Lecture 18: Microcontroller based uniform seed rate application system

Lecture 18: Microcontroller based uniform seed rate application system


Ah Welcome students to my 18th lecture which
I want to give you on a advanced technology which we have developed at I I T Kharagpur.
Ah It goes microcontroller based uniform seed rate application system. Well we have talked
of the different types of seed rate ah application systems or seeding systems we have talked
of. Now there are a certain lagoon of those ah
you because those units are driven by the ground field the metering mechanism or the
metering shaft the seed metering shaft is driven taking power from the ground field.
And you know that the ground field is ah ah facing ah the different types of soil. So,
we find that many times we get losses many times you get missings of the seeds.
Many times ah ah seed damage also takes place in the ah because of the metering device.
So, we have gone into a technology by which we are in a better position to solve all those
problems to some extent ah let us go through this. So, and using microcontrollers mazing
electronics. Here this is what ah you can say that use a precision agriculture; that
means, use of electronics in agricultural equipment design where ah we can solve some
of our problems because of the mechanical ah design which we were facing so far .
Well what is this mechanical system ah this actually when we are talking of a commercial
level mechanical planter the seed material mechanism operated by the ground wheel as
I said. What are the drawbacks of this? As I said earlier high missing adjustment of
seed rate is difficult. And then ah absence of seed monitoring system
actually, we are not in a position to monitor. So, these are some of the important difficulties
that we faced when we have this equipment. So, to in order to take care of this as I
said we need help of ah a system which we call from mechanical transmission, we are
talking of a mechatronics mechatronics transmission. Where we are going to use the electronics
part of it we are going to use a high level of mechanization ah for doing the seed metering.
It is a blend of ah this mechatronics is nothing, but the blend of mechan ah ah you can say
mechanical and electronics or mechanics or electronics to put it mechanical and electrons
put together ah what you get. The in in very simple definition of this at your level ah
as an agricultural engineer you must know what exactly this mechatronics means and that
is why in a very simple way I have tried to define it .
Advantage of this well, if you have seen the difficulties or the drawbacks the ah in the
system earlier definitely we if you overcome those then those are the ah advantages that
we are going to get if you have a mechatronics system. What are those? There would not be
any skidding because, we may not be taking power from the ground wheel uniform seed rate
application yes there will be uniform seeding which will take place there will be hardly
any missings and losses. Optimum use of seeds we will not be losing
seeds definitely we will have a precise and a ah pinpointed system by which we can put
seeds as well as we want. Then definitely there would not be any loss or optimum use
will be there electronic seed controller and seed monitoring system. The seed controlling
and monitoring will be an electronic one which will do very precise.
And of course, easy adjustment of the seed rate yes, this is another thing when you might
have seen that in the seed comfort laser drill or only a seed drill this if they fluted roller
type what we have done? We have changed the exposure ah length of the fluted role. And
there that way we have been an equation to adjust the seed rate , but then in this case
you can do it very easily you can do it very ah without any problem. So, these are definitely
the advantage of mechatronics system here .
A block diagram of uniform seed rate application system now what are the electronic parts what
are the components which are involved in in such a system? It is important for you to
know it is important for you to understand. See you how do we read how do you find out
the speed we want to know what is the speed at which my tractors will travel and ah what
will be relevant ah ah soil slippage which may take place ah to the tractor wheels.
So, for that we have the speed measuring there is a radar sensor, there is a radar sensor
here. So, if the radar sensor is fixed at a location ah in the tractor where it will
measure the actual speed of the tractor .This is very important we must know what is the
theoretical speed we can always get ah ah by rotating the field and this actual speed
when ah there is it load onto the field what will be there. So, we would like to measure
this and once we know these two then we will be in a position to and and to estimate what
is the level of slip the talkers. Then ah for seed detection and seed monitoring for
seed detection and seed monitoring we have the infrared sensor.
Now, this another aspect because we need this we want to know the whether the seed has been
falling or not whether the seed is going through the tube or not this monitoring and detection
is very important. So, these two aspects one will talk of the speed of movement the other
will talk of monitoring of the seed these information goes to a microcontroller here.
So, this microcontroller gives takes this information and once is equipped with all
this then it will go to the motor controller. It will then it will in advise the motor controller
to operate permanent magnet D C motor. Then this will do here this is P M D C motor. So,
operate the seed metering this will this are the say the information is once information
from these two comes the controller controller will then advise the motor controller. This
is the motor controller of the this particular P M D C motor. Then the job of metering mechanism
will be ah completed or this ah metering mechanism will take place.
