Firing Solution MVP Rundown
Slydev's picture
Posted on:
Sunday, May 19, 2019 - 21:46

This is a proposed firing solution for torpedos for our MVP. Being an MVP it is a much more simplified version that what the final will be. The primary aim of the MVP is for us to see how it performs in the hunter killer simulations and gather data on user interaction with the system. A lot of the numbers of the system have not been decided left and will be left out of this while they are tweaked. This post is less about the math and more about the method.

For now firing is design to happen at Impulse speed.

Firing can be split in to 4 phases:

  • Launch
  • Guidance
  • Wire break (active)
  • Impact
     

Launch Phase

A torpedo needs a tracked MDAR target to launch. Once one is picked a launch can be made. For the MVP only launches from the torpedo tubes at the front of the vessel can be used, as the torpedo will be guided by wire for a period of time it is suggested to have endeavour facing the target for maximum effectiveness.

The first number to be calculated on launch will be the speed of the torpedo. This will be based off two numbers:
- Speed of the vessel towards the vector of the firing line at the time of launch (so if we are moving backwards it will be negative, forwards positive)
- Power of the launch rail at the time (this will most likely be a fixed number for the MVP)
For now the power will just make a direct speed multiplier, but post MVP we have to account for the rail becoming less powerful the faster endeavour is going (read: throwing a baseball while going near the speed of light)

Since the rail speed is consistent (for now) the speed of the torpedo will be:
Endeavours forward speed + Our decided rail firing speed (We will be tweaking this so no point deciding on a number yet)

Guidance Phase

Once launched the torpedo will be guided towards the target via the ‘wire’. As the torpedo itself has very limited EMDAR range (not to mention once its EMDAR goes active it gives off a signal) it will need to be sent target position updates from the wire. While in this phase the torpedo will alter always head towards the target.

Active Phase (Wire break)

When the torpedo leaves the cone of the wire it is considered a ‘wire break’ at that point it will enter its 3rd phase. The wire can only break in three ways:
- The vessel turns and the torpedo is no longer in the cone
- The torpedo vector towards the target makes it leave the cone
- The torpedo has reached the maximum wire length (the number is TBD)

For this reason it is suggested to be facing the target you want to fire at for maximum effectiveness.

Once the wire is broken the torpedo will make a calculation to work out where it’s final destination is. This is going to be working out where the target will be in when the torpedo will reach it based off its current vector and speed.

This picture is a simplified idea for this, a proper formula will be worked out based off both speeds to work out and where to aim for.

Note: For vessels trying to avoid being hit this is a crucial moment! This is the best time to change vector and speed to try to be in a different position as the torpedo when it gets close.
 

Impact Phase

Once the torpedo reaches a close radius towards the target the last phase is calculated. At this point the torpedo’s onboard EMDAR turns on and it will give off a signal, it now will home towards its target.

As its target we will start the last phase of the whole system where it will calculate if the torpedo can hit or not.

To do this we will need to take a few things into account:
- Torpedos entry vector into the radius for this phase
- The targets position and size

We will have to calculate how much the torpedo will have to move to impact the ship, if it is not able to turn this much it will miss. The faster the torpedo is going the less it can turn here.

Note: this phase can sometimes not happen if the torpedo never gets into radius of the ship.

On a hit we will calculate damage, still up in the air how we will do this for the MVP. Down the track we want to calculate where it will hit and what systems that will take out. At the very least we will be calculating the simple F = MA with most likely a simple HP for each ship for our hunter killer MVP. (or even a one hit one life).

Conclusion

This should setup the basic framework for a firing solution for our MVP and hunter killer simulations. From this we will gather some data and learn a lot more about what works and what does not. I am putting this here first before making an LIAS article so that I can get some feedback, there might be some very obvious things I have missed and I would like to catch them now before I start to do some formulas to get this to all work. I welcome any feedback anyone may have but do keep in mind this is and MVP, we want to keep it as simple as possible while also getting the fundimentals of firing across in the simulation. I hope this all makes sense and look forward to some feedback :)

comments

Comments

NeerajA's picture

Interesting! So you're expecting a middle phase between wire-guided and active, where the torpedo is effectively guided by the last known course and speed of the target? Presumably post-MVP you could select from search-pattern options that the torp would follow in this phase? The option could be selected in anticipation of the target's likely behaviour.

For MVP how detailed do we expect to get about the location, scale and type of damage at the target? Or is it more just whether or not there's a "hit"? 

The system currently has the ability to return which vessel plane is facing (ie port/staboard, aft/forward, dorsal/ventral) depending on your vector and bearing and the target's heading, so you could make basic system-damage calculations based on that. For example if the torp hit the forward/port/dorsal planeyou would know which systems are located under that plane and select one or more for damage?

Slydev's picture

Matt can give more of an insight on this part, but the torpedos onboard EMDAR is not good enough to work at a large radius without the wire so they are blindly trying to reach a destination. Having to select a profile for the targets likely movements is interesting but I guess it all comes down to the radius we choose for the torpedos EMDAR to kick in, if it is a large enough range the target would have to move quite interestingly to avoid the torpedo (not to mention it wont be able to detect it till its EMDAR kicks in). I really feel we will need more data on this to decide the best way forward and will be tweaking these values a lot.

For MVP damage we want it to be as simple as possible as we want to get hunter killer up and see if the whole system needs to be changed/scrapped/modified. The less depth we get into the easier it will be to change when we get more data on how users interact with it all. The first phase of this system is going to quite boringly be 1 hit = 1 life, after that we will look at building a damage layer for the ships and then a systems damage layer around the last phase using what you described.

There are a lot of things I would love to do but in the interest of a true MVP we should keep it all as simple as possible I think for now.

mattm's picture

To clarify, the overall "MVP" is ready to go - that includes impulse navigation (to fly the ship) and EMDAR (to locate other ships) so that we can do hunt/kill sims. Under this current capability, the sim ends when the first team acheives an EMDAR track on their opponent.

The torpedo capability will be added to this in due course, so that the sims will end when a team fires a torpedo and scores a hit. In keeping with the agile approach we're taking, the torpedo capbility will be it's own MVP - as Slydev sates, it will be pretty simple to start with. We'll then keep adding capability to it to make the sims more and more realistic.

NeerajA's picture

I can see there'd be some significant tactical decisions to be made around launch speed, when to cut the wire, etc