Tactile sensors can be used to sense a diverse range of stimulus ranging from detecting the presence or absence of a grasped object to a complete tactile image. A tactile sensor consists of an array of touch sensitive sites, the sites may be capable of measuring more than one property. The contact forces measured
by a sensor are able to convey a large amount of information about the state of a grip. Texture, slip, impact and other contact conditions generate force and position signatures, that can be used to identify the state of a manipulation. This information can be determined by examination of the frequency domain, and is fully discussed in the literature.
Tactile sensors and their robotic applicationsAasheesh Tandon
This presentation discusses about artificial tactile sensors, it's comparison with human tactile senses. Further different types of tactile sensors are enlisted ,with a few given in more detail.
Robotic applications are also discussed and then finally future developments in this area is mentioned.
The document discusses sensors, defining them as devices that measure physical quantities and convert them into signals. It describes qualities of good sensors such as sensitivity and lack of influence on the measured property. Additionally, it covers common sensor types, errors, and measurement definitions like sensitivity, deviation, and resolution.
This document discusses load cells, which are transducers that convert force or pressure into an electrical signal. There are three main types of load cells: hydraulic, pneumatic, and strain gauge. Strain gauge load cells work by bonding strain gauges to an elastic material, where forces cause strain that is detected as changes in electrical resistance. Load cells have applications in areas like tank level control, bag filling machines, and weighing systems. They offer advantages like rugged construction and accuracy, though mounting and calibration can be difficult.
Proximity sensors detect objects without physical contact using various technologies like inductive, capacitive, ultrasonic and optical. Inductive sensors detect metallic objects using a coil and oscillator to create a magnetic field. Capacitive sensors detect metallic and nonmetallic objects by measuring capacitance changes between the sensor and object. Ultrasonic sensors use sound waves above human hearing range, while optical sensors use light beams reflected off objects. Key features of good sensors include precision, accuracy, response speed, operating range, reliability, easy calibration and low cost.
Motion sensors have a long history dating back to when early humans used movements of stars and crops to determine seasons. They were first widely used in World War II in mines and claymores to detect enemy movement. Technologically, motion sensors work by emitting waves that bounce off objects and are detected, with the information used to trigger a device. Today they have many applications in security, lighting, tracking, and more, bringing both benefits like convenience and disadvantages like easy accidental triggering. Motion sensors continue advancing, with potential uses like tracking performance through sensors embedded in clothing.
A sensor is a device that detects and responds to input from the physical environment. The specific input could be light, force, heat, motion, moisture, pressure, or any one of a great number of other environmental phenomena. The contemporary industrial world relies heavily on sensing devices and switches.
Introduction to Micro Sensors and Transducers. Application of MEMS in industries and their basic architecture. MEMS accelerometer and gyroscope explored a bit i.e. their structures and their applications.
This document discusses thermal imaging and its various applications. It begins by explaining that thermal imaging produces images based on the heat detected from objects and was originally developed for military purposes. It then provides details on:
- How thermal imaging cameras work to detect differences in temperature and produce images.
- Common applications of thermal imaging in fields like firefighting, law enforcement, medical, agriculture, and more.
- The advantages of thermal imaging like its ability to see in total darkness and penetrate obscurants like smoke.
- Specific uses of thermal imaging in border security, condition monitoring, night vision, medical screening, and evaluating solar panels.
Tactile sensors and their robotic applicationsAasheesh Tandon
This presentation discusses about artificial tactile sensors, it's comparison with human tactile senses. Further different types of tactile sensors are enlisted ,with a few given in more detail.
Robotic applications are also discussed and then finally future developments in this area is mentioned.
The document discusses sensors, defining them as devices that measure physical quantities and convert them into signals. It describes qualities of good sensors such as sensitivity and lack of influence on the measured property. Additionally, it covers common sensor types, errors, and measurement definitions like sensitivity, deviation, and resolution.
This document discusses load cells, which are transducers that convert force or pressure into an electrical signal. There are three main types of load cells: hydraulic, pneumatic, and strain gauge. Strain gauge load cells work by bonding strain gauges to an elastic material, where forces cause strain that is detected as changes in electrical resistance. Load cells have applications in areas like tank level control, bag filling machines, and weighing systems. They offer advantages like rugged construction and accuracy, though mounting and calibration can be difficult.
Proximity sensors detect objects without physical contact using various technologies like inductive, capacitive, ultrasonic and optical. Inductive sensors detect metallic objects using a coil and oscillator to create a magnetic field. Capacitive sensors detect metallic and nonmetallic objects by measuring capacitance changes between the sensor and object. Ultrasonic sensors use sound waves above human hearing range, while optical sensors use light beams reflected off objects. Key features of good sensors include precision, accuracy, response speed, operating range, reliability, easy calibration and low cost.
Motion sensors have a long history dating back to when early humans used movements of stars and crops to determine seasons. They were first widely used in World War II in mines and claymores to detect enemy movement. Technologically, motion sensors work by emitting waves that bounce off objects and are detected, with the information used to trigger a device. Today they have many applications in security, lighting, tracking, and more, bringing both benefits like convenience and disadvantages like easy accidental triggering. Motion sensors continue advancing, with potential uses like tracking performance through sensors embedded in clothing.
A sensor is a device that detects and responds to input from the physical environment. The specific input could be light, force, heat, motion, moisture, pressure, or any one of a great number of other environmental phenomena. The contemporary industrial world relies heavily on sensing devices and switches.
Introduction to Micro Sensors and Transducers. Application of MEMS in industries and their basic architecture. MEMS accelerometer and gyroscope explored a bit i.e. their structures and their applications.
This document discusses thermal imaging and its various applications. It begins by explaining that thermal imaging produces images based on the heat detected from objects and was originally developed for military purposes. It then provides details on:
- How thermal imaging cameras work to detect differences in temperature and produce images.
- Common applications of thermal imaging in fields like firefighting, law enforcement, medical, agriculture, and more.
- The advantages of thermal imaging like its ability to see in total darkness and penetrate obscurants like smoke.
- Specific uses of thermal imaging in border security, condition monitoring, night vision, medical screening, and evaluating solar panels.
