So the concept is about high efficiency, high altitude and long range. In other words, these are called as HALR.None of these concepts have been designed yet. But I think we have now defined a goal that can be used as a target where to aim at.And what is the motivation for this? For fun of course. And because we can.

The plan now has the following steps:

 1. Develop, test fly, measure scale model aircraft of the full size concept. Electric propulsion is going to be used.The aircraft shall model the full size aircraft in configuration and prototype control mechanisms of the model 2 aircraft.Possibly more than 1 RC model needs to be built to validate feasibility of different configuration features. This step is very likely to succeed. There are no impediments for executing this plan.

 2. Develop, test fly, measure a human piloted scale model of the full size concept. The plane is intended to utilize electric propulsion. The aircraft shall be able to carry at least 100 kg payload, stay at least tens of minutes in air and then safely land on a grass runway.This requires some feasibility analysis – this one needs to be super-light because the full size one needs to be light as well, and needs to be able carry substantial amount of fuel (300-400 kg). I will blog about what I will learn about structural design and alsocan validate the feasibility of the concept along the way. We saw that single place CriCri size small aircraft is ideal test bed for testingconfigurations, technologies etc. for the full size aircraft. This one must work from our summer cottage neighbor’s airfield, in other words, needs to be relatively STOL. This has good chance to succeed but there are few impediments to clear out before this can succeed.

 3. Develop, test fly the full size plane, and then fly it to Oshkosh. The plane is intended to have hybrid propulsion.The aircraft shall be able to fly at high altitude non-stop from Helsinki to Kangerlussuaq, refuel, and continue and fly next leg non-stop to Oshkosh.The plane shall be practical efficient transportation tool that can partially replace using commercial aviation. The plane shall carry at least two persons plus rescue equipment plus baggage plus full fuel, and must defeat Toyota Prius 2011 model in transportation efficiency. Some serious problem solving is required before this will succeed.

The plane shall be able to fly long distances non-stop to avoid cost of landing fees and other costs associated by stopping on places of no interest.There are no guarantees of success of any of the mentioned steps, but this is the intent. The intent is subject to change. But this is where we are at today. We are very limited by the budget unfortunately and it can affect to the timing and success of each step. If we had substantial budget for this available, we would like to work on this full time, but unfortunately this is not the case.
  

Some analysis would be needed how much this would help. Of course it would depend on the weight of the plane. The heavier the plane, the more leakage to the tip, the more tip vortex would form. The bigger the benefit of having a opposite direction swirling motion to nullify the tip vortex formation.

John Roncz was talking in his presentation about wing span, and finally noted about wing area, that he does not care about wing area, because induced drag has nothing to do with aspect ratio. That’s why gliders have not only skinny wings, but also very long wings. That’s why Rutan’s aircraft have long wings, not only skinny wings. Lots of span is needed for low induced drag.

However, there is a geometrical relation about AR to the drag: The lower the AR, the higher is the wetted area for the given span. Wetted area is bad, it causes drag, you don’t want extra wetted area. So the wing becomes skinny by definition. But now the wing is skinny (high AR) but also very long, and not only skinny.

There is another problem: I would think then that I want 20 meters long wing span, but very very narrow chord. The chord can not be infinitely narrow in order it to be structurally any sound, especially in speed. Therefore the higher the AR gets, and the lower the wetted area gets, the heavier the wing becomes. And the heavier it becomes, the worse gets the span loading if this is added to the weight of the plane. Then there is the another consideration, where I could taxi such plane which would have 20 meter span? On our airport even the Diamond’s comparatively modest wing span is in some places a bit tricky.

Interesting dilemma. This also answers why there are multiple pods on some Rutan’s aircrafts, along the span. The reason is to reduce induced drag, by moving the weight from the center more along the span. Then the lift required on the center where the lift given by the wing is worst does not give that unfavorable dip to lift distribution. And it reduces induced drag. On planes, like Globalflyer, induced drag plays major role in how much range the Brequet’s equation gives.

But there is even more to this: the higher the AR gets, the lower the Re gets. The higher the altitude, also the lower the Re is again. The lower the Re, the higher is the profile drag. To get high L/D and thus efficiency one has to get also the profile drag down. And airplane efficiency is all about L/D (lift/drag), no less.

So my basic concept remains and does not need to be revised for another configuration alternatives:
- conventional (to be able to use efficient flaps)
- large span, low span loading (to reduce induced drag)
- high aspect ratio, relatively high wing loading (to avoid extra wetted area and that way to reduce drag and AR also to have steep lift curve slope (in other words, closer to the 2D airfoil simulations of infinite wings)
- larger than minimum size elevator for larger CG allowance – this is for practicality rather than minimum trim drag
- The large AR is also needed for this: cruising with high wing loading causes need for high Cl for cruise, which in turn causes high alpha. To reduce alpha, the steepness of the lift curve slope is your friend. The lift curve slope steepness will make the plane to cruise fairly low angle of attack despite of flying at high Cl at high altitude with high wing loading.

This article on the EAA news tells that some carplane designer thinks Burt’s Bipod is “too slippery”. I really wonder what is the definition of too slippery. There is a group of misguided people who want airplanes to have lots of drag for them to “not be too slippery”, in other words have aerodynamics of brick. I have bumped into Cessna pilots who think like that and they look for example our Diamond that “oh that is too slipperly plane for me”. From my standpoint, that is not too clever.

Drag is always unfavorable and waste of resources. There can never be too little drag (except in landing configuration when drag is helpful to land the plane in a meaningful distance). Low drag when plane is cruising, has absolutely nothing to do with the flying qualities of the plane. Having more drag does not make the plane any easier to fly. Having more drag just means you have to burn more fuel, you have to have bigger engine, you have to beef up structure, to compensate, you have to put even bigger engine, and have even more fuel on board. Airplane being slippery is a myth. Some Cessna pilots think our Diamond is “slippery” or “too slippery for them”. Yeah right, the truth is that the Diamond has better flying qualities than the C172, is easier to land and especially flare and it also stalls softer.

I wholeheartedly agree with Burt [about his Bipod]:  “Gee, he complains that we have too much drag as a car but not enough drag as an airplane!”

I think the US LSA specification is deeply flawed as they have introduced the top speed limit. It will limit the category of LSA planes to such that it is not worth to make efficient planes and high drag has been made a standard. That is not too clever either. Apparently the rules have been set by non-pilots who do not have slightest clue on what makes airplanes safe and what makes them easy to fly [and land]… It is all about stability, stall speed, stall charasteristics and inertia. Europeans have understood that better since there is no top speed limit in Europe but there is a stringent stall speed requirement. Low inertia, low stall speed and gentle handling qualities, and no matter what is the top speed, the plane will be easy to fly.

