How to analyze skateboarding using PVDF film
A couple of months ago I beat Tony Hawk Pro Skater and decided that I, too, would be as cool as the main character of the game. The plan looked like this:
1) I buy a board;
2) Magically learn to do all the tricks;
3) Heifers, cars, money, sponsors, fame.
As you know, the path to the calves and money was a little longer than I imagined. One of the important problems I encountered is the impossibility of analyzing my own achievements. Even if I do the trick, I can’t say how right it is. I can not say for sure even at what height I jumped - what could be more up to more subtle moments. Because of this, learning speed drops.
I tried to shoot my attempts on camera, but it turned out very badly. Firstly, there is only one perspective; secondly, it takes a lot of time to watch. If the skating site is hung with cameras from all sides, then I will look very strange and the chicks will still get around me.
In this article I will try to find a solution to this problem with the help of quite technical means. I ask you to take this rather as an open-ended question, rather than an answer, because the real solution certainly requires a deeper study.
So, we need to remove two types of parameters:
1) The position of the legs on the board, as well as the force of pressing the board in different places.
2) Speed, turns in air, height of rise.
')
I see a solution to the problem of using a piezoelectric layer in a skateboard that would generate a current using the direct piezoelectric effect. I recently worked with PVDF, and he, of course, seems to me a good candidate for the role of this layer. PVDF is inert, has good parameters of durability, wear resistance, temperature conditions also suit us.
This layer should be under the sandpaper (coating), right on the deck. The skateboard diagram shows where. Putting the film on the deck can not be due to serious physical exertion.
Unfortunately, to obtain a piezoelectric effect, it is necessary to deal with the polarization of PVDF, which is associated with very high voltages, and in industrial production it is not as fun as in a laboratory.
The main problem that I cannot overcome at the level of a mental experiment is the coordinate grid. OK, PVDF generated a current, we were even able to understand with what force the skater stepped on the board. But the position of the legs remains a mystery to us. The solution is still seen only within the framework of matrix touch screens , but I don’t like their structure, since it is completely unsuitable for serious physical exertion.
Here we have already thought of everything. Gyroscopes of tons of riveting on Chinese factories to take their place in the iPhone, and the accelerometer was still in my old player LG. The question is in the design of the scheme, since I initially intended to use the Rasberry Pi, but there are no similar functions.
Data transfer should be carried out via Bluetooth 4.0, since it is more than enough to transmit simple parameters. Synchronization takes place with the phone.
We have all the necessary parameters in our pockets and here the most interesting begins. I knowingly mentioned the computer game at the beginning - it is transferred to reality. In addition to solving purely practical issues, such as comparing results and underlining mistakes in execution, this is a gamification of a completely real action. For all the jumps, you can earn points, you can take quests and do them, you can use the data and compare them with friends - the scope for such actions is simply huge, and I will try to describe the specific application in the next article. What is important is the fact that we turn training into a game, and also add an element of sports competition to the activity that is mostly individual.
In essence, I propose to discuss several issues:
1. How to deal with the coordinate grid?
2. Is there a better material than PVDF?
Accordingly, I would like to gradually publish the course of work on this idea, if some solutions to the problems are found.
1) I buy a board;
2) Magically learn to do all the tricks;
3) Heifers, cars, money, sponsors, fame.
As you know, the path to the calves and money was a little longer than I imagined. One of the important problems I encountered is the impossibility of analyzing my own achievements. Even if I do the trick, I can’t say how right it is. I can not say for sure even at what height I jumped - what could be more up to more subtle moments. Because of this, learning speed drops.
I tried to shoot my attempts on camera, but it turned out very badly. Firstly, there is only one perspective; secondly, it takes a lot of time to watch. If the skating site is hung with cameras from all sides, then I will look very strange and the chicks will still get around me.
In this article I will try to find a solution to this problem with the help of quite technical means. I ask you to take this rather as an open-ended question, rather than an answer, because the real solution certainly requires a deeper study.
So, we need to remove two types of parameters:
1) The position of the legs on the board, as well as the force of pressing the board in different places.
2) Speed, turns in air, height of rise.
')
Skateboarder's foot position and pressure
I see a solution to the problem of using a piezoelectric layer in a skateboard that would generate a current using the direct piezoelectric effect. I recently worked with PVDF, and he, of course, seems to me a good candidate for the role of this layer. PVDF is inert, has good parameters of durability, wear resistance, temperature conditions also suit us.
This layer should be under the sandpaper (coating), right on the deck. The skateboard diagram shows where. Putting the film on the deck can not be due to serious physical exertion.
Unfortunately, to obtain a piezoelectric effect, it is necessary to deal with the polarization of PVDF, which is associated with very high voltages, and in industrial production it is not as fun as in a laboratory.
The main problem that I cannot overcome at the level of a mental experiment is the coordinate grid. OK, PVDF generated a current, we were even able to understand with what force the skater stepped on the board. But the position of the legs remains a mystery to us. The solution is still seen only within the framework of matrix touch screens , but I don’t like their structure, since it is completely unsuitable for serious physical exertion.
Speed, speed, height, data transfer
Here we have already thought of everything. Gyroscopes of tons of riveting on Chinese factories to take their place in the iPhone, and the accelerometer was still in my old player LG. The question is in the design of the scheme, since I initially intended to use the Rasberry Pi, but there are no similar functions.
Data transfer should be carried out via Bluetooth 4.0, since it is more than enough to transmit simple parameters. Synchronization takes place with the phone.
And for what?
We have all the necessary parameters in our pockets and here the most interesting begins. I knowingly mentioned the computer game at the beginning - it is transferred to reality. In addition to solving purely practical issues, such as comparing results and underlining mistakes in execution, this is a gamification of a completely real action. For all the jumps, you can earn points, you can take quests and do them, you can use the data and compare them with friends - the scope for such actions is simply huge, and I will try to describe the specific application in the next article. What is important is the fact that we turn training into a game, and also add an element of sports competition to the activity that is mostly individual.
In essence, I propose to discuss several issues:
1. How to deal with the coordinate grid?
2. Is there a better material than PVDF?
Accordingly, I would like to gradually publish the course of work on this idea, if some solutions to the problems are found.
Source: https://habr.com/ru/post/226295/
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