Improved Control Engineering of Rocket Guidance

Kuto

Hello,
I really enjoy Cosmoteer so far, and find that the Crew AI is really well written.
However I found the Guidance of the guided Missiles extremly frustrating, because they always miss their Targets, but as my background is control engineering in the aerospace industry, I know that this can be fixed easily with a simple algorithm:
In real-life, most missiles use the PN-Guidance law, or a derivative of this guidance algorithm, to guide themselves into their target. Therefore I would like to suggest to you, to implement this extremly simple algorithm in order to make the Missiles go where the player intends them to.

(If you however intend the missiles to have this really wonky behavior, then please ignore my comment. )

Best,
Kuto

TheSillyFox

Kuto
I feel that if missiles always directly hit, it would make the game a bit boring. but I can see what you mean.

jbox1

Kuto

Cosmoteer:

Putting the “miss” in “missiles”

Kuto

No that is actually not the case. PN-Guidance neglects accelerations of the ship. Additionally, the missile itself can only turn with a certain rate and overshoot etc. These effects introduce errors, which result in the missile not always hitting at the intentioned spot (actually real missiles suffer the exact same sources of error...).

But I am really tired of the missiles "hunting" behind the ship if two ships are not on a direct confrontation course.

Walt

I'll look into this, thanks!

Added to trello: https://trello.com/c/Yg5SmoiW/135-improve-missile-guidance

Kuto

If you need help in the control engineering side of the missiles behavior, say so, I would be glad to help.

Mc2

I always though that missiles behave like this, to make them bit less OP as they are.

jbox1

Mc2 I agree, adding a PID system to missiles would make them even more so...

But come to think of it, a special type of missile WITH the PID system, but slower reload and firing time WOULD be cool.

simon1954

jbox1 wait, your saying a missile with a PID attached to the missle

jbox1

simon1954 yah!

Kuto

Just to clarify, what I proposed, is not a PID control method (Like PID, LQR or MPC), but rather a Missile guidance method. The difference is that in the former case you try to get the missile to attain a certain parameter (for example point in a certain direction or attain an lateral acceleration etc.) in the latter case you try go generate a setpoint such that the missile hits a target.
The control loop would be formed as follows:
1. The PN-Guidance calculates a setpoint target which the missile should attain (in this case a lateral acceleration)
2. The Controller (For example a PID controller, but a lot of other controllers exist), tries to attain this setpoint by controlling the low-level controls of the missile (fins, gimbal of rocket motor, side-firing RCS etc.)