I'm contemplating a casual 3D modeler app for phones. Here's the rough concept sketch: http://versuspad.com/image/3d-modeler.png
Would you think it is possible to program this, or do the Gyroscope and other approaches just not yield the desired data at all?
(I was not sure whether to post this here at Stackoverflow or at programmers.stackexchange.com, but choose the former for now, hope it's correct.)
hmm... well quite innovative.. I must say.. you should have signed an NDA with all the viewers of your post..!!
coming back to the question, yes it is possible to read accelerometer values they way your app demands but the real thing will be the use that data to generate your desired application's output.
Absolute position is the double integral of acceleration. Double integration amplifies noise and starting velocity errors so much, that any 3D model would get stretched way out of shape very quickly, and look nothing like the gestures in space.
This is totally possible with the iPhone. It would more use the Accelerometers than the Gyro, but do-able.
Coding it will be very difficult - but it is possible.
Just search around on Google and Stack Overflow and you might find a few useful ways how to use it. E.g. for gyro and accelerometer
Related
according to sensiya(http://www.sensiya.com/) their SDK can detect motions like walking running sitting driving etc.
I guess acceleration data can be used for classifier to detect run and walk.
But sitting and driving are quite the same, what else technique they used in order to distinct driving and sitting? does anyone have any insight?
Many thanks
For full disclosure, I am working at Sensiya. Many algorithms that recognize device's user activity rely mainly on the accelerometer sensor data analytics, as you mentioned, but if you want to fine tune and expand the type of activities you want to track I suggest using other device's sensors like proximity, magnetic field etc, or just use our tools ;)
For the specific driving and still recognition technique:
Differentiation of the still and driving states is a tough task. A simple solution will be to recognize that the device is in still state but its gps location changes, although this solution will not be efficient in terms of battery life. Our driving recognition tries to save battery life during this kind of recognition and we succeeded to find a slight difference between device's perfect still state and driving still state in terms of real time data you can collect from the device.
This is a good material to start with:
dialnet.unirioja.es/descarga/articulo/3954593.pdf
Presume I have two+ iPhones connected to the same server.
Using the sensors built in the iPhone and any possible calculations based on their information, is there any way to tell which direction one phone is from another?
They would be in the same room, so the fluctuation of GPS would not work very well here.
I've tried to model two points on a graph using only their compass readings, but I do not think this will work alone. I could be wrong though.
You could setup a calibration phase in your program where you start each phone in an exact position, and then using the 6 axis motion continually calculate the exact current position (in all 6 axis). But the longer you run that calculation the further from true position you will be and eventually (given a long enough time) one phone could think it's in canada and the other in Mexico.
So It could work for short term spurts if you do a calibration every time you want to start.
There is also the possibility of bluetooth localization, but that would require at least 3 phones and the sharing of positional data between them. Or you could do wifi location, but that would require the same as the bluetooth.
Long story short if you want inches localization it's not going to happen. If you want yards localization it's possible, but not as usable.
As you already mentioned, GPS does not work very well when used inside buildings. Thus, it is not possible to get the direction, as you don't have two reliable positions.
Indoor localisation should be much easier with iOS7 and location beacons .. but this does not help much now.
as I am developing for iPhone, I've just bought an iPhone 4 to test my application which needs to measure the coordinates of my location. I don't have any Internet (3GS, GPRS or whatever...) on my iPhone and the problem is:
1) Without internet I get a 1744m horizontal accuracy, and that's very bad. (I've also tested the accuracy in other applications too, and it is always as bad or worse)
2) With WiFi-Internet I get a 80m horizontal accuracy.
Is that normal? What can I do to improve my coordinates-measurement accuracy?
Thanks in advance for any help.
From my experience you need cellular data reception (3G or Edge) to get an accurate location on any iPhone. With that and a clear view of the sky you should be able to get within a few meters of your actual location.
Yes, this is normal. To improve accuracy, you can move somewhere with a clear view of the sky.
First thing I'd advise is make sure you have a clear view of the sky to get a good satellite signal.
I think that it is becoming somewhat "accepted" that the iPhone's GPS accuracy is somewhat lacking (in comparison to other handhelds)... I had to search through my history, but I remembered reading about this very issue on Hacker News - http://news.ycombinator.com/item?id=1526664.
If you don't want to follow the thread, here is the article directly - http://rnr.davidlokshin.com/post/825290568 .
I learned recently that the phone needs to download a batch of coordinate files in order to make any real sense of the GPS data it picks up. So without an internet connection, GPS service is very poor or possibly completely unavailable.
I'd bet your poor accuracy with WiFi is because you were indoors... That's my guess anyway.
Is there any way to simulate CMMotionManager's gyroscope output in the iPhone 4 simulator? CMMotionManager's gyroAvailable seems to indicate that the simulator itself won't do it (which is understandable, given that it doesn't simulate acceleration data either), but I figured someone may have written a simple simulator drop-in for testing a project.
The new phone's are in short supply in my city so far and it would be nice to give things a reasonable work out in the meantime!
This is a pretty old post, but may give you a starting point:
http://ifiddling.blogspot.com/2009/01/dummy2.html
i want to track how fast my iPhone is moved.
i checked the AceelerometerGraph Example App, where the maximum Amount was about 2.0 (in this app)
i want to know how exactly i can track the speed of my moving iphone. in this example app the maximum amount is reached very fast. Is there a way to get better results ?
Sry for my bad english :( Comment me if you dont know exactly what i mean
I don't know what your question is. The subject doesn't really fit the rest of your "question". It is impossible to detect speed with an accelerometer. You can only measure acceleration. I heard the maximum acceleration that can be detected with the iPhone's accelerometer is approximately 2.5g, but I'm not sure.
Yeah, it's about 2.5G... Unfortunate, I really wanted to build the iphone version of E39. Oh well.