Read about Burt Rutan’s Bipod here:
http://www.airventure.org/news/2011/110727_bipod.html

I created this new airfoil which has 70% laminar flow according to the simulation (please note, this is not tested in wind tunnel). It has a little larger pitching moment than the other airfoils I have done, but the L/D at low angle of attack (zero degrees angle of attack is Cl 0.35) reaches L/D over 100 at Re 5000000. The minimum drag count is 30 (Cd = 0.0030) at Re 7000000. At 5000000 the drag count increases to 31.

The airfoil can be downloaded here: KS-70PLAMINAR.dat.

Simulation results at Re 500 000, 1 000 000, 5 000 000, 7 000 000, 10 000 000 (Cl-Cd polar):

Simulation results at 500 000, 1 000 000, 5 000 000, 7 000 000, 10 000 000 (L/D polar):

I will build RC scale model of this airfoil and test it with RC plane. At RC scale it will be a bit worse than best thin turbulent airfoils, but according to simulations, the polars are smooth to low Re which is desirable of course and this airfoil reaches at least the same Cd at the low Re than NACA 2415 unlike some other laminar airfoils.

Read more here: http://www.homebuiltairplanes.com/forums/aircraft-design-aerodynamics-new-technology/10349-specifications-coefficient-lift-dyn-aero-lafayette-mcr-ban-bi.html

Yes, I am myself flying airplanes for fun, and the fun is very important. And the fun will need to remain important in the future as well. The fun part should therefore not be taken away. Airliners are taking the fun away, sitting in economy class is more like suffering than fun and business class is not fun either, everything has been made to take the attention away from the aviation, people are eating and drinking and not looking out of the window. Windows even are ridiculously small, even in business class.

Then if we look road transportation. How many people prefer traveling in bus rather than in a private car or taxi? Are you a bus-fan? At least I am not. We drive with our Prius to work everyday and my carbon emissions are less than they would be if we would drive with the 1/3 filled bus. You could argue that the bus drives anyway, but that is not the point. Bus travel is like being in the economy class, it does not have anything that I could describe with fun or enjoyable. However driving with own car or sitting in taxi can be much better experience.

So I think here is the cure for general aviation:
1) Diesel piston engine based efficient air taxis that can carry 5-6 persons. Requirement for the aircraft would be that they would need to be efficient (leading to low passenger mile cost), safe and comfortable. Low passenger mile cost means cost comparable to airline ticket price. This cost should be able to include the whole thing: aircraft cost, insurance, pilot, everything. I think this is doable, but requires some novel engineering and not doing things like they have been always done. These planes would look more like Burt Rutan’s special machines with very long wings or they could be possibly also blended flying wings but one could not expect these to look like Cessna C150.

2) Personal aircraft (I am not repeating what cafe is saying about PAV, this is my personal view on this) intended for serious transportation with large level of automation. This calls for fly-by-wire and stability augmentation. Pilot would rather choose to which direction to drive rather than correcting for bumpy air or cross wind. It would be different from autopilot, you could still drive the plane, but the plane would make driving a lot more convenient and so much easier that most car drivers could learn it. There could be additional aids, such as landing aid which would automatically line up the plane with the runway. It could use machine vision to be able to help the landing path all the way to full stop on runway independently from navigation aids. It would be still fun to fly even if it would be much easier. Why the definition of fun has to be hard? These aircraft geared for personal transportation would be at least 4 place machines making them comparable to family car capability.

Lots of people are shouting that “more entry level planes are needed”. I do not fully agree. There are lots of planes which are very suitable for flight training. For example the LSA planes, Diamonds, Cirruses etc. Of course if the intention was to fly a fly-by-wire PAV-machine, there could be a different path that would be trained with these PAV machines. Logical step in that direction would be to drop all medical, currency etc. requirements, but rather make the flying with these with similar requirements than driving a car. If flying these would be so easy, you simply would not need check rides now and then, BFRs etc. And then planes are made with unreliable parts which were certified 40 years ago while cars almost never break with parts that were designed one year ago.

In personal aircraft you fly with the computer the flying machine. This license should be upgradeable to a normal pilot’s license which would require then learning to fly with planes with traditional controls and avionics. Some could argue that this would be so expensive as the computers would be so heavy and they would cost more than a plane and what not. I don’t think so. Computer that can run this kind of algorithms in real time does not need to cost a fortune. In mass production, a reasonable price is hundreds of dollars, not tens of thousands or hundreds of thousands. Such computer weights less than 0.3 kg and while it would need some more weight for all the control hardware, it would not be that complicated. Actually telephones are so much more complicated today than any electronics in aircraft, in fact, these things are so low hanging fruits that they are waiting for somebody to implement.

What slows down the progress on this area in my opinion, is very conservative thinking in the aviation circles, not thinking out of the box and at least in Finland there seems to be a tendency to repeat old beliefs like they would be teachings in a church and even clever people may take silly things for granted. Of course that is all they can do, as there are no alternatives, but that does not mean it would be right. In fact, the situation with aviation is so desperate that this feels like some alternate universe in Stargate TV-series where things have gone real badly wrong. We are that dystopic parallel universe and someone needs to do something to fix it. So aviation in general needs a major overhaul. New kind of airplanes are needed, new kind of regulations are needed (while dropping old obsolete ones), new kind of air traffic control system is needed (when there are millions of personal planes in the air, there is no way for the current system to work, it is a dinosaur already, you can not have centralized system in a case where traffic is so huge, car traffic already has hard data about that) and new kind of attitudes are needed. New more efficient and less expensive mass produced planes and regulations are necessary enablers for the attitudes becoming more positive towards flying.

So what I am complaining about attitudes? Consider this: I was one day few years ago in cafeteria of the Malmi airport. There was a some mother with her child there. The little boy said that he wants to drive airplanes. The little boy spoke out the truth of what he wants. His mother then replied that “No, you can’t fly planes, they are so expensive that only richest of the rich people can afford that and these planes are just fancy toys for yuppies”. I was sorry to hear that. The no-way-you-can-fly attitude seems to be brainwashed to children at young age and their dreams are severed “ah that was the thing I can’t do, so I don’t consider about it”. This must change, personal and air taxi -like flying needs to become common practice to get from point A to point B. Not something that is for only rich people, but something that is for everyone.

No densely packed people in huge planes like in cattle car. No queues in security checks. No limitations on liquids, take as much Coca Cola you like. And you just pack your gear to the plane and make departure and arrive shortly after to your destination. No flight planning, you just drive the plane and all your plan is almost automatic. No radio communications with air traffic control unless you are in trouble for some reason. It would all be automatic that computer would do for you.

Personal and air taxi style travel can augment or even replace domestic travel and also part of the travel to neighboring countries in Europe. Busses and trains are still needed despite there are personal cars and taxis, but this what I described above is the breakthrough that needs to happen. It does not happen by itself. It does not happen by government (FAA, CAA, LAA etc.) making it readily available for you. No it does not happen without lots of work. It requires you. When I was little child, I was thinking that “what kind of technology there is in year 2010″. Later I realized that no, the technology is not given, it has to be done by people like you and me. Nothing is given, someone is always needed to invent, plan, design and implement it. Breakthroughs can be made by thinking out of the box and not just improving the envelope of the old. You can help by doing your part on that.

