Other interesting projects

The floor of the Target Center Arena is movable to allow for configuring the venue for different events.  The primary sports are basketball, hosting the NBA Timberwolves and the WNBA Lynx, and hockey, hosting the NCAA Frozen Four tournament.  Additionally, the arena hosts concerts, rodeos, trade shows, motocross, monster trucks, and whatever else they can fit.   The floor is a 4 million pound concrete slab, which can be raised or lowered 5 feet.  In the raised position, the hockey rink is at the right level for the first row of seats.  When lowered, the floor is in the right position for the basketball court, with additional seating installed to fill the gap.  The floor is lifted on 98 screw jacks, but the original control scheme was completely inadequate, leading to frequent failures of the system.  We designed a new control, using Temposonic linear transducers to accurately measure the movement at each jack, and crated an algorithm that maintains the position of each jack to within 0.032" of a the moving average.  Installation was done by local contractors, and we oversaw commissioning,