversity, industrial control systems share many common aspects — they measure physical quantities using sensors, they condition and process the resulting signals and they take actions that depend on the results.
Why use custom ICs in control systems?
In any industrial setting, the variable a plant manager wishes to monitor is typically analogue, such as temperature or pressure. In any industrial setting, the physical quantity under control will be measured by an electronic transducer. This transducer will likely produce an analogue signal, which can be taken by a mixed-signal ASIC, converted into a digital quantity and processed. Using a custom IC design allows manufacturers to optimise the performance of their system, producing unique functionality that differentiates their product from the competition.
Industrial sensors are often located in confined and difficult environments where they must remain in operation for many years. Needless to say, reliability is a key attribute. ASICs can be a highly rugged solution and are designed with non-obsolescence in mind. With a Swindon ASIC, component supply is co-ordinated for the lifetime of the product, averting potential future system redesigns.
Mixed signal ASICs have long been used in motor controllers, supporting the development of low cost variable speed drive systems (VSDs). VSDs sense electrical current, shaft position and rotational speed, in order to supply appropriate control signals to the motor whilst communicating with the wider system. Using a custom IC for this application allows the VSD to be optimised providing unique performance in comparison to off-the-shelf alternatives.
Linear and rotary encoders
Many industrial control systems use linear and rotary encoders. A linear encoder is a sensor, transducer or read-head paired with a scale that encodes position. It can also be used to determine motion, as a change in position over time. Linear encoders are found in diverse devices from metrology instruments to high precision machine tools including digital callipers and CNC mills.
A rotary encoder converts the angular position or motion of a shaft to an analogue or digital signal. A variety of applications that require precise shaft rotation employ rotary encoders — industrial controls, robotics, rotating radar platforms and even special purpose photographic lenses.
While serving different purposes, both linear and rotary encoders include a sensing element that converts a physical stimulus into a weak electronic signal. An ASIC is used to receive, condition and digitise this signal, passing this data onto the central processing unit (CPU) where position can be calculated.
A custom IC can offer better accuracy than can be obtained using standard components’. The unique design of an ASIC allows investment in performance where it matters, for example a non-linearity specification.
Industrial control system is a very broad term, used to describe different types of control system in a variety of applications. However, using an ASIC can be beneficial, providing bespoke performance and functionality and resulting in a smaller solution using less power. Mixed signal ASICs are a proven method of differentiating yourself, both technically and commercially, from the crowd.
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