Ultrasonic radar is a sensor device that uses ultrasonic waves to measure distance. It is typically integrated around the robot chassis (such as on the hubs, chassis edges, or within protective housings) to provide real-time perception of the robot’s distance from surrounding obstacles, their positions, and movement states. Its core function is to calculate the time difference between the transmitted and received ultrasonic signals, thereby determining the distance to an obstacle. This offers robots a low-cost, real-time solution for short-range environmental sensing.

Ultrasonic radar is a key component for achieving cost-effective, real-time obstacle avoidance and navigation in robot chassis, especially excelling in dynamic environments, low-speed movement, and edge-following tasks. It plays a critical role in the following areas:

Short-Range Obstacle Detection and Avoidance: By emitting ultrasonic waves and receiving reflected signals, it detects the distance and position of nearby obstacles (such as walls, furniture, and pedestrians) in real time, offering millimeter- to centimeter-level accuracy for obstacle avoidance.

Dynamic Obstacle Avoidance and Path Planning: Using high-frequency sampling (≥10 Hz) and the Doppler effect, ultrasonic radar captures the direction of moving obstacles (approaching or receding). Combined with SLAM algorithms, it enables dynamic path adjustment in response to environmental changes.

Edge-Following Navigation and Boundary Sensing: By measuring the distance between the robot and fixed boundaries (e.g., walls, shelves, furrows), it maintains a consistent distance (e.g., 10 cm), enabling edge-following behavior or boundary tracking.

Terrain and Boundary Recognition: Detects changes in ground height (e.g., steps, ditches) or material differences (e.g., grass vs. concrete), assisting the robot in determining passability.

Multi-Sensor Integration

To compensate for the limitations of ultrasonic radar, such as short detection distance, limited accuracy, and strong material dependency, multi-sensor fusion technology is often used to enhance the environmental perception capabilities of robot systems.

Low Cost: Compared to other radar technologies, ultrasonic radar is generally more cost-effective, making it ideal for large-scale deployment.

Flexible Deployment: Supports multi-sensor arrays (e.g., 4–8 sensors), suitable for mass production in applications like AGVs (Automated Guided Vehicles).

Detection Range: Typical detection range is 2 cm to 5 meters in air, covering key safety zones around the robot chassis.

Fast Dynamic Response: Response time from 10 ms to 50 ms, enabling real-time obstacle avoidance at low speeds.

Wide Beam Angle: A single sensor can cover a detection angle of 60° to 120°. With proper layout, multiple sensors can achieve full 360° surround view coverage.

Multi-Obstacle Recognition: Capable of detecting multiple reflection points simultaneously (such as table legs, wall corners, or moving people), and can distinguish between static and dynamic obstacles through algorithmic processing.

Strong Environmental Adaptability: Unaffected by lighting conditions (darkness, strong light), smoke, or dust. Ideal for scenarios where visual sensors may fail, such as fire rescue missions or underground pipe inspections.

Low Power Consumption: Typically operates at a current below 20 mA, making it well-suited for battery-powered mobile robots.

Sleep Mode: Some sensors support low-power standby modes, further extending battery life.

Non-Contact Measurement: Wireless ultrasonic distance measurement and detection can be used to avoid contact with the target object, and can be used to measure and monitor sensitive objects. Detecting human approach or gestures (such as waving to control the robot to start) can achieve contactless operation.

Motion Detection: Can detect the direction of obstacle movement (approaching or receding), enhancing the reliability of obstacle avoidance decisions.

Indoor Environments: Used in smart home applications for object detection, distance measurement, and human presence sensing. It is unaffected by indoor lighting or dust conditions (e.g., the "drop prevention" and "collision avoidance" functions in robotic vacuum cleaners).

Outdoor Harsh Weather Conditions: Can operate normally in rain, fog, snow, and other adverse weather conditions with minimal impact from environmental factors. However, temperature can affect the speed of ultrasonic wave propagation. In environments with large temperature variations, temperature compensation is required to maintain measurement accuracy.

Some industrial environments: For example, in factory workshops, it can be used for object position detection, distance measurement on production lines, etc., and can adapt to certain noise and vibration environments.