Ford Motor Co Develops a Unique Way to Keep Self-Driving Vehicle Sensors Bug-Free

author: Eric Walz   

Human drivers rely on windshield wipers in order to be able to see in rain, snow or even mud. A driver can simply activate the windshield washers when rain, dust, insects or mud obscures their vision. 

Self-driving cars are outfitted with a suite of important sensors that are used to "see" the world around them, including forward facing cameras, lidar and radar. The sensors are equally as important as a human driver's eyes, and just like the glass windshield of a vehicle, sensor windows need to remain free from road debris, including insects, to operate correctly and more importantly safely.

Over the last few years, Ford has invested significant research into making sure self-driving vehicles can always see the world around them and in the process the automaker developed a unique way to keep its autonomous vehicle sensors bug free.

In a recent blog post on Medium, Ford's Autonomous Vehicle Systems Core Supervisor, Venky Krishnan shared some details of how the company working to keep insects away from it autonomous vehicle sensors. 

Krishnan said Ford consulted with zoologist Mark Hostetler, to gain insight into the various insects that are regularly making contact with vehicles — and how often they're doing so. 

Ford even developed a "bug launcher" that shoots insects at vehicle sensors at highway speeds, so the team could really understand the best way to clean off the mess they make.

All the various sensors on these cars are constantly working to deliver the best picture of the world they possibly can, but an untimely bug splat could seriously interfere with their ability to do that.

Surprisingly, Ford's latest research led to an important question amongst the team, "Wouldn't it be a lot easier if we just kept our self-driving sensors from getting hit with bugs in the first place?"

To tackle this problem, the team at Ford decided to take maximum advantage of the "tiara," which is the the structure that sits on the roof of Ford's self-driving vehicles. The roof-mounted tiara holds the collection of cameras, LiDAR and radar that helps the car "see" and navigate safely. 

The solution Ford came up with was to redesign the tiara to prevent insects from crashing into the various sensors.

As the car is driving, the tiara funnels air out through different vents near the camera lens. Krishnan said that it creates an "air curtain" that actually deflects bugs away from the sensor itself. 

So anytime bugs are making a bee-line for a camera lens, the air flowing out of the tiara pushes it aside so it doesn't make contact with the lens. Krishnan compared it to "changing the course of an asteroid on a crash-course with Earth."

This simple method proved remarkably successful. Ford's tests showed that the air curtain successfully diverted the vast majority of insects away from our self-driving sensors.

However, the solution wasn't perfect. Insects could still break past the air curtain in some situations, so Ford needed a way to successfully clean its sensors as needed.

In addition to the air vents, Ford integrated a cleaning system into the tiara. The cleaning system features tiny next-generation nozzles next to each camera lens that can spray washer fluid as needed to clean the sensors. 

Using Software Algorithms to Detect if a Sensor Needs Cleaning

Ford is using advanced software algorithms to determine when a sensor window is dirty. Khrisnan said that the cleaning system can specifically hone in on individual camera lenses, cleaning each one individually without wasting washer fluid on already-clean sensors.

After a sensor has been sprayed with the cleaning solution, the tiara has a clever way of drying itself off, it releases a burst of air through a slot which quickly "dries" the surface of the lens. 

Engineers at Ford have gone through great lengths to test the effectiveness of the bug cleaning system, taking one of its test vehicles and driving it through the Huron-Manistee National Forests in western Michigan too see how our cleaning system reacted to swarms of bugs in the summer. 

This system has also been equipped on Ford's third generation of self-driving test vehicles, which are now being tested on streets in Detroit, Pittsburgh, Miami-Dade County and Washington, D.C., in order to test its effectiveness in various environments.

Krishnan stressed that these are not optional features on a self-driving vehicle, rather they are critical functions that vehicles must be able to carry out on their own in order for safe deployment.

In additional to the software and neural networks that process what's happening in the environment, a self-driving car must be equipped with the tools to deal with each unique environment, including swarms of insects that a autonomous vehicle might have to drive through.

Krishnan said that Ford's team has already submitted around 50 patents related to self-driving cleaning and structural systems, demonstrating that there's a lot of innovation to address the problem of keeping sensor windows clean and free from insects.

Eric Walz

Originally hailing from New Jersey, Eric is a automotive & technology reporter covering the high-tech industry here in Silicon Valley. He has over 15 years of automotive experience and a bachelors degree in computer science. These skills, combined with technical writing and news reporting, allows him to fully understand and identify new and innovative technologies in the auto industry and beyond. He has worked at Uber on self-driving cars and as a technical writer, helping people to understand and work with technology.