CSCI 473/573Human-Centered Robotics

Robot Sensing

What is the purpose of sensing?

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What are sensors?

• Sensors are physical devices that measure physical quantities.

• Sensors are a key physical component of the perceptual system of a robot.

• Sensors do not provide state, but measurement or observation

• Examples: ▪Contact: switch ▪Distance: radar ▪Magnetic field: compass

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Sensor Types

• Based on energy emission:▪ Passive: receive energy only

• Vision• Hearing

▪ Active: emit energy• Radar, sonar• Structured light• Touch

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Sensor Types

•Based on data source

▪ Internal information (Proprioceptive): • Battery level• CPU temperature• Joint angle and force

▪ External information (Exteroceptive):• Distance• Vision

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Common Robot Sensors

•Sonar: a transducer generates a sound pulse and then listens for echo

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Common Robot Sensors

•Sonar: a transducer generates a sound pulse and then listens for echo

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Common Robot Sensors

•2D laser scanner is a remote sensing technology that measures distance by illuminating a target with a laser and analyzing the reflected light.

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Common Robot Sensors

•2D laser scanner is a remote sensing technology that measures distance by illuminating a target with a laser and analyzing the reflected light.

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Common Robot Sensors

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Common Robot Sensors

•PTZ camera: a camera that is capable of remote directional and zoom control (pan-tilt-zoom)

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Common Robot Sensors

•360 omnidirectional camera

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Common Robot Sensors

•Omni-directional camera: a camera with a 360-degree field of view in the horizontal plane, or with a visual field that covers (approximately) the entire sphere.

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Common Robot Sensors

•Omni-directional camera: a camera with a 360-degree field of view in the horizontal plane, or with a visual field that covers (approximately) the entire sphere.

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Common Robot Sensors

•Thermal cameras

Common Robot Sensors

• Other traditional sensors• light level -> photo cells, cameras• sound level -> microphones• rotation -> encoders• temperature -> thermometer• gravity -> inclinometers• acceleration -> accelerometers• orientation-> gyroscopes

• IMU: inertial measurement unit uses a combination of accelerometers, gyroscopes, and sometimes magnetometers.

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3D Sensing

•3D laser scanner: • Type 1: point-by-point with a laser beam• Type 2: time-of-flight camera captures the entire with

each laser or light pulse

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3D Sensing

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LiDAR (Light Detection and Ranging) is a device that measures distance to a target by illuminating that target with a laser light.

Common Robot Sensors

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3D Sensing

•Stereo camera: Two (or more) cameras looking at the same scene from different perspectives provide a mean for determining three-dimensional shape and position.

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Fl

Il

Pl

Left camera

system

Fr

Ir

Pr

Right camera

system

P

Pr Pl

Il

Ir

= disparity

(a) (b)

3D Sensing

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•Stereo camera: Two (or more) cameras looking at the same scene from different perspectives provide a mean for determining three-dimensional shape and position.

3D Sensing

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•Structured light cameras (e.g., Kinect, Intel RealSense)

Robot Sensing

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What sensors are needed by a self-driving car to perceive external

situations?

Robot Sensing

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Robot Sensing

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Robot Sensing

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What sensors are needed by a Security Robot to perceive human-

social situations (e.g., in a mall)?

Common Robot Sensors

From SMP Robotics, 2019 31

Applications of HCR: Security

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Robot Sensing

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Mars Rovers 2020

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