{"id":16676,"date":"2021-03-11T09:41:05","date_gmt":"2021-03-11T07:41:05","guid":{"rendered":"https:\/\/acktar.com\/?p=16676"},"modified":"2021-12-28T11:10:09","modified_gmt":"2021-12-28T09:10:09","slug":"autonomous-cars","status":"publish","type":"post","link":"https:\/\/acktar.com\/autonomous-cars\/","title":{"rendered":"Object Identification for Autonomous Cars"},"content":{"rendered":"
Autonomous vehicles are expected to result in fewer road casualties and more efficient traffic.<\/p>\n
But driver assistance systems also protect lives. For a safe function of the optical sensors\u2013 the basis of autonomous driving-, the stray light must be certainly suppressed<\/a> as far as possible.<\/p>\n With a lane departure warning system, it is theoretically possible to practically drive short distances autonomously.<\/p>\n Before true autonomous driving is possible, however, the car must first learn to see and react without errors.<\/p>\n This requires perfectly functioning \u201ceyes\u201d and powerful electronics.<\/p>\n The car sees with optical sensors such as cameras for day and IR, ultrasonic and radar sensors and laser scanners called Lidar (light detection and ranging) and laser systems.<\/p>\n To obtain a perfect 360\u00b0 image of the surroundings, several sensors are distributed around the vehicle.<\/p>\n For this, the test vehicles are equipped with a good dozen cameras, ultrasonic sensors, several radars, a Lidar sensor, and a powerful onboard computer.<\/p>\n The fact that it took so much time for car manufacturers to develop a driverless car that is ready for serial production, shows that autonomous driving is not easy.<\/p>\n The autonomous car must be able to recognize objects and people beyond doubt, know the traffic rules, and be able to anticipate dangers.<\/p>\n To accomplish this, cameras, radar sensors, and laser scanners must work together.<\/p>\n In other words, what one sensor overlooks is likely to be seen by the other \u2013 but only if they work properly.<\/p>\n A big problem here is stray light because it makes the sensors partially blind.<\/p>\n Stray light is caused by the reflected light from lenses and the image sensor, by the diffuse reflection at lens edges, apertures, or other components inside the lens or the camera.<\/p>\n Stray light depends on the lighting conditions, especially if there are bright light sources inside or right outside the image angle.<\/p>\n Bright light sources include sunlight, street lamps, illuminated buildings, illuminated shop windows, etc.<\/p>\n In addition, there is heat radiation corresponding to the temperatures in the vehicle.<\/p>\n Dust particles or other impurities on the lens surfaces also produce stray light.<\/p>\n Optical surfaces can also become dirty by fogging\u2013 a milky, cloudy coating of vapors, e.g. from plastic softeners, which condenses on the lenses and scatters the light.<\/p>\n According to the sources, the stray light, therefore, covers a wide spectral range from EUV (extreme UV, from 30 nm) to FIR (Far IR, up to 1000 \u00b5m).<\/p>\n Design improvements and matt black absorber coatings provide a remedy.<\/p>\n These coatings tolerate the extreme challenges of optical sensors in vehicles, such as very high-temperature differences, permanent vibrations, etc.<\/p>\n Many of these paint coatings consist of oxides with a carrier material and to apply them, they are sprayed on.<\/p>\n The adhesion of the paint layer to the substrate, however, can be problematic, because the large temperature fluctuations and vibrations that are possible (especially in cars), cause the layer to peel off over time.<\/p>\n In addition, spraying produces a relatively uneven thickness and the carrier material must outgas.<\/p>\n ACKTAR avoids this problem by coating its proprietary Black layers in a vacuum<\/a>.<\/p>\n This produces optimally uniform, very thin layers with secure adhesion that can even withstand space conditions<\/a> and absorbs about 99% of EUV-UV, VIS and NIR-FIR.<\/p>\n