# Intelligent Grounding System

#### DreamTheater

Joined Jul 2, 2008
12
Im currently doing my final year project which is the intelligent grounding system... But im not sure abt certain parts of my project, and i cant ask my advisor too since is away, his having a minor operation and will be back in 3 weeks times... So the project to put in a nutshell, can be potrayed as the following
scenario:

When the sun is at its peak during the day, the light intensity is very high. The sensor will sense this intense lighting and thus its resistance will decrease. The sensor will trigger the water sprinkler into operation, whilch is basically operate the valve in order to pour out the specified solution in order to decrease the resistance value of the ground.

My idea of doing tis project is by using a ldr sensor which after doing some experimental work i should be able to predict the ground resistance according to the light intensity.The output of the sensor will be interfaced to a microcontroller and the output of the microcontroller should be like a time based output which opens the sprinkler for a certain amount of time depending on the increase of the ground resistance and pour some type of solution in order to decrease the ground resistance to the optimal level... Will this work? can anyone please point me to the stuffs that i should be looking at for the sensor and micro-controller in order to design them... im assigned to the sensor and microcontroller part of this project... any opinion would be welcomed... i really need some advice... thanks in advance

#### beenthere

Joined Apr 20, 2004
15,819
Improving the quality of a made ground is usually handled a bit differently. Where the subsoil is less conductive, the approach is to utilize an grid of ground rods. Each rod is driven or buried several feet below grade, and may have local conductivity improved by pouring a copper sulphate solution in the vicinity of each rod at the time of burial.

The problem with a sprinkler system is the time for the water to percolate down far enough to have any effect on conductivity.

Possibly, I have misunderstood the nature of the grounding you are working with. Can you expand on that?

#### thingmaker3

Joined May 16, 2005
5,084
Shouldn't you be measuring conductivity of the soil instead of looking at the sun?

#### DreamTheater

Joined Jul 2, 2008
12
dear beenthere, the concept that u mentioned makes perfect sense, but this is wat my lecturer asked me to do... using a ldr sensor circuit to sense the intensity of the light which is interrelated to the ground resistivity.. with the assumption that more light gives increase to the ground resistance...i might just say that this method is just one of the concepts ,and the concept u just said can be in the future works column bro.

dear thingmaker3, i will hv to do an experiment to find out the resistance of the ground when there is a certain light intensity on it. so when ever i get a certain light intensity i would hv someting like a look up table and get the grounds resistivity from that table wif out measuring. But im not really sure that it will work.

Im really hoping that i will get some info from u guys coz i cant even consult my lecturer since his away

#### SgtWookie

Joined Jul 17, 2007
22,221
Beenthere has given you a good suggestion already. It seems to me that you should approach this in a scientific manner, and attempt to verify the correlation (if any) between the conductivity of the earth vs the intensity of the sun.

I have no clue where you live, but here in the USA they sell eight foot long (about 2.4 meters) copper-clad grounding rods at hardware and electrical supply stores. These are driven into the earth using various equipment, but a large heavy hammer (perhaps 3 lbs/1.5 kg or more) should work in all but the hardest soil.

Get one of those grounding rods, and pound it into the earth about 10 feet/3 meters from the existing grounding rod. Measure the resistance between your new rod and the existing rod over a period of time, during various parts of the day and night, while measuring the light intensity at the same time. A microcontroller would be a good tool for this. Choose one that has a good deal of storage so that you can save the results in non-volatile memory for later readout.

#### beenthere

Joined Apr 20, 2004
15,819
Just for the record - is this a design project in a purely academic sense, or is this going to be actually built?

#### DreamTheater

Joined Jul 2, 2008
12
sad to say it has to be built... i hv 8months to do so.... from ur idea i hv made up a few procedure and altered the design.. wat do u guys think:

I am making the system work once a day... after 7 pm when the sun if out
im using the readings for that day... to predict the conditions for the next day... and make the soil dampened for the next day... so that the resistance will be in a safe region. i will be using rods and a ldr circuit which gives the reading for the whole day.. and this data will be send to a
microcontroller which gives insturction to the water sprinkle... to pour out a specified amount of moisture.... this is how the steps of my project will look like, just a rough draft :

1- get the resistance reading and light intensity reading for a whole day
for a few weeks and get the a pattern on the resistance and light
intensity of the particular site. ( not very sure abt this part yet )

2- get the amount of mixture that is to be poured on the site on a
daily basis.... someting like a look up table... for the amount of ground
resistance and light intensity recorded during the day the amount of
mixture to pour on the site during the night.
might be able to build this look up table from the data collected from the
daily observation.

3- After the mixture is poured on the ground... the ground resistance
should be low enough to last the whole of next day... just below the
max allowed ground resistance ( which i need to research on )

4- The design, will consist of a LDR sensor circuit, grounding rods,
a micro controller ( which i think should tell tell the watering system
how long it should water the ground ) and finally the watering system
that will work according to the data from the micro controller

All this can be done wif the assumption that back to back days hv the
same amount of light intensity and grounding resistance

#### blocco a spirale

Joined Jun 18, 2008
1,546
Before you think about building anything you should do some research, as has already been suggested. Engineering isn't about finding complex solutions for problems that don't exist.

