subject: The Hardware Of The Robot: Sensors [print this page] Sensors are the perceptual interface between robots and their environment. On the one hand we have passive sensors like cameras, which capture signals that are generated by other sources in the environment. On the other hand it has active sensors for example, radar, sonar, laser which emit energy into the environment. This energy is reflected by objects in the environment. These reflections can then be used to gather the information needed.
Generally active sensors provide more information than passive sensors. But they also consume more power. This can lead to a problem on mobile robots which need to take their energy with them in batteries.
It has three types of sensors. These are sensors that either
Record distances to objects, or
Generate an entire image of the environment, or
Measure a property of the robot itself.
Many mobile robots make use of range finders, which measure distances to nearby objects. A common type is the sonar sensor. Alternatives to sonar include radar and laser. Some range sensors measure very short or very long distances. Close range sensors are often tactile sensors such as whiskers, bump panels and touch sensitive skin.
The second important class of sensors is imaging sensors. These are cameras that provide images of the environment that can then be analyzed using computer vision and image recognition techniques.
The third important class is proprioceptive sensors. These inform the robot of its own state. To measure the exact configuration of a robotic joint motors are often equipped with shaft decoders that count the revolution of motors in small increments.
