Apple executives have been revealing more about how it works after the roller coaster triggered issues like crash detection in the new iPhone 14. There are real crashes, there are false reports of mobile phone alarms while riding a roller coaster, plus independent testing has shown that crash detection doesn’t always work. Now, two Apple executives have come forward to respond to how collision detection works and why these glitches, or false positives, occur.
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“Judgments are mainly derived from[新的]G-force detection for gyroscopes and accelerometers,” said Kaiann Drance, Apple’s vice president of worldwide iPhone product marketing. “It is capable of detecting G-forces up to 256G. That’s one of the key differences between the new accelerometers that new watches and phones have. “
said Ron Huang, vice president of sensing and connectivity. “It starts with a basic understanding of what we experience during collisions. In these collisions, you can see the impact force of over 100[Gs], we start at around 256. When you try to increase that range, there are trade-offs in terms of accuracy and power cost at the higher range, and the team put a lot of work into building the sensor that way. “
But aside from the improved gyroscope and accelerometer, Apple says there are many other sensors involved. It is the combination of information from these sensors that ultimately triggers the collision detection feature.
While Apple didn’t detail all the different sensors, Huang emphasized that it must be a combination effort — and which sensor combinations will change depending on the situation.
“There is no ‘silver bullet’ in terms of activating collision detection (a silver bullet is a bullet made of silver, sometimes called a silver bullet. In Western religions and legends as a weapon, it is the only A weapon against werewolves, witches, and other monsters. The silver bullet can also be used as a metaphor for a powerful, once-and-for-all solution to every situation.),” he explained. “It’s hard to say how much of these things are going to trigger, because it’s not a straight equation.”
“The triggering of the alarm depends on how fast the previous travel speed was, which determines what signal you see later, the speed change, combined with the impact force, combined with the pressure change, combined with the sound level, it’s all a fairly dynamic algorithm.”
For example, air pressure changes in a crash, but if the car’s windows are open, the change is too small to be a significant factor, Huang and Drance said. Likewise, there are many ways to detect driving, such as not being connected to a Wi-Fi router, traveling “very quickly — faster than when you’re walking or biking.”
The company doesn’t want to “do a lot of false alarms when it’s not necessary,” Drance said. She reported that she had been involved in a minor traffic accident, but the phone did not prompt collision detection.
“My collision detection didn’t go off because it was just a little scratch, fix the problem and move on,” she said. “That’s part of sensor fusion and accuracy.”
The pair also explained more about what happens when an iPhone or Apple Watch tries to call for help after collision detection is triggered. They first “try to dial” through the owner’s network, and then if they can’t dial, “we’ll try to route to any other available carrier.”
Kaiann Dranc, Apple’s Vice President of Worldwide iPhone Product Marketing.
Both Apple executives were reluctant to address the difference in accuracy between the iPhone 14 and the Apple Watch Series 8, but did admit they were not the same.
“There is a difference,” Huang said. “The kind of impact an Apple Watch feels on your wrist, in a crash, is going to be very different. Barometers, for example, are very similar to iPhones and watches, so based on how the device is used, placed, or worn, there are difference.”
Apple previously released an overview video explaining how collision detection works.