Thanks for reading and happy rest of the week.

Therefore I am proposing now this series hybrid idea to flying wing instead. It would also save the long drive shafts and the associated problems which are in the Northrop early designs there.

The engine that drives the generator could reside in CG inside the wing and the electrical drive which is light could be distributed in the trailing edge to several motors and propellers.

This way also it would be possible to get lower disc loading for the same power for high altitude flight by distributing the power to several propellers which would be distributed in the trailing edge. This would work as alternative for using large propellers as these many props would move as much air as the two large props which would make the landing gear unbearably tall. These smaller props could also be inside the wake getting drag reduction benefit from the Goldschmied wake propeller idea but in a bit different form. These props would be easier to manufacture because of the lower power per prop and also smaller diameter for aeroelasticity considerations and it would also enable optimizing the prop planform to reynolds number on the rotation speed meaning very drastic taper ratio (very pointy blades with thick roots, and high curvature).

Interesting case example for poor power to weight ratio flying wing is Northrop N1M. 120 hp takeoff power for 1750 kg plane. That is enormously low power figure. The plane was upgraded later to a bit higher power, but it flew with that power, indicating that it would be realistic to design a rather heavy plane as a flying wing without needing to ending up using enormously big engines.

So these are now:
Tier 1: Conventional simplicity: Low drag low power low cost twin. Small wing but high aspect ratio. Compromise: Medium power to weight ratio required. Concept usable for personal aviation.
Potential outcomes: RC-models, UAVs, Private aircraft.
Budget: Shoe-string

Tier 2: Flying wing: Suitable for diesel power, series hybrid and other non-optimal power/weight ratio powerplants. Large wing. Compromise: Poor power to weight ratio is ok.
Potential outcome: Plane with long range and diesel economy. UAV applications possible.
Budget: Shoe-string, external funding possibly needed for the large craft

Tier 3: Ladder: Large aspect ratio, climb machine. Compromise: High power to weight ratio beneficial, has impact in fuel consumption. Interference drag from multi-fuselage configuration.
Budget: External funding required. Implementation requires substantial investments in infrastructure and machinery.

Tier 4: Scissor wing delta: Aircraft that are optimized for speed and altitude.
Budget: Requires substantial investments.

Tier 5: Will happen only if tier 1-4 succeed. Idea not announced. Not all of these will be guaranteed to produce real flying aircraft, these are just categorization for a family of concepts.

I was trying to figure out how to connect button click to C++. Here is very short how (sorry for bad formatting due to this html which does not like code):
main.cpp:

For this I had these includes:
#include
#include
#include
#include
#include
#include “qmlapplicationviewer.h”
#include

Then continued with my program specific includes
…

int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QmlApplicationViewer viewer;
qmlRegisterType (“MetarClasses”,1,0,”Metar”);
viewer.setOrientation(QmlApplicationViewer::LockPortrait);
viewer.setMainQmlFile(QLatin1String(“qml/PilotHelper/main.qml”));
viewer.show();
Metar met;

return app.exec();
}

metar.h (from my unfinished application):

#include
#include

class Metar : public QObject {
Q_OBJECT
public:

explicit Metar(QObject *parent = 0);
~Metar();
QString readMetar(QString location);

public slots:

void replyFinishedSlot(QNetworkReply *reply);
void retrieveMetarClickedSlot();

private:
QNetworkAccessManager* nam;

};

metar.cpp:

implements clicked function

void Metar::retrieveMetarClickedSlot(){

qDebug () << "Click" << "\n";
QString myreply = readMetar(“EFHF”);
qDebug () << "METAR=" << myreply << "\n";

}

Then QML:

Imports:

import Qt 4.7
import QtQuick 1.0
import MetarClasses 1.0

Then button that sends click to the metar class:
Metar
{
id: met

}

Button
{
anchors.centerIn: parent
height: 50; width: 400
text: “Retrieve metar”
onClicked:(met.retrieveMetarClickedSlot())
}

(The button is custom button not defined in this snipplet, use your own button or button from meego (follow Kate Alhola’s Forum Nokia blog’s instructions how to do that).

Turnigy CA120-70 Brushless Outrunner (100cc eq)

With two of these a small single seater would fly quite easily.

Cafefoundation: Pipistrel hybrid

Looks pretty much like aerodynamically quite much cleaned up Diamond DA40 with some features somewhat resembling Nemesis NXT racer (e.g. the wing geometry) although with higher aspect ratio. I am confident that Pipistrel will succeed with this project and will show how the general aviation planes of tomorrow can be both efficient and fast and will not require many hundreds of horse power to be fast. I think this is one of the most interesting ones of the new production aircraft coming in sometime in the future.

The blog post says it is not a parallel hybrid, would that indicate then that it would be a series hybrid. It will be very interesting to see what will come up from this project. I will write more about it when I find more details.

UPDATE: Noticed from Cafefoundation page the bottom note; (Editor’s Note: Pipistrel will roll out the airplane in the new year, and will not allow disclosure of more than what has been shared here until then.) – this may mean that we don’t hear more about this aircraft before 2012.

UPDATE 2: The new year referred on the previous post was written 2010, so if we are lucky, we will see roll out of the craft this year 2011 then. Lets wait and see. I am sure it will have specifications that will make some jaws dropping. Will be very interesting.

http://www.dragonplate.com/default.asp

Ready-made carbon sheets (could be used as bulkheads and wing ribs)
Pultruded carbon rods
Connection parts for the pultruded carbon rods.

With the connection parts available for example from this company, one could build a new kind of tube-fabric airplane or facet mobile, just glue some rods and sheets together and you are done. No welding required and end result will be stronger and lighter! It could be possible also build wing spar/internal wing structure like on the sky lifts from the rods and connection parts. It could be interesting how much longer wings could be achieved by optimized rod structure (and it could lead to higher aspect ratio for the same weight without aileron reversal and flutter problems).

I bumped into this manufacturer about which somebody flying a Ford engine was very happy about. So I decided to share the link if that interests you any.

http://www.alternate-airpower.com/

Not sure if the price-what you get ratio is anywhere one could call affordable (7500 per unit) taking in account that this is a chain drive unit rather than a sophisticated reduction gear. However, reportedly this works. And the web page says at the moment “PSRUs are temporarily unavailable “. Maybe this is temporary I hope.

First I tried using ffmpeg and it failed – apparently it only converted keyframes successfully and the frames between them were gray with only the changing part of the frame visible (and obviously it looked really bad). Then after that I tried using mplayer. It was more successful.

