While Tesla's CEO, Elon Musk, and Google's co-founder, Larry Page, are friends, Musk has criticized Google's use of LIDAR ((LIght Detection And Ranging) in their early-stage self-driving cars.
At a press conference held last October, Musk claimed that the LIDAR technology "doesn't make sense" to implement in an autonomous car and that he's "not a big fan of LIDAR". While he doesn't state directly that Google is using the wrong technology for their cars, he does believe that it isn't something Tesla will implement in their Autopilot systems.
Regardless, with his prenotions of using LIDAR in self-driving cars, Musk utilized LIDAR on SpaceX's Dragon to determine the range of the spacecraft whilst docking to the ISS.
Musk has made a name for himself by creating and popularizing ideas such as PayPal, SpaceX, and Tesla. However, he might be wrong about Google's approach to creating the first self-driving car. Google's Self-Driving Car Project was created to ensure a safe mode of transportation that would completely eliminate any human error. Google has taught their cars to navigate through city streets using sensors and software that sense and avoid objects such as animals, cyclists, pedestrians, vehicles, and more.
Below is a short video explaining how a self-driving car performs throughout the city:
Google's Use of LIDAR
While Google and Tesla have a common goal of making transportation on the road safer and eventually operator-free, their techniques are quite different.
Google self-driving cars use LIDAR, which maps out the car's surroundings using lasers. LIDAR measures the shape and contour of the ground from the sky. It reflects multiple laser pulses off of objects that surround the car and measures the distance and time that each pulse has traveled.
From these measurements, the LIDAR system can provide accurate information on the height and distance of objects.
Image courtesy of Google
While this system is taking great strides in creating a fully driverless car, it comes at a hefty cost. Google used Velodyne's 64 Channel LiDAR sensor, whic is priced at about $80,000 for just one sensor.
This might be one reason that Elon Musk refuses to use LIDAR technology in Tesla's Autopilot systems.
Tesla's Use of Optical Sensors and RADAR
Musk believes that passive optical sensors and a RADAR system can accomplish the same thing as Google's LIDAR system.
Musk equipped Tesla vehicles with 12 long-range ultrasonic sensors that provide a 360-degree view around the vehicle. In addition, each vehicle has one forward-facing RADAR system. Integrating these components together helps power Tesla's Autopilot system.
Like a LIDAR system, a RADAR system sends out signals, but in the form of periodic radio waves that bounce off of objects in the cars proximity. Once they hit an object and return to the car's system, it will measure the time it took for the radio waves to travel to and from the object.
The advantage of radio waves is that they can be transmitted through rain, snow, fog, and even dust. By comparison, laser beams used in LIDAR cannot.
Image courtesy of Tesla
Different Tools for Different Tasks
While Elon Musk has made some bold comments regarding Google's methods, most people don't realize that they are working on two completely different tasks. Google is using Velodyte's 64-channel (64 beams) LIDAR to place itself with an accuracy of 10 cm on a pre-existing map. Google is also utilizing the LIDAR system to not only create a 360-degree model of the car's surroundings but also predict the movements of nearby pedestrians and vehicles.
On the other hand, Tesla's Autopilot system uses forward-facing cameras that are produced by Mobileye. These cameras can accurately pick up the location as well as curvature of highway lane markers which help keep the vehicle in its lane and make basic lane changes.
While each company's technology is exceptional, they each work towards different results. Tesla's Autopilot system is inexpensive and will prove to be useful for Elon Musk's initial goal: automating 90% of driving within just a couple of years. However, the other 10% of driving scenarios are quite hard to implement.
Google began working towards this same goal quite some time ago and instead focus now on something different: a fully autonomous car that will completely eliminate any human errors.
So, was Elon in the wrong for calling out Google on their LIDAR system? Well, yes and no. It is a pricey system that will eventually need to be altered if Google wants to make it affordable for consumers. However, Google is working on eliminating the need to drive a car while Tesla is working on providing for eliminating some of the daily driving we need to do. From that perspective, LIDAR might be the right choice after all.