Then this will happen now here are the seed metering device seed. In fact, this is seed
measuring plate which is being ah ah seen here and these are the seeds which are shown
here ah I mean at this location now these are cut off device ah in over here. So, this
is a block diagram of the seed application system the of the of a microcontroller based
system here. Now how we have done definitely this requires
knowledge of the electronics ah on the part of the design you may not be an agricultural
ah an aggregate as an agricultural engineer you may not have gone through some of the
courses, but I think at I I T Kharagpur. Ah We are learning this part of it and then trying
to apply by taking help from our ah colleagues from different departments and um even ah
somebody is interested to learn he can learn the courses.
These courses on his on his own and use these ah um ah equipment ah the devices and components
for getting a good ah seed application system. So, these are the components of ah a shown
in the block diagram . Motor speed control method how do you control
the motor speed? Well it is important we must know what is the science behind it? Because
how the seeds are falling?. So, the N is the R P M of the D C motor. So, N is the R N is
the R P M of the D C motor, V is the forward speed of the tractor V is the forward speed
of the tractor then desired seed spacing what desired seed spacing we want this is here.
Then the number of holes in the seed plate well ah I have shown you in this .
See this is the ah holes which are ah there the locations where the ah the seeds will
be will be there and this is the location where it will be cut off and it will fall.
So, number of holes in the seed plates there are n 8 ah are shown here over here this one
seed plate here. Then seed spacing very nicely shown here you can have a look at this then
S d is the desired seed spacing these are the two locations where the seeds are ah spaced.
So, using this you can know what is the R P M of the motor what R P M of the motor should
be there. If you want to have a certain number of seed
at certain spacing for a particular crop because the crop will differ and the styles I type
of the seed will be differing at many things will be there. So, when you want to have for
a particular crop what should be the R P M this has to be designed. And this is this
is the formula using which you can design. Now once this is designed the other um tra
power transmission are reduction unit. That is P M D C motor is here this forward
D C chain drive because then we with the motor now we are in a position to operate the seed
ah metering mechanism. So, this is the chain and sprocket type of mechanism. So, we are
talking of mechanical and then electronics. So, there are certain portions we will talk
of the electronics input information and directly um ah ah mechanical device to do the job this
is what is done ah in this case here. So, motor a speed control method this is how we
do in the ah mic microcontroller may met ah equipment .
Measurement of static torque on seed metering shaft very important see ah as a designer
you must know what is the torque which is coming on to the seed. Because you will design
when you are thinking of designing of a seed drill you will definitely think of a seed
hopper then you will think of the seed um metering shaft.
And then there will be the metering mechanisms ah either it is a um plate inclined plate
or a vertical plate or you will think of a ah opening or whatever maybe decides when
you think of this you must know how much is the power required what is the torque on the
um shaft which is required. So, measurement of static torque on seed metering shaft we
have done this part it is very essential as a designer. So, ah I will just tell you that,
we have done this part there is a load cell here yes so, torque measurement here so; there
is a load cell here this load cell. In fact, we are interested to know through
see we can you we have used the mechanism here to see what is the ah distance and then
how much is the ah load force we when we apply through this what is the load coming on to
their to the system. And the this is the ah assembly which you write shown earlier about
the ah the power transmission the chain and sprocket power transmission. There is a ah
idler here which will talk of the tension of the ah chain ah digital display. Now this
is the digital display that we are getting about what is the distance and what is the
force applied here through this so, known distances are there.
So, we are in a position when we are ah measuring the torque we are in a position to measure
the force and that display is um ah shown over there . Now, ah so, the load cell has
a standard load cell had been used in this case .
Mechatronics a transmission system now, then what is this mechatronics? Now here when we
are talking of the see P M D C motor .We have given information to the motor to rotate now
this encoder is the one which will talk of the ah R P M of ah ah R P M of this. So, we
are in a position to monitor the R P M and then chain drive is ah of course, is there
which will now ultimately ah meter the C D metering mechanism. So, what we are doing
in this is the the P M D C motor which has instruction through the ah microcontroller
by it is it is own controller. And then we are in a position to utilize the
rotation of this ah shaft which is the over here ah through the encoder. And then we are
in a position to pa to transmit power from this ah is sprocket to this sprocket. So,
depending upon the ratio we are in a position to know what is the ah speed at which it should
move depending upon the ah seed rate that we want, depending upon the type of seed we
have and the crop etcetera and the speed at which the whole tractor is moving.
So, we need to ah we need to design all these things in a in a befitting manner, while keeping
in point keeping in view the electronics part of it what are the electronics components
give you and then what are the mechanical parts and how they should be matched together
to get the total output of ah not scaling and then getting everything the way we want
for this mechatronics system the advanced system which was ah not there earlier .