This line converted my movie into png sequence
mplayer MVI_2894.MOV -ao NULL -vo png

There are still problems:
- voodoo takes in tga sequence and now I have a png sequence
- there is a gamma problem, this video has different gamma than the image sequence that results – the image sequence has too high contrast.

I will try to continue with this quest but decided to type this short mention that what seems to be a good way to extract the image sequence out of the H264 HDSLR video.

Here is an interesting article about a guy that made a prop that was 90 percent efficient by not abiding the “old truths” but thinking out of the box:

http://www.eaa.org/experimenter/articles/2009-02_elippse.asp

Having a strong taper certainly makes sense since the propeller tip travels very much faster than the root through the air. Also the old saying that single blade prop is most efficient does not make sense if you think it in detail: the air that enters in the next blade is not the same air that went through the previous blade because of the forward movement of the aircraft. This could be extrapolated in a such way, that the faster the aircraft travels, the more blades the propeller can have without sacrificing the propeller efficiency. This should not actually require very high mathematics, but I am quite sure that it could be estimated with simple calculations where the downwash of the previous blade goes in relation to the next blade on the speed range intended for the aircraft being designed.

High altitude propeller will require some additional thinking for the tip chord because the Reynolds number will become low if the chord is this short. The TAS is much higher at high altitude, therefore the air travels faster through the prop, that would mean that the prop could have more blades. The high altitude propeller does not require full efficiency at low altitude because to be able to operate at high altitude, there needs to be a lots of excess thrust available regardless.

Example:
altitude = 20000 m
velocity = 80 m/s
wing chord = 0.8 m (80 cm)
=>
Re = 396331.94
M = 0.2711

Therefore it is beneficial that the airfoil used in this kind of aircraft is such that provides maximum L/D at low Re, here around 400000.

Here are some simulations:

Then some airfoils that I created:
http://www.katix.org/karoliina/airfoils/KS414.dat
http://www.katix.org/karoliina/airfoils/KS415%2014.3.dat
http://www.katix.org/karoliina/airfoils/KS416%2014.20.dat

KS416:

More simulation at low Re, two conditions: 80 m/s at 600000 ft and 111 m/s (400 km/h) at 60000 ft:

Added case 154 m/2 (300 kts) at 60000 ft:

Of these, the KS415 exhibits the lowest drag. Here is the geometry of the KS415:

Here is a smoothed version of KS415/14.3:
http://www.katix.org/karoliina/airfoils/KS415_14_3sm.dat

And simulation for a Reynolds number range:

So consider this (high excess power) case hypothetically:
- Airplane with high aspect ratio (low span loading) with high power engines with high power to weight ratio. Example: Chevrolet LS9 (600 hp).
- If the plane can maintain level flight with minimal power. 35000 ft we have remaining power 0.2 * 600 = 120 hp.
- Diamond flies nicely with 120 hp, actually 90 hp is quite sufficient for it for normal cruise speed. With lower span loading much less should keep the plane level.

So now the naysay would be “nah, LS9 can not sustain 600 hp continuous without breaking”. However, 120 hp is hardly 600 hp continuous even if the engine is at full throttle and giving all it can at the altitude. It is still stressed only for the 20 percent power.

Same engine, with single stage turbocharger, it should be possible to extend this quite a bit further. With two stage turbocharger even higher altitude should be possible, 70000 ft might be feasible given that the other challenges that come with the altitude are solved somehow.

So you could have a 1200 hp airplane with 240 hp used at altitude for cruise (in case of twin). This should give a quite generous cruise speed at the altitude given that the props are big enough (disc loading low enough).

KS400 wing at altitude 20 km, speed = 155 kts

Here is the dat-file. Download it here: KS400.dat

Works from Re 500 000 up.

More simulations to follow later.

These first two do not feature any presentations or presenters, devices (like the Lenovo idea pad which I did not receive myself btw), they are just trying to illustrate the location and few attendants. The latter one has myself also for a short moment visible.

First one (not color corrected, no music, clips just joined together):
Raw footage from Aviva Stadium

Second one (color corrected, with music):
Aviva Stadium (with Music)

If you were there, I hope you like the imagery I captured and it will help keeping the first MeeGo Conference in your memories.

I may publish some of the videos later on Vimeo but because I am not plus member, I can’t upload there more than one video per week, therefore these first ones are coming via Youtube (worse quality), sorry about it.

End titles

In addition to the Rob Papen blue, Apple loops and some other drum samples were used.

DISCLAIMER: This track contains very heavy bass and is therefore best reproduced with audio system capable of reproducing the deepest notes. I have set high pass to 20 Hz, therefore it should not break a good subwoofer, but less capable sub can bottom with this track when played loud. I recommend playing this loud because this is the point. If your sub breaks, get a better one next time!

When we got our youngest cat, a somali cat, it was sold with requirement of doing some offspring with the cat. However, maybe luckily, it was found out that the cat had a white spot in the fur. Nothing special, in fact it looks cute, but for the cat breeders it seemed to look most revolting error that the cat can have. Well I started wondering that “What are these people talking about?”. True love for a cat is unconditional love because the cat is my friend, not because it is perfect for some cat competition and perfect representation of the custom designed cat race and family.

So I am glad my little cat is out of the competition and cat production plant things and is just my committed friend. Every day waiting me to come home and every day talking to me, sleeping on top of me on the bed during nights (I fall asleep to the cat purring), and sharing life with me. They are my little children sort of.

So this is how this cat ended up on us and how he is my friend. Next I will write about how to raise a cat properly, and especially about what to not do. Many people do critical errors on raising a cat because they don’t understand them. You have to be able to talk with them and understand their talk and feelings and you both need to adore each other (you need to become a mother cat), then you can raise them properly. So stay tuned, more to come.

So how this applies to e.g. Microsoft article that was mentioned in my Facebook: Praising the importance of some old technology that has been around and everybody has used for long long time is the Vorlon thinking “status quo”. Has been like this and will be like this forever. However, this is not how it works out. It is instead “What do you want?”. So “Who are you?” “What do you want?”. The truth is out there.

After one evening of doing things with varying success (in some places syntax is a bit weird and it required some patience to get over it) for one evening and I got a simple button and a dialpad with buttons implemented. Well it is not very usable dialpad, it even does not have 0 or any other buttons that might be necessary on it. Actually I was thinking of doing a calculator and that’s why I collected the buttons like this. I did not try it on N900 yet, but started trying it out on desktop because it is the fastest way to learn this new thing. After getting into it it started to feel pretty nice and many of the difficulties I immediately faced in the beginning were RTFM errors. Good idea is to read some documentation about it before swearing too many curse words – after all it is not bad at all. I got some help from Kate Alhola who is a guru with the QML already and it saved my time a little bit.

