ECE 477
Digital Systems Senior Design Project
Rev 9/12
Homework 12: Environmental Impact Lifecycle Analysis and Ethical
Challenges
Team Code Name: Autonomous Rescue Vehicle Group No. __10____
Team Member Completing This Homework: Vipul Vishnu Bhat
E-mail Address of Team Member: vbhat @ purdue.edu
NOTE: This is the last in a series of four “professional component” homework assignments,
each of which is to be completed by one team member. The body of the report should be 3-5
pages, not including this cover page, references, attachments or appendices.
Evaluation:
SEC
DESCRIPTION
MAX
SCORE
1.0
Introduction
5
5
2.0
Environmental Impact Analysis
40
38
3.0
Ethical Challenges
40
35
4.0
Summary
5
5
5.0
List of References
10
10
TOTAL
100
93
Comments:
Grader: George Toh
Good work! A few edits required before adding this homework to the final report.
ECE 477
Digital Systems Senior Design Project
Rev 9/12
1.0 Introduction
The Autonomous Rescue Vehicle’s ( ARV ) main goal is to navigate to a certain location
using GPS and then return to the starting location. Before the ARV can be marketed as a
commercial product, the ethical and environmental impact of manufacturing and using such a
product must be taken into consideration. The IEEE Code of Ethics requires engineers “to accept
responsibility in making decisions consistent with the safety, health, and welfare of the public,
and to disclose promptly factors that might endanger the public or the environment “[1]. Seeing
how one of the main functions of our project is to locate a person using GPS, misusing our
product for invasion of privacy is a concern that needs to be addressed. The ARV consists of a
sturdy aluminum chassis that weighs slightly over 6 pounds and uses ultrasonic sensors to detect
obstacles. If the sensors fail to detect an obstacle properly, we must take into account, the
damage that the heavy chassis can cause by running into things/beings.
Finally, from an
environmental perspective, a quick look at our project shows us that it utilizes items that might
be environmentally harmful in the manufacture/disposal process (PCBs, rechargeable batteries).
2.0 Environmental Impact Analysis
The following sections shall describe the potential environmental impact our project will
have over the course of its lifetime i.e Manufacture, Operation and Disposal. We will be
looking into the environmental impact of the parts/aspects of our project, which specifically
include that of the the printed circuit board, the rechargeable batteries, aluminum chassis and
power consumption and steps that can be taken to mitigate these effects.
2.1 Manufacture
Printed Circuit Boards are responsible for releasing several pollutants into the
surrounding air and water during the manufacturing process. One of the major water
pollutants in PCB manufacturing is copper [2]. Processes in the manufacture of PCBs such
as plating, etching, cleaning etc, also release air pollutants besides the waste water generated
[2]. One of the ways we can contribute to the environmental cause with respect to PCB
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ECE 477
Digital Systems Senior Design Project
Rev 9/12
production is to maybe reduce the size of the PCB. Though it may seem insignificant, if the
ARV were ever to go into mass production, a smaller PCB might make a difference.
The other major environmental impact caused by our project might by the use of
anodized aluminum for the construction of our chassis. Aluminum is anodized to improve
hardness and corrosion resistance [3]. Anodizing aluminum results in the production of
Aluminum Hydroxide, a major water pollutant [4]. As with the PCB, using a smaller chassis
might result in a positive impact on the environment if the product were to go into mass
production. Using a smaller chassis with fewer motors poses many advantages. To begin
with we would be using lesser aluminum. Fewer motors means, fewer H bridges on our
PCB, which in turn will help us reduce the size of the PCB. Moreover, fewer motors would
mean a lower power consumption which would help us in increasing our battery life. That’s
essentially killing not two, but three birds with one stone.
2.2 Normal Use
During normal use, the main concern is the power consumption by the motors. We use
rechargeable NiMH batteries to power our 6 motors. The battery is rated at 3000 mAh at 7.2
V. Our 6 motors draw approximately 10 A when they are operated at 50% duty cycle (3.6V).
This gives our robot a power consumption of around 36W. Using a smaller chassis with 4
motors would bring our power consumption to around 24 W. The current operation time per
charge is around 45 minutes. This might increase the operation time for each charge of the
battery by around 30%.
2.3 Disposal
When it is time to dispose of the product, there are a few things to be kept in
mind. The ARV has a PCB and uses rechargeable batteries. Both of these items have to
be disposed of in an appropriate manner. Even if the PCBs are ROHS compliant, they
contain precious metals such as Gold, Palladium, Silver etc. There are companies that
will pay an individual for their PCB and will recycle them in an appropriate manner [5].
