A robotics sensor is a device that detects and measures physical quantities from its surroundings and converts them into a signal a robot can understand. These sensors are essentially the robot’s “eyes, ears, and sense of touch,” providing the input needed for it to perceive its environment and make decisions.

Types and Functions

Robotics sensors are categorised by the type of data they measure. Different sensors help a robot accomplish various tasks, from navigation to object manipulation.

• Proximity and Distance Sensors: These sensors measure the distance to objects without physical contact.
  • Ultrasonic Sensors: They use sound waves to determine distance, similar to how bats navigate. They are great for detecting objects and avoiding collisions.
  • Infrared (IR) Sensors: These sensors emit and detect IR light. They measure proximity and are often used in obstacle avoidance and line-following robots.
  • LiDAR (Light Detection and Ranging): LiDAR uses pulsed lasers to create a detailed 3D map of the environment. Autonomous vehicles and advanced robots use them for precise navigation.
• Tactile Sensors: These sensors act like a robot’s sense of touch, detecting physical contact and pressure.
  • Force and Torque Sensors: They measure the force or rotational force applied to an object, enabling a robot to handle delicate items without crushing them.
  • Touch Sensors: Simple on/off sensors that detect when a robot has made contact with a surface.
• Vision Sensors (Cameras): A camera acts as a robot’s eyes, providing visual data.
  • 2D and 3D Cameras: They capture images or video, which the robot’s programming can then analyze to identify objects, read QR codes, or perform facial recognition.
  • Time-of-Flight (ToF) Cameras: These cameras measure the time it takes for a laser or light pulse to reflect back, creating a 3D depth map.
• Internal and Positional Sensors: These sensors provide data about the robot’s own state and position.
  • IMU (Inertial Measurement Unit): An IMU combines an accelerometer, a gyroscope, and a magnetometer to track the robot’s orientation, tilt, and acceleration. This is crucial for maintaining balance and navigating.
  • Encoders: Encoders measure the rotation of a motor or joint, allowing the robot to know the exact position of its limbs.

How Sensors are Used in Robotics

A robot typically uses multiple sensors in combination. For example, a self-driving car uses LiDAR for detailed mapping, cameras for traffic light and sign recognition, and an IMU to track its own movement. The data from all these sensors is fused together by the robot’s central processor to create a comprehensive understanding of its environment, enabling it to operate autonomously.