2014 Fujian University students Electronic Design competition test and control team's experience notes

First of all to say a sorry, because this month began to the company internship, so did not spend too much time to prepare this speech, PPT is also done very shabby, very perfunctory, simply paste a few pictures is a ppt. I have considered how to introduce our work, if it is to tell you about the whole process, the principle of four-axis aircraft, will inevitably be very boring, and some students have not done know the aircraft project, said too complex afraid of everyone 1:30 will not digest, said I would like to introduce a brief introduction of our works, Then say a few words about my teammates and my entire competition.

Because the last national game is to do the aircraft, and in recent years, the topic is more and more avantgarde, began to run from the ground of the smart car in the sky to fly, so, my teammates and I decided this year's provincial race must be a question about the aircraft, as to the specific topic is how, we do not come, But we think that at least in the summer time to make the plane, as to how to achieve the difficulty of the flight, we do not care, at least to fly up, to be able to hover stably in the air. Therefore, we start from the summer vacation began to do four-axis aircraft, as to why do four-axis, very simple, popular so much information, many enthusiasts are playing four-axis, online ready-made solutions are also many, so do four axes is the inevitable choice. Although the information on the Internet, but we still first asked to do the aircraft's seniors, that is, Chen Shingbin seniors, here I would like to thank Chen Shingbin Seniors, in the entire production process to help us a lot, do the aircraft need module list is according to Chen Shingbin seniors recommended configuration. We started in a forum and posted on the bar, a lot of information, but not all, for a team who do not know anything about the aircraft, the data is not a big obstacle, because even if you do not know whether it is missing, and then where to find the missing. A few days ago I and teammates are looking for information, visit the forum and paste, I can find the download of things to pack, to teammates, teammates also put him to find the good things to me, after a contrast, found to see things are almost, we can in addition to Baidu or Baidu, for the method of finding data I think is very important, Several commonly used websites to register, some need to spend money to buy points, there is a need to spend some money, after all, not spend much money, so more convenient. Finally we decided to use a program called "Anonymous", this guy is a technology house, he has all the things open source, but also uploaded a flight video, source code and circuit diagram are very comprehensive.

So we began to study the code, after all, you are to participate in the game, you have to put in every line of code thoroughly understand and then to modify the code to participate in the game, for the code, we have spent nearly one weeks to thoroughly understand, in the middle also gradually learned how to modular programming, the project is relatively small, All the code is in one. c file inside the implementation, so after looking at the aircraft this huge I also learned how to go to module programming, and later, when working with teammates, I will do the module I do a. c and. h files, and then write a description of the document, so that teammates are very convenient to use. Then we began to follow the online program resume their own engineering documents, which we also want to explain is that we use the processor is stm32, why use this processor, the first is popular, because the popular information is very rich, and in the classroom also heard that many companies are now using the processor, So it is necessary to learn this processor, this processor has a thing is, the manufacturer provides a very rich firmware, a lot of the bottom of things have been done for you, set IO, serial, SPI,IIC, etc. are available functions can be called, use up very stupid, Now some students are learning this processor, and then go to see the thick of the authoritative manual, lighting a LED also a register to set, I think there is no need to learn this, not only trouble efficiency is not high, but also particularly prone to error. Before the software engineering has been established, our plane has been out of the way, in addition to the processor line has not yet received, after all, the line how to connect with the software is directly related. And so the software is done we start to download the program, start debugging, I said the software done is said to compile through the no error, as for can fly, we do not know, after all, only try to know. About debugging the means of communication with the aircraft, the most ideal of course is wireless, the preferred is NRF module, communication distance, but this module to program, testing time has been a problem, the computer can not receive, I spent one weeks of time did not take this module, so temporarily give up, back and beg second, Instead of the serial port, is in the fuselage pull a line USB cable to the computer, is very inconvenient, in the race days before we think of Bluetooth module, with Bluetooth module is really convenient, without programming, directly borrow two serial port PIN, computer on a Bluetooth receiver, you can use.

After we began debugging, debugging process is also experienced hardships, because the plane and intelligent car is not the same, one is the ground running, one is flying in the sky, running on the ground you how to run or in a two-dimensional plane, and the plane is not the same, three-dimensional three-dimensional, and the entire program has not been verified, so, Refers to the program downloaded after the start of the run, the plane flew to where, although the beginning and did not encounter such a problem, but after all, the aircraft pull the serial line, so, the results of the commissioning is limited, after the use of Bluetooth after the pull after the real debugging, debugging the first problem is balanced, The first is to ensure that the four motor plus the same throttle when you can fly upright, and not the random flying, mainly to adjust a six-axis sensor 0 Drift point and PID parameters, there are users suggest to adjust the balance can be divided, balance has two direction, we first put a direction fixed, adjust another direction, And so on another direction okay again change this direction, so slowly try, have done the control class of the classmate know how long and painful tuning PID process, PID specific how to adjust I said, the relevant information is very much, most of the comments are the first tune that again, and then two together tune.

