Self driving car's detection accuracy enhanced by tech from Panasonic
Panasonic developed crash preventing technologies for car by improving the detection accuracy of the radar. It can detect cars, pedestrians and bicycles in less than 0.1 seconds, on the condition that they are separated by 20cm .By applying this technology to 79GHz radar, accidents can be prevented at road crossings/intersections. In fact, this technology helps a lot in designing a self driving car.
The advantage of mm-wave radar is it can detect people and vehicles in night time and bad weather conditions. Panasonic says its technologies allow the operation of multiple millimeter radars, enables for a wider field-of-view (FOV) system.
Panasonic claims it has used unique coding technologies to millimeter-wave radar to achieve an accuracy which is 2.5 times higher than that of previous models of the millimeter-wave radar.
The simultaneous operation of multiple millimeter-wave radars has been is realized by controlling the interference between multiple radars, widening the FOV, and making it suitable for monitoring an overall area of a typical intersection.
The new technological elements developed by Panasonic includes:
Multi-dimensional electrical scanning technology Census the location very fast and maintains a high degree of sensitivity for pedestrian detection by the suppression of noise due to reflections from metallic vehicles.
The orthogonal complementary coded modulation technology has superior separation capabilities without interference, realizing both a high resolution and wide FOV simultaneously, even for a multiple radar configuration operating at the same frequency,.
On the new radar technology, Panasonic holds 27 patents in Japan and 14 patents overseas including pending applications.
Further explanation of the technology by Panasonic:
1. Multi-dimensional electrical scanning technology:
Coded pulse modulation technology using complementary codes has been applied to 79GHz radar which can utilize the wide frequency band over 1 GHz. Therefore, a physical property of millimeter-waves can be exploited to gain larger Doppler frequency shifts than in the case of using the microwave band. Specifically, by the use of wide band in the 79GHz band, it has achieved a 20cm resolution that is 2.5 times better performance than the previous millimeter-wave radar models, and at the same time it has realized 1km/h resolution in velocity calculated by the Doppler frequency sifts. Moreover, the electrical scanning technology which independently measures range, angle, and velocity with high resolution that has been developed, in addition to reflected power sensing technology with a high dynamic range that suppresses a level of reflected noise from car body to less than -40dB. This high resolution scanning in 4-dimensional domains can be adopted for millimeter wave radar, so that it can provide more stable separation detection for pedestrians and bicycles nearby cars and other vehicles.
2. Orthogonal complementary coded modulation technique:
Code modulation radar method using complementary codes, which is a kind of pair codes, has an essential characteristic that completely cancels range side lobes which are the factors of increasing the noise level due to strong reflected waves. On the other hand, when multiple radars are simultaneously operated, the strong reflected waves from car bodies or others cause mutual interference between radars at the direction of which each antenna beam is closed in angular domain. At this time, through coded multiplexed beamforming technology such as orthogonal coding superposed on the sequence of the complementary codes, succeeding in suppressing the mutual interference between pulse radars to less than -40dB. As a result, multiple millimeter wave radars are capable of simultaneous operation with sectoring in angular domain that has achieved both an FOV of more than 120 degrees and a data cycle less than 0.1 seconds.