Relative humidity sensors are commonly used to measure atmospheric humidity. They work by measuring the ratio of actual water vapor pressure to the saturation vapor pressure at a given temperature. Ceramic, semiconductor, and polymer materials are often used as the sensing elements in relative humidity sensors. Ceramic sensors typically function through the Grotthuss mechanism, where adsorbed water layers allow protons to tunnel between water molecules. Capacitive and resistive relative humidity sensors also exist, where the capacitance or resistance of a hygroscopic material changes with varying humidity levels. Other humidity measurement techniques include psychrometers, chilled mirror optical sensors, and radiation absorption hygrometers. Humidity sensors have applications in fields like industrial processes, agriculture, weather monitoring
The document discusses smart sensors, providing details on their architecture, fabrication, advantages, disadvantages and applications. Some key points:
- Smart sensors integrate a sensor, analog/digital converter, processor and communication interface on a single chip, allowing them to process and communicate sensor data.
- The basic architecture includes a sensing element, amplifier, ADC, memory, processor and communication components. Fabrication uses techniques like micro-machining and bonding.
- Advantages are reduced system load and faster operation. Applications include industrial monitoring, automotive controls, biomedical devices, and smart dust networks of tiny sensors. Disadvantages include higher initial costs and issues with mixing old and new devices.
Vibration sensors detect vibrations and convert them into electrical signals. There are two main types: contact sensors that must mount directly to the object, and non-contact sensors that measure vibrations without direct contact. Common contact sensors include piezoelectric accelerometers, piezoresistive accelerometers, and strain gauges. Common non-contact sensors include microphones, laser displacement sensors, and eddy current sensors. Vibration data can be analyzed in both the time and frequency domains to diagnose machine problems.
Sensors are devices that measure physical quantities and convert them into signals that can be read by observers or instruments. They are used in many applications from cars and machines to medicine and more. Sensors come in different types including optical sensors, which detect light, and biosensors, which are used in biomedical applications and detect biological components. The resolution of a sensor refers to the smallest change it can detect in the measured quantity.
The ultrasonic sensor transmits ultrasonic waves above 20 kHz and detects the reflected waves with a receiver to measure distance. The HC-SR04 module can measure distances from 2 to 400 cm with 5V power and works by sending a 10 microsecond trigger signal to initiate a transmission, then measuring the echo pulse width to calculate the distance. Ultrasonic sensors can be used to measure distance, level, presence and more without contact and have applications in obstacle detection robots, parking assistance systems and more.
Sensors are devices that measure physical quantities and convert them into signals that can be read by observers or instruments. The document discusses several common sensors: infrared (IR) sensors, sound sensors, temperature sensors, and discusses their working principles and applications. It also provides details on using timers and integrated circuits like the 555 timer IC to process sensor output signals.
This Presentation provides some basics of Sensors Technology.........
It gives few ideas to learn about sensors which are as normally used as electrical & electronics applications.......
This document discusses inductive proximity sensors. It defines inductive proximity sensors as electronic devices that can detect metal objects without physical contact through the use of magnetic fields. It explains that inductive proximity sensors work by inducing eddy currents in nearby metal objects using a magnetic field, which are then detected. The document notes there are differences between shielded and non-shielded inductive sensors and provides examples of inductive sensor applications like position determination, camshaft interrogation, and use in wind power plants.
This presentation discusses robotic sensors. It defines a robot and explains that robotic sensors detect physical signals and convert them to electrical signals to estimate a robot's environment and condition. The document then categorizes and describes various types of robotic sensors including light, sound, temperature, contact, proximity, distance, pressure, tilt, voltage, current, IMU, and acceleration sensors. It provides examples and applications of each sensor type. The presentation concludes by noting sensors allow robots to complete various tasks and that more complex robots require more sensors.
The document describes the Tongue Drive System (TDS), a wireless assistive technology that allows people with severe disabilities to control devices using their tongue. The TDS uses a small magnet attached to the tongue and magnetic sensors to detect tongue movements and wirelessly transmit commands to targeted devices. It can take 30 minutes to learn to use the TDS. The TDS aims to help severely disabled individuals experience independent living.
This document discusses signal conditioning circuits. It defines signal conditioning as the manipulation of an analog signal to meet the requirements of subsequent processing stages. Some key functions of signal conditioning circuits include amplification, filtering, attenuation, and linearization. Operational amplifiers are commonly used to amplify signals in signal conditioning stages. The document provides examples of signal conditioning circuits and discusses their use in applications like analog to digital conversion and control engineering.
A light sensor detects ambient light levels and can include photoresistors, photodiodes, or phototransistors. It works by measuring changes in electrical resistance, voltage, or current caused by exposure to light. Light sensors have a wide range of applications including in street lights, cameras, alarms, and automatic lighting controls.
This document discusses different types of sensors and their characteristics. It covers the differences between active and passive instruments, as well as null-type and deflection-type instruments. It also discusses analogue versus digital instruments and some key sensor performance characteristics such as accuracy, precision, threshold, resolution, sensitivity, linearity, hysteresis and more. Key factors that influence sensor selection are resolution requirements, cost, accuracy needs, and application environment. Proper sensor selection depends on balancing these factors for each unique measurement scenario.
Ultrasonic sensors use sound waves to detect objects and measure distances with millimeter precision under many conditions. Passive infrared (PIR) sensors detect infrared light given off by objects to trigger motion detectors. Temperature sensors like the TMP36 output a voltage linearly proportional to temperature in degrees Celsius without external calibration.
The document discusses sensors, actuators, and input/output devices used in computer-controlled processes. It describes:
1) Sensors that measure continuous and discrete process variables and transmit signals to computers.
2) Actuators that receive signals from computers to control continuous and discrete process parameters.
3) Analog-to-digital and digital-to-analog conversion devices that allow computers to interface with analog sensors and actuators.
4) Input/output devices that allow computers to interface with discrete and pulse data from processes.
MEMS sensors are microelectromechanical systems that use mechanical and electrical components to detect and measure physical quantities. There are several types of MEMS sensors including inertial, optical, pressure, and chemical sensors. Common MEMS sensors are used in smartphones for functions like orientation detection, motion sensing, proximity detection, ambient light sensing, and fingerprint scanning. Other applications of MEMS sensors include robot vacuums that use infrared, cliff, and object sensors to navigate, and smartwatches that measure heart rate using green LEDs, infrared light, or a combination. Emerging applications of MEMS sensors include molecular identification sensors and 3D scanners.
