Green Access Control System
(2021) EITM01 20211Department of Electrical and Information Technology
- Abstract
- The number of fixed-installation resource-constrained devices, such as Internet of Things devices, has been growing rapidly in the past years. One challenge of accommodating these large numbers of connected devices is the need to power them all. In this thesis, we investigate ways to reduce the power consumption of the door controller in an existing physical access control system, without compromising on system functionality or latency. Existing power management solutions of other resource-constrained devices were evaluated and suggested. Protocols and hardware components present in the system were researched, with focus on how power consumption and latencies can be reduced. Power measurement tests were performed on Linux power management... (More)
- The number of fixed-installation resource-constrained devices, such as Internet of Things devices, has been growing rapidly in the past years. One challenge of accommodating these large numbers of connected devices is the need to power them all. In this thesis, we investigate ways to reduce the power consumption of the door controller in an existing physical access control system, without compromising on system functionality or latency. Existing power management solutions of other resource-constrained devices were evaluated and suggested. Protocols and hardware components present in the system were researched, with focus on how power consumption and latencies can be reduced. Power measurement tests were performed on Linux power management systems CPUFreq and CPUIdle to evaluate their impact, as well as when suspending the CPU. Our results show that CPUFreq and CPUIdle are a simple way to reduce overall power consumption without compromising on system latency, and that over 25% of total power can be saved by suspending the CPU when the device is not in use. These results suggest that the greatest power savings are found when suspending the door controller CPU, and that system adjustments must be made to accommodate a suspended CPU. With this work, we hope that this type of device could adopt a battery-based power solution, reducing upfront installation costs. (Less)
- Popular Abstract
- The number of smaller electronic devices such as mobile phones, sensors, smart devices, scanners and smart home appliances are increasing rapidly in our society and becoming more commonplace every year. It is important to make these devices more power efficient to reduce their collective energy costs and negative impacts on the environment. We have implemented ways to let a device save as much as 25% power by entering different low-power modes.
In this thesis, we have investigated a physical access control system, which is used to allow or deny access to people who want to enter a building or a room. More specifically, we have looked at the door controller of this system, which is responsible for inspecting the card credentials of the... (More) - The number of smaller electronic devices such as mobile phones, sensors, smart devices, scanners and smart home appliances are increasing rapidly in our society and becoming more commonplace every year. It is important to make these devices more power efficient to reduce their collective energy costs and negative impacts on the environment. We have implemented ways to let a device save as much as 25% power by entering different low-power modes.
In this thesis, we have investigated a physical access control system, which is used to allow or deny access to people who want to enter a building or a room. More specifically, we have looked at the door controller of this system, which is responsible for inspecting the card credentials of the person requesting access and then telling a connected door or gate to unlock. The device as it currently exists cannot be powered by a battery for longer periods of time, but if its power consumption is reduced, it could be possible to make a battery-powered variant of the product which would be simpler and cheaper to install.
We have compared how effective different power saving features are. We found that the energy consumption can be reduced somewhat by enabling certain features in the door controller's operating system and can be reduced much more by forcing the device’s processor into a sleep mode when nothing is happening. For an access control system, it is common for nothing to be happening, since there are many times of day when nobody is trying to enter or exit.
When the processor is in its sleep mode, it cannot do anything until something causes it to wake up. A large part of our work has been to make sure that the processor wakes up quickly and reliably when someone wants to enter or something else happens. This turned out to be more complicated for one of the two protocols the device uses to communicate with card readers, due to that protocol being more complex and requiring the device to regularly send messages to the card reader. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9058250
- author
- Lundahl, Jonas LU and Rosenqvist, Jos LU
- supervisor
- organization
- course
- EITM01 20211
- year
- 2021
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- power consumption, physical access control, embedded systems, Internet of Things
- report number
- LU/LTH-EIT 2021-826
- language
- English
- id
- 9058250
- date added to LUP
- 2021-06-24 14:31:47
- date last changed
- 2021-06-24 14:31:47
@misc{9058250,
abstract = {{The number of fixed-installation resource-constrained devices, such as Internet of Things devices, has been growing rapidly in the past years. One challenge of accommodating these large numbers of connected devices is the need to power them all. In this thesis, we investigate ways to reduce the power consumption of the door controller in an existing physical access control system, without compromising on system functionality or latency. Existing power management solutions of other resource-constrained devices were evaluated and suggested. Protocols and hardware components present in the system were researched, with focus on how power consumption and latencies can be reduced. Power measurement tests were performed on Linux power management systems CPUFreq and CPUIdle to evaluate their impact, as well as when suspending the CPU. Our results show that CPUFreq and CPUIdle are a simple way to reduce overall power consumption without compromising on system latency, and that over 25% of total power can be saved by suspending the CPU when the device is not in use. These results suggest that the greatest power savings are found when suspending the door controller CPU, and that system adjustments must be made to accommodate a suspended CPU. With this work, we hope that this type of device could adopt a battery-based power solution, reducing upfront installation costs.}},
author = {{Lundahl, Jonas and Rosenqvist, Jos}},
language = {{eng}},
note = {{Student Paper}},
title = {{Green Access Control System}},
year = {{2021}},
}