Robotics Lecture 3: Sensors for Robotic Systems
45 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What does a sensor provide in response to a specified physical input?

  • A mechanical output
  • A usable output (correct)
  • An automated process
  • A manual reading

Which type of sensor is used for measuring sound levels?

  • Thermal sensor
  • Gyroscope
  • Microphone (correct)
  • Ultrasound sensor

What is the correct formula expressed by Ohm’s Law?

  • I = V/R
  • R = I/V
  • R = V/I
  • V = IR (correct)

Limit switches are primarily used to detect what?

<p>Proximity of a moving part (D)</p> Signup and view all the answers

What does the switch indicate when it is closed?

<p>The presence of a workpiece (D)</p> Signup and view all the answers

What type of sensors measure distance?

<p>Ultrasound and radar (C)</p> Signup and view all the answers

What is the voltage output when a switch is open?

<p>0 volts (D)</p> Signup and view all the answers

Which of the following is NOT categorized as a type of sensor?

<p>Electric motor (D)</p> Signup and view all the answers

What is the typical detection range of a capacitive proximity switch?

<p>4 to 60 mm (D)</p> Signup and view all the answers

Which component carries out the on-off switch function in a transistor circuit activated by voltage?

<p>Transistor (C)</p> Signup and view all the answers

How does a capacitive proximity switch detect non-metallic objects?

<p>Through dielectric properties (B)</p> Signup and view all the answers

What determines the capacitance of a pair of plates in a capacitive proximity switch?

<p>The distance between the plates (D)</p> Signup and view all the answers

What type of core is used in an inductive proximity switch?

<p>Ferrous metallic (C)</p> Signup and view all the answers

What happens to the inductance in an inductive proximity switch when a ferrous object approaches?

<p>It increases (B)</p> Signup and view all the answers

Which of the following statements about the operation of proximity switches is correct?

<p>They can detect both metallic and non-metallic objects (B)</p> Signup and view all the answers

What is the relationship between capacitance and distance in a capacitive proximity switch?

<p>Capacitance decreases with distance (C)</p> Signup and view all the answers

What is the primary function of a phototransistor in reflective opto-sensors?

<p>To convert light into electrical signals (B)</p> Signup and view all the answers

Which application is NOT commonly associated with photoelectric sensors?

<p>Ambient temperature measurement (C)</p> Signup and view all the answers

What impacts the effectiveness of photoelectric sensors according to their limitations?

<p>Surface color and texture (C)</p> Signup and view all the answers

In light sensors, what change occurs as the brightness of light increases?

<p>Lower resistance (A)</p> Signup and view all the answers

What role do potentiometers play in devices like stereos?

<p>Adjust resistance for volume control (D)</p> Signup and view all the answers

What is the typical detection range for inductive proximity switches?

<p>2 to 15 mm (C)</p> Signup and view all the answers

Which of the following is NOT an advantage of proximity switches?

<p>High thermal sensitivity (C)</p> Signup and view all the answers

In which form are the main types of proximity switches available?

<p>Cylindrical, rectangular, and slot (D)</p> Signup and view all the answers

What type of connections can proximity sensors use when connected to a power supply?

<p>Two-wire and three-wire connections (A)</p> Signup and view all the answers

What type of circuit does an inductive proximity sensor use to detect ferrous metal objects?

<p>Resonant circuit (C)</p> Signup and view all the answers

Which aspect of proximity switches improves their effectiveness in applications involving high-speed objects?

<p>Effective response to high-speed approaches (B)</p> Signup and view all the answers

Which characteristic makes proximity switches preferable in toxic environments?

<p>Durability to vibrations (C)</p> Signup and view all the answers

Which of the following devices can be activated by the current from a proximity switch?

<p>Electronic switch circuit (B)</p> Signup and view all the answers

What does a retro-reflective photoelectric switch primarily use for reflecting the light beam?

<p>Many small corner-cube prisms (B)</p> Signup and view all the answers

How does a diffuse-reflective photoelectric switch operate?

<p>It relies on direct reflection from the detected object. (B)</p> Signup and view all the answers

What is the range of detection distances for photoelectric switches?

<p>Less than 10 cm up to 1500 cm (A)</p> Signup and view all the answers

What is a characteristic of the 'Dark On' operation in photoelectric switches?