The document discusses sensors and their uses in manufacturing. It defines a sensor as a device that measures a physical quantity and converts it into a readable form. Sensors are then classified into different types including tactile, proximity, range, miscellaneous, and machine vision sensors. Examples are provided for each type along with their working principles and applications in robotics and manufacturing for tasks like distance sensing, contour tracking, machine vision, process monitoring, and quality control. Key desirable sensor features and concepts like accuracy vs precision are also covered at a high level.
This document discusses smart sensors and the Internet of Things (IoT). It begins with introducing the group members and then outlines topics to be covered such as definitions of smart sensors, their evolution, examples of smart sensors used in IoT applications, and the benefits of a world connected by smart sensors and IoT. Specific types of smart sensors are explained in more detail such as temperature, proximity, pressure, gas, accelerometer, level, motion detection, optical, and gyroscope sensors. Applications of smart sensors for smart cities, utilities, and environmental monitoring are presented. Both pros and cons of smart sensors are listed.
The document outlines various topics related to biomedical instrumentation including biometrics, physiological systems of the human body like cardiovascular and respiratory systems, the kidney, bioelectric potentials, biopotential electrodes, and transducers for ECG, EEG, and EMG. It also provides details on the characteristics of biomedical instrumentation systems and describes concepts like bioelectric potential, action potential, and the recording setup for ECG, EEG, and EMG.
This document discusses sensors and transducers used in robotics. It describes desirable features of sensors such as accuracy, precision, operating range, speed of response, calibration, reliability, and cost. It then categorizes the main types of sensors used in robotics: tactile sensors, proximity and range sensors, miscellaneous sensors, and machine vision systems. Under tactile sensors, it describes touch and force sensors. It provides examples of proximity sensors like infrared sensors and describes how optical, acoustic, electrical, and other technologies can be used to design proximity and range sensors.
Relative humidity sensors are commonly used to measure atmospheric humidity. They work by measuring the ratio of actual water vapor pressure to the saturation vapor pressure at a given temperature. Ceramic, semiconductor, and polymer materials are often used as the sensing elements in relative humidity sensors. Ceramic sensors typically function through the Grotthuss mechanism, where adsorbed water layers allow protons to tunnel between water molecules. Capacitive and resistive relative humidity sensors also exist, where the capacitance or resistance of a hygroscopic material changes with varying humidity levels. Other humidity measurement techniques include psychrometers, chilled mirror optical sensors, and radiation absorption hygrometers. Humidity sensors have applications in fields like industrial processes, agriculture, weather monitoring
The document discusses smart sensors, providing details on their architecture, fabrication, advantages, disadvantages and applications. Some key points:
- Smart sensors integrate a sensor, analog/digital converter, processor and communication interface on a single chip, allowing them to process and communicate sensor data.
- The basic architecture includes a sensing element, amplifier, ADC, memory, processor and communication components. Fabrication uses techniques like micro-machining and bonding.
- Advantages are reduced system load and faster operation. Applications include industrial monitoring, automotive controls, biomedical devices, and smart dust networks of tiny sensors. Disadvantages include higher initial costs and issues with mixing old and new devices.
Vibration sensors detect vibrations and convert them into electrical signals. There are two main types: contact sensors that must mount directly to the object, and non-contact sensors that measure vibrations without direct contact. Common contact sensors include piezoelectric accelerometers, piezoresistive accelerometers, and strain gauges. Common non-contact sensors include microphones, laser displacement sensors, and eddy current sensors. Vibration data can be analyzed in both the time and frequency domains to diagnose machine problems.
Sensors are devices that measure physical quantities and convert them into signals that can be read by observers or instruments. They are used in many applications from cars and machines to medicine and more. Sensors come in different types including optical sensors, which detect light, and biosensors, which are used in biomedical applications and detect biological components. The resolution of a sensor refers to the smallest change it can detect in the measured quantity.
The ultrasonic sensor transmits ultrasonic waves above 20 kHz and detects the reflected waves with a receiver to measure distance. The HC-SR04 module can measure distances from 2 to 400 cm with 5V power and works by sending a 10 microsecond trigger signal to initiate a transmission, then measuring the echo pulse width to calculate the distance. Ultrasonic sensors can be used to measure distance, level, presence and more without contact and have applications in obstacle detection robots, parking assistance systems and more.
Sensors are devices that measure physical quantities and convert them into signals that can be read by observers or instruments. The document discusses several common sensors: infrared (IR) sensors, sound sensors, temperature sensors, and discusses their working principles and applications. It also provides details on using timers and integrated circuits like the 555 timer IC to process sensor output signals.
This Presentation provides some basics of Sensors Technology.........
It gives few ideas to learn about sensors which are as normally used as electrical & electronics applications.......
This document discusses inductive proximity sensors. It defines inductive proximity sensors as electronic devices that can detect metal objects without physical contact through the use of magnetic fields. It explains that inductive proximity sensors work by inducing eddy currents in nearby metal objects using a magnetic field, which are then detected. The document notes there are differences between shielded and non-shielded inductive sensors and provides examples of inductive sensor applications like position determination, camshaft interrogation, and use in wind power plants.
This presentation discusses robotic sensors. It defines a robot and explains that robotic sensors detect physical signals and convert them to electrical signals to estimate a robot's environment and condition. The document then categorizes and describes various types of robotic sensors including light, sound, temperature, contact, proximity, distance, pressure, tilt, voltage, current, IMU, and acceleration sensors. It provides examples and applications of each sensor type. The presentation concludes by noting sensors allow robots to complete various tasks and that more complex robots require more sensors.
The document describes the Tongue Drive System (TDS), a wireless assistive technology that allows people with severe disabilities to control devices using their tongue. The TDS uses a small magnet attached to the tongue and magnetic sensors to detect tongue movements and wirelessly transmit commands to targeted devices. It can take 30 minutes to learn to use the TDS. The TDS aims to help severely disabled individuals experience independent living.
This document discusses signal conditioning circuits. It defines signal conditioning as the manipulation of an analog signal to meet the requirements of subsequent processing stages. Some key functions of signal conditioning circuits include amplification, filtering, attenuation, and linearization. Operational amplifiers are commonly used to amplify signals in signal conditioning stages. The document provides examples of signal conditioning circuits and discusses their use in applications like analog to digital conversion and control engineering.
A light sensor detects ambient light levels and can include photoresistors, photodiodes, or phototransistors. It works by measuring changes in electrical resistance, voltage, or current caused by exposure to light. Light sensors have a wide range of applications including in street lights, cameras, alarms, and automatic lighting controls.
