On the subject of higher dimension mathematics, I recently discovered this video : "The most beautiful formula not enough people understand"
You might find it interesting too.
186 karma · joined March 1, 2023
You might find it interesting too.
The first game here is to understand what the code does without a high-level README.
I will explore your game source too.
[0] is a thread reproducing what I described. In that case I would like Phind's last answer to provide me with a link to the documentation or source code of 'NormalizedLandmarkList'.
I hope you find it useful.
Maybe it's just the case you're describing but I'm pretty sure I was really looking for appropriate sources and they weren't provided.
If you want, I can send you my queries if I see this again.
So my workflow was :
- ask a question
- quickly read the given answer
- go to the main sources to decide if they are trustworthy or not
I noticed that the new version does not always give the sources, even when I ask. Is this intentional or do you plan to revert this in the near future ?
It also solves the problem of not reducing the traffic to the content creators you use.
Anyway, congratulations for making this tool and offering a free plan to test it.
I just discovered Josh Newans' projects and tutorials about mobile robotics on ROS2.
I find them particularly clear and straightforward, and I think some HN people here might find them interesting as well.
It can be great for beginners to explore the project, but as a robotics engineer myself, I also find some specific topics really useful and well explained. The ROS2 documentation is not always as clear as it could be.
Hope you enjoy!
- create a simple html template using simple.css [0]
- write markdown files
- wrap pandoc [1] in a simple bash script to manually convert markdown to html
- and that's it.
By minimalist, I mean: no script, no component, no database, no react, no SEO.
The result is a minimalist website that you write in markdown.
It's very limited compared to full-featured frameworks, but it can do the job for a simple website.
Here is mine: [2] (I'm not a web developer at all).
Indeed the advantage of your photovoltaic solution is versatility in the face of clouds and lower mechanical costs.
But the drawback is the larger panel area, higher panel cost and probably shorter panel lifetime.
Photovoltaic efficiency is about 20%, while even low-cost mirrors reflect 90% of the energy.
It really depends on the specific application and the answer does not seem so obvious to me.
I answered your question too quickly, I'm near Clermont-Ferrand, we have several local brewery here.
As suggested by pjc50 in another comment [0], a passive safety would be good for this application.
The main drawback being the space required to protect the entire danger zone.
> Bon travail et bonne chance!
Merci beaucoup
> it occurs to me that your system only requires an occasional movement rather than a rapid movement for tracking purposes
Right, actually the system wakes up every 10 seconds to check if the angle needs to be adjusted. It often does not and waits for the next 10 seconds.
There is an opportunity to implement true "hibernation" while the system is waiting to save some more power, but it's not done yet.
> Secondly, the motion system appears to be single-ended and based upon a rope and a stepper motor. It would perhaps be useful to consider conversion to a more rigid system.
Actually there are two geared motors, allowing to control both angles.
Yes, I use simple ropes, the system is stable enough thanks to the counterweight (all ropes are always under tension, making the whole system stable).
> In short, if you have knowledge of your own geometry, have known orientation relative that fixed point, and can before activation determine the TOF distance to your target, and have a GPS fix thus solar inclination at that moment is calculable, then it should be possible to track the target without the need for visual feedback.
My project takes the opposite approach: using a low-cost camera board to avoid having to measure all the geometric aspects precisely.
> In terms of temperature sensing, you can obtain remote temperatures using infra-red linear systems which should be effective.
Good idea, I haven't implemented temperature sensing yet, but I'll look into infrared sensors.
> In terms of safety, laser TOF ensuring no change in distance would ensure the subject is still within the programmed range and an intermediate object hasn't been introduced for combustion.
It may be too late, the intermediate object/person is already heating up by the time we detect it.
> In terms of gathering interest, not sure where you are based in France but I could suggest structuring the system as a public sculpture and holding events including eating food cooked by the system which could involve the additional sponsorship of local wineries, cider, etc. to garner social support.
Yes I'm in France, it would be nice to present the system at such events. For the moment I'd much rather get to work on the technical side.
> Smiles from Sydney. I applaud your work toward the application of technology to social and environmental concern, we need more of this.
Thank you
It was clever.
