Robotic sensors

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Types of robot sensors (Light and Sound sensors)

Robotic sensors are used to estimate a robot's condition and environment. These signals are passed to a robot controller to control robot functionality.

Sensors in robots are based on the functions of human sensory organs. This is why terms such as vision, tactile, and other terms used for sensory functions are commonly used in discussions about robotic sensors. Robots, like humans, must gather extensive information about their environment in order to function effectively.

Part-Picking

In a special parts feeder, an alignment pallet is not necessarily required. The reason for this is an automatic system can be constructed at low cost for alignment operations, such as vision sensors that perform inspection, pick bins, etc. Insertion robots can precisely perform fitting and insertion operations of machine parts with the help of different kinds of sensors. Different phases' parts are attached by the robot after matching. Such a robotic system can perform tasks that a human cannot perform.

Robot Sensation

Robot Sensation is a term that refers to sensory input, allowing robots to measure physical properties. Depending on the type of sensors embedded in the robot, a robot can measure physical properties, such as the distance between objects, the presence of light, and the frequency of sound. Robots can measure:

• Object Proximity: The presence/absence of an object, bearing, color, distance between objects.
• Physical orientation. The co-ordinates of object in space.
• Heat: The wavelength of infrared or ultra violet rays, temperature, magnitude, direction.
• Chemicals: The presence, identity, and concentration of chemicals or reactants.
• Light: The presence, color, and intensity of light.
• Sound: The presence, frequency, and intensity of sound.

Sensor Classification

Sensors in robots are similar to our eyes, nose, ears, mouth, and skin. The following are major capabilities required by a robot:

• Simple Touch: Sensing the presence or absence of an object.
• Complex Touch: Sensing the presence of an object plus some information on its size and shape.
• Simple Force: Measureing force along a single axis.
• Comples Force: Measuring force along two or more axes.
• Proximity: Non-contact detection of an object.
• Simple Vision: Detecting edges, holes, corners, and so on.
• Complex Vision: Recognizing shapes.

For motion control, potentiometers, tacho-generators, encoder, etc. are used as joint sensors, whereas strain-gauge based sensing etc., are used at the end-effector location for contact force control.

Internal sensor

Internal sensors, as the name suggests, are used to measure the internal state of a robot. They are used to measure properties such as position, velocity, acceleration, etc. at a particular instance.

Position sensors measure the position of each joint (i.e., the joint angle of a robot). The following are different position sensors:

• Encoder: An encoder is a digital optical device that converts motion into a sequence of digital pulses.
• Potentiometer: A potentiometer, also referred to as a "pot"，is a variable resistance device that expresses linear or angular displacements in terms of voltage.
• LVDT: The linear variable differential transformer (LVDT) is one of the most widely used displacement transducers, particularly when high accuracy is needed. It generates an AC signal whose magnitude is related to the displacement of a moving core.
• Synchros and Resolvers.

Velocity Sensors, or speed sensors, measure consecutive position measurements at known time intervals and compute the time rate of change in the position values or it directly finds it based on different principles.

See also

• Robot
• Robotics
• Tactile sensor
• Robot locomotion
• Outline of robotics
• Robot App Store
• Liquid handling robot
• Glossary of robotics
• Index of robotics articles
• Mechatronics
• Outline of robotics