Meet ESTHER, your new tennis-playing robot partner

Your search for a practice partner will never end in vain, should Georgia Tech professor of robotics Matthew Gombolay have his way.

For the last two years, Gombolay has put his expertise to work on a passion project: a tennis-playing robot called ESTHER that mimics the movements and strokes of a human, going beyond the traditional ball machine as a training tool. A passionate recreational tennis player, Gombolay had long been playing with the idea of how a robot might be able to assist a player in developing their tennis skills.

Thus, ESTHER was born, and the name is fitting in many ways. As he began the research for his project, Gombolay discovered that the movements of wheelchair tennis could be most easily replicated by a robot. ESTHER is an acronym for Experimental Sport Tennis Wheelchair Robot, and a tribute to Hall of Fame wheelchair tennis player Esther Vergeer.

ESTHER has a racquet connected to a single, robotic arm, and is able to cover both ends of a tennis court on wheels.

The progress has only continued since the initial idea and prototype was born. Gombolay and 20 students recently authored a paper on building ESTHER, which was accepted to be published in the Institute of Electrical and Electronics Engineers Robotics & Automation Society’s Automation Letters. The team recently was able to program ESTHER to recognize when a ball is coming towards it, and hit a return.

The long-term vision for ESTHER is for it to be able to play a rally, while Gombolay and his students eventually hope that the technology that built ESTHER can be used in manufacturing, construction or other fields.

“What really excites me is that it could be a partner for me one day,” Gombolay said. “It can also be my opponent. It can help me train. I could have it pretend to be the one guy I always lose to because he can exploit this weakness in my game.

“Training against an opponent is psychologically more stressful. Getting closer to simulating real match conditions can help you improve performance.”