At Tesla's AI Day, Elon Musk shows off "Optimus," a robot that looks like a human.

Elon Musk, the CEO of Tesla, will show off his much-talked-about humanoid robot "Optimus" on Friday at a company event called "AI Day."

A business based on robots, the billionaire said, would be worth more than a business based on cars. He wants to move on from self-driving cars, which he has promised many times but has not yet come true.

A model of the robot walked onto the stage and waved to the people sitting there. A video of the robot carrying a box, watering plants, and moving metal bars was shown in the automaker's factory.

Musk said at the event, which was held at a Tesla office in Palo Alto, California, "Our goal is to make a useful humanoid robot as soon as possible."

"There is still a lot of work to be done on Optimus to make it better and show that it works."

Musk said that humanoid robots today "don't have a brain" because they don't have enough intelligence to move around the world on their own. He also said that they are expensive and that only a few are made.

He said that Optimus, on the other hand, would be a "extremely capable robot" that would be made in the millions and cost much less than a car, less than $20,000.

Musk was also expected to talk about the long-awaited technology Tesla has been working on for cars that drive themselves.

In May, the CEO of the most valuable car company in the world said that if the company didn't have fully self-driving cars, it would be worth "basically nothing." The company is also facing more and more technological and regulatory problems.

Musk said on Twitter late Wednesday night, "There will be a lot of technical detail and cool hardware demos." He also said that the event was made to find new engineers. Tesla hasn't done all of his live demonstrations perfectly.

Most launches get cheers, but when Musk told an employee to throw a steel ball at the armored window of a new electric pickup truck in 2019, the window broke.

The robot's most important test is how well it can handle things that don't go as planned.

Musk talked about Tesla's plan for humanoid robots at last year's AI day. This year, AI Day was moved from August to September so that the robot prototype could be tested and production could start as soon as next year.

Tesla posted a picture of metal robot hands making a heart shape on social media as a hint about when the public would be able to see the robot. But Heni Ben Amor, a robotics professor at Arizona State University, said it is very hard to make hands that look like human hands and can do different things.

Musk says that Optimus used to do boring or dangerous jobs, like moving parts around Tesla factories or using a wrench to put a bolt on a car. This was a reference to the strong and kind-hearted leader of the Autobots in the Transformers franchise.

"There are so many things that people can do with their hands that robots cannot do at all. And that won't change whether the robot is a robot arm or a humanoid, said Jonathan Hurst, the chief technology officer at Agility Robotics, a company that makes humanoid robots.

Musk has said that in the future, robots could be used in people's homes to do things like make dinner, mow the lawn, take care of the elderly, and even be a "buddy" or sex partner.

At the event on Friday, he will also talk about Dojo, Tesla's high-speed computer that was shown off last year and is a key part of the company's work on self-driving technology.

Musk has said that he thinks Tesla will be fully self-driving by this year and that a robotaxi without a steering wheel or pedals will be mass-produced by 2024.

Musk said at a "Autonomy" event in 2019 that he would make 1 million robotaxis by 2020, but he hasn't given anyone one yet.