Browse Definitions:
Definition

pressure sensing

Pressure sensing is the capacity for some system to sense the force exerted on a surface per unit area and express that force in the strength of an electric signal. For example, pressure sensing is what allows a robot to tell when it collides with something, or when something pushes against it. Pressure sensors can be used to measure force, and in some cases, to determine the contour of an applied force.

A capacitive pressure sensor employs two metal plates separated by a layer of nonconductive foam. This forms a capacitive transducer. The transducer is connected in series or parallel with an inductor. The resulting inductance-capacitance (LC) combination determines the frequency of an oscillator. If an object strikes or presses against the transducer, the plate spacing decreases, causing the capacitance to increase. This lowers the oscillator frequency. When the pressure is removed, the foam springs back, the plates return to their original spacing, and the oscillator returns to its original frequency. A capacitive pressure sensor can be fooled by metallic objects. If a good electrical conductor comes very close to the plates, the capacitance might change even if physical contact is not made. If this occurs, the sensor will interpret this proximity as pressure.

An elastomer pressure sensor solves the proximity problem inherent in the capacitive device. The elastomer is a foam pad with resistance that varies depending on how much it is compressed. An array of electrodes is connected to the top of the pad; an identical array is connected to the bottom. Each electrode in the top matrix receives a negative voltage, and its mate in the bottom matrix receives a positive voltage. When pressure appears at some point on the pad, the material compresses at and near that point, reducing the resistance between certain electrode pairs. This causes a current increase in a particular region in the pad. The location of the pressure can be determined according to which electrode pairs experience the increase in current. The extent of the pressure can be determined by how much the current increases. If the electrode matrix is fine enough, the contour of the pressure-producing object can be determined by a microprocessor that evaluates the electrode current profile.

The output of a pressure sensor is analog, but it can be converted to digital data using an analog-to-digital converter (ADC). This signal can be used by a robot controller. Pressure on a transducer in the front of a robot might cause the machine to back up; pressure on the right side might make the machine turn left. The presence of pressure might be used to actuate an alarm, or to switch a device on or off. Calibrated pressure sensors can be used to measure applied force, mass, weight, or acceleration.

See also: back-pressure sensor, proximity sensing, robotics

This was last updated in December 2016

Continue Reading About pressure sensing

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

  • internal audit (IA)

    An internal audit (IA) is an organizational initiative to monitor and analyze its own business operations in order to determine ...

  • pure risk (absolute risk)

    Pure risk, also called absolute risk, is a category of threat that is beyond human control and has only one possible outcome if ...

  • risk assessment

    Risk assessment is the identification of hazards that could negatively impact an organization's ability to conduct business.

SearchSecurity

  • computer exploit

    A computer exploit, or exploit, is an attack on a computer system, especially one that takes advantage of a particular ...

  • cyberwarfare

    Cyberwarfare is computer- or network-based conflict involving politically motivated attacks by a nation-state on another ...

  • insider threat

    Insider threat is a generic term for a threat to an organization's security or data that comes from within.

SearchHealthIT

SearchDisasterRecovery

  • business continuity and disaster recovery (BCDR)

    Business continuity and disaster recovery (BCDR) are closely related practices that describe an organization's preparation for ...

  • business continuity plan (BCP)

    A business continuity plan (BCP) is a document that consists of the critical information an organization needs to continue ...

  • call tree

    A call tree -- sometimes referred to as a phone tree -- is a telecommunications chain for notifying specific individuals of an ...

SearchStorage

  • OpenStack Block Storage (Cinder)

    OpenStack Block Storage (Cinder) is open source software designed to create and manage a service that provides persistent data ...

  • SATA Express (SATAe)

    SATA Express (SATAe or Serial ATA Express) is a bus interface to connect storage devices to a computer motherboard, supporting ...

  • DIMM (dual in-line memory module)

    A DIMM (dual in-line memory module) is the standard memory card used in servers and PCs.

SearchSolidStateStorage

  • hybrid flash array

    A hybrid flash array is a solid-state storage system that contains a mix of flash memory drives and hard disk drives.

  • 3D XPoint

    3D XPoint is memory storage technology jointly developed by Intel and Micron Technology Inc.

  • RRAM or ReRAM (resistive RAM)

    RRAM or ReRAM (resistive random access memory) is a form of nonvolatile storage that operates by changing the resistance of a ...

SearchCloudStorage

  • Google Cloud Storage

    Google Cloud Storage is an enterprise public cloud storage platform that can house large unstructured data sets.

  • RESTful API

    A RESTful application program interface breaks down a transaction to create a series of small modules, each of which addresses an...

  • cloud storage infrastructure

    Cloud storage infrastructure is the hardware and software framework that supports the computing requirements of a private or ...

Close