Unmanned aerial vehicles face the challenge:
All the time, UAV obstacle is a long-standing, and now on the market mainstream electric multi-rotor unmanned aerial vehicle obstacle system is mainly three, namely, ultrasonic, tof (laser radar ranging) and visual distance, all have more or less the problem.
| Sensor | Principle | Altitude | Accuracy | Adaptive scene | Advantage | Disadvantage |
|---|---|---|---|---|---|---|
| ultrasonic | sonar | 0.5~5m | 10cm | relatively high | low cost | ranging distance is short, interference large |
| infrared laser | TOF+3Dmodeling | 50m | 5cm | relatively high | dark light conditions are very sensitive, the effect is better | interference, strong light effect is very poor, high cost |
| visual sense | camera | 50m | 5cm | low | high precision, imaging | weather, sunlight, reflector greater impact |
| mmw radar | cw | <50m | 2cm | high | environmental adaptability, all day and all weather word | the accuracy is slightly higher relative to the vision |
What is a millimeter wave radar?
The millimeter-wave radar detects the target by transmitting and receiving high-frequency electromagnetic waves. The back-end signal processing module uses the echo signal to calculate the target information such as the existence, velocity, direction, distance, and angle of the moving object. Millimeter-wave radar has a small size, light weight, high degree of integration, sensitive and other characteristics, its unique through the fog, smoke, dust, the ability to achieve all-weather, all-day application.
Millimeter-wave radar obstacle detection report:
| Test time | 2017.03.31 | UAV platform | A2Flight controlS550 |
|---|---|---|---|
| Testers | engineer | Test product model | NRA24 |
| Test place | outdoor reality | Testing scenarios | outdoor |
| Test method target | |||
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UAV installed a NRA24 mm wave radar sensor, NRA24 for UAV obstacle avoidance sensor for different types of obstacles detection performance |
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Detection performance:
Single cable cable GB 2x4.0 square, stable tracking 7m, detection distance 10m; multi-strand cable (3 ~ 4) stable tracking 10 meters, detection distance 20m. General trees, detection tracking distance of up to 50m.
NRA24 as a UAV collison avoidance sensor for different types of target obstacles have a relatively stable detection effect, especially for other types of sensors (ultrasonic, laser, visual) compared to the millimeter-wave radar on the wire, glass wall detection Outstanding advantages, due to faster response time, 50Hz refresh rate, advantage is more obvious in moving platform.
NRA24 is a compact K-band altimeter / collision avoidance radar developed by Hunan Nanoradar with 24GHz ISM band, ± 2cm measurement accuracy, compact size, high sensitivity, light weight, easy integration, stable performance, applications in Flight platform (UAV / UAS), helicopters, small airships and other many areas, the product has been applied to dozens of UAV manufacturers.