Here is what I did: I downloaded latest Qt SDK 4.7.0 to my Mac. I also installed it on my Linux laptop, but this example I created in the evening on Mac. I created empty QML project with Qt Creator. I added the following files to the project.

qmlwiz.qml (this is going to be my main, renders here a numeric keypad)
SimpleButton.qml (this contains the button code)

Unfortunately Blogger strips down all indents and the code looks a bit ugly, but I hope you can still read it somewhat. At least this is quite short reducing the chance of confusion.

SimpleButton.qml:

qmlwiz.qml:

Text {
text: "Karoliina's Magic Keypad"
}
}
}


To run the application, there is a button with green triangle on near to the bottom of the left hand side toolbar on the Qt Creator. When the main program file is selected on the file list and this button is pressed, the program is run from Main.

I looked the documentation further and discovered that there is also a repeater functionality which can be used to build e.g. the dialpad or calcpad shown above without repeating the SimpleButton instantiations manually for each number.

There is plenty of room to make this nicer, actually I like a lot a such button that is composited from two layers: basic layer illustrates the button itself. Then a translucent highlight layer is composited on top of the button when press down occurs. When mouse button release occurs, the composited top layer is faded away with alpha channel ramp. I may try that next, but I did not have time to do the graphics for the highlight yet (as it looks the best when it is made with e.g. Inkscape and not attempted computationally). I may try that later. Now I wanted to finish something before going to sleep.

Bottom line is that QML is very nice and super easy. With short time it is possible to learn to do some quite nice things already. I rotated the scene a bit because I like how the menus on Colin McRae: Dirt are rotated. Actually with QML it is very easy to make similar dynamic animated rotation so that the scene slightly turns by itself on time back and forth. To do that, I was thinking using the NumberAnimation. I may try that after doing the composited button which I think is even cooler. Then I need to also hook these to C++ application to do the calculation logic on the C++ side. Kate has a nice AR-Drone control app doing this exactly already, so I need to look her code to see how to do it. Quick look reveals that it is very easy. I need to try maybe tomorrow if I have time.

iPad provides control input (which direction one wants to go) and the computer inside the AR-drone provides artificial stability (so it is very easy to fly unlike RC-helicopters).

I have been thinking this a lot. So later I realized that it does not work like that. Future is not something that is given. It does not come by itself. What we predict for the future today will not happen if somebody does not do those things. You see we don’t have all the wonders of science fiction of the past predicted at hand now except for the very fancy telephones – in fact much nicer superphones than even Star Trek ever predicted. But that is only one thing. We can have so much more and we need to have much more than this.

So who is this somebody who will fabricate the future? Some special person that will do all the work for you? No. That special person don’t exist. You and me are responsible of fabricating the future.

So if you think that year 2020 we will have this and that, because it is already 2020, stop. Think again. It will only happen if you do it. We all are fabricators of the reality and the future. Every little thing matters. You might think “this has been always done like this and I am required to do it like this”. Stop this and think how you could do it better or how you could invent something that gets it done for you. Think out of the box and do not think that you can’t make it because it is impossible. Nothing is impossible. You can do it if you want. One step at a time and you will get results. Try to make a change.

Every little drop forms an ocean and this is the only way to make dreams come true. And what the dreams are? These form new drops in the ocean which grows on each cycle bigger and bigger. And this is how breakthroughs happen. And these are very important for the future of you and me and the human kind.

So on next Monday when you go to work. Think how you could improve things. Tell what you would like to be done better. And do it yourself. Continue one task at a time until it is done. You can do it. I can do it. We can all do it. And the revolution begins. The future will happen because you created it, we created it. It is not given, but achieved. We all are the instruments of the future, we fabricate it.

So what are the breakthroughs needed for this? I doubt that the internal combustion engines can do this ever very well and turbines are out of question as well because nobody can afford flying to shop with turbine power. So I think this will require electric motors and advanced battery technology. Hybrid design could possibly work too.

Large helicopter propeller blades will become a problem when landing on congested place and it would cause also safety issues. You could hit something with the rotating prop and newspapers would be full of horrific accidents very soon. Someone sliced somebody or sliced somebody’s house or whatever. The props should be shrouded for safety of general public. Then how many props? One prop and it will require tail and tail rotor. Not so nice. Coaxial rotors, that would be better but still will require one to be helicopter pilot. I think the case of how it would work is very simple, and the case example already exists in small scale as sort of “RC copter”:
http://ardrone.parrot.com/parrot-ar-drone/usa/

So computer controlled fly by wire and the user would be just selecting to go forward or backward or up or down or to rotate. Computer handles the rest. Each prop would have electric motors, big ones instead of the small ones found from the little thing. This plane could even have small wings, which could be optimized for cruise only (and not for landing at all) and could be possibly pivoting – when airspeed increases less vertical thrust would be needed. This could be “the flying car” that everybody can control. Not everybody can become a helicopter pilot or even airplane pilot – requirements are all the time becoming more and more and less and less will ever succeed to become pilots (from those who dared to start the training), but anybody that can drive a car, can select up, down, turn left, turn right, go forward, go backwards. This thing could be done so that all “flying cars” would have a data link to other “flying cars” nearby. The computer could automatically avoid collisions without the need of centralized air traffic control at all. Actually air traffic control is a system that can not scale to the level of cars are used on the roads, no matter what. The only way to manage the huge amount of traffic is to not have centralized control at all, but the control would need to be between the aircraft and it would need to be automatic data link, not this antiquated AM radio we are using to call ATC. I think it would be reasonable to make the system such that there could be as many flying cars in the air than there are cars on the ground now. Traffic congestions could be easily avoided because there is lots of space in the vertical plane in the air (when we forget about airspace altitudes and minimum altitudes etc.).

The four rotor configuration would also solve the problem of placing ballistic parachute. It could be directly at the CG and it could be even made automatic, if something fails, parachute would be pulled right away.

So what would be needed:
- lightweight electric motors with high power (already possible with today’s technology)
- fly by wire system (already possible with today’s technology)
- data link to other aircraft (would be already possible with today’s technology)
- combustion engine to charge batteries (already possible with today’s technology)
- high capacity light weight batteries (this might require next generation batteries to have good enough usefulness)

For these to be good for mass market, the following points must be considered:
- it must not require pilot’s license
- it must not require medical of any kind
- it must not be over-regulated, otherwise it will never gain any popularity
- it needs to be very much automatic and very easy
- there must not be super-restrictive regulation where one can land and take off, the usefulness of this concept depends on possibility take off and land from and to everywhere, it would make no sense to take off from airport and to land to airport
- it would not replace airplane, instead one could fly with this kind of machine to airport to get far away with the airplane, I don’t see that this kind of design could be made ultra long range and super fast.
- it is unavoidable that this design actually requires more space still than a car, quite large diameter props needs to be used for efficiency. However, each of them would be more reasonable size compared to one helicopter rotor and less expensive to manufacture. Also four rotors provide more thrust and lower disc loading than a single rotor.

