Several sensing methods about sensors

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. Sensor selection depends on physical, environmental and control conditions. These include:

mechanical:

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

pneumatic:

These proximity sensors work by disrupting or disrupting airflow. Pneumatic proximity sensors are examples of contact sensors. But these products cannot be used on lightweight parts that may blow away.

Optics:

In its simplest form, optical proximity sensors work by breaking a beam of light 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 extremely careful. For example, the optical sensor may be obscured by the flash during arc welding, and dust and smoke clouds in the air may hinder the transmission of light, etc.

electric:

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

Range sensing:

Proximity sensing involves detecting how close or far a component is from the sensing location, although they can also be used as proximity sensors. Distance or proximity sensors use contactless analog technology. Short range sensing between a few millimeters and hundreds of millimeters using capacitive, inductive and magnetic techniques. Longer range sensing is performed using various types of emitted energy waves (e.g., radio waves, sound waves, and lasers).

There are six types of 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 quantity because it must be specified in both magnitude and direction. Therefore, force sensors are analog-operated and are sensitive to their direction of action. The six forces are:

①. Tension

②、Compression force

③. Shear force

④, twisting force

⑤. Bending force

⑥. Friction

These involve situations where movement is to be restricted, so friction is indirectly detected using a combination of force and motion sensors. For example:

Haptics refers to sensing through touch. The simplest type of tactile sensor uses an array of simple touch sensors arranged in rows and columns, these are often called matrix sensors.

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

Mechanical, optical and electronic tactile sensors have been implemented.

Thermal sensing may be required as part of process control or as a means of safety control. There are several methods to choose from, the choice of which mainly depends 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 may be used.

Acoustic sensors can detect and sometimes differentiate between different sounds. They can be used for speech recognition to issue spoken commands or 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 large amount of background noise.

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

Gas or smoke sensors that are sensitive to a specific gas rely on chemical changes in the materials contained in the sensor that produce physical expansion or generate enough heat to trigger the switching device.

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

.Robotic
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 enable the robotic system to respond to the analyzed images and take appropriate actions during the execution of the task set.

The improvement of robot vision will enable the full potential of artificial intelligence in industrial robots. Its uses include detecting presence, location and movement, identifying and identifying different components, patterns and characteristics.

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