Ultrasonic radar offers several advantages, including low cost, strong penetration, and waterproof/dustproof properties. Its detection range is typically between 0.1 and 3 meters, providing high accuracy, making it particularly suitable for scenarios such as reversing and parking. Furthermore, ultrasonic radar can be categorized into different types, such as UPA and APA ultrasonic radars, used to measure the distance to obstacles in front of and behind a vehicle, and to its sides, respectively. UPA radars are generally mounted on the front and rear bumpers of a vehicle, with a detection range of 15 to 250 centimeters, while APA radars are mounted on the sides of the vehicle, with a detection range of 30 to 500 centimeters.
However, ultrasonic radar also has some disadvantages. For example, it is easily affected by weather conditions, with significant errors under different weather conditions and vehicle speeds, which is not conducive to long-distance signal propagation. Furthermore, the detection angle and frequency of ultrasonic radar also affect its performance. Generally, higher frequencies result in higher sensitivity, but smaller detection angles in the horizontal and vertical directions. Therefore, in practical applications, it is necessary to select the appropriate ultrasonic radar type and parameters based on the specific scenario.
The main performance indicators of ultrasonic radar include:
Operating frequency: This refers to the frequency of the ultrasonic waves emitted by the ultrasonic radar. The choice of frequency affects the radar's detection resolution and accuracy, as well as its propagation characteristics in the atmosphere. Generally, higher frequencies can improve detection resolution and accuracy, but propagation in the atmosphere is more limited. Lower frequency radars have a relatively longer propagation distance, but their resolution is relatively lower.
Ultrasonic radar typically operates between 20kHz and 200kHz, with common frequencies including 25kHz, 40kHz, 50kHz, 60kHz, 80kHz, 100kHz, 125kHz, and 150kHz. Different types of ultrasonic radar may employ different operating frequencies to suit various application scenarios and requirements. Generally, higher frequencies result in higher sensitivity but also smaller detection angles in both the horizontal and vertical directions. Therefore, in practical applications, it is necessary to select the appropriate ultrasonic radar operating frequency based on the specific scenario.
Detection range: This refers to the maximum distance at which a radar can detect a target object. The detection range of ultrasonic radar is affected by various factors, including the radar's operating frequency, transmission power, receiving sensitivity, the reflection characteristics of the target object, and environmental conditions. Generally, the detection range of ultrasonic radar is between 0.1 meters and 3 meters, with an accuracy of 1-3 centimeters.
Furthermore, different types of ultrasonic radars have different detection ranges. For example, the detection range of UPA (parking assist radar), which is used to measure obstacles in front of and behind a car, is typically between 15 and 250 centimeters, while the detection range of APA (automatic parking assist radar), which is used to measure the distance to obstacles to the sides, is typically between 30 and 500 centimeters.
It is important to note that the detection range of ultrasonic radar is limited by its operating principle. Ultrasonic waves are affected by factors such as air density, temperature, and humidity when propagating through the air, resulting in scattering and attenuation, which in turn affects the radar's detection performance. Furthermore, the detection range of ultrasonic radar is also affected by the surface characteristics of the target object, such as surface roughness, shape, and size.
Detection Angle: The detection angle refers to the coverage area that an ultrasonic radar can detect. This is typically achieved by changing the shape and direction of the beam emitted by the transmitter to adapt to different application scenarios. Ultrasonic radar detection angles are divided into horizontal and vertical detection angles. The horizontal detection angle is generally 120° (UPA) or 80° (APA), while the vertical detection angle is generally 60°~70°. The vertical detection angle is approximately half that of the horizontal detection angle; this is to avoid false alarms caused by road feature feedback triggering signals.
Sensitivity: Sensitivity is a key performance indicator of ultrasonic radar, determining the size and distance of the smallest target object the radar can detect. Higher sensitivity means the radar can detect smaller targets and has a longer detection range.
Sensitivity is typically affected by a variety of factors, including the radar's operating frequency, transmit power, receiver design, and signal processing algorithms. Furthermore, the reflectivity of the target object also impacts radar sensitivity. For example, targets with rough surfaces, poor sound absorption, or poor reflectivity may reduce radar sensitivity.
In practical applications, selecting the appropriate ultrasonic radar sensitivity requires a trade-off based on the specific application scenario and requirements. Higher sensitivity may help detect smaller targets, but it may also lead to false alarms or interference. Therefore, it is necessary to select an appropriate sensitivity based on factors such as the size of the target object, its distance, its reflection characteristics, and environmental conditions.
