UK tourism booms with PLC magic
The Suffolk coastal resort of Southwold is booming as the 'staycation' becomes the holiday of choice for many British families. One of its most popular attractions is the refurbished pier which, thanks to Mitsubishi controllers and a truly original-thinking engineer, combines Edwardian elegance with surreal amusements.
Through the latter half of the twentieth century most English seaside towns seemed to be in terminal decline. None could compete with cheap flights to sunny climes and few were managing to reinvent themselves for a younger generation.
But the tide began to turn with the new millennium and this year many resorts are having their best season in decades. Southwold in East Anglia is virtually unrecognisable compared to 10 or 20 years ago. Large areas have been completely refurbished, the beaches are busy and the shops buzzing. There are attractions for families, young singles, naturalists, sportsmen, culture-vultures, sun seekers and much much more.
Perhaps the biggest success is the pier. This Art Nouveau masterpiece had degenerated to a dangerous and depressing eyesore, until it was bought and re-built by local philanthropist and businessman Chris Iredale. It is now home to the Under the Pier Show, probably the wackiest and most original amusement arcade ever built.
Conceived, design and built by Tim Hunkin, each hand built machine takes visitors on a mind-bending journey to the surreal and fantastic. Behind their dream-like facades each machine has a small, but often complicated and always unique control system based on a Mitsubishi programmable logic controller (PLC).
The newest machine is 'Pet or Meat', which graphically illustrates the possible outcomes for a baby lamb. A favourite since its timely installation in 2009 is 'Whack a Banker'. Another is 'My- Nuke' where you can load plutonium rods into your very own nuclear reactor. Then you can test your skills on the 'Mobility Masterclass', 'Walk the Dog' through Southwold and get your mother-in-law frisked!
Halfway along the pier is Tim's original masterpiece, the Water Clock, which chimes on the half-hour very cheekily with its naughty boys. And right at the end of the Pier look out at sea through the Quantum Tunnelling Telescope, sponsored by the European Onion with shark attacks, mermaids and daring air-sea rescues!
Pet or Meat is fairly typical of Tim's approach to control engineering. "It uses a Mitsubishi FX PLC configured with 16 inputs and 14 outputs in a driven type application. We spin a table and over-speed flywheel, then use the PLCs timers to disconnect these using an electric clutch. The variable amount of momentum in the system is then used to display a unique sequence of illustrations telling the lamb's life story - be it happy or sad.
"While this all sounds very simple, we add soundscapes, lighting sequences and other special effects to enhance the experience. In fact the control system runs off 435 lines of code, so as a programme it is comparable to many in mainstream engineering."
All of Tim's machines use FX controllers, right from the first he ever built, a water clock for his own garden. "That FX has been ticking away for many years and is still 100 per cent reliable.
"In fact I built that clock as a hobby; Chris Iredale walked down my road and knocked on by door saying he wanted one for his new pier! It was a surreal start to what has become a full time business. I have now built machines for many organisations, including London Zoo and San Francisco's Exploratorium, where I spend a month a year designing and building highly educational machines for young people."
As you might expect from someone as enthusiastic as Tim, his machines and control systems often grow in ambition as they are built. Whack a Banker, for instance started as a topical take on the traditional fairground game of Whack a Mole, but wanted to also capture the randomness of a fruit machine and the erratic action of a pinball.
"I started out with a small FX, upgraded to a larger one, then ended up using both. In fact this was something of a watershed for me; previously I had confined myself to one FX per system but as the machines were getting more complicated I was ending up with lots of rather old-fashioned relays. I have also recently discovered the delights of Mitsubishi's Alpha controller - a programmable relay."
Some of the attractions are large and robust. For instance what appears to be a two-person bird-watching hide is in fact a simulator-type ride so there are several axes of movement synchronising with images and sounds. Most simulators cost hundreds of thousands of pounds and include any number of control loops to cross check and ensure that video, sound and movement are in sync.
"With Mitsubishi's industrial automation equipment, complicated systems architecture is unnecessary," asserts the unconventional engineer. "With quartz-based timing built into the controllers once you set them up they are accurate to the atomic second, so there is no need to close the signal loops. If mechanicals and visuals start off in sync, they stay in sync.
"The FX is my favourite controller. The sensors and switches go in one side and relay contacts come out the other - there's no soldering and everything is very robust and protected against voltage spikes etc. The stepladder programming language is very versatile and quick once you've got used to it. I doubt the Under the Pier Show would be possible without FXs."
Other News from Mitsubishi Electric
Latest news about PLCs