Well here it is um shown that the real time seed counting system there is a um there is
a you can see here, there is a seed counting system these are sensors ah in each one of
them I r sensors in each one of them. So, you are in ah yes, ah so that real time seed
countering we can do this is this is one view of the machine which has been shown to you
here and there is a twelve volt D C motor which um ah we discussed earlier .
So, we are in a position to know from each each location as to whether the seeds are
falling or not and there are sensors. And there are other mechan methodologies and there
are other aspects of how to know whether the seed is actually falling or not or um there
is a condition of the seed in between the um tube etcetera that we are in a position
to see and understand . With performance parameters of precision planter
I think ah ah um well precision ah we we do need to know what are the performance parameters
of of precision planter? You see here miss index in fact, we we should be talking of
missing index how what what are the misses how many misses will take place when the seed
is falling actually this is what it is? So, the miss index here I um I is the percentage
of spacing greater than 1.5 times the set planting distance S in millimetre.
W ell these are some of the aspects which we need to ah need to design um on the basis
of the um ah literature available, on the basis of literature available as to for a
particular seed what what is what is this and how this value should be actually thought
of. Because we do not want several missings because,
otherwise this will talk of a bad performance of the ah equipment. Then multiple index,
now this may also ah happen that multiple seeds are there, see we are talking of precision
planting we are talking of precision application of everything either seed fertilizer whatever.
So, we want certain amount only should go which is just required.
So, for that we do not want that ah there should not be ah ah anyone at the same time
we do not want that there should be multiple of that when I want one, I just want one only
I do not want multiple I do not want the zero at some point of time. So, we do not want
this multiple index also. Which also say is that multiple index is the percentage of spacing
that are less than or equal to half of the set plant now S .
The some aspects, some spacing ones we have ah um planting distance we have measured.
So, if you would like that there should be multiple should not be there within a certain
distance that is what we will describe explain as the multiple index. And multiple see ah
um seeds falling, we would like to consider this in this particular as per this definition.
Then quality of feed index, what is the quality of feed index? That means, how the ah feeds
after how is the metering shaft working? Now you can see here quality of feed index I q
is the percentage of spacing that are more than half more than half, but not more than
1.5 times the set planting distance. Now, if this is ah um well we have designed these
aspects looking into the several other parameters and the um plant population which actually
is desired by the agronomist. So, keeping into these, these performance indicators for
a precision planter have been ah developed and design um .
See here it shows that I q is equal to 100 minus I means I multiple; that means, the
number the missing index and the multiple index both we would not like to have them.
So, out of the 100 if we reduce or if we subtract this is the one which we are talking of the
quality. So, this um I q is the one which we are they said and if this. In fact, this
is a very simple way of defining so, all of you you must look into this and if you feel
that there is some ah some other improvement in this you could ah you could may addum.
Ah Because we are not talking with respect to the power source we are not talking with
respect to any accuracy of any other equipment. What we are talking is? Whether the seed is
flowing at that location or not, whether multiple seeds are coming, if they are coming, what
is the distance between seeds multiple seeds are coming, how far is the distance between
these two? . So, then precision in spacing yes, this is
the ah crux. In fact, we are all talking of precision we are talking of the ah distances
where, we would like to ah keep the seeds because until unless this is maintained then
ah the whole aspect of the whole purpose of precision will be defeated say.
So, the precision in the space I p is measure of the variability coefficient of variation
you can say what is the level of variation we can ah allow in in the spacing S between
seeds or plants? So, this precision spacing we will like say, there has to be because
when the equipment is working there is possibility that there will be some dispersion of the
seeds when they are fall into the going ah into the ah into the furrow while the tractor
and the equipment is going forward it is quite likely . So, we need to have a monitoring
about the forward speed we need to have monitoring of the system which we are ah having whether
electronic system or a mechanical system. And then we would like to see what is the
ah deviation or the variability ah measure of the variability of the spacing we would
like to have. So, that has been given as this would be suffix I think S this is suffix here
S d has shown here. So, it is a suffix is the Standard Deviation and. So, S d by S where
S is the spacing between the seeds or the plant so, between between spacing this is
the one which is there. So, this is these parameters the miss index, the multiple index
the quality of index, the precision in spacing, these are the ones which talk of the performance
parameter of a precision planter. We have talked of these, because we find that
the um the moment we talk of the um precision equipment seeding is one which is very important
from all counts. And um the ah the losses etcetera should not be there and what happens
is that the seed um if it is properly placed at the right, place in the right environment
of the soil and with the less congestion around it of other plants or unwanted plants or weeds.
