Motion simulator rides rely on SHG-TT incremental linear encoder

When one of India's leading designers and manufacturers of motion simulator entertainment for amusement parks needed to source a supplier of rugged encoders to provide position feedback from its hydraulic actuators, the company opted for the IP67-rated SHG-TT incremental linear encoder from Newall Measurement systems. Such has been the success of the encoder that the devices are now fitted to a total of 14 three/four-axis motion simulator rides at leading theme parks across India.

Established in 2000, BlueChip Amusements (India) Pvt Ltd is part of the reputable Sudarsan Group of engineering companies based in India. Although young, BCA has already grown into a sizeable concern that today employs 34 people at its Chennai headquarters. From the outset, the company's focus has been on sourcing components for its equipment of the highest standards of reliability and quality.

Although the rides are only simulators, considerable forces are involved in tilting and swivelling the seats taken up by theme park visitors (seat movements are meticulously synchronised to action-packed movie scenes). Repeatable and reliable operation is essential to ensure safety.

Closed-loop servo hydrualic system

"We had designed a closed-loop servo system for our hydraulic actuators and needed a suitable encoder that would provide reliable position feedback in harsh conditions because the construction of the machine was such that the linear encoders would be partially exposed," explains BCA's project manager, Mr K Jagadeswara Rao. "Product failure when a ride is in operation is not something we can contemplate. We build safety into our products and every vital sub-product or accessory comes only from reputed manufacturers. We do not compromise when it comes to quality."

With this in mind, BCA commenced its search for an IP67-rated incremental linear encoder, identifying the SHG-TT via the internet. "Without doubt the SHG-TT best matched our motion controller specifications – it was ideal for our requirements."

That was in 1999 and, since then, BCA has had no cause to regret its decision. The Newall encoders are now fitted to 14 motion simulator rides at theme parks across India, including: Veegaland Amusement Park at kerala; Wonderla Holidays Theme Park in Bangalore; Blackthunder Theme Park at Nilgiris; Kishkinta and VGP Universal Kingdom Theme Parks in Chennai; and the R-world multiplex at Ahmedabad. Most of the simulators have four axes while others utilise just three.

Accuracy of +/-0.003mm

Newall's SHG encoders are capable of achieving an accuracy of +/-0.003mm. They are sealed to IP67 and resistant to severe shock, vibration and RFI, making them highly suitable for BCA's requirement. The SHG can deliver real-time feedback at traverse speeds of up to 20m/s. As with all Newall inductive linear encoders, the SHG models are impervious to contamination and require no maintenance. They are compatible with the majority of DROs and control systems, offering a differential quadrature output at RS422 TTL levels. A comprehensive measuring length range is offered, giving travels ranging from 50 to 10,004mm.

Mr Jagadeswara Rao concludes: "The Newall SHG-TT encoders provide us with excellent performance, even in cold or dusty conditions. We are very satisfied with the product and with Newall, who have provided us with first-class support from the outset."