Tesla set to update Autopilot system

Elon Musk has said that US carmaker Tesla will outline upgrades to software for its Autopilot system on Thursday, in changes which could be applied within the next few weeks.

The company's CEO tweeted the news on Wednesday, with AutoPilot 8.0 and 8.1 expected to introduce features which make its vehicles safer.

Musk's company has faced criticism recently following investigations into its self-driving system after the death of a driver who was using the system at the time.

The original version of the software was launched in October 2015, allowing cars to take over some of the responsibilities from its driver, including steering and lane changes.

The tweet said that major improvements will be made to the system "primarily through advanced processing of radar signals."

Also on Wednesday, Tesla said in a filing with the Securities Exchange Commission it hopes to raise more investment this year in order to pay off some convertible debt.

Musk caused controversy last month as he announced Tesla's purchase of another company that he has a controlling stake in, SolarCity.