{"id":9571,"date":"2020-01-16T10:27:35","date_gmt":"2020-01-16T15:27:35","guid":{"rendered":"https:\/\/blogs.sw.siemens.com\/simcenter\/?p=9571"},"modified":"2026-03-26T06:20:25","modified_gmt":"2026-03-26T10:20:25","slug":"keeping-vehicle-adas-clean-in-harsh-operating-conditions","status":"publish","type":"post","link":"https:\/\/blogs.sw.siemens.com\/simcenter\/keeping-vehicle-adas-clean-in-harsh-operating-conditions\/","title":{"rendered":"Keeping vehicle ADAS clean in harsh operating conditions"},"content":{"rendered":"\n

A year and a half ago, I wrote about my new car with some slightly disappointing driver safety technology<\/a> that worked well in the summer, but less well when I needed it most: in the perpetual rain and snow of a New York winter. <\/p>\n\n\n\n

In this post, I\nmentioned then that both the European Union and the United States were\nmandating that all vehicles be equipped with autonomous emergency brake and forward-collision\nwarning systems by 2020.<\/p>\n\n\n\n

Well, we are at the dawn of 2020. So, it\u2019s time to go deeper and tell you more about the state-of-the-art simulation technology which supports engineers with improving advanced driver-assistance systems (ADAS) performance under harsh environmental conditions. And not only at Daimler<\/a> thought.  <\/p>\n\n\n\n

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Figure 1: Aerodynamic pressure force driving water on side window – Daimler presentation<\/figcaption><\/figure>\n\n\n\n

The use of sensors in ADAS and autonomous vehicles has been accelerating over the past few years largely driven by regulatory and consumer interest in safety applications. These sensors help with monitoring, warning, braking, and steering tasks to prevent accidents and protect drivers. But that is pretty useless if the sensors can\u2019t handle all the harsh environments that a driver routinely encounter.<\/p>\n\n\n\n

Vehicle\ndesigners and suppliers are working to address these needs. One method would be\nto add a liquid cleaning system, like the ones used by vehicle wipers. This\nwould add additional wiper fluid, which adds weight, mechanical complexity and additional\nmaintenance to the system. Another critical step OEMs are investigating is\nusing the vehicle aerodynamic design to help locate sensors, and keep sensors\nclean, to minimize the maintenance of the sensors. And more important than\nthat, help me to avoid bending the fender of my next new car. <\/p>\n\n\n\n

Today, it is common to use simulation to investigate the aerodynamic contribution of a vehicle to its fuel consumption and acoustic signature. Including dirt\/water management as part of the aerodynamic design cycle represents a relatively new challenge. Simulation allows engineers to solve problems before the first prototype is built, reducing the high costs of making changes late in the design cycle. This allows engineers to look at the trade-off between styling, aerodynamic drag losses, acoustic noises, and rain\/dirt management. To learn more, feel free to join our Live Webinar event on January 22nd<\/sup><\/a>.  <\/p>\n\n\n\n

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Figure 2: Influence of water film on the bumper<\/figcaption><\/figure><\/div>\n\n\n\n

Simulating vehicle soiling can be quite challenging, modeling the physics needed to capture a realistic solution in a time frame in which engineers can impact design. There are many different techniques today balancing the trade-off between physics for realist solutions with computational resources. For speed, physics models of particles and fluid flow generally are separated to enhance performance. Examples are particle-based methods that focus on particles traveling free from the airflow. There are wall film models that help computationally reduce 3D modeling for thin films. More expensive models include the volume of fluid and resolve multi-phase between the water and air which are referred typically as Volume of Fluid<\/a> (VOF) in a cell. The VOF modeling allows the user to track the motion of free surfaces.<\/p>\n\n\n\n