This document discusses different types of sensors and their characteristics. It covers the differences between active and passive instruments, as well as null-type and deflection-type instruments. It also discusses analogue versus digital instruments and some key sensor performance characteristics such as accuracy, precision, threshold, resolution, sensitivity, linearity, hysteresis and more. Key factors that influence sensor selection are resolution requirements, cost, accuracy needs, and application environment. Proper sensor selection depends on balancing these factors for each unique measurement scenario.
Ultrasonic sensors use sound waves to detect objects and measure distances with millimeter precision under many conditions. Passive infrared (PIR) sensors detect infrared light given off by objects to trigger motion detectors. Temperature sensors like the TMP36 output a voltage linearly proportional to temperature in degrees Celsius without external calibration.
The document discusses sensors, actuators, and input/output devices used in computer-controlled processes. It describes:
1) Sensors that measure continuous and discrete process variables and transmit signals to computers.
2) Actuators that receive signals from computers to control continuous and discrete process parameters.
3) Analog-to-digital and digital-to-analog conversion devices that allow computers to interface with analog sensors and actuators.
4) Input/output devices that allow computers to interface with discrete and pulse data from processes.
MEMS sensors are microelectromechanical systems that use mechanical and electrical components to detect and measure physical quantities. There are several types of MEMS sensors including inertial, optical, pressure, and chemical sensors. Common MEMS sensors are used in smartphones for functions like orientation detection, motion sensing, proximity detection, ambient light sensing, and fingerprint scanning. Other applications of MEMS sensors include robot vacuums that use infrared, cliff, and object sensors to navigate, and smartwatches that measure heart rate using green LEDs, infrared light, or a combination. Emerging applications of MEMS sensors include molecular identification sensors and 3D scanners.
The document discusses sensors and their uses in manufacturing. It defines a sensor as a device that measures a physical quantity and converts it into a readable form. Sensors are then classified into different types including tactile, proximity, range, miscellaneous, and machine vision sensors. Examples are provided for each type along with their working principles and applications in robotics and manufacturing for tasks like distance sensing, contour tracking, machine vision, process monitoring, and quality control. Key desirable sensor features and concepts like accuracy vs precision are also covered at a high level.
This document discusses smart sensors and the Internet of Things (IoT). It begins with introducing the group members and then outlines topics to be covered such as definitions of smart sensors, their evolution, examples of smart sensors used in IoT applications, and the benefits of a world connected by smart sensors and IoT. Specific types of smart sensors are explained in more detail such as temperature, proximity, pressure, gas, accelerometer, level, motion detection, optical, and gyroscope sensors. Applications of smart sensors for smart cities, utilities, and environmental monitoring are presented. Both pros and cons of smart sensors are listed.
The document outlines various topics related to biomedical instrumentation including biometrics, physiological systems of the human body like cardiovascular and respiratory systems, the kidney, bioelectric potentials, biopotential electrodes, and transducers for ECG, EEG, and EMG. It also provides details on the characteristics of biomedical instrumentation systems and describes concepts like bioelectric potential, action potential, and the recording setup for ECG, EEG, and EMG.
This document discusses sensors and transducers used in robotics. It describes desirable features of sensors such as accuracy, precision, operating range, speed of response, calibration, reliability, and cost. It then categorizes the main types of sensors used in robotics: tactile sensors, proximity and range sensors, miscellaneous sensors, and machine vision systems. Under tactile sensors, it describes touch and force sensors. It provides examples of proximity sensors like infrared sensors and describes how optical, acoustic, electrical, and other technologies can be used to design proximity and range sensors.
A capacitive sensor uses changes in capacitance to detect proximity or contact with a target. The sensor has a sensing area that produces an electric field, and a change in the gap between this area and a target alters the capacitance in a way that can be measured. Capacitive sensors are used for applications like touchscreens, thickness measurement, and position sensing due to their non-contact operation and insensitivity to the target material. They provide flexibility and cost advantages over mechanical switches in human-machine interfaces.
This document summarizes a study that tested the effects of varying width and length on the behavior of a soft, stretchable sensor. The sensor consists of a stretchable fabric substrate and a composite of multiwall carbon nanotubes in a polymer matrix. Samples of the sensor were fabricated with three different lengths (30, 60, and 90 mm) and four different widths (5, 10, 15, and 20 mm). The samples underwent static and dynamic testing using a custom extensometer and load cell. Preliminary results showed that sensors with larger dimensions had lower resistivity, as there were more opportunities for carbon nanotube cross-paths to allow electron flow. Future work will analyze dynamic test results and sensor performance in practical applications
This document proposes a soft robotic supernumerary device (SR device) to help people with impaired hand function due to stroke. Standard exoskeleton devices are expensive, heavy, and uncomfortable. The proposed SR device would attach to the body and coordinate with the patient's motions through feedback between the human and robot. It would be made of soft silicone materials, making it cheaper to manufacture, lighter weight, and more comfortable fitting than rigid metal exoskeletons. Sensors in a glove will collect data on hand motions and forces to program the SR device to compliment the patient's limited range of motions.
The document discusses various types of force and pressure sensors. It describes Newton's laws of motion and defines force and pressure. Quantitative and qualitative force sensors are discussed. Common force sensors include strain gauges, load cells, and tactile sensors. Tactile sensors are further divided into touch, spatial, and slip sensors. The document also covers different types of pressure sensors and transducers, including strain gauges, piezoelectric sensors, capacitive sensors, and optoelectronic pressure sensors. Common components of pressure transducers like the piston, Bourdon tube, bellows, and diaphragm are also summarized.
Sensors are devices that detect and respond to some type of input from the physical environment. This document discusses several common sensors used in manufacturing, including proximity sensors, LVDT sensors, ultrasonic sensors, encoders, switches, inductive sensors, optical sensors, strain gauges, and pressure switches. It provides details on their functions and applications for tasks like distance sensing, contour tracking, machine vision, and process parameter monitoring. Essential features for sensors in manufacturing include precision, accuracy, response speed, operating range, reliability, ease of calibration, and cost.
1) Sensors are devices that detect physical quantities and convert them into signals that can be measured. They are needed for industrial monitoring, safety, and automation.
2) Common sensors include position, proximity, range, touch, and force sensors. Position sensors like LVDT and RVDT convert linear or angular displacement into electrical signals.
