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 controller to enable appropriate behavior.[1][2]

Sensors in robots are based on the functions of human sensory organs. Robots require extensive information about their environment in order to function effectively.

Classification[edit]

Sensors provide analogs to human senses and can monitor other phenomena for which humans lack explicit sensors.

  • Simple Touch: Sensing an object's presence or absence.
  • Complex Touch: Sensing an object's size, shape and/or hardness.
  • Simple Force: Measuring force along a single axis.
  • Complex Force: Measuring force along multiple axes.
  • Simple Vision: Detecting edges, holes and corners.
  • Complex Vision: Recognizing objects.
  • Proximity: Non-contact detection of an object.

Sensors can measure physical properties, such as the distance between objects, the presence of light and the frequency of sound.[3] They 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.[4]

Motion controllers, potentiometers, tacho-generators and encoder are used as joint sensors, whereas strain-gauge based sensing is used at the end-effector location for contact force control.

Internal sensor*[edit]

It is the part of the robot.Internal sensors measure the robot's internal state. They are used to measure position, velocity and acceleration of the robot joint or end effectors.

Position sensor[edit]

Position sensors measure the position of a joint (the degree to which the joint is extended). They include:

  • Encoder: a digital optical device that converts motion into a sequence of digital pulses.
  • Potentiometer: a variable resistance device that expresses linear or angular displacements in terms of voltage.
  • Linear variable differential transformer: a displacement transducer that provides high accuracy. It generates an AC signal whose magnitude is a function of the displacement of a moving core.
  • Synchros and Resolvers

Velocity Sensor[edit]

A velocity or speed sensor measures consecutive position measurements at known intervals and computes the time rate of change in the position values.

Applications[edit]

In a parts feeder, a vision sensor can eliminate the need for an alignment pallet. Vision-enabled insertion robots can precisely perform fitting and insertion operations of machine parts.[5]

See also[edit]

References[edit]

  1. ^ "Automation and Robotics ( Robot Store )". Robot Store (HK). Retrieved 23 January 2015. 
  2. ^ "Robotics sensors (Active)". Active Robots. Retrieved 23 January 2015. 
  3. ^ "Robot Sensation". British Pathe. Retrieved 27 January 2015. 
  4. ^ "Types of Robot Sensors". Robot Platform. Retrieved 23 January 2015. 
  5. ^ "Random Bin Picking & Automated Assembly". Universal. Retrieved 23 January 2015.