Can you add value to your machines, perhaps adding greater sophistication and complexity, without impacting on development time and programming cost? Robert Brooks and Karl Walker look at the evolution of a new breed of machine controllers. At the heart of every machine is a machine controller. That might seem an obvious thing to say,
It’s sometimes easy to forget that production safety is not just a question of obeying the law: it can actually have a direct and positive impact on productivity, reliability and output quality. That’s been proven in practice by Helios Energy Europe (Heliene), one of Spain’s leading manufacturers of high-output photovoltaic energy systems. These generate electricity from sunlight, using solar panels of photovoltaic cells, and they are increasingly used as a source of renewable energy, especially for newly built houses, offices and factories.
Heliene has a reputation for making high quality and innovative products that are both efficient and competitively priced. To a large extent, this reputation derives from the company’s customised and highly automated production lines which optimise productivity and maintain quality.
The solar panels are made up of 156mm square cells, which are precisely positioned and linked in 6 x 10 arrays with short ribbons of copper. These are soldered together, before the panel is laminated. The final stage is to assemble the panels into aluminium frames before they are tested to make sure that they meet the required standards.
The whole process is carried out using a line of robots, with very little human intervention apart from machine control, visual inspection and some cleaning of the products as they move down the line. One of the most critical points in the line is before lamination, when all air must be evacuated from between the layers, since this would adversely affect generating performance. Once the panels are laminated, it is almost impossible to rectify any defects, so the need for precision is paramount. Safety is another key consideration: the delicate – and expensive – materials must be handled with extreme care to avoid damage, or injury to the trained staff who work the line.
Advanced safety systems
Precision and safety are fully integrated and standardised. Control of the robots, and the entire production line, is through a series of NS10 PLCs, interfacing with Omron motors and inverters, sensors, relays and controllers. Safety is controlled by an NE1A safety PLC, which has expansion modules along the production line on a DeviceNet bus. This set-up controls the emergency stop pushbuttons at each of the robot stations, limit switches on the safety doors around the robots, and F3S-TGR-CL safety light curtains protecting the loading/unloading sections.
José Cardenas, part of the management team at Heliene, explains that using integrated and automatic systems for both control and safety has improved reliability and precision in the production process: “Compared with previous lines, we get more speed, improved quality, and safety assurance. Relying on a single brand for the equipment also makes maintenance and expansion much easier.”
Reliable, versatile and flexible
Oscar Chillón, Process Engineer, agrees: “Robotic manufacturing processes like this need production and safety systems that are reliable, versatile and flexible. We’ve achieved that with this line, and we’ve made productivity improvements as a result.”
Building safety into automated production – rather than seeing it as a separate but necessary add-on – does more than create a more secure working environment. It can help to increase output (because lines can run faster) and improve quality at the same time.