3) Sensors have characteristics like range, sensitivity, accuracy, and response time that determine their effectiveness. Understanding sensor types and properties is important for robotics applications.
New electromagnetic force sensor measuring the density of liquidseSAT Publishing House
1. The document describes a new electromagnetic force sensor that can be used to measure the density of liquids.
2. The sensor works by measuring the induced voltage between two flat coils as the distance between them changes when a mass is attached. The voltage increases as the coils get closer together.
3. The sensor was used to measure the density of water-ethanol mixtures at different mole fractions. The measured densities agreed well with values found in literature.
Proximity sensors can detect objects without physical contact by emitting electromagnetic fields or beams and detecting changes in the fields. They have no moving parts so they are reliable with long lifespans. Proximity sensors are used to detect vibrations in machines and as touch switches. The main types are capacitive, inductive, radar, sonar, magnetic, photocell, and infrared proximity sensors. Capacitive sensors detect changes in capacitance from objects. Inductive sensors induce eddy currents in metals using magnetic fields. Radar and sonar use radio waves and ultrasound. Magnetic sensors detect disturbances in magnetic fields. Photocell and infrared sensors use light. Proximity sensors are used for applications like presence detection, object counting, and
1. Sensors allow machines and robots to monitor their surroundings in various ways and for many applications.
2. The document discusses different types of sensors like position, proximity, range sensors and their uses in industry, environment, and safety.
3. It also explains the characteristics and working principles of important position sensors like LVDT and RVDT, which can convert linear or angular displacement into electrical signals.
3.3 LIGTHING TECHNIQUES WITH CONTACT & NON CONTACT SENSORS.pptxJAYASOORIYAMSEC2020
This document provides an overview of various sensing techniques used in robotics, including contact and non-contact sensors. It discusses structured lighting approaches, time-of-flight sensors, laser rangefinders, tactile sensors, touch sensors, binary sensors, analog sensors, force/torque sensors, wrist sensors, ultrasonic range finders, and slip sensors. The document provides detailed descriptions of how each type of sensor works to enable robots to sense their environment. Videos and an MCQ link are also provided for additional learning.
1. Occupancy and motion sensors use technologies like ultrasonic, microwave, capacitive, visible light, and infrared to detect movement or occupancy.
2. Microwave sensors emit and receive reflected waves to detect movement, while ultrasonic sensors use echo location like bats.
3. Capacitive sensors detect changes in capacitance from nearby objects, and passive infrared sensors detect changes in infrared emissions.
This document describes a flexible and sensitive motion sensor created using silver nanowires embedded in an elastomer substrate. The sensor is highly elastic and sensitive, able to detect both tensile and compressive strain from human motion. It was fabricated using a microfabrication process involving spin coating, curing, and bonding of silver nanowire thin films to a flexible PDMS substrate. Experimental testing showed the sensor has excellent stability and sensitivity when detecting finger bending motions, with potential applications in biomedical monitoring and entertainment.
Sensors in Different Application Area Topics Covered: Occupancy and Motion Detectors; Position, Displacement, and Level; Velocity and Acceleration; Force, Strain, and Tactile Sensors; Pressure Sensors, Temperature Sensors
Ulas Ayaz has designed several optical sensors using microspheres as the sensing element. His shear stress sensor was the first to directly measure wall shear stress of reattaching flows. It has a flexible design that allows adjustment of resolution and bandwidth by changing the sphere material and size. Testing showed it performed well in measuring both steady and unsteady flows. Ayaz also developed a seismometer that directly measures acceleration up to 1 micro-g with high sensitivity and bandwidth up to 20 Hz using whispering gallery mode optics. Further, he designed miniature pressure, electric field, and prosthetic sensors using similar microsphere techniques.
This document discusses the use of sensors in robotics. It begins by introducing how sensors give robots human-like sensing abilities like vision, touch, hearing, and movement. It then describes several key sensors used in robotics - vision sensors that allow robots to see their environment, touch sensors that allow robots to feel contact and interpret emotions, and hearing sensors that allow robots to perceive speech. The document also lists and describes other common sensors like proximity, range, tactile, light, sound, temperature, contact, voltage, and current sensors and their applications in robotics.
The document discusses different types of proximity sensors, including inductive, capacitive, ultrasonic, and optical sensors. It provides details on the working principles, components, advantages, and disadvantages of each type. Common applications are also described for each proximity sensor technology. The document concludes that proximity sensors have widespread uses in various industries like manufacturing and that their market is expected to continue growing.
Force sensors can be quantitative, measuring the exact force value, or qualitative, indicating if a threshold is exceeded. Common quantitative sensors include strain gauges and load cells, while keyboards use qualitative sensors. Force is measured via strain, displacement, or other effects. Pressure is a distribution of force over an area. Common pressure measurement methods involve springs, bourdon tubes, diaphragms, and other elastic elements. Deflection is converted to electrical signals using strain gauges, piezoelectric materials, or other transducers. Tactile sensors detect touch or force spatially and can use piezoresistive, capacitive, or optical methods.
This document provides an overview of sensors used in robots. It discusses that sensors allow robots to perceive their environment and perform tasks reliably. The document then describes various types of internal sensors like position, velocity, force sensors and external sensors like proximity, range finding, color and motion sensors. It provides details on specific position sensors like potentiometers, optical encoders, LVDTs and magnetic sensors. The document also discusses velocity sensors such as encoders and tachometers. Finally, it mentions new developments in sensor technology including MEMS, MOEMS and smart sensors, and provides an example of the humanoid robot ASIMO which utilizes various sensors for functions like vision, balance and intelligence.
Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
DEEP LEARNING FOR SMART GRID INTRUSION DETECTION: A HYBRID CNN-LSTM-BASED MODELgerogepatton
As digital technology becomes more deeply embedded in power systems, protecting the communication
networks of Smart Grids (SG) has emerged as a critical concern. Distributed Network Protocol 3 (DNP3)
represents a multi-tiered application layer protocol extensively utilized in Supervisory Control and Data
Acquisition (SCADA)-based smart grids to facilitate real-time data gathering and control functionalities.