It might be possible with an expensive camera.
Yes, it might be complicated to build.
https://lm.solar/order/4-square-rigid-aluminum-composite-mir...
Do you know the mirror area used here?
I still naively think that we could make mirrors completely encased in glass to limit their degradation (pure speculation here).
I didn't take the time to describe the cable-bot concept in detail.
I modeled almost all the mechanical parts with OpenSCAD, but I struggled to model the cable itself.
In the "mechanics" README [0] you can click on any image to view it in an online 3D viewer.
The following note in the same README tries to explain how the cable is used :
Each cable is actually wrapped around the motor axis, then passed through the pulley and tied to a fixed ring in the corner of the panel.
You can see these elements in the main 3D viewer [1]
> How are you getting the right mirror orientation for each mirror (aka canting)?
I use one bolt that pulls the mirror holder in the center and 3 bolts that push it in the corners.
By screwing or unscrewing the corner bolts you can precisely orient each mirror independently.
The "panel_board_exploded" view tries to show this [2]
> One trick for closed-loop control with many heliostats/panels is to have a few cameras surrounding the receiver.
Super clever, thanks for the explanation!
I think it might be tricky to calibrate.
[0] https://github.com/remipch/solar_concentrator/blob/master/me...
[1] https://remipch.github.io/solar_concentrator/view_3d.html?mo...
[2] https://remipch.github.io/solar_concentrator/view_3d.html?mo...
If I understand correctly, their main feature is that they do not focus on a focal point, but instead diffuse the light.
So I'm not sure if it would be applicable to my project.
I need to dig deeper to fully understand how it works exactly, thanks for the hint.
Anyway, tungsten melts at 3422°C, I don't know if it's feasible.
Some of their projects follow the same idea of a grid of small square mirrors.
However, they choose to put the mirrors on the ground (which is simpler) and move the target at the focal point (which is not simpler).
Good source of inspiration, I will watch their videos.
That's 48€/m2, I couldn't find a photovoltaic panel at that price.
Add to that:
- photovoltaic efficiency is about 20%, while such mirrors reflect 90% of the energy
- photovoltaic panels have an average lifespan of 20 years, while mirrors do not wear out.
Anyway, we're comparing apples and oranges, because we have to add the mechanical installations, which are very different depending on the specific application.
I'm not against photovoltaic in general, I just think that for some applications there are some interesting alternatives.
- the global position on the planet
- the date and time
- the size and position of some background elements
- the number, size and position of the panels in the grid
The solar power estimation uses :
- the Python code provided in this article [1] to estimate position of the sun (thank you John Clark Craig)
- the simplified formula [2] to estimate the direct insolation from the sun position
- a custom light projection implemented using Panda3D game engine [3]
[0] https://github.com/remipch/solar_concentrator/blob/master/so...
[1] https://levelup.gitconnected.com/python-sun-position-for-sol...
[2] https://en.wikipedia.org/wiki/Direct_insolation#Simplified_f...
I'm not sure it's a viable way to produce electricity on a small scale because:
- high thermodynamic efficiency requires high temperature difference
- photovoltaic panels are mass-produced and increasingly efficient
Personally, I think small scale concentrated solar power is most useful for applications that require direct heat (cooking, desalination, foundries).
In these cases, photovoltaics have a lower efficiency and a shorter lifetime.
However a 20cm x 20cm square spot can be better for some applications.
If you want to cook something it's best to spread the heat over the entire baking sheet to ensure even cooking.
Indeed, the closed-loop control was the initial idea which convinced me that it would be possible to build the mechanical parts by hand with common tools. In other words, the software "smartness" compensates for the mechanical "ugliness".
Another initial idea was to do multi-panels (several orientable panels) with a single camera looking at the target. Indeed, it's not easy, so I finally went back and decided to finish and release something with a single panel.
Nevertheless, I have some ideas to do multi-panels with a few more cameras. I would like to work on them in the near future.
Thank you for all the references, I will spend time to explore them.
There is also a company that uses vacuum to adjust the mirror shape, I'll try to find it and post it here.
I wanted to emphasize the inherent risk because my project is not a finished product, but a work-in-progress/proof-of-concept.