The high cost of smart cars is on a laser scanner, which means that the recognition of the road environment is high, but the algorithm in complex environments is also important. 2007 race to join the 60 km city road, requiring vehicles Sensor in the unmanned at the same time, to comply with traffic rules. The star of the race is GM's car with Carnegie Mellon University 'Boss', 2007DARPA City Challenge runner-up - Stanford University's 'Junior'. Photo of the people called Sebastian Thrun, he and some team members were then Google dig away, so with Google Car.
Now unmanned vehicles can appear to a large extent dependent on the progress of the sensor. In fact, as early as the 1980s, the United States through the magnetic nail navigation to complete a lot of unmanned experiments. They are buried in the ground with magnetic nails, by looking for magnetic nail way to complete the high-speed cruise, and Road, overtaking and other Fuel Rail Pressure Sensor columns of the experiment. But it is clear that this cost is too high, only as an experiment. SICK company laser radar. Used to detect the surrounding obstacles, unmanned vehicles need to be able to perceive the surrounding environment, and can not be as simple as the eyes to complete, so this thing can return to the distance around the obstacles, the error millimeter level. The first difficulty of the unmanned car is the sensor. Set a fixed base station, fixed base station calibration position, and then pass the signal to the vehicle equipment, vehicle equipment, after receiving the base station signal and GPS signal obtained after the difference. But the effective range of each base station also 30km, how a wide range of applications.
The traditional gps protocol is 0183 format, this format allows 4 decimal places. Military level gps on this basis and added two, as to how many of the more out of the accuracy can not know, and have to use an absolute position to teach about. If the accuracy of '1 m' is basically enough for vehicle positioning, GPS must be able to get this level of positioning accuracy in open space. In the shade, the building, the tunnel can not reach the GPS signal, then you need mileage + gyroscope, commonly known as inertial navigation unit. The principle of this system is: the more money, the longer the effective time. There is Temperature Sensor an obstacle in front of the vehicle, the obstacle is moving or still, the car is stopped or around. This part of the main difficulty is to identify obstacles from the sensor, in the vehicle under the premise of movement to determine the state of obstacles. That is to say you have to calculate the speed of another object relative to the coordinate system in the coordinate system of motion and make a judgment.