Robust Intrusion Detection Systems (IDS) are necessary for early threat detection and mitigation because
of the interconnection of these networks, which makes them vulnerable to a variety of cyberattacks. To
solve this issue, this paper develops a hybrid Deep Learning (DL) model specifically designed for intrusion
detection in smart grids. The proposed approach is a combination of the Convolutional Neural Network
(CNN) and the Long-Short-Term Memory algorithms (LSTM). We employed a recent intrusion detection
dataset (DNP3), which focuses on unauthorized commands and Denial of Service (DoS) cyberattacks, to
train and test our model. The results of our experiments show that our CNN-LSTM method is much better
at finding smart grid intrusions than other deep learning algorithms used for classification. In addition,
our proposed approach improves accuracy, precision, recall, and F1 score, achieving a high detection
accuracy rate of 99.50%.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
A review on techniques and modelling methodologies used for checking electrom...nooriasukmaningtyas
The proper function of the integrated circuit (IC) in an inhibiting electromagnetic environment has always been a serious concern throughout the decades of revolution in the world of electronics, from disjunct devices to today’s integrated circuit technology, where billions of transistors are combined on a single chip. The automotive industry and smart vehicles in particular, are confronting design issues such as being prone to electromagnetic interference (EMI). Electronic control devices calculate incorrect outputs because of EMI and sensors give misleading values which can prove fatal in case of automotives. In this paper, the authors have non exhaustively tried to review research work concerned with the investigation of EMI in ICs and prediction of this EMI using various modelling methodologies and measurement setups.
ACEP Magazine edition 4th launched on 05.06.2024Rahul
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Tactile Sensing
1. Credit to Dr. RM Crowder
Tactile sensing
Touch and tactile sensor are devices which measures the parameters of a contact between the sensor and an
object. This interaction obtained is confined to a small defined region. This contrasts with a force and torque
sensor that measures the total forces being applied to an object. In the consideration of tactile and touch
sensing, the following definitions are commonly used:
Touch Sensing
This is the detection and measurement of a contact force at a defined point. A touch sensor can also
be restricted to binary information, namely touch, and no touch.
Tactile Sensing
This is the detection and measurement of the spatial distribution of forces perpendicular to a
predetermined sensory area, and the subsequent interpretation of the spatial information. A tactile-
sensing array can be considered to be a coordinated group of touch sensors.
Slip
This is the measurement and detection of the movement of an object relative to the sensor. This can
be achieved either by a specially designed slip sensor or by the interpretation of the data from a
touch sensor or a tactile array.
Tactile sensors can be used to sense a diverse range of stimulus ranging from detecting the presence or
absence of a grasped object to a complete tactile image. A tactile sensor consists of an array of touch
sensitive sites, the sites may be capable of measuring more than one property. The contact forces measured
by a sensor are able to convey a large amount of information about the state of a grip. Texture, slip, impact
and other contact conditions generate force and position signatures, that can be used to identify the state of a
manipulation. This information can be determined by examination of the frequency domain, and is fully
discussed in the literature.
As there is no comprehensive theory available that defines the sensing requirements for a robotic system,
much of the knowledge is drawn from investigation of human sensing, and the analysis of grasping and
manipulation. Study of the human sense of touch suggests that creating a gripper incorporating tactile
sensing requires a wide range of sensors to fully determine the state of a grip. The detailed specification of a
touch sensor will be a function of the actual task as it is required to perform. Currently no general
specification of a touch or tactile sensor exists the following can be used as an excellent basis for defining
the desirable characteristics of a touch or tactile sensor suitable for the majority of industrial applications:
A touch sensor should ideally be a single-point contact, through the sensory area can be any size. In
practice, an area of 1-2 mm2
is considered a satisfactory compromise between the difficulty of
fabricating a sub-miniature sensing element and the coarseness of a large sensing element.
The sensitivity of the touch sensor is dependent on a number of variables determined by the sensor's
basic physical characteristic. In addition the sensitivity may also be the application, in particular any
physical barrier between the sensor and the object. A sensitivity within the range 0.4 to 10N,
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2. together with an allowance for accidental mechanical overload, is considered satisfactory for most
industrial applications.
A minimum sensor bandwidth of 100 Hz.
The sensor’s characteristics must be stable and repeatable with low hysteresis. A linear response is
not absolutely necessary, as information processing techniques can be used to compensate for any
moderate non-linearities.
As the touch sensor will be used in an industrial application, it will need to be robust and protected
from environmental damage.
If a tactile array is being considered, the majority of application can be undertaken by an array 10-20
sensors square, with a spatial resolution of 1-2 mm.
In a dexterous end effector, the forces and relative motions between the grasped object and the fingers need
to be controlled. This can be achieved by using a set of sensors capable of determining in real time, the
magnitude, location, orientation of the forces at the contact point. This problem has been approached by
using miniature force and torque sensors inside the finger tips, to provide a robot with an equivalent to the
kinesthetic sense found in humans. The integration of skin like and kinesthetic-like sensing will result in
robots being equipped with artificial haptic perceptions.
Touch sensor technology
Many physical principles have been exploited in the development of tactile sensors. As the technologies
involved are very diverse, this chapter can only consider the generalities of the technology involved. In most
cases, the developments in tactile sensing technologies are application driven. It should be recognised that
the operation of a touch or tactile sensor is very dependant on the material of the object being gripped.. The
sensors discussed in this chapter are capable of working with rigid objects. However if non-rigid material is
being handled problems may arise. Work has shown that conventional sensors can be modified to operate
with non-rigid materials.
Mechanically based sensors
The simplest form of touch sensor is one where the applied force is applied to a conventional mechanical
micro-switch to form a binary touch sensor. The force required to operate the switch will be determined by
the its actuating characteristics and any external constraints. Other approaches are based on a mechanical
movement activating a secondary device such as a potentiometer or displacement transducer.
Resistive based sensors
The use of compliant materials that have a defined force-resistance characteristics have received
considerable attention in touch and tactile sensor research. The basic principle of this type of sensor is the
measurement of the resistance of a conductive elastomer or foam between two points. The majority of the
sensors use an elastomer that consists of a carbon doped rubber.
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3. In the above sensor the resistance of the elastomer changes with the application of force, resulting from the
deformation of the elastomer altering the particle density.
If the resistance measurement is taken between opposing surfaces of the elastomer, the upper contacts have
to be made using a flexible printed circuit to allow movement under the applied force. Measurement from
one side can easily be achieved by using a dot-and-ring arrangement on the substrate. Resistive sensors have
also been developed using elastomer cords laid in a grid pattern, with the resistance measurements being
taken at the points of intersection. Arrays with 256-elements have been constructed. This type of sensor
easily allows the construction of a tactile image of good resolution.
