Ready for Take-Off
German amusement park supplier Wiegand is implementing innovative position measurements into two fairground rides. In the future, the rides will rely on a system consisting of encoders and RFID read/write heads from automation expert Turck, connected to a Hima safety controller. Wiegand previously used an optical encoder in its Wie-Flyers and Bobkart circuits that only offered limited performance in severe outdoor environments.
After the component was discontinued, Wiegand and its integrator ARI-contact came across a permanently robust solution based on Hima and Turck products. Turck encoders, RFID tags and read/write heads will ensure safe movement for these fairground rides in future. Through the combination of incremental and RFID position sensing, the system reliably prevents any collisions.
By Karl-Josef Franke, Sales Specialist for System Solutions, Turck
Mild winter led to the invention of the summer toboggan
The fairground business, dedicated to the amusement of others, seems like a very fulfilling profession. That was also Josef Wiegand's motivation for opening his first ski lift in 1963. For many years he followed the motto of “Ski and toboggan well”. In 1975, a drop in sales resulting from mild winter weather led him to expand his seasonal product portfolio: the Josef Wiegand company created and patented the summer toboggan run. Today, the company is a worldwide leader in the fairground business sector.
Flying rides, water slides, and more
Whilst the portfolio of the company with headquarters in Rasdorf initially consisted of standard summer toboggan runs, its current portfolio includes flying rides, water slides, Bobkarts, and other types of toboggan runs. The former one-man company has now grown into a medium-sized family business with ten branches and 450 employees worldwide. Besides the planning and production of the amusement rides, Wiegand also handles the installation of its products worldwide.
The water slides, for example, can even be found on large cruise liners such as the AIDA. If a fault occurs during a Mediterranean cruise, Wiegand fitters carry out the repair directly on site. Wiegand has now introduced technical innovations based on RFID to its flying rides, the so-called Wie- Flyers, and to its Bobkarts ride.
Automated collision prevention
The Wie-Flyer is a suspended gondola-shaped two-seater, in which the riders can control their speed as required. They “fly” at speeds of up to 40 km/h through the bends of the suspended rail system as on a big dipper. The power for the flyers is supplied via a system integrated into the rails. An automatic distance control system is integrated in order to prevent collisions. This system measures the position of the individual gondolas and lets them communicate with each other. This way, the following gondola always knows the location of the gondola in front. The gondolas are offered in two different versions – either an open gondola, the so-called twin-seater or twin-flyer, in which the riders sit side-by-side, or a closed gondola, where the seats are arranged one behind the other.
One controller, two different rides
The Bobkarts are electrically driven toboggans that run through a stainless steel track. They are supplied with energy via a touch proof conductor rail, which is run in a channel connected to the track. As with the Wie-Flyer, customers also control the speed of the Bobkart toboggan themselves. As the Bobkarts have the same controller as the Flyers, the same speed and rear-end collision prevention features are used. However, the special feature of the Bobkarts is the fact that they do not need a hill.
If the ride is located on a level section, the track functions just as well as on a slope. This was also the thinking behind the development of the Bobkarts, as they solve the problem of many amusement parks being located on level ground. They can thus also be used in restricted spaces. The possibility to run the track in loops enables space saving and versatile designs.
Optical encoder needed to be replaced
In the previous design, Wiegand used optical encoders in its Wie-Flyers and Bobkarts in combination with a Hima safety controller. When the optical encoder was discontinued by the manufacturer, Wiegand looked for a suitable replacement for the positioning of its amusement rides. In addition, the previous solution was very susceptible to faults, leading to frequent mechanical problems. “We were often called out to our customers to carry out repairs, even as far away as China,” workshop manager Oliver Grothkopp recalled.
Hima found the RFID solution at Turck
Wiegand, Hima, and its integrator ARI-contact then started to search for an alternative solution. The controller manufacturer found the solution at Turck. Hima knew the requirements that the position sensing and safety system had to fulfil due to their previous collaboration. The system had to determine the position of the individual gondolas and control or restrict their speed on the basis of this information. Fail-safe position sensing also had to be guaranteed even at high speeds. In addition to the encoder, position sensing also used RFID technology.
“Hima found the Turck encoder to be a reliable solution,” confirmed Andreas Meyne, the responsible project manager at the controller manufacturer. The non-contact design of the QR24 encoder makes it particularly suitable for operation in harsh environments, since its operation is not impaired by vibration, humidity, or contamination. The inductive measuring principle enables the design of the positioning element and the sensing unit to be combined in a fully enclosed and encapsulated unit.
Turck developed RFID firmware
The position sensing solution using RFID and the encoder enables the controller onboard the gondola or kart to coordinate its location. Turck developed a firmware specifically for its RFID read/write heads. Hima provided a function block for this that was specifically designed for Turck's RFID system. “This solution enables us to achieve a guaranteed read speed,” said André Aßmus from system integrator ARI-contact.
The QR24-INCR incremental encoder transfers pulses to the controller, which calculates the actual speed of a gondola from this. The encoder is located on a guide roller in the upper section of the Flyer. If there is a deviation, or if the preceding Flyer is too close, the controller of the following vehicle initiates the rear-end collision prevention measures. Programmed tolerance values prevent any unnecessary intervention.
Controller: HIMatrix F35 034
The HIMatrix F35 034 controller used is an SIL3-certified safety controller with shortened reaction times that are considerably below ten milliseconds. This makes it ideal for use in this project, which requires fast communication and reaction times. The controller is also compact and shock-proof, which enables its use in any vehicle. The HIMatrix is also used centrally at Wiegand. As a controller is provided in every ride, a controller in the control cabinet takes over the higher-level network controller function.
Rides are in worldwide use
The Bobkart runs and other amusements rides from Wiegand are used worldwide. The Wie-Flyers have so far only been used on the testing grounds of the company in Brotterode, Germany. Another track has been sold as a Twin-Flyer in Mexico City, to be used as an attraction in a shopping centre. The Bobkart runs are already in operation at 20 locations, including in China, Japan, Kuwait, and Saudi Arabia, as well as in German amusement parks such as the Ravensburger Spieleland.