In the wake of a series of Tesla crashes this year, the maker of electric cars said Sunday it is rolling out an upgrade to its semi-autonomous Autopilot feature that may help make it safer to use.

The company said that although its vehicles' existing software may cause a Tesla on Autopilot to scrape against a car that's partially in its lane, or to ram into an obstacle that another driver ahead has swerved to avoid, an update that will be rolled out around the world in the coming weeks will address both problems — as well as a host of others.

It will give radar technology a more active role in Autopilot — a feature drivers can enable to allow the car to stay within its lane and to keep it from hitting other vehicles. Tesla said that it will allow the radar system to initiate automatic braking on its own, without requiring its vehicles' optical cameras to verify whether the maneuver is needed. In addition, by bouncing radar signals underneath the car ahead, a Tesla will be able to see an additional car-length in front of itself — giving it a better chance of anticipating oncoming road hazards, chief executive Elon Musk said.

"I am highly confident this will be quite a substantial improvement," Musk told reporters.

More importantly, all Teslas that enable Autopilot will now start using radar to build a three-dimensional map of the world. The map will help Tesla understand what's normal — street signs, highway overpasses and so on — and what's not, such as an unexpected obstacle ahead that requires automatic braking. It will bring Tesla that much closer toward Google's vision of a robotic car in that Google uses a mixture of laser-based sensors, radar and traditional video cameras to see.

Teslas are not equipped with laser sensors and previously used radar as a "supplementary" system to back up what its optical cameras could pick up. But as some drivers are discovering, the cameras can be foiled by poor lighting, road conditions or extreme temperatures. That's what probably led to a fatal crash involving Autopilot in Florida earlier this year, when a Tesla's cameras couldn't distinguish the body of a truck from the bright sky behind it.

By giving radar a big promotion, the company believes it can help cut down on errors. But, Musk said, the risk of a crash while Autopilot is enabled will never be zero.

"It's about minimizing the probability," he said, "minimizing the probability of death, not the illusion of perfect safety."