Problem Effective Canadarm Docking with Dragon and other Dragon-Canadarm problem

[PhantomCruiser]

Sis-in-law asked me to proofread one of her papers she was going to turn in for a college class (I think it was English Comp or something, anyway it was years ago). The whole paper was maybe 2.5 pages, all one paragraph with no punctuation. And it was full of chatspeak, grammar and spelling errors. When I handed it back to her she was furious with me, because I'd done exactly what she'd asked. It was (metaphorically speaking) dripping red ink with all the corrections. She didn't speak to me for years, ahh, good times :thumbup:

 

[Nicholas Kang]

Ok, mentor. I don't want to interfere your personal matters. It is normal to face situations like this between family members. Hopefully now your sister-in-law and you had buried the hatchet.

Now, mentor, let's talk about something serious. Have you tried out the Pursuit MFD? Can you show me some tutorials? (Maybe video tutorials? That is the best as I can see what's going on.)

Thanks you, Mentor PhantomCruiser

Regards,

Nicholas.

 

[PhantomCruiser]

Cras explained it pretty well. I'll see if I can maybe put together some kind of a checklist and a scenario for you to practice on.

I learned intercept and rendezvous the old fashioned way, so when PursuitMFD came around, I found I didn't need it so much. But it is a hand tool to have available.

 

[Linguofreak]

boogabooga, I don't understand why you laugh until you roll down your bed and just keep on flipping as if they were no frictional force to stop you down. Is it offensive to address PhantomCruiser as Mentor? He said he didn't want to see the word Mr. So, I regard him as my mentor. Is he still angry with me? It is very dangerous in the forum when the moderator hates you. h:

It's not offensive, it just that "mentor" isn't really used as a title like that in English, and using it as such makes it sound much more formal even than "Mr.". Americans are very, very informal, especially on the Internet, and generally expect you to address then as a peer, not a superior. PhantomCruiser isn't angry with you for using the term "Mr.", it's just that titles generally aren't used in a situation like this, and it sounds sort of silly if they are. In general, on the English-speaking Internet, you can refer to anyone by their username alone without causing offense. And, in general, when speaking to an American, you don't need to use a title if you don't know their surname, and, unless they've introduced themselves or been introduced to you with a title, it's usually not necessary even if you do know their surname (although I generally will refer to someone as "Mr. [Surname]" in written/e-mail correspondence until I've seen them sign their name with just their first name, but even that I think is more formal than many Americans tend to be). Since people on Internet forums generally go by made-up usernames rather than their real names, it is pretty much never necessary to use a title (since titles are only used with surnames, or, occasionally in *very* formal situations, with full names).

 

[boogabooga]

Cultures can be way different on the respect issue.

I had a Korean colleague who needed to send a buisness e-mail to two of our higher-ups. He asked me which one was older. I said that I didn't know their ages. Shocked, he looked at me and said, "well, how do you know which name to put first in the recipient list..."

 

[Nicholas Kang]

Ok, to both Linguofreak and boogabooga,

This all comes to cultural difference. In the eastern culture, pay respect to the elderly is a MUST. It doesn't matter how old you are, as long as someone is older than you, logically, he/she must have gained more life experience than you. So, you should respect them.

This is the same across the east Asia, be it China, Japan and Korea (hence boogabooga's case). I am a chinese, so I inherit my culture from ancient China. We should pay respect to the experienced and the elderly or simply anyone older than us in those days. (Just watch some ancient China movies with English translation, maybe that helps a lot.)

In boogabooga's case, it must be the older recipient's name be written first, followed by the younger one. Think of this, you send a formal letter to a school teacher. Will you simply address the teacher without mentioning the principal? No, you won't. So, address your teacher by mentioning this letter is sent through the principal. This is normal (at least in the East)

Before this, I thought we need to know how old people are in the Internet so that we (especially young people like me) can adjust our tone when replying based on one's age. For example, when talking to boogabooga and PC, I should be more serious.

Now I know Americans are very informal in the Internet. So, the next time I reply PC I will stop addressing him "mentor". Thanks for telling me this, Linguofreak. Actually, I was shocked when boogabooga told me he is over 30 years old.

Also, boogabooga, how things are going? Any ways to show me how to use PursutMFD with (video tutorial?). The manual is really complex. Of course, Linguofreak can help too.

Regards,

Nicholas.

