In cooperation with HOAC, Visual act delivered 6 Visual act Advanced Wagons to Poeun Art Hall, YongIn, Korea.
The wagons allows free and programmable motion in any direction without tracks or other mechanical limitations. The wagons can rotate and move simultaneously, and various motions can be linked to create longer or complex motions. Standard motions – such as moving from the side stage to meet the stage elevators – are pre-programmed and can be activated by the operator at any time.
The three wagons can operate individually or can be locked together by a total of 16 automated locks. When the three units are connected together the machinery from the center wagon is used to power the revolving stage. To keep the platform height at a minimum the revolving stage rests directly on the floor. It is mechanically guided along its perimeter and can therefore operate at any position. The advanced algorithm of the Visual act control system allows the revolving stage to rotate as the entire wagon moves. This was a specific requirement of the customer.
Each wagon contains 4 drive units with a maximum speed of 0,5 meters / second and a load moving capacity of 2750 kg. Each drive unit is placed in an individual lift cassette actuated by pneumatic cylinders. The cassettes serve two functions. The use of pneumatic cylinders to press the wheels against the floor guaranties even pressure on the floor, regardless of the flatness of the floor or the load on the wagon. This ensures sufficient traction in all situations while eliminating the risk of overload and ensuing damage to the stage floor. In addition the cassettes can be used to lift the drive units from the floor, allowing a wagon to continue to operate even when a drive unit has failed. As an ultimate backup, all drive units can be lifted from the floor and the wagon can be pushed by hand.
The modular nature of the system allows the user to create smaller stage wagons, adding even more flexibility to the system. Wagons can be built in any size starting with a base unit of 2 x 5 meters.
The laser based navigation system uses a set of reflectors placed in the perimeter of the stage area. A second set of reflectors is placed to allow motion on the lower level created by lowering the stage and compensating elevators. Each wagon uses two scanners and can achieve position repeatability to plus/minus 5 millimeters. When the center wagon is working as a revolving stage the laser navigation system cannot be used, so the revolving stage gets its position by using a bar code scanner to read barcodes placed on the surrounding wagon.
Each wagon has three 120 VDC battery packs providing a total of 39 Ah of power, allowing a full day of operation based on overnight charging.
Motions are created on the operator desk by drawing, as in a cad program, or by entering coordinates or selecting from predefined positions. Motions are downloaded to the wagon controllers over a radio link to allow for real time operation. The operator has full control of the motion – both forward and backward – from a joystick on the operator desk. He can also operate a wagon or combination of wagons in “free mode” using 3 axis joystick to control and combine motion along the x, y and rotational axes.
A hand control can be plugged directly into a single wagon to allow direct control for maintenance or backup operation.
To simplify maintenance all parts of the system – controllers, drives, mechanics – are placed in modular cabinets or frames and are connected by cables with locking connectors. In the event of component failure it is simple to replace the actual module with a reserve module.