SAN FRANCISCO — Microsoft’s co-founder Paul Allen said Wednesday that he was pumping an additional $125 million into his nonprofit computer research lab for an ambitious new effort to teach machines “common sense.”

The money for the Allen Institute for Artificial Intelligence will about double the lab’s budget over the next three years, helping to fund existing research as well as the new effort, called Project Alexandria. In the years and decades to come, the lab hopes to create a database of fundamental knowledge that humans take for granted but machines have always lacked.

“To make real progress in A.I., we have to overcome the big challenges in the area of common sense,” said Mr. Allen, who founded the software giant Microsoft in the 1970s with Bill Gates.

Today, machines can recognize nearby objects, identify spoken words, translate one language into another and mimic other human tasks with an accuracy that was not possible just a few years ago. These talents are readily apparent in the new wave of autonomous vehicles, warehouse robotics, smartphones and digital assistants.