 

[Linguofreak]

In boogabooga's case, it must be the older recipient's name be written first, followed by the younger one. Think of this, you send a formal letter to a school teacher. Will you simply address the teacher without mentioning the principal? No, you won't. So, address your teacher by mentioning this letter is sent through the principal. This is normal (at least in the East)

Actually in America you might offend the teacher by doing that in certain situations (because involving his boss would imply that he didn't know how to do his job), and in some situations the principal might feel you were wasting his time (because nothing in the situation is beyond the teacher's authority to handle, and the teacher is not not doing anything wrong, so why does the principal need to be involved?).

 

[Nicholas Kang]

I think I need to clarify my statement. Actually, for certain letters of course you don't have to mention the principal. For example, you are absent for the school because your family member passes away, so simply include the death certificate and a letter to your teacher stating your reason for not coming to the school-attending funeral, etc.

In the above case, and also in case you are sick (requires medical chit only), you simply address your teacher and that is enough. You need not mention the principal.

However, in formal occasions, like participating in national or international level competitions, you need to mention the school name, the principal and details about your competition. Also, a copy must be sent to the school's extracurricular activities department. Of course, you must mention your teacher's name as well.

Hopefully that clears the doubt and minimizes misunderstanding between us.

Yours sincerely,

Nicholas.

 

[Urwumpe]

Actually in America you might offend the teacher by doing that in certain situations (because involving his boss would imply that he didn't know how to do his job), and in some situations the principal might feel you were wasting his time (because nothing in the situation is beyond the teacher's authority to handle, and the teacher is not not doing anything wrong, so why does the principal need to be involved?).

Exactly.

Also, in many cultures it is considered very rude to assign persons honorary titles by yourself. Such titles are understood as acid sarcasm, if they are not granted by the proper institution. It is really resulting as the opposite: Instead of addressing somebody as superior in a hierarchy, you reject any superiority.

It is the same with calling somebody master/Meister here. It is a title of achievement, recognized by peers - without achievement (a masterpiece), addressing somebody as master is highly informal language, which typically means that somebody is no master at all.

Also about intercultural competence... we once had an epic failure when dealing with surprising visitors from China. We had 15 minutes to prepare and got incorrectly briefed about the roles and seniority of the persons, which we did not realize until a few days after the visit and after days wondering what we had been doing wrong. Was a tough lesson for us. No, most Chinese will not help you then and correct your misunderstanding. :lol:

 

[boogabooga]

Okay Nicholas. Finally, here is your Pursuit MFD station keeping tutorial. See the attachment.

Actually, I was shocked when boogabooga told me he is over 30 years old.

Why is that? Do I come across as immature or something... :shifty:

Regarding the age respect thing, what I would add is that there is a huge difference here between age and seniority. For example, I had many teachers that were much older than the principal. People's ages aren't really common knowledge here. There is almost always a better way to differentiate between seniority levels than age, which is why my Korean colleague's question was weird.

 

[Nicholas Kang]

You see, I have thanked so many people's post, but no one cared about mine. Do I come across as idiotic or something ... :shifty: (Joking)

For Urwumpe,

I was just about to address you Master Urwumpe (since you don't like to be my mentor), then I stopped abruptly after seeing your post. Thank you for informing me before you hate me forever.

Regarding your treatment towards the Chinese visitors, are they mean to you? Did they show unhappiness written all over their faces? How did you know you had addressed them incorrectly? Who told you you had made a mistake? Where did those Chinese come from? China? or Immigrants like me, a Chinese from Malaysia, and those from Singapore, etc. (Sorry, lots of questions that require you to answer.)

To boogabooga,

Thanks a lot. Now, I have succeeded in holding the Dragon at a fixed distance from the Canadarm. But there is a problem with the docking orientation. (Any other members an help too)

See here:

Dragon failed to be grappled by the Canadarm due to angle problem.




Here is a close-up view of the angle difference.



Then, I rotate the " grapple head" of the Canadarm and the angle slowly decreases until about a little more than 11 degrees.



Another view of the angle.



Why can this happen? The two situations just look the same and it is hard to notice unless one rotates the "grapple head." This is quite a waste of time, although it is challenging and thus more precise. In real life, I believe Dragon shouldn't wait until the "grapple head" rotates to match Dragon's grapple point. How is this error avoided then?

Also, boogabooga. You don't look childish but I thought you are young because your user name "boogabooga" suggests that this member must be a young boy fond of rockets. Now, I learn a lesson. Don't judge a book by its cover. Sorry, boogabooga.

To both boogabooga and Urwumpe and also other members like PC,

I have a question regarding Pursuit MFD. boogabooga has done a quick and short PDF tutorial that is accurate and pretty straightforward. Special thanks to boogabooga for his effort. I notice there are other buttons apart from the mentioned like APD, DIS etc.

