Vision as an enabling technology for control & automation

The UK is no exception, with the most recently published statistical information from the VDMA (the German Engineering Federation) revealing that in 2013, the total sales of machine vision components and systems from European companies into the UK was second only to Germany across the EU. Not only that, the growth of those sales in the UK was the greatest in the EU, rising by an impressive 23.2% during this period. Vision has an important role to play in the automation of many manufacturing processes which in turn serves to improve the competitiveness in the manufacturing sectors.

Even though the growth in UK manufacturing output has slowed during 2014, figures published in September by the Office for National Statistics showed that manufacturing output grew by 0.5% from Q1 to Q2 2014 providing the largest upward contribution to production growth. The enormous range of capabilities offered by industrial vision, combined with overall reducing unit costs means that vision has become a genuine enabling technology in control and automation in a wide range of manufacturing industries.

Robotics, inspection & process control

The ability of vision to monitor, regulate, check, analyse, sort and classify with high precision and safety, means that historically it has been associated with inspection of product for quality control purposes. Link the output of a vision system into a reject gate and there is the very first level of automation, where ‘out of spec’ products can automatically be rejected ensuring only ‘good’ product reaches the customer. However this can lead to a lot of waste – even if the defective product can be reworked, the energy consumption required and time wasted in producing defective product cannot be recovered.

In principle, the earlier in the process that a vision system can be used, the earlier it would be possible to detect if the product is starting to go out of specification. This allows preventative action to be taken with the objective of eliminating defective product altogether, and if no defective product is ever manufactured, costs can be minimised and profits optimised. By linking the vision system directly into the process control system, another layer of automation is introduced to improve manufacturing competitiveness. Even if processes are adjusted manually as a consequence of the data produced by the vision system, the vision system is making a positive contribution. Almost any vision inspection process is de facto a move towards automation and vision has effectively become a currency of automation.

The ability of vision systems to read 1D and 2D codes as well as alphanumerics means that they are used extensively in track and trace applications and vision will have a key role to play when the Falsified Medicines Directive is introduced to provide traceability for drug manufacture right the way through to an individual pack of medication. Vision technology developments move at a fast rate, meaning that ever more complex inspection tasks can be carried out at production line speeds. In the last few years, genuine 3D inspection technology has become affordable and is being used increasingly in inspection applications. Creating complex 3D images is computationally intensive and therefore time consuming. So it is has been the emergence of processors capable of handling the computational overhead required at production line speeds that has been the key to establishing true 3D measurement techniques and made it a credible alternative to 3D contact measurement and metrology.

Vision also has an important role to play in guiding robots in pick and place applications, particularly in the automotive and pharmaceutical industries. Robot picking of unordered parts enables manufacturers to save a lot of time and resources shifting or organizing parts in the manufacturing process or feeding robots and machines with parts. The challenge lies in acquiring images in 3D, building a mathematical model and analysing the position of something in 3D space and then transmitting 3D picking coordinates to a robot, all in just a few seconds to meet the cycle time of the robot and avoid it having to wait for the next set of coordinates. Fortunately it is possible to do this using stereo vision imaging techniques, where features are extracted from 2D images that are calibrated in 3D.

Vision in action

The importance and use of vision in industry can be illustrated in a number of ways. At the recent PPMA (Processing & Packaging Machinery Association) Show held in the UK, no less than 34 exhibitors were showing some sort of vision system. Some of these were vision specialists, but there were also companies who had integrated vision into their equipment, such as food packaging equipment, food portioning equipment, filling and capping systems, control specialists etc – a perfect example of how vision is an enabling technology! There are so many real-life applications for vision that it is difficult to do it justice, but just a tiny flavour can be given from some of those featured this year in UKIVA’s (UK Industrial Vision Association) ‘Vision in Action’ newsletter:

• Identification of part-filled or incorrectly dated coded multi-slot packs in the food industry
• Reading of DOT code, tyre model, and specification on automotive tyres
• Automated pick and placement of disc brakes
• Woundcare product packaging inspection using infrared imaging
• Pleat detection in aluminium bottles
• Robot picking system for dog meat
• 100% testing of vehicle steering components
• Label inspection of food products
• Robot picking of unordered automotive components
• Inspection of automotive door handles
• Automated vehicle door installation
• Automated detection of in-service railway track defects
• Automated adjustment of product positions within packaging to avoid trapped in seal faults

Vision is extraordinarily versatile and can be integrated into OEM equipment, built into new production and processing lines or retrofitted into existing lines. So vision is an enabling technology and an integral part of automating industrial process, but how easy is it to apply? This is an area where UKIVA can help.

The application of vision

Technological advances in vision technology take place on a continuous basis. The extensive range of cameras, lenses, lighting and software available may seem bewildering, but choosing the best system starts with defining and understanding the particular problem that you are trying to solve. The integration of vision systems into industrial processes is now easier technically than ever before. From individual components with a choice of inputs and outputs, external triggers, industry standard data transfer protocols and easy to program inspection software, to smart cameras where the result of an inspection can be transferred over an Ethernet connection, the vision industry is now very much geared towards lower cost integration.

Some companies will have vision specialists within their engineering ranks, but vision users don’t need to be experts in the field - they can call on the expertise of the vision component vendors and system integrators to define the most appropriate system and many such vision technology suppliers and system integrators are UKIVA members. The UIKVA, whose main objective is to promote the use of vision technology by manufacturing industry, is experiencing its fastest growth in membership this century and interestingly, the majority of the new members are vision systems integrators, highlighting the demand for adding vision into existing manufacturing processes. The full membership list can be found at www.ukiva.org.