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ECE 477
Digital Systems Senior Design Project
Rev 9/12
As Isidor Buchmann states in his article ‘Recycling your battery ‘, “Although
NiMH batteries are considered environmentally friendly, this chemistry is also being
recycled. The main derivative is nickel, which is considered semi-toxic. NiMH also
contains an electrolyte that, in large amounts, is hazardous to the environment” [6]. Isidor
Buchmann also talks about a non-profit organization called ‘Rechargeable Battery
Recycling Corporation’ that collects rechargeable batteries and donates them to
companies that specialize in recycling rechargeable batteries [6].
In order to address these issues, information can be provided in the user manual
regarding proper disposal of the batteries and the PCB. We could provide the user with a
list of vendors that offer services with respect to PCB and rechargeable battery disposal.
Another solution would be to provide the user with a small monetary compensation in
order to send back the product if they intend on disposing it. That way, the robot can be
cannibalized for useful parts and the PCBs and batteries can be disposed of properly by
the manufacturer.
3.0 Ethical Challenges
From an ethical perspective, our product could be misused to track someone without
his/her knowledge. Our GPS rescue point transceiver could be placed in someone’s vehicle
without their knowledge/consent. This problem can be addressed by modifying our rescue
point transceiver to make a loud beeping noise once every 10 minutes or so in an attempt to
alert the person carrying it.
As with every other product, we need to address potential safety hazards associated with
the ARV before we release it to the public. First off, the chassis is pretty heavy ( weighs
over 6 pounds ) and has sharp edges. In the event that the ultrasonic sensors fail to detect an
obstacle in time or fail to function all together, the ARV might run into someone/something
and potentially hurt them. In order to avoid this and also in an attempt to be able to detect
obstacles better, the ARV’s cruise speed has been reduced to around 2.5 miles an hour. If the
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ECE 477
Digital Systems Senior Design Project
Rev 9/12
ARV is ever mass produced, given more time and resources, we could improve upon the
quality and quantity of our sensors in order to avoid obstacles better.
Another safety concern would be the exposed PCB and wires. Some of the parts on our
PCB such as the H bridges and voltage regulator tend to get very hot after a short amount of
time. It is essential that we cover the PCB and wiring adequately not only from a safety
standpoint, but also to protect our electronics from water and dirt. Our batteries are currently
not securely fastened, so a sudden jolt sometimes disconnects the motor or microcontroller
from power. If our microcontroller were to lose power but our motors stayed powered
(micro and motor powered by separate batteries), our robot might run at max speed into
something. In order to avoid this, the wires connecting the microcontroller to power have to
be completely secure.
Finally, warning labels indicating that the robot is strictly meant for outdoor use should
be provided. The ARV is not meant to be used as a toy and might prove to be dangerous if
used indoors as the obstacle detection algorithm isn’t very efficient in cluttered spaces.
4.0 Summary
This report briefly goes over the ethical and environmental impact of the ARV.
Regarding the environmental issues of the ARV, a potential solution would be to remodel
the ARV to decrease chassis and PCB size and decrease power consumption. Instructions
can be provided to the user on the proper disposal of the product or provide them with
incentives to return product to manufacturer. From an ethical perspective, it is important that
we take steps to avoid the misuse of our product such as the invasion of privacy. There are
also a few safety measures that need to be incorporated such as better quality sensors for
improved obstacle detection. Packaging is another area that needs to be addressed for not
only the safety of the user/ bystander but also for the safety of the robot.
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ECE 477
Digital Systems Senior Design Project
Rev 9/12
5.0 List of References
[1]
IEEE.org. “IEEE Code of Ethics. Internet:
http://www.ieee.org/portal/cms_docs/about/CoE_poster.pdf [Accessed April 10, 2013]
[2] International Network for Environmental Compliance and Enforcement. (1998, Feb 16).
“Printed Circuit Board Manufacturing” Internet:
http://www.inece.org/mmcourse/chapt7.pdf [Accessed April 10, 2013].
[3] “Anodizing”. Internet:
http://en.wikipedia.org/wiki/Anodizing#Anodized_aluminium [Accessed April 10, 2013]
[4] “The Environmental Impact of Anodizing”. Internet:
http://www.thomasnet.com/articles/custom-manufacturing-fabricating/anodizingenvironmental [ Accessed April 10, 2013 ]
[5] “B.W. Recycling Inc.” Internet:
http://www.webuyics.com/scrap-pcb.htm [ Accessed April 10, 2013 ]
[6] I. Buchmann. Cadex Electronics. (2001, April). “Recycling your Battery.” Internet:
http://www.buchmann.ca/article16-page1.asp [Accessed April 10, 2013].
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Digital Systems Senior Design Project
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