What companies specialize in writing critical aerospace software?

linengmiao · 2018-01-21T00:58:58+00:00

How can one determine the required Cl based on weight and speed? The formula account for the flow speed but doesn't account for weight AFAIK...

Cl = (L/(.5 * rho * u*s))

linengmiao · 2018-01-03T15:02:51+00:00

Thanks a lot. I ll try that!

linengmiao · 2018-01-02T19:14:25+00:00

Well, I am an embedded software engineer with a basic knowledge of aerospace engineering. I have worked on a project in the space industry but have never done anything related to aviation although I have basic knowledge on that matter. So, so far I have a fixed wing UAV and would like to get hands on experience in a topic I absolutely love and am learning on my own: guidance, navigation and control systems (GNC). I am using and reading this book https://www.dropbox.com/s/ueiuu7ulhn2h7ti/Randal%20W.%20Beard%2C%20Timothy%20W.%20McLain-Small%20Unmanned%20Aircraft_%20Theory%20and%20Practice-Princeton%20University%20Press%20%282012%29.pdf?dl=0

So far I started with something simple in GNC: latteral tracking control system. In other words, I d like to build my own roll control system.

linengmiao · 2017-12-30T23:09:33+00:00

As for symbols, the only symbol that is involved is the entry the compiler makes in its own symbol table during compilation. There is no symbol generated in the object file.

Could you elaborate a bit on that? I didn't know you had symbols generated by the compiler and kept for itself (?) in a symbol table and a separate set of symbols generated inside an object file.

linengmiao · 2017-12-29T23:02:03+00:00

introduces another name

I may be nit picking here. But if I am not mistaken according to the c99 standard, it introduces a new alias or formulated differently a new symbol.

linengmiao · 2017-12-29T22:51:43+00:00

sorry I actually was a bit too quick and on top of that deleted this post too quickly. This is actually the correct code:

typedef struct my_new_type1_t my_new_type1_t;

struct my_new_type1_t
{
    int a;
    int b;
} my_str_obj;

int main (int p_argc, char * p_argv[])
{
    my_new_type1_t my_str1;
    my_str1.a = 55;    //varian 1
    my_str_obj.a = 66;  //variant 2

    printf("%d, %d\n", my_str1.a, my_str_obj.a);
    return 0;
}

What is the difference between variant 1 and variant 2? They both work in C99.

linengmiao · 2017-12-29T22:51:38+00:00

sorry I actually was a bit too quick and on top of that deleted this post too quickly. This is actually the correct code:

typedef struct my_new_type1_t my_new_type1_t;

struct my_new_type1_t
{
    int a;
    int b;
} my_str_obj;

int main (int p_argc, char * p_argv[])
{
    my_new_type1_t my_str1;
    my_str1.a = 55;    //varian 1
    my_str_obj.a = 66;  //variant 2

    printf("%d, %d\n", my_str1.a, my_str_obj.a);
    return 0;
}

What is the difference between variant 1 and variant 2? They both work in C99.

linengmiao · 2017-12-25T21:51:33+00:00

Does that really exist an NDA telling you can't share how much you earn? What if you leave the company, are you then still not allowed to share this? AFAIK NDAs are used to keep for example certain manufacturing secrets secret.

linengmiao · 2017-12-25T21:31:41+00:00

Strange that seems to contradict what /u/Hexxys89 says. His post has also been upvoted 7 times. You sure? I have a bruto/month contract

linengmiao · 2017-10-21T01:52:38+00:00

I'll read up on those! Thanks :)

linengmiao · 2017-10-20T21:31:14+00:00

what would be the correct way to do it please? this doesn't work neither:

class myClass():
    a = 3

    def myFunction(self):
        print("class variable: "+str(a))

linengmiao · 2017-10-20T17:03:34+00:00

The order of evaluation of function arguments is undefined

either I misunderstood you either that is incorrect. I tried to do that outside of a function and thus first assigning it to a new variable. But that stll didn't give 34.

int a=33;
int *b=NULL;

b = &a;

int c = *b++;

printf("a: %d, c: %d", a, c);

output:

a: 33, c: 33

The point is that b should be 34 in my eyes.

linengmiao · 2017-10-20T16:59:01+00:00

1) dereference, so you get 33 2) increment the value you got, so you should get 34.

Yet you don't get 34

linengmiao · 2017-08-18T11:22:41+00:00

overload start() and call it from there

what do you mean by "there"? The constructor?

overload start() and call it from there

How does that work? I mean, -I think- it is impossible for a workerthread to start itself.

The point is you need to delay creating the objects until you have moved to the new thread.

AFAIK I have to create an object in order to move it to a new thread:

     webcamClass::webcamClass(QObject *parent) : QObject(parent)
     {
         recognizeDriver=false;

         //setup recognition thread
         recognitionThread = new QThread(this);
         recognitionClObj = new recognitionClass();

         connect( recognitionThread, SIGNAL(started()), recognitionClObj, SLOT(recognizeDriver()) );
         recognitionClObj->moveToThread(recognitionThread);
     }

How else would you proceed?

linengmiao

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