I am particularly interested in the button HLD. It sound like HOLD. What is the difference between HLD and APD. Aren't they both the same autopilot function? In fact, in my early trials of using this PursuitMFD, I used to engage both HLD and APD at the same time. I suspect this is the reason my Dragon kept on spinning wildly.

Another problem concerns with the Maths problem. In boogabooga's PDF, I noticed the Pythagorean Theorem formula. I am familiar with that. Just right below this formula there is a description of inputting numbers for X- Y- and Z- frame position. boogabooga mentioned:

"So, Z: 100 will change to Z: 10 once you enter."

I don't understand this sentence. Z-value was still the same as I entered when I tried Pursuit MFD. That is, I entered 10 for Z position (after pressing DIS) and the value 10 was displayed on the screen. I didn't have to enter 100 in DIS to get the value 10 displayed. Anything wrong, boogabooga?

Yours sincerely,

Nicholas.

 

[Urwumpe]

I was just about to address you Master Urwumpe (since you don't like to be my mentor), then I stopped abruptly after seeing your post. Thank you for informing me before you hate me forever.

I thank you for your respect. :thumbup:

---------- Post added at 11:09 AM ---------- Previous post was at 10:44 AM ----------

Regarding your treatment towards the Chinese visitors, are they mean to you? Did they show unhappiness written all over their faces? How did you know you had addressed them incorrectly? Who told you you had made a mistake? Where did those Chinese come from? China? or Immigrants like me, a Chinese from Malaysia, and those from Singapore, etc. (Sorry, lots of questions that require you to answer.)

Coarsely Shanghai, and no, just a very reserved conversation and no further contact after we mailed a short brochure with the available post-processing operations to them as they had requested. Pretty unusual for somebody initially interested in getting a localized and possibly customized version of our software suite. We did not even get a message about them changing their mind, just plain silence.

Can hardly tell you about further sociological details.

 

[4throck]

About age, this year I went back to University to take some computer science classes.
Well, I'm 39 and that made me 20 years older than most students there. And yes, older that some teachers.
The treatment between students was always first name based, with the teachers being called "Teacher". So it's hierarchical rather than age based and it seems to work well.

 

[Buck Rogers]

I think one can receive being addressed as mentor as friendly sarcastic humor (this is not an invitation though!)
... and I was sure that Mr Phantom Cruiser is a real name!??
anyway...
I use PursuitMFD on a daily basis; can't get home without it! (tm)
So if I may assist:

HLD: HOLD rotational attitude autopilot.
APD: sounds like approach & dock? not quite sure why it's there but it seems it won't dock without it, so activate on final.
Dist: are for your translation offsets, you must type "Z50" for a 50m offset on your Z axis (which hopefully is your docking approach axis!). These are controlled by your TrimAll autopilot, but you can disengage individual control channels, which I appreciate very much!
You must then set Z to 0 to dock ...capture and hard dock.
Great for semi- automatic approaches to Station V!

 

[boogabooga]

I am particularly interested in the button HLD. It sound like HOLD. What is the difference between HLD and APD. Aren't they both the same autopilot function? In fact, in my early trials of using this PursuitMFD, I used to engage both HLD and APD at the same time. I suspect this is the reason my Dragon kept on spinning wildly.

HLD (Hold) sets your attitude to point parallel to the target docking port, but it will not control your translation. So you can drift around at will.

TRA (Trim All) will do vice versa: you will station keep at the coordinate you've chose, but you can rotate around freely.

APD sets both TRA and HLD together. I suspect that what happened is that you pressed APD, then HLD, which would turn off the HLD attitude control function. Thus, you spun wildly.

In case you are wondering: it is possible to engage HLD and TRA together without pressing APD. Then you will not see red "DOCK" text. However, I have not noticed any difference in functionality between HLD + TRA and APD. There may be some difference, but I do not know what it is.

Another problem concerns with the Maths problem. In boogabooga's PDF, I noticed the Pythagorean Theorem formula. I am familiar with that. Just right below this formula there is a description of inputting numbers for X- Y- and Z- frame position. boogabooga mentioned:

"So, Z: 100 will change to Z: 10 once you enter."

I don't understand this sentence. Z-value was still the same as I entered when I tried Pursuit MFD. That is, I entered 10 for Z position (after pressing DIS) and the value 10 was displayed on the screen. I didn't have to enter 100 in DIS to get the value 10 displayed. Anything wrong, boogabooga?

I didn't explain well.

Er, just small point that whatever coordinates you select with DIS will display on the screen after you press the enter button.

So in the example screenshot, the target coordinate for some reason started at 0 0 100. You hit DIS and then 0 0 10. Hit enter button. Then the MFD display will update to display the target coordinate as 0 0 10.

