Passenger safety was foremost, correcting load shifts in each car to maintain stability of each. Reliability and availability were important; downtime is lost revenue, so maintenance and self-diagnostic capability were critical. AWC Inc., a Siemens partner with the automation provider, provided local service and support.
Motion control, safety, and related operator controls and power included integrated automation and motion control with drives and wired and wireless communications, Power-over-Ethernet (PoE), advanced programmable logic controllers (PLCs), TUV-certified fail-safe software controller, redundant PCs, operating system, radio voice communications, integrated safety and cybersecurity features, and remote input/output (I/O).
For the controls, including capsule motion control, Intamin deployed PLC software and PLCs on dual, redundant PCs, each with automatic failover. The software controller has functional independence from the Microsoft Windows 10 operating system so operation continues during a Windows restart or failure. PCs reside in the control booth; three trained technicians provide human oversight of the wheel’s operation. Operators have full wheel views, inside and out, via video in each capsule and from overlapping fields of view from cameras mounted on the wheel’s superstructure. Operators have radio voice communications with the person loading passengers into each module.
Remote I/O modules (in a small panel in each passenger capsule) communicate with the PLC controls over an industrial Ethernet network via industrial wireless technology. Local motion control for 14 motor drives is arranged in a 7×7 counter-opposed configuration. This design minimizes capsule motion. The wheel operates using a 7 kW electric motor, which has two redundant backup generators for immediate switchover, should local utility power fail.
Remote I/O modules in each passenger capsule communicate with the master PLC software controller via an industrial wireless LAN (WLAN) comprised of IEEE 802.11n radio access points and client modules transmitting over an industrial Ethernet protocol. (IEEE 802.11n is a higher-throughput subsection of the international standard for wireless local area networks (WLANS)).
E-stop functionality is a click away, backstopped by automated pre-sets if certain conditions occur. The control booth personnel monitor the PLC software for a wide range of operating parameters, including wheel and capsule speeds, motion control drive status, capsule weight, motion, and A/C temperature, and others.
The software controller used is the first TÜV-certified fail-safe software controller. It includes integrated safety features, certified in accordance with International Electrotechnical Commission (IEC) 61508 Functional Safety of Electrical/Electronic/Programmable Safety-Related Systems, for remote I/O communications for local control of the drives on each capsule.
The wireless components combine reliability and security in a solid-state, rugged aluminum package well-suited for the application. Using multiple-input, multiple-output technology to multiply the capacity of radio channels, they can achieve bandwidth throughputs of up to 450 Mbit/s, more than enough for the wheel’s requirements.
Access points and client modules have PoE to minimize cabling. Protection against unauthorized access is provided by advanced firmware mechanisms for user authentication and data encryption. The ride safeguards its wireless and wireline networks with a layered, defense-in-depth cybersecurity program.