Hi there ! I am trying to build my own quadcopter from A to Z. I mean I will build everything myself except for the engines. So far, by using newton laws, I got these equations : (notice : I am totally neglecting air drag but not sure if that right at quad speed range). By plugging these equations into an arduino, we could control each engine force (Fe) , then converting that force into required RPM ?? 1. reach a vertical speed : Fe = m/4((v-v0)/t) + g) m: quad mass v : actual speed v0 : velocity to reach t : time to reach v0 2. Hover Fe = 1/4 * (m . g) g : gravity 3. Displacement Fe = 0.25 * (m/sin(O)) *((v-v0)/t + g) where O = tan-1(( ((v-v0)/t) + g) / ((v-vs)/t2 + g) ) v : actual speed v0 : vertical velocity to reach vs : speed to reach t : time to reach v0 t2 : time to reach vs O : angle of tilt I have the following questions : Is these equations right ? Could I control engines without ESC ? Should I neglect air drag ? How to convert Fe to RPM based on engine and props specs ? thanks for reading and replying.
Welcome - but you are definitely in the wrong forum (site). This is a site for beginning and intermediate pilots - and mostly for RFT (ready to fly) quadcopters. You will likely do much better at dyidrones.com where you can talk with fellow engineers, etc.
Is these equations right ? I hate math, but the easier answer to your base question is below........its the Ecal website link. If you know the motor / Prop performance, total UAS weight....you can change the formulas to arrive at the answer easier. And as Webman said..... www.dyidrones.com will fill in the blanks. Could I control engines without ESC ? No, ESC is needed to run the brushless motor, but you could make your own that the Arduino could run. Should I neglect air drag ? On a multi-rotor, no use worrying about it, they are flying bricks no matter what. How to convert Fe to RPM based on engine and props specs ? Web site for you............. http://www.ecalc.ch/ Use the multi rotor calculator and it will tell you if the motor / prop you chose will work, and what size (power rating) ESC you need to buy or build for.