Then how these could be manufactured?
- For mass market I think they should be pressed with 3d molds from aluminium with monococue type construction like cars are made of steel. This should be feasible with today’s technology because Piaggio P-180 Avanti is manufactured from this type of aluminium construction.
- There could be no rivets and there could be no hand layup in anywhere in the structure to make the price down
- The price of high capacity batteries must drop to get the price down
- the electric motors are inexpensive to manufacture in great volumes

So I don’t believe in Möller’s design as such (combustion engines driving ducted fans), but this slightly different version (with helicopter like but shrouded rotors) could possibly be feasible. And these could be made aesthetically to look very stylish unlike helicopters, and they could have bigger mass market appeal also because of that.

One reader proposed either push-pull hybrid where one engine would be diesel and the other would be electric motor. There was another possibility also considered, with coaxial propellers the same thing. This is a valid point and would work. There are some challenges on it therefore here is some cons I considered and hereby listed for this setup:

I may post this as a separate article also because otherwise it possibly does not get read by that many:

This is reply to a commenter for the earlier article:
There is a little incompatibility here that I don’t see how to overcome:
- the diesel engine operates at medium rpm which requires reduction drive
- the electric motor can designed to be direct drive and low rpm without need for reduction unit

Having series hybrid there is weight penalty of two brushless DC motors and the engine and the battery, but no other systems. The engine runs the brushless DC motor without reduction gear and the motor that is used as generator can be designed to operate at the rpm the engine operates. The other motor which drives the prop can be made to operate at low rpm.
-> this sytem has NO:
- weight penalty of reduction gear unit
- reliability penalty of reduction gear unit
- need for propeller clutch and the associated reliability penalty and weight penalty
- need for drive shaft to achieve aerodynamic cowling shape

You already listed the most of the pros for the diesel direct drive. I list the cons:
The diesel direct drive cons:
- would not work without clutch, the power pulses would make the prop come off in flight if it did not fail on ground testing already
- does not get necessary power to weight ratio from the engine because of the need to run it at low rpm because of the prop requires low rpm
- weight penalty of the additional gear reduction unit
- reliability penalty of the additional gear reduction unit
- weight penalty of the clutch
- reliability penalty of the clutch (in Thielert engines they have failed now and then, especially in the original design, the latest engine models might have addressed this issue but I am not sure)
- added complexity
- aerodynamic cowling shape may require drive shaft, and reliable drive shaft has been proven to be hard to design and manufacture such way that it would be 100% reliable
- the diesel engine is harder for the prop than a electric motor because of power pulses (even with clutch) and more expensive propeller is needed than would be needed with the electric motor alone.

There is however a case what has not been talked about for your case:
- planetary gear system for driving the electric motor and the diesel engine at the same time – Toyota Prius hybrid synergy drive thing. That is about bullet proof and single point of failure will not stop the prop, one motor is enough to continue driving the prop.
- This of course has associated weight penalty. On Toyota Prius it does not matter, but on aircraft it does matter.

Case for push-pull:
- To avoid drive shaft, the diesel engine would need to be the front engine.
- case for achieving any kind of laminar flow to the fuselage would be pretty much lost
- inefficiency problems on the rear prop because of the front prop. I have not quantified this on the other hand, apparently nobody is able to answer how much is the penalty, it is not even exact in literature.

http://www.protonet.org/doc/

Go to get them, good stuff.

The style is this time a bit like Vangelis.

We had an opportunity to play live at Nokia Summer Party. I had earlier composed this song for our internal team building event, but then I went and asked from Eastway if we could fit our band to the schedule. So this is it, engineers from Meego playing live! It was fun. Jani Mikkonen made on-topic nice lyrics on it. It was fun for us! I hope you will enjoy it. I play the Nord Modular, Jani Mikkonen is singing and Peter Vajda is on bass. The rest of the band is myself on the last few weeks at my home studio, playing the tracks in the Logic Pro one by one. The final part has very many tracks and voices at one time, sad that it is hard to hear from this recording. We will put a proper hifi quality soundtrack later online separately.

Here is the vid. Enjoy the summer:

Meego Band Live on Vimeo: http://www.vimeo.com/12807797

Yes jou meegou!

I played live yesterday. Here is a video of it. I played the Nord Modular live.

VIMEO: Karoliina and Meegoband playing Meegosong

Because universe may be a much more complicated than you or me can see or understand or comprehend. Even 100 years of advanced technology might be indistinguishable from magic. Think of a civilization that would be 1000 000 years ahead of humans. Then when you think that (don’t think captain Kirk, that is not 1000 000 years ahead of us I hope), how could you tell the difference between a god and this kind of being? I am sure you couldn’t.

You could compare yourself to ant. Ants would believe that everything they know and see is the universe that exists. However, they can not comprehend beings like humans for sure. But still we humans exist.

And what it comes to the topic, death:
- each cell dies because it has programmed to die
- different animals have different lifespans, because they have different genetic code, not because they would be worse designs that are worn out faster – think what if you could change the genetic code? Dying becomes obsolete.
- I can already also predict one another thing: humans will have life span of at least 1000 years before humans are capable of any kind of interstellar travel. Forget captain Kirk that dies under age of 100 years. The real captain Kirk could be 900 years old or more. And in fact, it would not be out of the question even that the real captain Kirk would live in a computer and the biologic bodies would have been long time abandoned already as obsolete, or it could be that the beings are combinations of technology and biology (cyborgs).

There can be many levels of existence and everything is relative and biased by the eye of the beholder and with the very limited knowledge, it is impossible to draw sure conclusions, and with more information, already done conclusions are usually refined and corrected. You never can play only one horse, because there are many horses, and the likelihood that you play the wrong horse is higher than when you would not be conclusive about which horse to play. I find being agnostic the only way to be without religious belief. Because just a belief that something simply does not exist is a belief already, and it is not scientific.

This just works for me, please do not follow if you are not willing to take the responsibility of potentially ruining your paint:
0. Do not use base paint or raw epoxy method, you don’t need to fill pinholes, just forget about pinholes with this method! In other words, you can directly apply like this on top of smooth sanded dry micro or automotive polyester filler!
1. Apply thick layer of Teknodur 2 component polyurethane paint (e.g. white) on top of the composite structure. Any other similar polyurethane paint works too (I have also tested with Hempel 2-component boat polyurethane paint). Base paint is not necessary, the Teknodur takes on a bare epoxy surface which is sanded to dull (be sure it is sanded to dull, if it is not, then it will not take, but peels off). Do not use solvent to make the paint thinner, the thick property is desirable. The thick paint blocks the pinholes on the surface below.
2. Let it cure and then inspect. Look, 1 layer of paint and no pinholes! There may be runs, but you can get rid of the runs easily!
3. Wet sand the surface smooth. Use quite coarse grit at this point.
4. Add second layer of Teknodur paint. You can use a bit solvent now, and you will get no pinholes. Try to avoid runs more carefully at this time.
5. Wet sand to completely smooth finish.
Use all available wet sand paper grits up to 2000 if you can find 2000 grit. 1200 grit is fine though.
6. Use polishing compounds to finish the surface to high gloss.
7. Add vax and polish.

