In Europe´s biggest roller coaster, the Helix at the Liseberg amusement park in Gothenburg, POG 10 HeavyDuty incremental encoders from Baumer monitor the speed of the carriage’s drive as it approaches the start ramp. The HeavyDuty technology guarantees high reliability and precision under extreme environmental conditions – serving up both thrills and reassuring safety for riders.
Liseberg in Gothenburg is Sweden’s largest amusement park. The Helix roller coaster is one of the attractions that swirls up an adrenalin kick. With a 1380 meter track, Helix is the longest looping roller coaster in Europe and the second-longest in the world. It hurls its riders at up to 90 km/h through six loops and exposes them to up to five times their own body weight. This is the first time anywhere in the world where half of the riders, Helix takes up to 28, sit facing backward, making the ride even more exciting. Before the start, the riders have to be brought to the start ramp at a height of 41 meters.
Controlled asynchronous drives with 315 kW of power are used to move the carriages into the start position. The speed of this drive is recorded by the original Hübner Berlin POG 10 HeavyDuty encoder from Baumer. No easy task, as the roller coaster is freely exposed to the elements – heat from the sun, moisture from rain or wind currents.
Reliability is critical
The POG 10 incremental HeavyDuty encoder and its sister model, the HOG 10 with a hollow shaft, are among the most versatile product ranges of the Baumer HeavyDuty encoders. They deliver reliable speed data in a host of potential applications and operate under the toughest conditions. As a result, they help prevent failures and maintain the availability of machines and systems. This saves downtime costs in a host of applications. With the roller coaster, it even makes a valuable contribution to the safety of human life – a malfunction in the drive of a carriage would at best be annoying for the riders, and at worst a life-threatening experience.
The HeavyDuty technology of the POG 10 guarantees high-reliability under challenging environmental conditions through numerous specific features. Thanks to solid and generously dimensioned wall thicknesses and a warp-resistant design, the die-cast housings are extremely robust and highly resistant to vibration and shock.
Bearings at both encoder shaft ends and the metallic incremental disk offer huge power reserves and unparalleled durability through extreme resilience to axial and radial forces. For outdoor use, in a roller coaster for example, the excellent anticorrosive properties of the CX category of HeavyDuty encoders to EN ISO 12944, achieved through an optimal choice of material and high-resistant coating, are also extremely important. These properties allow the encoders to be used even on or in the ocean, in the Arctic, in the tropics or in the desert.
The combination of labyrinth and shaft seals also protects the inner workings of the HeavyDuty encoders from solid, moist and paste-like contamination. This sealing concept conforms to protection classes IP 66 and IP 67 within a broad temperature range of up to 95 degrees Celsius¤ Current-insulated bearings ultimately protect the ball bearings of the encoder from current flashovers, and this averts any impairment of the lubricant effect. The result is an almost indestructible full package that effectively prevents potential malfunctions and failures, even during tough continuous use in a roller coaster.
This is all the more important as a replacement can get very costly — not because the encoder itself is expensive, but because it is typically mounted in barely accessible locations, as is the case on a roller coaster.
HeavyDuty as an all-encompassing performance promise
HeavyDuty means highly resilient. This is not only about a tight, solid housing and protection against the elements. The intrinsic values have to be right as well. “Of course, it’s always the strong ones, so to speak, that are used when the going gets tough, explains Steffen Günther, Head of the HeavyDuty Business Unit at Baumer. “Yet HeavyDuty offers an all-encompassing performance promise: such encoders must, first and foremost, function under extreme conditions at all times. Secondly, however, their signal accuracy must not suffer under these adverse conditions. For an encoder to be called HeavyDuty, it must be absolutely durable, impermeable and precise.”
Reliable precision is ensured by the interference-immune scanning function with highly robust, optical circuits (Opto-ASIC). This guarantees optimum electromagnetic compatibility with a burst strength for high-voltage pulses of up to 4 kV. In addition, the Enhanced Monitoring System (EMS) continuously checks numerous encoder functions, swiftly detects connection and encoder errors and transmits the encoder status to the inverter or to the control via an error output. The HeavyDuty encoders achieve the best possible SinCos signal quality through the LowHarmonics technology for outstanding control quality, low drive heat-up and high energy efficiency. The incremental square signal outputs also have short-circuit proof, powerful transistor drivers for peak currents of up to 300 mA. They ensure reliable signal quality even over long-distance transmissions of up to 350 meters.
These features – resilience and precision – make an important contribution to ensuring that the Gothenburg roller coaster riders are brought to the start ramp safely and at the correct speed. A good thing too, since this ascent to 41 meters is thrilling enough without any failures¤
Baumer guarantees to keep this all-encompassing performance promise every time with original Hübner Berlin technology through rigorous sample tests and by putting each and every HeavyDuty encoder through a full inspection before it leaves the factory. Resistance to electromagnetic fields, vibration, shocks, dust, hose water, salt spray and much more is ensured on test benches during series production. Detailed quality certificates confirm that these tests have been passed and give the customer the confidence that their encoder won’t leave them high and dry.
The manufacturer can draw on experiences garnered in this encoder class since the 1950s. For 25 years now, the HOG 10/POG 10 product range has been considered the Non-Plus-Ultra in the segment. An original, often copied by the competition, but never equaled, in pursuit of offering more “Beyond the Standard” – more precision, more functionality, more resilience and more benefits for the user. A “more” that can be achieved only through the know-how created from decades of experience with the subject.
It can be assumed that the riders on the roller coaster in the Liseberg amusement park have no idea what’s going on. This promise of resilience and precision, however, keeps the operators safe in the knowledge that their ride will never become a roller coaster of feelings for them¤
When is an encoder “HeavyDuty”?
“HeavyDuty” is neither a protected expression nor the name of a standard. The HOG 10/POG 10 product range of Baumer Hübner, however, has generally been considered the defining “original” for 25 years now¤ The features that set this range apart and against which the segment is benchmarked are:
• Mechanical resilience: resistance to hard shocks, vibration and forces on the rotary shaft for many years
• Impermeability: sealed against dirt, dust and moisture
• Electrical resilience: electronic components inside the encoder shielded against electromagnetic fields and powerful output drivers
• Precision: reliable signal delivery, allowing a precise open-loop and closed-loop control of drives and generators
“HeavyDuty” is an all-encompassing performance promise. It guarantees that an encoder will function reliably and precisely at all times over a prolonged period and under adverse conditions.