<p>The switch is activated when the beam of light is interrupted. (D)</p> Signup and view all the answers

In which configuration are both the emitter and receiver placed in diffuse-reflective photoelectric switches?

<p>In a single housing unit (D)</p> Signup and view all the answers

What occurs when an object interrupts the light beam in a 'Light On' operation?

<p>The switch becomes de-energized. (D)</p> Signup and view all the answers

What is a common feature of both retro-reflective and diffuse-reflective photoelectric switches?

<p>They use a single housing for integration. (A)</p> Signup and view all the answers

Which of these statements distinguishes retro-reflective from diffuse-reflective photoelectric switches?

<p>Retro-reflective uses corner-cube prisms for reflection. (A)</p> Signup and view all the answers

What is the primary function of photoelectric switches?

<p>To detect the presence of an object at long ranges (D)</p> Signup and view all the answers

Which type of photoelectric switch offers the longest sensing distance?

<p>Through-beam switches (B)</p> Signup and view all the answers

What components are essential in a through-beam photoelectric switch?

<p>Emitter and receiver units (C)</p> Signup and view all the answers

In which scenario might you commonly find break beam sensors used?

<p>Counting objects passing through a boundary (D)</p> Signup and view all the answers

How does the sensing distance of a through-beam photoelectric switch depend on emitter and receiver alignment?

<p>Perfect alignment maximizes sensing distance (B)</p> Signup and view all the answers

Which of the following describes the primary difference between retro-reflective and through-beam switches?

<p>Retro-reflective switches use a mirror to return light (B)</p> Signup and view all the answers

What type of light can photoelectric sensors utilize for object detection?

<p>Both visible and infrared light (D)</p> Signup and view all the answers

Which type of object detection technique do photoelectric sensors primarily use?

<p>Optical beam interruption (C)</p> Signup and view all the answers

Flashcards

Sensor Definition

A sensor is an input device that produces an output in response to a physical input.

Types of Contact Sensors

Sensors that detect by physical contact, commonly a simple switch.

Limit Switch

A switch that detects presence/passage of a moving part, often actuated by cam/roller/lever.

Ohm's Law

V=IR (Voltage = Current x Resistance).

Signup and view all the flashcards

Mechanical Switch

Generates an on-off signal based on mechanical input.

Signup and view all the flashcards

Simple vs. Complex Sensors

Sensors range from basic to sophisticated, like a simple switch vs. a complex camera.

Signup and view all the flashcards

Sensor Levels of Processing

Different sensors have different ways of interpreting data (e.g., a switch has an on/off level, while a camera is more complex).

Signup and view all the flashcards

Distance Sensors

Sensors that detect distance, using technologies like ultrasound, radar, or infrared.

Signup and view all the flashcards

Capacitive Proximity Switch

A proximity switch that works by measuring the capacitance between a sensor plate and a nearby object to detect its presence.

Signup and view all the flashcards

Capacitance

The ability of a capacitor to store an electrical charge.

Signup and view all the flashcards

Proximity Switch

A switch that detects the presence of an object without physical contact.

Signup and view all the flashcards

Inductive Proximity Switch

A switch that detects the presence of ferrous metal objects by measuring changes in inductance.

Signup and view all the flashcards

Detection Range (Capacitive)

Between 4-60mm from the sensor.

Signup and view all the flashcards

Detection Range (General)

Between 0.5 and 20mm.

Signup and view all the flashcards

Ferrous Metal

Metal containing iron, affected by magnetic fields.

Signup and view all the flashcards

Inductance

The property of a coil to oppose changes in current

Signup and view all the flashcards

Photoelectric Switches

Solid-state sensors that detect objects at long ranges using a beam of light (visible or infrared).

Signup and view all the flashcards

Through-Beam Photoelectric Switch

A photoelectric switch with a separate emitter and receiver. The receiver detects the light beam emitted from the emitter.

Signup and view all the flashcards

Through-Beam Sensing Distance

The maximum distance between the emitter and receiver where the light beam is still detected. It's highest when the emitter and receiver are perfectly aligned.

Signup and view all the flashcards

Retro-reflective Photoelectric Switch

A photoelectric switch that uses reflectors to reflect the emitted light back to the receiver.

