It’s a cold Thursday afternoon in Pittsburgh and the Penguins are slated to play the Panthers later that night when Jack, one of the Penguins’ Zamboni drivers, calls in sick. Recently, there’s been a shortage in the number of experienced Zamboni drivers, so the Penguins have been forced to hire new recruits. It takes 2-3 weeks just to get these new drivers trained, not to mention the many more hours required for them to learn to consistently produce NHL quality ice. As a result, the Penguins only have one trained driver available for the game tonight, Mike. However, resurfacing the ice in the 10-minute time slot allotted during intermission requires two Zambonis to be driven at once.
Later that night, when the horn blows to mark the end of the first period, all of the players exit the ice and the Zamboni gates open. With everything clear, Mike drives out onto the ice on his Zamboni to begin the resurfacing process as usual. Immediately behind Mike is the second Zamboni needed for resurfacing which, much to the surprise of all the fans in attendance, has no driver sitting behind the steering wheel. What the fans don’t realize is that the second, driverless Zamboni has been outfitted with autonomous convoy technology developed by AIce that allows it to follow the Zamboni driven by Mike around the ice. While Mike drives his normal resurfacing pattern, the autonomous follower detects where the leader Zamboni is and localizes itself relative to the leader’s current position and heading. The follower also estimates the current speed of the leader Zamboni and estimates its own speed and pose. Using the data about itself and the leader, the follower Zamboni plans a path forward that would allow it to follow the path of the leader, but with a lateral offset of one body length to the right.
The details of this path are then used to generate steering, acceleration, and braking commands that are sent to the drive-by-wire system that the follower has been retrofitted with. The drive-by-wire system allows the follower to accelerate, brake, and steer on its own to follow the leader Zamboni driven by Mike around the ice as the convoy carries out the resurfacing operation.
A few minutes into the intermission, one of the ice technicians begins to head walk off the ice having just finished the routine maintenance done around the goals. The ice technician, not paying attention, accidentally walks into the path of the autonomous follower Zamboni. The follower detects the presence of the technician and alerts him that he is in the way of the Zamboni. The follower also automatically begins to slow down and stops short of where the technician is standing to avoid an accident. Once the technician moves out of the way, the follower continues along its path.
After 10 minutes of operation, the entire rink has been resurfaced, and the convoy exits the rink, ready to return for the next intermission. After another 10 minutes, intermission is over and play resumes on the fresh and level ice. Figure below shows a snapshot of the autonomous Zamboni convoy in action.