Here is another episode, we do this time the other provinces of the game has come out, we saw the topic of speculation that the game with the processor should be required to use TI Company's 430 or TIVA4, of course, this is only speculation, we do not have the full grasp, we ask the teacher, the teacher thinks is not, But for the sake of insurance, or at this time decided to abandon the stm32, instead of TIVA4, this process is my teammates to complete, although it is a strange chip, but after all, is the arm architecture of the processor, so there are a lot of common, so, and did not encounter very many difficulties, And this chip also has a function library, we need to use the function is also directly called, so it is very convenient, from the use of these two chips, I think, no matter which new processor in the future to be popular, after all, to have their own fixed library, to the original manual is not enough, so not only to shorten the developer's time to get started , but also greatly shorten the entire product development cycle, the use of the more fool the better, the lower the learning cost the better, I think the apple phone gives the feeling is to pick up can use, if coupled with reasonable price, if there is such a chip we have what reason not to use it?

The following I said a few days before the game how we debug, to begin with, we are on the plane tied a rope, a person pull this, a person with computer control, according to the flight of the flight body debugging parameters, the first goal is to do hover, we began to think that hover is the most basic, But to the back to hover is the most difficult, you want to let the plane to fly in a direction, as long as the program in a direction to cut an angle can be, the direction of the basic can be scheduled to fly, but hover is not the same, the commissioning of the time according to our settings, the aircraft should be stopped this does not understand, but always drift This question is very serious, if the game requires hovering, so a drift to drift out of the outside, it is not fall short, so, to solve this problem is urgent, and began to use the method of tuning PID, but this time the drift is not so serious, the next change a battery, because the reason for the battery change, We suspect that the cause of the change in the body center of gravity, and then every time the battery, we have to carefully put the battery in place to the original position, to the maximum degree of keeping the center unchanged. But you can not be too careful to do the same as the original, so, I used to carry with the car key to the rack, I never thought, the effect is very good, but also do not have to worry about the reason for each change of the battery to re-tune the PID once. Hover of the problem is almost with such a simple rough way to solve, at that time our decision is in the commissioning of the body to find how to add the key to the law, in the game can have the fastest speed of the hover problem solved, it can be seen that the robustness of our algorithm is quite poor.

But things are not smooth sailing, the next is the fixed high problem, the module used is the ultrasonic module, the use of the module is very simple, with the introduction of the manual, but the theory and practice is often not so consistent with the beginning is good, and then we can safely rip off the rope tied to the fuselage, and then the problem arose , this occurrence of the problem, almost put me and my teammates frightened, in the game the next day, the plane suddenly smoke crazy, kept to fly, directly into the ceiling of the baffle, and then a few oars broken, one of the motor dropped directly on the ground broke, fortunately, the rack did not break, because the oars and motor are more buy, But the rack did not, die rack to break, that can really be a careless full plate lose, so later the flight test process, even if the state of the plane how stable, we are still tied rope.

Then we took part in the competition, the first time in the school, the result is very good, better than we expected, the topic requires the aircraft landing point more accurate scores, usually in the test always can not fall so accurate, but this test of the landing is quite ready, impartial fall on the midpoint, this is the factor of luck, and we have nothing to do.

When the test, we still have to be good, but the landing is not the first time so accurate, so, about the drop in the performance of a grade, but for the award we are still very confident. Here we have to say, we can see from the topic, the basic part is very simple, is basically the plane flew over a rope, about the landing and stability can not much requirements, many groups of students can do, the difficulty is hovering 3S, and many groups in hover did not do, our advantage is here, If we can get the first place in this topic, it's really thanks to my key.

Well, about the course of the game introduced here, I believe that everyone also heard a little annoyed.

If you want to make a summary, I think there are the following points:

One is experience, if we are not the first to participate in the game, I believe we can do it faster and better.

Two is the interest, the interest is the best teacher.

There is nothing more than hard work to persevere perseverance and so on.

Thank you.

2014 Fujian University students Electronic Design competition test and control team's experience notes