Signup and view all the flashcards

Diffuse Photoelectric Switch

A photoelectric switch that uses scattered light from the object to detect its presence.

Signup and view all the flashcards

Advantages of Through-Beam Photoelectric Switches

These switches have longer sensing distances compared to other types, due to the direct communication between the emitter and receiver without reflections.

Signup and view all the flashcards

Break-beam Sensors

Sensors that use any pair of compatible emitter-detector devices to create an interruption-based detection system.

Signup and view all the flashcards

Photocell

Another name for a photoelectric switch.

Signup and view all the flashcards

How does an Inductive Proximity Switch work?

When a metal object enters the sensor's magnetic field, it changes the inductance of the coil, altering the current flowing through it. This change in current triggers a signal.

Signup and view all the flashcards

Sensing Range

The maximum distance at which an inductive proximity switch can reliably detect an object. Typical ranges are 2 to 15 mm.

Signup and view all the flashcards

Proximity Switch Applications

Inductive proximity switches are used in various applications like detecting the presence or absence of objects, controlling machinery movement, and safety systems.

Signup and view all the flashcards

Types of Proximity Switches

Common types include cylindrical, rectangular, and slot shapes, designed for different applications and mounting configurations.

Signup and view all the flashcards

Two-Wire and Three-Wire Connections

Inductive proximity switches can be wired with two or three wires. Two-wire connects power and output together, while three-wire separates power, output, and a common ground.

Signup and view all the flashcards

Advantages of Proximity Switches

Compared to other detectors, proximity switches offer long life, durability, versatility with AC/DC power, and responsiveness, with no moving parts.

Signup and view all the flashcards

Inductive vs. Capacitive Proximity Switches

Inductive switches detect metal objects via magnetic field changes, while capacitive switches use changes in capacitance to detect a wide range of materials, including non-metallic ones.

Signup and view all the flashcards

Corner-Cube Prism

A type of prism used in retro-reflective photoelectric switches to reflect light back to the receiver almost parallel to the entering beam.

Signup and view all the flashcards

Diffuse-reflective Photoelectric Switch

A type of photoelectric switch where the light beam is reflected directly from the surface of the object being detected.

Signup and view all the flashcards

Dark On Operation

A photoelectric switch is energized when the light beam is interrupted.

Signup and view all the flashcards

Light On Operation

A photoelectric switch is energized when the light beam reaches the receiver.

Signup and view all the flashcards

Detection Distance

The maximum distance a photoelectric switch can detect an object.

Signup and view all the flashcards

Photoelectric Switch Types

There are two main types: retro-reflective and diffuse-reflective.

Signup and view all the flashcards

What is the primary difference between a retro-reflective and a diffuse-reflective photoelectric switch?

The retro-reflective switch uses a reflector to send the light beam back to the receiver, while the diffuse-reflective switch relies on the object reflecting the light directly.

Signup and view all the flashcards

What is a Photoelectric Switch?

A sensor that uses light to detect the presence or absence of an object.

Signup and view all the flashcards

Types of Photoelectric Sensors

There are two main types:

  1. Dark-on: Only activated when light is blocked (object is present).
  2. Light-on: Only activated when light is detected (object is absent).
Signup and view all the flashcards

Reflective Opto-sensor Components

It uses both an emitter and a detector. The emitter, usually an LED, sends light, and the detector (a photodiode or phototransistor), receives it.

Signup and view all the flashcards

Photoelectric Sensor Limitations

They are affected by factors like surface reflectivity (color and texture), ambient light, and sensor calibration.

Signup and view all the flashcards

Light Sensor Function

A light-sensitive resistor that changes its resistance based on the amount of light. Brighter light means lower resistance, and darker light means higher resistance.

Signup and view all the flashcards

Study Notes

Robotics Lecture Notes

  • Robotics - Lecture presented by Mahmoud Abdelaal
  • Lecture 3 - Sensors for Robotic Systems I

Sensors for Robotic Systems

  • Definition: A sensor is an input device that provides an output based on a specific physical input. Example: A thermocouple converts temperature difference to an electrical output.
  • General Question: Given a sensor reading, what was the situation in the world like?
  • Example: Skin
  • Sensors: Range from simple to complex.

