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Robots are comprised of various parts based on the application they are designed to perform. For instance, the hand of the robot (commonly known as an end effector) may be made as a specialized tool such as a spray gun, spot welder or general-purpose gripper.
To facilitate such functions, a significant element of robotics control technology - sensors - is utilized. A robotic system realizes its environmen using sensors through which subsequent actions can be adjusted.
Some of these sensor types include distance, tactile, speed and acceleration, force and torque, and visual sensors. These sensors ensure proper operation and enable the robot to adjust to variations according to the position of the objects while picking them up.
Most industrial robots use simple binary sensing, which is analogous to an on/off switch. Binary sensors, through the help of limit switches and microswitches, inform robots when there is another robot in its direct line of sight. These sensors create a binary output signal indication to indicate if contact has been made with the object.
Working Principle
Binary sensors operate based on the principle that the distribution of touch and no-touch values across the sensor array would provide a measure of the spatial distribution of force. These sensors are contact switches that are placed on the inner side of each finger of a robotic hand. This type of sensing can sense an object by moving the hand over the object and making contact with its surface.
Each finger can be designed with multiple switches to provide more tactile information. These switches are mostly mounted on the external surfaces of the hand to produce a control signal for directing the hand over the workspace. Meanwhile, the proper manipulation and grasping of the object in the workspace can be achieved via centering of the fingers using the information given by the binary sensors.
The binary sensor detects whether the robot or object has crossed it, and it maintains a sensing abstraction that includes various physical sensing modalities such as swap lines that indicates the change of angular position of the workspace, linear markings in the plane, and other actual detection beams in the surrounding. All such information will be utilized in identifying the presence of objects.
Applications
Binary sensor networks can be applied in a wide range of monitoring applications. They can detect the presence or absence of a target object in their sensing regions; they could also provide localization functionality by dividing a monitored area into sub-regions.
Binary sensors could also be utilized in various applications, including transportation, communication, or chemical engineering. For example, radio frequency identification (RFID) readers can detect the presence of RFID tags. These tags are usually used as wireless tracking devices or access control in transportation.
Meanwhile, binary chemical sensors could detect the presence of chemical compounds, toxic plumes or oil spills in the fields and seas.
Sources and Further Reading
- Asadzadeh P et al, 2011, On Optimal Arrangements of Binary Sensors: Belfast, ME, USA: Springer Berlin Heidelberg
- Fu KS et al, 1987, Robotics: Control, Sensing, Vision, and Intelligence: New Delhi, India: Tata McGraw-Hill Education
- Hedge GS, 2006, A Textbook on Industrial Robotics: New Delhi, India: Laxmi Publications
This article was updated on 7th February, 2019.