 

[Donamy]

You see, I have thanked so many people's post, but no one cared about mine. Do I come across as idiotic or something ... :shifty: (Joking)

For Urwumpe,

I was just about to address you Master Urwumpe (since you don't like to be my mentor), then I stopped abruptly after seeing your post. Thank you for informing me before you hate me forever.

Regarding your treatment towards the Chinese visitors, are they mean to you? Did they show unhappiness written all over their faces? How did you know you had addressed them incorrectly? Who told you you had made a mistake? Where did those Chinese come from? China? or Immigrants like me, a Chinese from Malaysia, and those from Singapore, etc. (Sorry, lots of questions that require you to answer.)

To boogabooga,

Thanks a lot. Now, I have succeeded in holding the Dragon at a fixed distance from the Canadarm. But there is a problem with the docking orientation. (Any other members an help too)

See here:

Dragon failed to be grappled by the Canadarm due to angle problem.




Here is a close-up view of the angle difference.



Then, I rotate the " grapple head" of the Canadarm and the angle slowly decreases until about a little more than 11 degrees.



Another view of the angle.



Why can this happen? The two situations just look the same and it is hard to notice unless one rotates the "grapple head." This is quite a waste of time, although it is challenging and thus more precise. In real life, I believe Dragon shouldn't wait until the "grapple head" rotates to match Dragon's grapple point. How is this error avoided then?

Also, boogabooga. You don't look childish but I thought you are young because your user name "boogabooga" suggests that this member must be a young boy fond of rockets. Now, I learn a lesson. Don't judge a book by its cover. Sorry, boogabooga.

To both boogabooga and Urwumpe and also other members like PC,

I have a question regarding Pursuit MFD. boogabooga has done a quick and short PDF tutorial that is accurate and pretty straightforward. Special thanks to boogabooga for his effort. I notice there are other buttons apart from the mentioned like APD, DIS etc.

I am particularly interested in the button HLD. It sound like HOLD. What is the difference between HLD and APD. Aren't they both the same autopilot function? In fact, in my early trials of using this PursuitMFD, I used to engage both HLD and APD at the same time. I suspect this is the reason my Dragon kept on spinning wildly.

Another problem concerns with the Maths problem. In boogabooga's PDF, I noticed the Pythagorean Theorem formula. I am familiar with that. Just right below this formula there is a description of inputting numbers for X- Y- and Z- frame position. boogabooga mentioned:

"So, Z: 100 will change to Z: 10 once you enter."

I don't understand this sentence. Z-value was still the same as I entered when I tried Pursuit MFD. That is, I entered 10 for Z position (after pressing DIS) and the value 10 was displayed on the screen. I didn't have to enter 100 in DIS to get the value 10 displayed. Anything wrong, boogabooga?

Yours sincerely,

Nicholas.

What does the view look like from the EE camera?

 

[Nicholas Kang]

Well, thanks to all of you. I am actually enjoying my 2-week holiday now. The first week is about to over. (It starts from last Saturday.) This is going to be my last post now. I need to focus on my study from now on. I am sorry but you know that a student's job is to gain knowledge and study, basically, although I do learn from great masters from this forum.

Thanks for clarifying boogabooga.

Do you want me to call you master or you would prefer Mr. , Buck Rogers?

To Donamy,

I am sorry because I didn't quicksave the view of Dragon. I was using the CRS6 mission scenario "Dragon appraoching ISS" of Dragon.dll (I think it is your add-on or maybe BrianJ's, I cannot remember.) Once I stared the scenario I quickly changed my focus view to Dragon and select PursuitMFD and did what boogabooga wrote in his PDF manual. I apologizes, Donamy but I couldn't help.

Actually, I don't really have time now. I need to focus on my government exam in 4 months time, and the syllabus is not even completed. (both taught by my teacher and revised by myself.) I also need to focus on the Singapore ASEAN scholarship test in about a week time. My piano exam is next Wednesday.

So, you see, I am very busy this Holiday. One week for orbiter, the second week for other jobs. I think this is more than enough.

I try to spend some time in this forum if I am free. The maths and science carnival is held in late June or early July, but with boogabooga's Pursuit MFD, everything is fine. So, Donamy, I think trial and error for the case you mentioned is a partial solution, although not a complete solution. Just keep on rotating the "grapple head" until the error is within an acceptable range (maybe like the 11.5 degree you see in the screenshots is ok.)


I shall see you again, in worst case scenario, between 3-6 months later.

Thanks to all and Bye!

 

[boogabooga]

Good luck!