Types of Sensors

  • Contact: switches
  • Distance: Ultrasound, radar, infrared
  • Light level: photocells, cameras
  • Sound level: microphones
  • Strain: strain gauges
  • Rotation: encoders
  • Smell: chemical
  • Temperature: thermal, infrared
  • Inclination: inclinometers, gyroscopes
  • Pressure: pressure gauges (ex sensors)
  • Altitude: altimeters

Levels of Processing

  • Switch: Open = 0 volts, Closed = 5 volts
  • Digital scale
  • Microphone
  • Camera

Ohm's Law

  • V = IR
  • V = voltage (volts)
  • I= current (amps)
  • R = resistance (ohms)

Mechanical Switches/Limit Switches

  • Mechanical switch creates on/off signals when a mechanical input changes its state (e.g., presence/absence of a workpiece).
  • 1 Level: corresponds to 24 VDC input
  • 0 Level: corresponds to 0 VDC input
  • These switches are actuated by a cam, roller, or lever.

Limit Switches - Advantages

  • Limit switches are cheaper than proximity or photoelectric switches.
  • Wide range of sizes.

Proximity Switches

  • Basic types: inductive, capacitive, magnetic
  • Inductive operation: based on the variation of magnetic inductance.
  • Capacitive operation: variation of capacitance.
  • Magnetic operation: variation of magnetic flow.
  • Widely used in industrial applications: inductive and capacitive proximity switches.
  • Detection mechanism: presence of an object without physical contact.
  • Voltage amplitude: indicates proximity of metallic objects.
  • Range: typically 0.5 to 20 mm.

Capacitive Proximity Switch

  • Operates with metallic and non-metallic objects
  • Affected by the dielectric
  • The separation between two plates (sensor and the object) determines the capacitance.
  • The smaller the separation, the higher the capacitance
  • 4 to 60 mm is the typical detection range.

Inductive Proximity Switch

  • Consists of a coil wound around a ferrous core.
  • Placing a ferrous metallic object near the core changes the inductance of the coil.
  • This change can be detected using a resonant circuit.
  • The change in the amount of current in this circuit signifies the object's presence.
  • Typically detects objects within a distance of 2 to 15 mm

Photoelectric Sensors and Switches

  • Photoelectric switches: Solid-state sensors for detecting objects at long ranges.
  • Operation: use light beams (visible or infrared) which are interrupted or reflected.
    • Three types: Through-beam, retro-reflective, diffuse-reflective
    • Through-beam: Uses separate emitter and receiver units; high distance sensing potential.
    • Retro-reflective: Uses the same housing; utilizes multiple reflections to higher signal accuracy at lower distances.
    • Diffuse-reflective: Reflects light off of the object.
  • Detection distance: Varies with the type, size, and model.
  • "Dark ON" / "Light ON" operation: Dark ON = energized when the light beam is interrupted, Light ON = energized when the light beam reaches the receiver
  • Sensor limitations: Affected by light reflectivity, surface color, texture, and ambient light.

Light Sensors

  • Light sensors act as variable resistors; the light intensity affects the sensor's resistance
  • Brighter light equates to lower resistance; darker light translates to higher resistance.

Potentiometers

  • Used for volume control in stereos.
  • Often called "pots."

GuideCane Application

  • Uses various sensors (ultrasonic, compass, fluxgate) for obstacle detection and guidance
  • A system for visually impaired individuals.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Robotics Sensors Lecture 3 PDF

Description

Explore the fundamentals of sensors in robotic systems with this informative quiz. Learn about various types of sensors, their definitions, and how they process input to output valuable data. Test your knowledge on contact, distance, and other sensor categories.

More Like This

Robotics: Sensors and Actuators
5 questions

Robotics: Sensors and Actuators

ComfortingQuatrain1029 avatar
ComfortingQuatrain1029
AI Agents Overview and Types
10 questions

AI Agents Overview and Types

NonViolentMountain avatar
NonViolentMountain
Robotics Sensors and Actuators Quiz
25 questions

Robotics Sensors and Actuators Quiz

StylizedScholarship292 avatar
StylizedScholarship292
Robotics Sensors Overview
20 questions

Robotics Sensors Overview

SatisfactoryRhenium2021 avatar
SatisfactoryRhenium2021
Use Quizgecko on...
Browser
Open
Browser
Browser