Tesla wants to prevent child heatstroke with an in-car radar that alerts drivers who leave their kids behind

• Tesla filed a petition with the FCC in order to get approval for a motion detector that would detect when kids are left behind in the car.
• Elon Musk has never been keen on adding sensors to his cars, but seems to be making an exception here.
• GM and Nissan also have technology to prevent child deaths in cars.

In late July, Tesla filed a petition with the FCC to get approval for a radar that would detect when a driver leaves their children behind in the car, hoping to reduce the risk of child heatstroke.

The system would use millimeter wave radar technology to sense the number of vehicle occupants and their movements, including "micromovements" such as heart rates and breathing patterns. If approved, the sensor could help cut back on the number of deaths in hot cars. In 2019, 52 children died of heatstroke after being forgotten in cars, according to the National Highway Safety Administration.

Tesla's millimeter wave system would take the form of "4 transmit and 3 receive antennas driven by a highly configurable radar front-end unit." In the filing, Tesla lawyer Elizabeth Mykytiuk said the technology could also be used to "protect vehicle occupants from injury through advanced airbag deployment and seatbelt reminders, and enhance theft prevention systems."

Unlike cameras, this kind of radar sees through obstructions such as a "blanket covering a child in a child restraint." Also according to the filing, the sensors will be able to differentiate between a child and objects left on the back seat, in order to cut down on false alarms. Tesla needs the FCC's permission here because the sensor would operate in the 57-71 GHz band at a higher power level than the agency generally allows.

In the past, Tesla CEO Elon Musk has been reluctant to implement these types of sensors in cars, fearing "the options might not work well enough, could be expensive, and because drivers might become annoyed by an overly nagging system," according to The Verge. The electric automaker generally prefers updating its cars with new software rather than hardware.

Many automakers have some sort of system to stop drivers from forgetting their kids, either with dashboard reminders to check the back seat. Hyundai has a feature that will honk the horn if an ultrasonic sensor detects a child left behind. Nissan's Rear Door Alert system also honks the horn, if it senses that the rear door was opened at closed at the start of a ride, but not at the end.

This isn't Tesla's first foray into technology in order to help with driver and passenger safety. Dog Mode, which debuted in February 2019, allows owners to keep the car at a cool temp for dogs and flashes a message telling anyone who may pass by that the owner will be back soon. Sentry Mode keeps the vehicle's exterior cameras on even when the car isn't in use in order, to detect any potential theft.

The FCC will seek public comment on Tesla's waiver petition through September 21, before making a decision.