Bosch is currently readying a new mid-range radar sensor (MRR) for series production. It works in the same way as the current LRR3 long-range radar sensor in the 77 GHz frequency band, which means it can record the distance and position of obstacles with great precision, but is far less costly. When installed in the front of the vehicle, the new sensor has a range of up to 160 metres and a detection angle of 45 degrees. “The new mid-range radar sensor enables the cost-effective implementation of numerous safety and comfort functions,” says Dr. Werner Struth, president of Bosch Chassis Systems Control at Bosch, naming ACC (Adaptive Cruise Control) at speeds of up to 150 kilometres per hour and the predictive emergency brake assist function as examples. The new sensor can also be installed in the rear of the vehicle. “Here, it monitors blind spots or warns drivers of oncoming traffic when backing out of parking spaces,” adds Struth. Bosch is planning to start series production toward the end of 2012.
mid-range radar sensor can be integrated with ease into either the front or rear of the vehicle. It can even be fitted out of sight behind the bumper. Thanks to its range and angle of detection, vehicles on the road ahead and those cutting in are detected early on – providing the ideal basis for the ACC (Adaptive Cruise Control). At speeds from 0 to 150 kilometres per hour, the system automatically controls the set distance to the vehicle in front. In future, only higher target speeds achieved by high-end sedans will need a long-range radar sensor. It also facilitates a predictive emergency brake assist function, which detects when another vehicle is getting critically close. If the driver does not react, the system triggers a partial braking operation. At speeds of less than 30 kilometres per hour, it will even perform full automatic emergency braking.
Rear MRRs have a shorter range, but an even wider angle of detection. The sensors located in the rear corners create the basis for the lane change assistant, which monitors blind spots and warns of vehicles that are approaching quickly. The system also helps drivers handle tricky situations when backing out of parking spaces.
Powerful and compact thanks to 77 GHz frequency
Compared to existing 24 GHz versions, a 77 GHz sensor delivers enhanced performance in all areas. The new sensor’s object separation is up to three times better, and it can measure speeds and distances with three to five times the accuracy. The device is also much smaller than previous sensors, measuring less than 130 cubic centimetres. What’s more, it uses the frequency band permanently authorised for automotive applications worldwide. As a result, the Bosch 77 GHz MRR is ideal for global vehicle platforms. The silicon germanium technology used for the integrated high-frequency circuits enables a compact design without any moving parts.
Complementary radar and video sensors
Video sensors are the ideal complement for radar technology. Powerful software algorithms merge the sensor data to create a highly detailed “picture”, which is an interpretation of the situation ahead of the vehicle. Other assistance and safety functions, such as automatic full braking at higher speeds, can be added. At this stage, the system cannot prevent the accident, but it can significantly reduce the severity of the impact.