7 sensing methods of the sensor

Date:2021-09-15 00:00

  7 sensing methods of the sensor

  1. Proximity Sensing

  Proximity sensing usually means detecting:

  a. Whether there is an object.

  b. The size or simple shape of the object.

  Proximity sensors can be further classified in operation as contact or non-contact, and analog or digital. The choice of sensor depends on physical, environmental and control conditions. These include:


  Any suitable mechanical/electrical switch can be used, but since a certain amount of force is required to operate a mechanical switch, a microswitch is usually used.


  These proximity sensors work by disrupting or disturbing airflow. Pneumatic proximity sensors are examples of touch sensors. But these products cannot be used for lightweight parts that could be blown away.


  In its simplest form, an optical proximity sensor is dropped by breaking a light beam that falls on a light-sensitive device such as a photocell. These are examples of contactless sensors.

  It is worth noting that the lighting environment of these sensors must be very careful, for example, optical sensors may be obscured by flashes during arc welding, dust and smoke clouds in the air may obstruct light transmission, etc.


  Electrical proximity sensors can be contact or non-contact. Simple touch sensors operate by having the sensor and components form a complete circuit. Non-contact electrical proximity sensors rely on the principle of induction to detect metals or capacitance to detect non-metals.

  Range Sensing:

  Distance sensing involves detecting how close or far components are to the sensing location, although they can also be used as proximity sensors. Distance or distance sensors use non-contact analog technology. Use capacitive, inductive, and magnetic techniques for short-range sensing between a few millimeters and hundreds of millimeters. Sensing at greater distances is performed using various types of transmitted energy waves (eg, radio waves, acoustic waves, and lasers).

  2. Force sensing

  There are six forces that may need to be sensed. In each case, the application of force can be static (stationary) or dynamic. A force is a vector because it must be specified in both magnitude and direction. Therefore, the force sensor operates analogously and is sensitive to its direction of action. The six forces are:

  ①, tension

  ②, compressive force

  ③, shear force

  ④, torsion force

  ⑤、Bending force

  ⑥, friction

  Various techniques exist for sensing force, some direct and some indirect.

  Tensile force:

  Can be determined by strain gauges, which show a change in their resistance as the length increases. Changes in resistance measured by these gauges can be converted into forces and are therefore indirect devices.


  This can be determined by devices called load cells, which can "operate by detecting changes in cell size under compressive load, or by detecting an increase in pressure within the cell under load, or by changes in resistance under compressive load" .


  It can be seen as a combination of tensile and compressive forces, so a combination of the above techniques can be used.


  These involve situations where motion is to be restricted, so "friction is detected indirectly by using a combination of force and motion sensors.

  3. Tactile sensing

  Haptic refers to sensing through touch. The simplest type of touch sensor uses a simple array of touch sensors arranged in rows and columns, these are often referred to as matrix sensors.

  Each individual sensor is activated when it comes into contact with an object. The imprint of a component can be determined by detecting which sensors are active (digital) or the magnitude of the output signal (analog). The imprint is then compared to previously stored imprint information to determine the size or shape of the component.

  Mechanical, optical and electronic tactile sensors are currently implemented.

  4. Thermal sensation

  Thermal induction may be required as part of process control or as a means of safety control. There are a variety of methods to choose from, the choice of which depends mainly on the temperature to be detected.

  Some common methods are: bimetallic strips, thermocouples, resistance thermometers or thermistors. For more complex systems involving low-level heat sources, thermal imaging cameras can be used.

  5. Sound sensing (hearing)

  Acoustic sensors can detect and sometimes distinguish between different sounds. They can be used for speech recognition to issue verbal commands or to identify unusual sounds, such as explosions. The most common acoustic sensor is a microphone.

  In industrial environments, an obvious problem with acoustic sensors is the high amount of background noise.

  Of course, we could also simply tune the acoustic sensors to only respond to certain frequencies, allowing them to differentiate between different noises.

  6. Gas sensing (smell)

  Gas or smoke sensors that are sensitive to a specific gas rely on chemical changes in the materials contained in the sensor, which either create physical expansion or generate enough heat to trigger a switchgear.

  7. Robot Vision (Love)

  Vision is probably the most active area of ​​current robotic sensory feedback research.

  Robot vision refers to capturing an image in real time with some kind of camera and converting that image into a form that can be analyzed by a computer system. This conversion usually means converting the image into a digital field that the computer can understand. The entire process of image capture, digitization, and data analysis should be fast enough to allow the robotic system to respond to the analyzed images and take appropriate actions during the execution of the task set.

  The perfection of robot vision will enable the full potential of artificial intelligence in industrial robots to be realized. Its uses include detecting presence, position and movement, identifying and identifying different components, styles and characteristics.

  However, even the simplest vision techniques require large amounts of computer memory and can require considerable processing time.