With the rapid development in hardware and emergence of smart devices, it is naturally attractive to use readily available hardware and build application to suit customer needs. But have you observed there has been loss of data often when deployed in industrial environment, at times frustrating to restart the device. Then this article helps understand how to address the issue.
To have better understanding of hardware for mining equipment (commonly referred as HEMM), let us try understand various hardware that may be needed for mine management system. Typically, any system needs following:
a. Data capturing hardware
b. Data transferring hardware
c. Data compilation and storage hardware
Hardware for data compilation include servers, desktops etc., which are also available OTS. Hence, this is not discussed. Similarly, data transferring hardware is primarily the hardware that support communication network within the mine and is usually available off-the-shelf (OTS) largely. This hardware fairly established and maintained well. Hence, both these hardware is not discussed here.
In mine management systems, the data is captured in the HEMM automatically or with least manual input with hardware installed in HEMM. In this article, this is referred as hardware (though it has much broader scope). In mining industry, broadly three types of hardware used as below:
a. ‘OTS GPS tracking devices’, which are sold as GPS tracking or fleet management/monitoring devices in the market. They work on cellular network and send data to server. They are micro controller based and built special purpose with little scope to modify the device behavior to suit specific implementation requirements
b. ‘OS based OTS devices’, which are usually an advanced fleet management devices with more capabilities than OTS GPS devices. They are OS (android or linux) dependent microprocessor based and customers can build any apps to suit their specific need
c. Totally ‘purpose built devices’ with microcontrollers, which may not be as customizable as OS based devices but are built for purpose
Regarding OTS GPS tracking devices, we have detailed discussion previously why they may not be appropriate for mining requirements. Therefore, the focus in this article is on choosing between OS based OTS devices (microprocessor based) and custom built devices (purpose built microcontrollers based).
A quick glance at advantages of using micro processor based over microcontroller based devices/hardware is given below:
a. Faster processing of complex data manipulation
b. Easy to develop custom applications to suit deployment requirements
c. Hardware is standardized and eco-system is well established. Hence, availability of skills to develop apps is high. While, micro-controllers based devices require niche skills and require electronics background to develop apps
d. Handles complex data handling/storage leading to very intelligent edge devices with less dependency on external network
Given the challenges in mining environment such as unreliable communication network, a good edge device is an option, micro-controllers have certain advantages:
a. They are small in size, slow, but purpose built. Hence, consume much lesser power and do not get heated. Since, environment temperature is one critical parameter that can determine its choice
b. They do not get heated as much as microprocessors because micro controllers are not as fast and also they process simple processes, all of which are in the control of developer. While, app developer for a micro processor based device does not control the background processes
c. The boot time is short for microcontroller devices while it is longer for microprocessor based device because micro processor require to boot the OS before the app starts working
d. Sudden shutdown of microprocessor (without power backup) can corrupt/lose the data, while microcontrollers can function on super capacitors without needing power backups/batteries
Due to the above features of micro controllers are often used in real-time applications because, micro processor devices tend to hang when
i. internal processes get into loop
ii. device gets heated due to faster processing and multiple process handling
iii. due to external temperature
When the application gets hanged in micro processor, the device can be instructed to shutdown and restart. But the time it takes to restart the device and for application to start working can lead to loss of critical event data. This loss can lead misinterpretation of data and can be inaccurate in reporting. Microcontrollers are less prone to hang compared to microprocessors and even when microcontroller based devices have to be restarted the time it takes is far lesser compared to microprocessor based devices. Hence, for data capturing at the source it is always preferred to have micro controller based devices, while processing the data is good for micro processor based devices.
Though, there are edge devices using OS, if they are not meant to capture data continuously/regularly and are not mission critical then micro processor are good option. But where the availability of devices (without manual intervention) are critical to capture data continuously despite harsh environment, then microcontroller based devices are the best.
PS: The author has extensive experience in getting hardware developed and deploying in various mining conditions. Would welcome your comments, insights to enhance knowledge.