Search the Community

Hi, I've made a quadcopter and found I cannot control it. If I attach rotors to yaw/pitch/roll and thrust I am able control thrust but yaw/pitch/roll override each other so only one is effective. Thrust works because it's incremental while yaw/pitch/roll are absolute. At first I wanted do demand multiple overlapping controls to work additively (and they should) but then I realized that won't be enough. The collective throttle must lift the craft while axes control should only modify torque to control its movement and may work much weaker. So the torque for single engine could be calculated by a formula T=(1 - 3k)t + ky + kp +kr, where T is torque, t is throttle, and y, p, r are yaw pitch and roll, respectively. k is axes to throttle coefficient, let it be 0.1, for example. Now, this cannot be done. So I think the formula controller should be available for our creations. Of course this will be usable not only in quadcopters. Why not control ailerons in function od speed? In supersonic flight they are too strong while in low speed maneuvering they could work stronger. We could also describe by formulas hinges' movements as a function of time or the controller's value (then a controller's path could be a variable, not necessarily bound to a part).

I have had KSP for the PS4 a total of 4 days now, and it's complexity and intricacy exceeds what I prepared for. I am happy in this, but mortified as well. I have started a science save file, and have only researched 4 additional groups including: basic rocketry, engineering 101, general rocketry, and survivability. With the new parts acquired from researching these groups I built a simple, 3 stage ship, and have decided to try to achieve LKO. To do so efficiently, I delved into the KSP wikis and forums to find the relevant information. I understand to a certain point the rocket equation, or the "*dudes name I can't spell*'s equation". Anyways, I found the ISP of the rockets used in each stage, and I wasn't going for complete accuracy at first, using the ATM ISP for every equation done. Then, I found the total mass of each individual stage, as well as the dry mass of the stages by themselves. In order to do so I had to take the first to stages off, and measure the total and dry masses for the last stage, then add the second stage and subtract the total mass of both stages my the total mass of the last stage to get the total mass of the second stage. Then I proceeded to do so with the first stage attached as well. I found both total and dry this way for the first and second stages. Now that I have the ISP, M_FULL, and M_EMPTY, I figured I could calculate and add the answers together to find my overall delta-v, granted I SHOULD have more than I calculate based on the idea that my ISP for each equation will be the atmospheric ISP. My work: (weights are rounded) Stage 1 (final stage): pod, fuel tank, and 'reliant' thruster. - Dv = 265 * 9.8 * In (4/3) = 747 Stage 2 (second stage): 2 fuel tanks and 'reliant' thruster. - Dv = 265 * 9.8 * In (3.5/1.5) = 2,200 Stage 3 (first stage) 2 BACC thrusters, and 1 'hammer' thruster, with added radiator panels. Dv = 520 * 9.8 * In (19.5/4.5) = 7,472 I am now realizing that each stage must also push the weight of the stages above them, meaning I must carry the mass of those stages into that equation, adding to the total and dry mass of the stage being figured. If this is not so and I have created a false solution, please let me know, thank you.

Hi, everyone! I have a nasty problem to solve. Half by physics, half by math. And hope UE4 can help me with that too. I have an object in the space. We know the center of its mass (C). There also a lot of engines/thrusters. We know where are they placed (P1...Pn) and in which direction they turned (D1...Dn). Each engine has maximum thrust (0...Ti). All those values we know. Tasks are: 1) We should be able to move (strafe) the object in the space by custom normalized vector (V) with custom thrust power (0 <= T <= 1). 2) We should be able to turn the object on the place centered on (C) with custom thrust power (0 <= T <= 1). 3) Of course, there are situations, where it's impossible. If so -> T = 0. Any thoughts or formulas?

I was wondering if someone figured out a formula that would predict fuel consumption in a flight around the world. I already have the required numbers needed (0.30/s fuel, ~200/ms, Altitude of 2,000 m). Is there any available formula or technique for finding the required fuel?

How to measure the efficiency of a gravity turn To make my gravity turn challenge a bit more interesting the scores will be given as percentage scores. I have seen percentage scores used in game reviews, school tests and what not - so it must be a cool score measure right? I post the score description to this separate post in case anyone wants to discuss and/or refine the idea. Gravity turn efficiency score Imagine that we can send our vessel to orbit by doing two short powerful explosion-like burns. First a burn that will shoot us all the way to space, a burn of strength "v" (for vertical) say. Then, just above Kerbin's atmosphere our positive vertical speed runs out, and we do another burn to quickly accelerate to orbital speed, a burn of strength "h" (for horizontal) say. I imagine this 'burn model' as depicted in this (first) figure. Now imagine another way to send the vessel to orbit. Maybe we don't need to shoot the vessel all the way to space with the first burn. Instead we only clear the thicker part of the atmosphere with the first burn, and then we angle the second burn to take care of both the needed "h" (horizontal component) burn and the missing part of the "v" (vertical component) burn. I imagine that this improved 'burn model' looks like this (second) figure. The idea of the score is to make a guess for how much total burn strength it would take to first burn and fly vertical and then burn and fly horizontal. We could call this our worst case budget. Once we know how much burn we actually used in total in some instance, we expect to see that we did better than our worst case budget. Compare the actual total burn (i.e. fuel used) with the burn from the second figure to assess if the saving is large (i.e. a large alpha) or small (i.e. an alpha just barely above zero). Interpretation of alpha We pick some "worst case budget" as a reference and can then assign an alpha to the actual total burn that we record. The interpretation is that a negative alpha value means we used more fuel than our "worst case budget". We should, in theory, avoid this, as it implies we could save fuel simply by flying straight up and then accelerate along the horizon. In practice though, we might fly an inefficient path for non-fuel related reasons. An alpha of around zero percent means that our fuel usage turned out to match our "worst case budget". An alpha of 100 % is interpreted as the theoretically ideal composite of the vertical and horizontal burns. If the gravity turn efficiency is even better than that, then alpha rises to above 100 %; maybe that is achievable for space planes - time will tell. Technically alpha, as calculated by the formula below, can surpass infinity, but that requires a ridiculously cheap launch trajectory to orbit. Formula Label the actual burn strength total as "t", and the vertical and horizontal components of the worst case budget as "v" and "h" respectively. Assuming that "t" is larger than "v", alpha is equal to (h^2-(t-v)^2)/(2*v*(t-v)) . The Kerbal 1-5 case [edit: for KSP version 1.2.1] Let us take a "Kerbal 1-5" budget as an example. I have uploaded a KSP version 1.2.1 budget, that may be used to score the entries in this challenge. Budget and scoring spreadsheet The budgeted vertical and horizontal components are 2239 and 2220 m/s of vacuum delta-V. The delta-V potential of the stock configured Kerbal 1-5 is 4398 m/s, assuming the main throttle is kept closed until the boosters are done. The budget indicates that, if you fly straight up to 70 km before turning, then the rocket cannot make it to orbit. Notice that in practice, even if launching vertically, we probably want to turn the rocket towards the horizon before we reach 70 km, so the budget is really for a quite hypothetical worst case scenario. The threshold for an alpha-score of 100 percent is to get to LKO (70 km) using only 3153 m/s of delta-V. To me that goal seems unattainable. On the other hand, perhaps 3153 m/s is not an unreasonable indication of the upper bound for the gravity turn efficiency of the stock Kerbal 1-5. By the way, the reason the spreadsheet says "NO SCORE" is because the challenge is for an 80 km orbit, so 70 km is too low.

Currently reworking the 3D graphical calculator. Check back soon!