A little bit tedious with all the wet sanding, but on the other hand: full control over pinholes, no base needed, and most sanding goes to the paint without harming the critical glass/carbon fabric under it.

I am just in middle of painting a little composite part this way and I have noticed that it works. Before you ruin any large parts by using a method where the paint is misused and done differently than all painters will teach you, please try it to some scrap part first. I have finished two scrap parts like this and they have been in the snow and ice the whole winter without any harm done to the paint surface, so I would guess that this sanding method does not ruin the paint.

I am not sure, but it could be that:
- You would be even better off if you first apply a very thin layer of paint that enters the pinholes. Sand dull. Then don’t care about the pinholes, just add the thick layer of paint on top of the thin layer.

On the base and on the first layer, the sanding result does not need to be smoother than 240 grit. Anything more than that is waste of time because the thick paint rounds the minor irregularities.

Pros:
- Polyurethane paint is easy to sand, very very very very easy compared to sanding epoxy
- Runs on polyurethane paint is no big deal, just sand them off in a minute and you are done!
- Quick to finish
- The thick paint is very weather resistant and is as smooth as you sand it

Cons:
- The layer of paint becomes pretty thick and it is heavy, and in some cases might be undesirable.

Auto conversions most often fail, no surprise, because of the reduction gear or belt. The core engine is not the root cause in the problems and many problems with the reduction belt or gear system can not be seen beforehand because the dynamics of the vibrations of the engine, propeller and their inertia forces affecting each other is a bit more complicated than one could think at first – it is not that simple to make these parts to last for hundreds or thousands of hours.

So we came up (with Kate, we usually talk with Kate about these things and we kind of invent these things together, I usually happen to be the one who writes them down – and it is usually so that Kate is the opponent into which I test my idea’s feasibility before I write it here) with the idea of having a auto engine, possibly a diesel engine, running at constant power, most likely exactly at the optimum point of the engine, always. Then all the power variation would come from the electric motors which would drive the propellers. The idea is that the diesel engine only runs a generator.

The downside of this idea is the additional weight from the generator, batteries, motor controllers, electric motors and the props (depending how many electric motors are used, it is also possible to use just one if that is preferred). However, there are two several things possibly good about this:

- First the diesel engine burns less fuel, resulting smaller fuel tanks.
- Secondly the gearbox system is saved. The gearbox system can be very heavy duty in a high power aircraft engine and they still have tendency to fail. Possibly something like 40-50 kg is saved straight away.
- Thirdly the aerodynamic advantage – optimal aerodynamic shape without using long extension shafts and couplings to deal with the dynamics of the rotating shaft connected to a non-optimally rotating propeller and the power pulses of the diesel engine. Now there is the chance to put the engine anywhere in the airframe where it best fits and propeller drive don’t need to be considered at all.

Then there is the redundancy thing. Brushless DC electric motors usually never fail, but the prop can still fail in bad circumstances. Therefore having two independent props for the one diesel engine could be advantageous. Same thing with the batteries – if the diesel engine fails, the batteries could be sized such that the aircraft can fly without the diesel engine for example for 30 minutes in level flight. That might be enough in most cases to get safely on the ground, except on middle of an ocean. The most likely place for the engine to fail is the takeoff. This takeoff stress would never happen with this engine configuration – the engine would be run always at optimum and safe power, never on takeoff power. The extra power for the takeoff can be easily taken from the batteries if they have proper capacity and the electric motors are powerful enough. On takeoff the batteries at full power are not discharging that quickly, because the diesel engine is recharging the batteries at the same time. The takeoff power can be rarely used for longer than 5 minutes on an aircraft equipped with Lycoming engine either, so having a limited period of time for the full power is not that big problem.

Generator and electric motor can have very high efficiency, and the gap to a efficiency of a reduction belt system is not that great. Best electric motors (though heavy ones) are around 98% efficient.

On descent the diesel engine could be shut down providing there was enough battery capacity. The motors could actually regenerate also batteries when the pilot wants to decelerate the plane.

Maintenance cost would be like a single engine aircraft, but the reliability geared towards a twin. Of course there is the one little fine print: the battery pack is expensive and it has an expiration time and date, unfortunately. But nothing is perfect and without compromises.

Any comments about this idea? This surely would not be a racer as the power to weight ratio would be rather poor, but anyhow I am thinking, providing it would be efficient enough to climb adequately, this would be a quite economical thing to fly and also easy conversion-wise, almost stock auto engine would be okay, no reduction gear and prop installation and an assembly that takes the push or pulling loads, would be needed. Also waiting on the airport would not waste any energy, since props can be completely stopped when the plane does not need to move. For example Lycoming IO-360 consumes about the same amount of gasoline per hour when waiting on IFR clearance on the ground than our Toyota Prius car on highway. Consuming zero amount of fuel when still on the ground, but still being ready, would save some liters.

And answer to the question, why diesel and not gasoline when gasoline engines can be run very lean and quite great specific fuel consumption values can be achieved in optimal conditions – it is quite simple: availability of the 100LL/Avgas seems to be becoming poor. There has been three 100LL operators in Finland, but two of them decided to discontinue this year. There is only one left. When that only one decides that it is not profitable enough, there is no 100LL available for anybody and the whole country’s fleet of Lycoming and Continental based planes are grounded. The Jet-A1 is not going anywhere, so engine that can burn the jet fuel would be a safe bet. Jet engine, turboprop, or turbofan are out of the question because those are not available in meaningful sizes and power classes – there is not a small turbofan that would have high pressure ratio and bypass ratio available, nobody manufactures such a thing. And it is unlikely anybody will in the future because this personal flying all is a very niche market unfortunately until it changes for better (if it ever does).

The implementation possibilities have challenges; namely no such electric motor available (would require custom motors possibly), etc. And the weight also causes penalty for the efficiency and speed of the plane. But the power to weight ratio will be with this arrangement a lot better than on a pure electric aircraft. And pure electric aircraft is feasible, why an electric aircraft with a generator and a fueltank added would not be.

And by the way, even if it is first of April at the time of writing this, this blog post is not an April fool.

I find the trimaran configuration quite interesting – several different engine placement configurations for example can be used with this configuration without changing the aerodynamic shape of the concept very much. It is also interesting because it allows placement of the main gear away from the center fuselage and thus provides greater stability on the ground when the aspect ratio is high even if there is fuel placed to the wings very far away from the center of gravity. And as can be seen the same design suits several different missions: Global Flyer is very much like White Knight 2 with SpaceShipTwo under it on the center. Almost the same configuration, adapted to different kind of mission for very different kind of parameters (Global Flyer = long range cruise, White Knight 2 = optimized for climb).

