Alex's animatronics wow tradeshow visitors

Battle Creek, MI —Attracting potential customers and keeping them at a booth has always been a concern for trade show exhibitors. Mannetron, a mannequin and animatronics company, has found a solution through the use of an interactive robot named Alex. "If you take a robot and preprogram something, people lose interest in 30 seconds. But if it's live interaction, people will have a ball, they will stay around and have fun," says Peter Jungen, chief engineer at Mannetron and the creator of Alex.

Through animatronics (the use of computer technology and a form of radio control to animate puppets or other models) Alex is much more sophisticated than his theme park cousins. Controlled by a handler, he can move around in the crowd and carry on live conversations with trade show visitors.

The name of the game in animatronics is realism. Robotic movements must be smooth and lifelike. "What we're trying to do is to have a certain quality of motion," Jungen says. Mannetron relies on the 5950-series motion control cards from ACS-Tech80 (Minneapolis, MN). He notes, "I did a survey of the available cards. I found the way the 5950 card was set up and could interface was very logical. We set up a test arm to develop all the software around the Tech80 card, plus their support was excellent."

The heart of these compact, 3.6×3.8×0.9-inch cards is their PMD DSP (digital signal processing) chipsets. These chipsets handle the PID (proportional integral derivative) with a velocity feedforward servo algorithm for up to four axes per card. The dedicated DSP frees the host CPU for other tasks and isolates motion control functions from host software problems. The result is extremely fast motion control with positional accuracy within±1 count. Clamping diodes address the concern of "dirty" power from electromagnetic interference (EMI), a real concern in a trade show environment.

When robots interact closely with people, as at a show, safety is a big concern. Permanent magnet-dc motors drive the robot's appendages. To help keep all motions under control, the software that controls the Tech80 card inside Alex is set up to monitor motor torque. Jungen notes, "In this case, these arms are moved by this motor. If they hit an obstacle or a person and the person doesn't move out of the way, the arm will back off. We can make it behave like a clutch or any way you want it to. That's the great thing about these Tech80 cards."