Then it will grow it will get a lot of tillerings etcetera and we have found that the growth
is also yield is also very high in this case. That is why; it is very important ah that
precision planting must be done for these a ah ah crops whatever is the crop that we
are choosing in this context . Comparison of field test results well, when
we did this exercise when we did this job we wanted that ah what is the um efficiency
of our system as compared to other systems or the compare to systems which are all existing
because, in the existing system there was no mechatronics.
Ah It was all a mechanical system and the ah power is taken from the ground field and
the preparation of the ground is also varied from location to location several things.
So, in that context when we designed the machine and wanted to use electronics and mechatronics
in the system, we um we had these parameters and the changes which I discussed with respect
to the speed of operation with respect to the metering of the seed etcetera.
And then ultimately, when we measure the performance with regard to those parameters of machine
decks and then multiple seeds etcetera and variability we find a comparison. And it is
encouraging one you could have a look at this, this is very encouraging one. See this every
seed spacing in existing system is this. So, we are not very far off this is one which
we need that S it should not be very far up so very very close.
Average miss missing index is this. Now we have this value here, you can see that large
ah reduction in this missing index; that means, we are in a position to see that all the places
there will be ah 95 percent of the places there will be seeds available in this multiple
index you see the value of multiple index here that 10.8. So, much so, much of multiple
seeds are falling with the existing system because, of the skidding because of ah some
time some locations because of the ah soil moisture and all that it could be possible
multiple index is higher in this case we have very less.
Now average quality feed index is this and we have got this very encouraging very high.
So, you see that the quality feed index is 87.5it is 88 percent very close. Then average
precision index now you see here ah average precision index is 24.25, but 11.5 here. Now,
develop system ah I think here we would we will talking of the accuracy I think here
we are talking of the accuracy of this. So, you see the accuracy is better. So, the developed
system which has a mechatronics system ah developed at I I T Kharagpur is a innovative
one. And further work we are doing with respect
to in fact, using even the embedded systems and other ah ah electronic devices. And we
will continue to do that, but yes for your knowledge we would like we wanted you to have
an infer this information that work is going on you can think of such units in future.
Because, it is the when we are talking precision if this is the way ah by which if we have
better equipment um more and more tractor utilization or utilization of power will be
done because, we know that more power on the farm more will be the output this is direct
relation. So, how can you get more a power?. Not by manual power or the animal power to
that extent, but definitely we are talking of a ah tractor power. So, when you want that
better tractors are use more tractors are used, then the equipment has to be there which
will match the capacity of these . So, and in the performance of this then definitely
we have got all these equipment which are ah each per with respect to each parameter
we find that this is better. And cost is also we must also look into the
cost of this ah um system the cost of the system is also not very high. And a time will
come when when the multiple units when the manufacturers come and ah try to manufacture
all these equipment and use the units you will find the cost will also come down. So,
there will be a cost comparison also at one ah stage of time or one point of time and
we are called ah confident that definitely the the there is a future for such equipment.
Which are accurate and which we will be giving more precise and hence ah ultimately giving
higher yield . Comparison between conventional where some
more comparisons here I I can show you transmission system, vary variation of seed rate, seed
monitoring system, cost, yes I was talking of the cost wait this is the ah same. Say
with the same weight unit you can find out that the planter developed at I I T Kharagpur
we have certain comparisons here. And will just electric motor driven mechatronics a
system here this is mechaly mechanical transmission. We do not say here by the way it is not that
we are saying that this is a bad system existing, but we are thinking of improvement we are
thinking of high quality we are thinking of more and more precision. We are thinking of
advanced technology to be used for solving our problems which we had in this machine
mechanical system. So, we are talking with respect to that the
uniform seed spacing yes, we want and then leads to better yield saving in the seeds
and better yields losses are lesser. So, when losses are lesser also ah ah it will add to
more and more yield. Then variation of the seed rate the we have difficulty in variation
we have to change the gear ratios or interchanging these sprockets and things like that. But
here easily ah by an electronic control system which varies the motor speed this can be very
easily done and maybe the operator who is sitting on the ah tractor itself he should
be in a position to do this. Seed monitoring well there is there is no
seed monitoring at the existing one, but we have a seed monitoring here I discussed. Cost
yes, I said that there will be cost higher, but then when we talk of a unit which will
be multiple unit being the manufactured and large scale this will come down. And it will
be all advantages weight of course, remains to be same. So, with respect to what we have
design at IIT Kharagpur I think this is a new technology which is ah ah which is available
and more and more work is going on in this line and for your information we wanted to
let you know about this. Thank you.

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