An alternative of low-cost automation based on a minicomputer for edge computing

This paper presents the design and development of a strategy of low-cost automation by the use of a minicomputer Raspberry Pi, to implement web technology in hydraulic processes for edge computing, close to where data is produced. A web page was built to be an user interface, besides, the Ethernet standard has been used to establish the internet connection with the Raspberry board to manipulate the general purpose input/output pins. A program was coded in Python language to both receive signals from the limit switch sensors and control the servo valves through a relay module, because they are actuated by solenoids which require 24 V DC to be excited. The user may start, stop, and home-return the hydraulic process from any device with internet connectivity, thus it can be understood like an implementation of Industry 4.0. The logic sequence for the automation was proved in a simulation software to set a reference performance, then the experimentation, with Raspberry Pi plus the relay module in the manufacturing laboratory, shows successful results of the proposed strategy.