The conductive elastomer or foam based sensor, while relatively simple does suffer from a number of
significant disadvantages:
An elastomer has a long nonlinear time constant. In addition the time constant of the elastomer,
when force is applied, is different from the time constant when the applied force is removed.
The force-resistance characteristic of elastomer based sensors are highly nonlinear, requiring the use
of signal processing algorithms.
Due to the cyclic application of forces experience by a tactile sensor, the resistive medium within the
elastomer will migrates over a period of time. Additionally, the elastomer will become permanently
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4. deformed and fatigue leading to permanent deformation of the sensor. This will give the sensor a
poor long-term stability and will require replacement after an extended period of use.
Even with the electrical and mechanical disadvantages of conductive elastomers and foams, the majority of
industrial analogue touch or tactile sensors that have been based on the principle of resistive sensing. This is
due to the simplicity of their design and interface to the robotic system.
Force sensing resistor
A force sensing resistor is a piezoresistivity conductive polymer, which changes resistance in a predictable
manner following application of force to its surface. It is normally supplied as a polymer sheet which has
had the sensing film applied by screen printing. The sensing film consists of both electrically conducting
and non-conducting particles suspended in matrix. The particle sizes are of the order of fraction of microns,
and are formulated to reduce the temperature dependence, improve mechanical properties and increase
surface durability. Applying a force to the surface of a the sensing film causes particles to touch the
conducting electrodes, changing the resistance of the film. As with all resistive based sensors the force
sensitive resistor requires a relatively simple interface and can operate satisfactorily in moderately hostile
environments.
Capacitive based sensors
The capacitance between two parallel plates is given by:
where A is the plate area, d the distance between the plates, and e the permittivity of the dielectric medium.
A capacitive touch sensor relies on the applied force either changing the distance between the plates or the
effective surface area of the capacitor. In such a sensor the two conductive plates of the sensor are separated
by a dielectric medium, which is also used as the elastomer to give the sensor its force-to-capacitance
characteristics.
To maximize the change in capacitance as force is applied, it is preferable to use a high permittivity,
dielectric in a coaxial capacitor design. . In this type of sensor, as the size is reduced to increase the spatial
resolution, the sensor’s absolute capacitance will decrease. With the limitations imposed by the sensitivity
of the measurement techniques, and the increasing domination of stray capacitance, there is an effective
limit on the resolution of a capacitive array. The figure shows the cross section of the capacitive touch
transducer in which the movement of a one set of the capacitors' plates is used to resolve the displacement
and hence applied force. The use of a highly dielectric polymer such as polyvinylidene fluoride maximizes
the change capacitance. From an application viewpoint, the coaxial design is better as its capacitance will
give a greater increase for an applied force than the parallel plate design
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5. To measure the change in capacitance, a number of techniques can be, the most popular is based on the use
of a precision current source. A second approach is to use the sensor as part of a tuned or L.C. circuit, and
measure the frequency response. Significant problem with capacitive sensors can be caused if they are in
close proximity with the end effector’s or robot’s earthed metal structures, this leads to stray capacitance.
This can be minimized by good circuit layout and mechanical design of the touch sensor. It is possible to
fabricate a parallel plate capacitor on a single silicon slice, this can give a very compact sensing device, this
approach is discussed below.
Magnetic based sensor
There are two approaches to the design of touch or tactile sensors based on magnetic transduction. Firstly,
the movement of a small magnet by an applied force will cause the flux density at the point of measurement
to change. The flux measurement can be made by either a Hall effect or a magnetoresistive device. Second,
the core of the transformer or inductor can be manufactured from a magnetoelastic material that will deform
under pressure and cause the magnetic coupling between transformer windings, or a coil’s inductance to
change. A magnetoresistive or magnetoelastic material is a material whose magnetic characteristics are
modified when the material is subjected to changes in externally applied physical forces. The
magnetorestrictive or magnetoelastic sensor has a number of advantages that include high sensitivity and
dynamic range, no measurable mechanical hysteresis, a linear response, and physical robustness.
If a very small permanent magnet is held above the detection device by a complaint medium, the change in
flux caused by the magnet's movement due to an applied force can be detected and measured. The field
intensity follows an inverse relationship, leading to a nonlinear response, which can be easily linearized by
processing. A one-dimensional sensor where a row of twenty hall effect devices placed opposite a magnet
has been constructed. A tactile sensor using magnetoelastic material has been developed, where the material
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6. was bonded to a substrate, and then used as a core for an inductor. As the core is stressed, the material’s
susceptibility changed, which is measured as a change in the coil’s inductance.
Optical Sensors
The rapid expansion of optical technology in recent years has led to the development of a wide range of
tactile sensors. The operating principles of optical-based sensors are well known and fall into two classes:
Intrinsic, where the optical phase, intensity, or polarization of transmitted light are modulated
without interrupting the optical path
Extrinsic, where the physical stimulus interacts with the light external to the primary light path.
Intrinsic and extrinsic optical sensors can be used for touch, torque, and force sensing. For industrial
applications, the most suitable will be that which requires the least optical processing. For example the
detection of phase shift, using interferometry, is not considered a practical option for robotic touch and force
sensors. For robotic touch and force-sensing applications, the extrinsic sensor based on intensity
measurement is the most widely used due to its simplicity of construction and the subsequent information
processing. The potential benefits of using optical sensors can be summarized as follow:
Immunity to external electromagnetic interference, which is widespread in robotic applications.
Intrinsically safe.
The use of optical fibre allows the sensor to be located some distance from the optical source and
receiver.
Low weight and volume.
Touch and tactile optical sensors have been developed using a range of optical technologies:
(a) Modulating the intensity of light by moving an obstruction into the light path.
The force sensitivity is determined by a spring or elastomer. To prevent cross-talk from external sources, the
sensor can constructed around a deformable tube, resulting in a highly compact sensor:
In the reflective touch sensor below, the distance between the reflector and the plane of source and the
detector is the variable. The intensity of the received light is a function of distance, and hence the applied
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7. force. The U shaped spring was manufactured from spring steel, leading to a compact overall design. This
sensor has been successfully used in an anthropomorphic end effector:
A reflective sensors can be constructed with source-receiver fibre pairs embedded in an solid elastomer
structure. As shown below, above the fibre is a layer of clear elastomer topped with a reflective silicon
rubber layer. The amount of light reflected to the receiver is determined by applied force, that changes the
thickness of the clear elastomer. For satisfactory operation the clear elastomer must have a lower
compliance that the reflective layer. By the use of a number of matrix of transmitter-receiver pairs, the
tactile image of the contact can be determined:
(b) Photoelasticity
Photoelasticity is the phenomena where stress or strain causes birefringence in an optically transparent
materials. Light is passed through the photoelastic medium. As the medium is stressed, the photoelastic
medium effectively rotates the plane of polarization and hence the intensity of the light at the detector
changes as a function of the applied force. This type of sensor is of considerable importance in the
measurement of slip.