Since this is your final year project I don't understand why your lecturer seems to be driving it. If I were you I'd find a more worthwhile project

#### loosewire

Joined Apr 25, 2008
1,686
I Don't Understand All These Request For Under Ground
Experiments.cell Phone And Timing Must Do Project's. I Get
Losted Following Some Of The Detail ,s From Instructor's
And There Student,s To Do List. I Practice Remote Veiwing,but
I Have Yet To See Any Think. Maybe I Need Something That
Has A Devise With Two Wire's Going To Into Space.
Loosewire

#### beenthere

Joined Apr 20, 2004
15,819
Your first task is figuring out how the measure the "ground" resistance. Do you have a plan for that?

You might want to Google "radiometer" for some reading. That is a device that might aid in measuring the amount of sunlight energy that has fallen on the ground on any given day.

#### DreamTheater

Joined Jul 2, 2008
12
I think i hv figured out that part... i hv attached 2 documents abt the experimental procedure that i hv collected online... wat do u think...
One is the grounding resistance expriment and i will have a lux meter which i will use everytime so that i will know the light intensity at the time of ground resistance reading, and the second attachment is the LDR experiment which i will do inorder to collect data on the reistance value of the ldr for a range of light intensity.... wat do u guys think abt this? Any problem with this procedure? And i hope u guys can be more supportive since i hv already selected the project i cant change it anymore... Ive already got my feet wet And i have another 9 months to complete this project

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#### blocco a spirale

Joined Jun 18, 2008
1,546
I hope you don't think that I'm being negative but, if during your experiments, you find that light intensity is not a reliable indicator of ground resistance, will you still proceed with the project in its current form?

#### DreamTheater

Joined Jul 2, 2008
12
I don't think ur being negative, as long as its a worthwhile comment, bad or good doesn't matter, I had the same question... but wont the light intensity give me some sorta indication abt how fast my grounding moisture might be sucked up to the sky the next day. I mean like im just assuming u see... that the light intensity (assuming that back to back days hv same light intensity) would be a valuable parameter for me to make a better look up table? since more intensity is more heat and more heat cause my ground to dry much faster But the ground resistance might be enuf to predict the look up table... but would the light intensity give an extra safety parameter?

#### blocco a spirale

Joined Jun 18, 2008
1,546
If you monitor the thing you're trying to control i.e ground resistance and add moisture to the earth to maintain a near constant resistance then there would be no need to make assumptions and predictions in the first place. The water could be fed into the ground via the grounding posts themselves.

Your approach is a bit like developing a vehicle speedometer which works by monitoring the position of the radio volume control i.e. Higher speed = greater ambient noise = louder radio (assuming that road speed is the only factor affecting radio volume). Rather than simply monitoring the rotational speed of the road wheels.

#### DreamTheater

Joined Jul 2, 2008
12
Yeah.... u mean its like... i want to know the heat of my body in a room, and say i hv a device which shows me wat is my current body heat... but im like still finding out the room heat and predicting wat my body heat would be... someting like that rite? I think im gona see my lecturer when he gets back and drop the LDR sensor part, its kinda dumb to think abt it, a resistance rod sensor would be enuf i guess

And By the way... this is wat my lecturer posted on my project abstract,
wat do u think abt it? Am i heading the right way

Title 2182: Intelligent Grounding System
Faculty FOE Supervisor Naeem Mohamed Hannoon
Trimester 1
Session
2008/2009
Suitable courses EE,LE
Objective To model and design an effective grounding system which continuously monitor and control the resistivity of the soil
Description Sensors are employed to trigger water sprinkle into operation via relay station and readings are recorded. Solution is added when it is needed as interfacing is necessary part of the project

# actually i just noticed something in his objective.... continuously monitor and control the resistivity of the soil. Does that mean our after 7pm plan cant be used??

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#### blocco a spirale

Joined Jun 18, 2008
1,546
The control requirement looks pretty simple and could be met in a number of ways. A means of recording resistance values is also needed but it doesn't say how often readings are taken or how many should be stored.

You could go for a full micro-controller approach or perhaps use an analoge design for the sprinkler system and a micro for logging. Since grounding is a safety issue you could argue that as far as maintaining ground resistance is concerned a simple analogue design is potentially more robust than a micro which would be ideally suited to data-logging duties and could also raise an alarm should ground resistance become too high.

#### DreamTheater

Joined Jul 2, 2008
12
As a matter of fact, i think... maybe it should just, sprinkle moisture( quantity does not matter as long as its below the level) when the resistance exceeds the optimal level? that would make the design very simple... .... like it just hv a on off switch and wif a reference voltage,when the resistance exceeds this reference and it makes the sprinkler work... wont even need a microcontroller just an ADC for the pc interfacing part... the sensor might just be the rods, bjt and a relay.... But it wont
look very intelligent....

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#### blocco a spirale

Joined Jun 18, 2008
1,546
It would be better to call it an active grounding system. Not a bad project though as you need to design the control system itself and also a means of monitoring its effectiveness. There is still plenty of scope for good design: improved efficiency to minimise power and water consumption, safety, reliability etc.

#### DreamTheater

Joined Jul 2, 2008
12
The water consumption part, can the earlier design be used for that it saves water coz we do not pour a standard amount of water, we actually follow the resistance increase... with the look up table and all... or do u think this simple design we are talking about now is gud enuf for an undergraduate...

#### blocco a spirale

Joined Jun 18, 2008
1,546
Due to the time it takes for the water to propagate through the soil, a simple way to reduce water consumption would be to deliver the water in short bursts every 10 minutes or so until the target resistance is achieved. A continuous flow would oversaturate the ground.

The design spec doesn't say anything about a minimum level of complexity.