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Hardware for automation
Published in Benny Raphael, Construction and Building Automation, 2023
An electromechanical relay contains an electromagnet that attracts a metal piece when a current is passed through the magnet. See Figure 2.12. When a current is applied to the coil, the electromagnetic forces pull the metal piece S causing the circuit to open or close. Thus, the equipment can be started or stopped. The control current needed to activate the coil is small and can be sent through a controller. The voltage and power needed for the equipment could be large; this is not supplied by the controller and is part of a separate circuit with its own power source. The controller provides only a signal to activate the magnetic coil.
Smart Petrol Pump using RFID & GSM Technology
Published in Rajesh Singh, Anita Gehlot, P.S. Ranjit, Dolly Sharma, Futuristic Sustainable Energy and Technology, 2022
Jogi Naresh, Bille Naresh, Golla Ramakanth Yadav, Gaduputi Janardhan Naidu, Adigarla Mahesh Raja, Manoj Sindhwani
Relay is used as switch to on and off the circuit or current flow in them. Relay had a presence of coil which attracts and gives contact to them to get activate, when the coil is not energized the spring separates them.
Relay
Published in Hossam Fattah, LTE™ Cellular Narrowband Internet of Things (NB-IoT), 2021
A Relay is a switch which is electrically operated by an electromagnet. The electromagnet is activated with a low voltage. For example, a low voltage of 5V from a microcontroller pulls a contact to make or break a high voltage circuit such as a 220V light bulb, stove, fridge, electrical appliance, or a DC motor. Relay can be used to control high voltage electronic devices and appliances.
A cyber physical production system framework for online monitoring, visualization and control by using cloud, fog, and edge computing technologies
Published in International Journal of Computer Integrated Manufacturing, 2023
Rishi Kumar, Kuldip Singh Sangwan, Christoph Herrmann, Sachin Thakur
Figure 9 illustrates the process flow diagram for online monitoring, identification, and control of defects during 3D printing. A machine vision camera attached to the raspberry pi is used to take regular snapshots after printing of each layer as shown in Figure 10(a). These snapshots are imported sequentially with height information, turned to grayscale, and blurred before finding the outer edge of the printed specimen. The logic behind the identification, and control of defects is provided using image processing algorithm programmed using python language. Modelling consists of digital image processing using OpenCV for implementing real-time machine vision system. The specimen image is transformed into numerical features to identify printing deviations as compared to the CAD data and assigned dimensional tolerances. This is followed by image warping, where the length and interval of the coordinate arrays are restructured into equal length and interval. The contour arrays of the detected edge and CAD are compared in a sorted sequence for the given height. Comparison is made in terms of absolute distance between corresponding pixels. The output is then generated as a two-dimensional graphical representation along with quantitative value notification to the dashboard as shown in Figure 10(b). The product is continuously 3D printed until any defect is detected. Under faulty circumstances, printing is paused, and a notification is sent to the dashboard for the user to confirm. A relay module is also used as an edge device. A small voltage signal via the relay module energizes the electromagnets and thus opens the switch and vice versa. It is programmed to turn off the 3D Printer when anything goes beyond the nominal values like high VOC values in the enclosure, which can suggest unsafe working conditions and therefore automatically pause the 3D Printer. Alert messages are generated and sent to the manager using Gmail API and Google cloud console. A common cause of print failure is the printer running out of filament. If the printer being used does not have the capability to detect and pause filament runaway, then the entire print is wasted since the nozzle will continue to trace its path without depositing any material. To prevent this failure, a filament sensor is used to detect the filament availability for the subsequent printing. Filament sensor is hosted on edge computing for active feedback and control with reduced latency and response time. If the filament sensor detects no filament, it automatically pauses the print and lifts nozzle to a safe location so the user might change filament or resolve the issue manually.