Optical fibre based sensors
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8. In the previous section, optical fibres where used are solely for the transmission of light to and from the
sensor, however tactile sensors can be constructed from the fibre itself. A number of tactile sensors have
been developed using this approach. In the majority of cases either the sensor structure was too big to be
attached to the fingers of robotic hand or the operation was too complex for use in the industrial
environment. A suitable design can be based on internal-state microbending of optical fibres. Microbending
is the process of light attenuation in the core of fibre when a mechanical bend or perturbation (of the order
of few microns) is applied to the outer surface of the fibre. The degree of attenuation depends on the fibre
parameter’s as well as radius of curvature and spatial wavelength of the bend. Research has demonstrate the
feasibility of effecting microbending on an optical fibre by the application of a force to a second orthogonal
optical fibre.
Piezoelectric sensors
Polymeric materials that exhibit piezoelectric properties are suitable for use as a touch or tactile sensors,
while quartz and some ceramics have piezoelectric properties, polymers such as polyvinylidene fluoride
(PVDF) are normally used in sensors.
Polyvinylidene fluoride is not piezoelectric in its raw state, but can be made piezoelectric by heating the
PVDF within an electric field. Polyvinylidene fluoride is supplied sheets between as 5 microns and 2 mm
thick, and has good mechanical properties. A thin layer of metalization is applied to both sides of the sheet
to collect the charge and permit electrical connections being made. In addition it can be moulded, hence
PVDF has number of attraction when considering tactile sensor material as an artificial skin.
Strain gauges in tactile sensors
A strain gauge when attached to a surface will detect the change in length of the material as it is subjected to
external forces. The strain gauge is manufactured from either resistive elements (foil, wire, or resistive ink)
or from semiconducting material. A typical resistive gauge consists of the resistive grid being bonded to an
epoxy backing film. If the strain gauge is pre-stressed prior to the application of the backing medium, it is
possible to measure both tensile and compressive stresses. The semi-conducting strain gauge is fabricated
from a suitable doped piece of silicone, in this case the mechanism used for the resistance change is the
piezoresistive effect.
When applied to robotic touch applications, the strain gauge is normally used in two configurations: as a
load cell, where the stress is measured directly at the point of contact, or with the strain gauge positioned
within the structure of the end effector.
Silicon based sensors
Technologies for micromachining sensors are currently being developed world-wide. The developments can
be directly linked to the advanced processing capabilities of the integrated circuit industry, that has
developed fabrication techniques that allow the interfacing of the non-electronic environment to be
integrated through micro-electromechanical systems.. Though not as dimensionally rigorous as the more
mature silicon planer technology, micromachining is inherently more complex as it is involves the
manufacture of a three-dimensional object. Therefore the fabrication relies on additive layer techniques to
produce the mechanical structure.
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9. The excellent characteristics of silicon, that has made micromachined sensors possible, include a tensile
strength comparable to steel, elastic to breaking point, and there is very little mechanical hysteresis in
devices made from as single crystal, a low thermal coefficient of expansion.
To date it is apparent that microengineering has been applied most successfully to sensors. Some sensor
applications take advantage of the device-to-device or batch-to-batch repeatability of wafer-scale processing
to remove expensive calibration procedures. Current applications are restricted largely to pressure and
acceleration sensors, though these in principle can be used as force sensors. As the structure is very delicate,
there still are problems in developing a suitable tactile sensor for industrial applications.
Smart Sensors
The most significant problem with the sensor systems discussed so far is that of signal processing.
Researchers are therefore looking to develop a complete sensing system rather than individual sensors,
together with individual interfaces and interconnections. This allows the signal processing to be brought as
close as possible to the sensor itself or integrated with the sensor. Such sensors are generally termed smart
sensors. It is the advances in silicon fabrication techniques which have enabled the recent developments in
smart sensors. There is no single definition of what a smart sensor should be capable of doing, mainly
because interest in smart sensors is relatively new. However, there is a strong feeling that the minimum
requirements are that the sensing system should be capable of self diagnostics, calibration and testing. As
silicon can be machined to form moving parts such as diaphragms and beams, a tactile sensor can in
principal be fabricated on single piece of silicon. Very little commercial success has been obtained so far,
largely due to the problems encountered in transferring the technology involved from the research
laboratory to industry. In all tactile sensors their is a major problem of information processing, and
interconnection. An array has 2n connection and individual wires, any reduction in interconnection
requirements is welcomed due to ease of construction and increased reliability. A number of researchers
have been addressing the problem of integrating a tactile sensor with integral signal processing. In this
design the sensor’s conductive elastomer sheet was placed over a substrate. The significant feature of this
design is that the substrate incorporated VLSI circuitry so that each sensing element not only measures its
data but processes it as well. Each site performs the measurements and processing operations in parallel.
The main difficulty with this approach was the poor discrimination, and susceptibility to physical damage
However, the VLSI approach was demonstrated to be viable, and alleviated the problems of wiring up each
site and processing the data serially.
Multi-stimuli Touch Sensors
It has been assumed that all the touch sensors discussed in this section respond only to a force stimulus.
However, in practice most respond to other external stimuli, in particular, temperature. If PVDF has to be
used as a force sensor in an environment with a widely varying ambient temperature, there may be a
requirement for a piece of unstressed PVDF to act as a temperature reference. It is possible for a sensor to
respond both to force and temperature changes. This has a particular use for object recognition between
materials that have different thermal conductivity, e.g., between a metal and a polymer. If the complexity of
the interpretation of data from PVDF is unsuitable for an application, touch sensors incorporating a resistive
elastomer for force, and thermistors for temperature measurement can be constructed. By the use of two or
more force-sensitive layers on the sensor, which have different characteristics (e.g., resistive elastomer and
PVDF), it is possible to simulate the epidermal and dermal layers of human skin.
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