Global flyer drawing Google found from some site
Wikipedia has another great photo, this is from front

The configuration is not really so new and not so unproven either, as people might expect, here is one example where a similar configuration has been used a long time ago:
Northrop Widow
The only difference here is that the Northrop Widow was optimized for different mission than either of the abovementioned and that it had piston engines in front of the outer “fuselages” which were interconnected from the tail section similarly than in Adam A500 whereas the Global Flyer and White Knight Two have two separate tails. It is quite apparent why the tails are separate in these aircraft – because the outer fuselages are placed so widely apart from each other, connecting the tails would have made the tail unnecessarily large which would have caused negative effect for the drag despite it would have had fewer intersections. On the other hand, I have been looking different HALE concepts, and it is quite apparent that the number of intersections is not the major drag source in high altitude aircraft, but the induced drag is, and to minimize induced drag, more intersections can be allowed as the penalty from them is lesser than limiting the aspect ratio would be. This is why there are even some concepts considered at the moment which have wing struts – even if everybody knows that they produce drag, in some concepts, the significance of that drag can be proportionally small whereas the increased aspect ratio has major effect on minimizing the total drag of the aircraft. HALE aircraft have to be quite different than those which are designed to cruise at low altitude, the drag percentages of each contributors are quite different and “one size does not fit all”.

It is quite interesting area to explore when the structural efficiency is added to the equation in addition to the aerodynamics and the result is a compromise on both structures and aerodynamics instead of being optimized for either aerodynamics or for structures. The mission parameters tend to heavily affect both and best suited results can be achieved by combining these two and by knowing the intended use exactly, potentially bigger gains can be realized than in a concept that is a general purpose in everything (GA = GENERAL aviation).

But luckily yesterday I realized that Austin had added a link on top of the page. Small link on top of the web designer blob and that goes directly into an interesting page. Now today there are two links (as there is 9.50 beta for X-plane available too), but this one was particularly interesting in the topic of this blog: The Laminar Research X-1 Cavallo is conceived

So this is just my home-brewn theory style thinking, is based on collected information and my experience with flying the Diamond DA40, DA42 and Cirrus SR20 and SR22. I might be wrong as always, but here is some food of thought if you have been thinking why there is this airfoil with high L/D at high Cl and the airfoil also has fairly high pitching moment which some find undesirable because of for example trim drag.

Easy to use SMS and Messaging API to Maemo 5

Coding native applications can be tricky for newbie developers, but the possibilities are vast compared to running just for example javascript on top of some runtime or some proprietary environment with proprietary closed APIs.

What helps nowadays more in Maemo is the Qt, it makes the development of native applications a magnitude easier and more efficient. Instead of tinkering a lot with the user interface, now you can build one even with Qt Creator / Qt Designer.

Qt for Maemo 5, that Antonio Aloisio and Kate Alhola among others made it possible with their long work of hildonizing Qt, is now available as beta now from the Qt-labs. This technology luckily became officially supported from the roots of community supported port and hopefully this will get now even greater audience than before and attract more Maemo developers and prospective Maemo developers than before.

While Gtk is available and Maemo 5 applications have been done with Gtk, I would recommend to use Qt in the new future projects. PeterMaemo is saying that Qt is “forward-compatible technology on Maemo for years to come…”, I want to believe in that because the most wise thing to do is now stick with Qt for years to come to have best possible backwards compatibility for UI applications.

Recently there have been interesting development on native iPhone apps which utilize the power of the CPU (which would not be possible with some runtime without the CPU of the device being a supercomputer), like X-plane flight simulator, a controller for RC aircraft that streams video to the device and uses augmented reality to make a game on top of the cake, Voice Band where one can sing notes in a sequencer which translates them to notes and plays back with instruments so one can do convincing sounding compositions on the road without any musical instruments other than one’s voice etc.

I would be eager to see this kind of apps to emerge on Maemo. Maemo 5 has OpenGL ES 2.0 support, Qt, and a native application development environment. I think that is very cool, and one can do really creative and innovative things with it. If somebody will do X-plane quality simulator for N900, I will certainly even willing to pay for it. Same goes for Voice Band, I would eager to use it when I am not front of my iMac which is stationary in the corner of our living room – you know, you can’t really control when and how you compose, the ideas just pop in the head by itself in uncontrolled manner and they are gone (at least happens in my case) if they are not right away utilized. And I would like also augmented reality apps for the Maemo. Maemo has great camera and it is the most open phone out there, so I would think it would be the ideal place to hack this kind of things. And what’s more, there is even TV-out on the Nokia N900, I was thinking that one could connect data glasses to the TV out potentially and the image from camera and some computation could be used as augmented reality – not just in someday in the future, but right now today on Maemo 5! If you have some great idea, now it is a good time for pursuing it. Just remember to use Qt as UI toolkit and it has a good chance to survive also the future incarnations of the platform (you may need to do modifications to places where you use the lower layer, but if you do it wisely and in portable manner, you might not be so unlucky with future generation of Maemo and the Maemo devices).

A long time ago I was doing a loudspeaker box design program with Qt (actually that was before I even joined Maemo). The project unfortunately almost died. However, Kate found one day a backup from one hard drive and she uploaded the code to our home gforge. Luckily it worked out of the box with Qt 4.5.x on Today’s Ubuntu and possibly will also work with Qt 4.6. And luckily enough, the UI was actually designed with Qt-designer, so basically it is easily replaceable, and I can possibly produce a Maemo-version. Loudspeaker box design program may be niche, but since the current availability of them for other platforms than Windows is poor, it could be possibly cool to make this application a reality. It currently calculates correctly just closed box and the vented box calculation is broken. I will look if I can make it work with the vented boxes as well and then it could become somewhat useful compared to otherwise nothing available. It will not have all the features of e.g. WinISD initially, but it is cross platform and will run on Mac, Linux and Maemo, so that should be something. The cool thing about Qt is that you don’t need any high level language that would potentially cripple the features and performance to achieve cross platform compatibility (the calculation algorithm takes some time even on desktop machine, so it would be possibly too heavy for some Java app or similar). I think I will give it a try because it turned out that I will need this little software myself right now, so do it yourself is the best help yourself. It will be free GPL software.

I hope many people get inspired with the vast possibilities of the great Maemo platform and start making really cool things that utilize the CPU and GPU of Maemo device fully. Anybody can for example write a simple calculator app with some high level language, or maybe like somebody wrote the silly “I am rich -app” for iPhone, even entirely on QML, but when there are dozens of little calculator apps and silly apps which have no usefulness after 1 minutes of trying, it starts to be no point to be yet another on the sea of many. My recommendation: find something that does not already exist, get yourself an inspiration, aim for superhigh quality, and just go for it! Maemo is cool, but it is even cooler with your app, and your audience will love your creation!