Reliably monitoring the surroundings, recognising obstacles and hazards in a wide range of weather conditions, ensuring that all road users and passers-by are safe in all situations – the utilisation of sensor technologies makes autonomous driving possible in the first place. The car roof – the highest point of the vehicle – provides the ideal conditions for positioning this sensor technology.
Leading sunroof supplier Webasto has developed a prototype Roof Sensor Module that combines a total of 14 camera and lidar sensors, together with functions that ensure sensor availability and that can be elegantly integrated into an openable panoramic roof.
“Technological progress in the field of autonomous driving is impressive – but the solutions offered to date are simply not visually appealing,” explains Jan Henning Mehlfeldt, responsible for the global roof business at Webasto. “We have leveraged our decades of expertise to develop a slimline roof system that offers space for various technologies yet blends aesthetically into the vehicle’s architecture.”
Coordinated technology set
The five lidar sensors integrated into the Webasto roof system measure distance and the speed of moving objects. Located at the centre and corners, they create a 3D point cloud of the vehicle’s surroundings in order to understand the car’s driving situation. Ten cameras recognise colours and objects, making it possible to assess the meaning of traffic lights, traffic signs and lane markings too.
The new Roof Sensor Module is also capable of determining distances, thanks to the use of stereo cameras. The entire sensor set, together with other antennas, is concealed under a full-surface polycarbonate cover, blending in with the vehicle’s silhouette.
A thermal management system maintains the sensors within their ideal operating temperature range. A cleaning system that uses vehicles`s washer fluid and air jets to deal with contamination caused by dust, mud, snow or insects. The sensor covers remain ice-free in winter thanks to a de-icing function, while de-fogging prevents the sensors from misting over. Multiple Automated Driving System lights (ADS) inform other road users that the vehicle is driving autonomously.
Partners in progress
To integrate these new technologies into the roof system, Webasto – as a mechatronics systems integrator – relied on a network comprising both long-standing and newly established development partnerships.
For the sensor portfolio, the roof system specialist collaborates closely with market-leading suppliers. Luminar Iris long-range lidar, along with Hesai and Innoviz, supplies the lidar technology for the existing prototypes, while the innovative cameras come from Bosch.
For the cleaning systems, Webasto relies on the expertise of dlhBowles. In terms of de-icing and de-fogging on Canatu, cooling and the intelligent thermal management system was developed in collaboration with Delta Electronics. The elegant polycarbonate cover was realised in collaboration with Covestro. “Combining our competencies with our partners’ expertise allows us to offer our customers a reliable and scalable solution,” explains Mehlfeldt.
One module, many possibilities
Webasto’s prototype, which houses 14 lidar and camera sensors, is just one of many options for integrating sensors into the roof. Webasto states that automakers can customise and assemble the desired technology set for their roof system. In the Lotus Eletre electric SUV, for example, the company’s Roof Sensor Module with a single retractable lidar is already in series production.
At the IAA Mobility exhibition to be held in September in Munich, Webasto (Hall B3, Booth C40) will present further sensor sets in combination with a large panoramic roof, opening function or retractable display.