"Hi Hugues, here's some info on FOC, with comparision to block commutation (method that is used on almost all ESC's): link.
It has benefits, one of which is that you can precisely position the rotor :), and with today's microcontrollers and advanced…"
"Hi Marc, commercialized maybe someday in the future, but I don't know if there is a market for over-the-top ESC's with 300A MOSFETs :). Communication right now is RS485 with dynamixel ver.2 protocol. There is CANBUS hardware on the board and uC has…"
A while ago I posted about ESC I was making with FOC motor control.Now it was time to mount it on something. In the video propellers are 7 inch plastic, I decided that it is too dangerous to have three 15 inch CF props spinning in confined space…
"It's the same configuration, except that I am using these motors for propulsion and these servos for tilting. Unfortunately electronics in servos is not exactly reliable and one of the motors died on me, so I made my own controler...consequently…"
"I'm building a tricopter/plane hybrid from X8 flying wing. And one thing that I don't want to happen is to have to redesign everything because I chose to use components with inadequate power. So for planned weight of ~6 kg there will be three tilt…"
"So 8S battery gives you ~30V, @30A this is 900W on each ESC/motor. If we assume 95% efficiency for motor and ESC, you get 45W on ESC and ~45W on motor. If each FET dissipates equal amount of heat, we get 2,5W on each FET. With the setup that this…"
"FPU is good as you can write code with SI units (e.g. you can have current in amperes, voltages in volts, speed in RPM etc), which is not really efficient on fixed point uCs, but if you use manufacturers libraries for FOC, which are optimized to…"
"What were the simptoms of the failures? I hand-made ~5 or 6 boards and had no problems with any of them.
Have you considered using libraries for FOC? I am using Freescale's and got motor turning over a weekend."
"It could, because for sensorless operation, you need some minimal speed to get feedback for position. After you have reliable position, you can use rotation speed to predict/correct position. So until you have enough speed to get reliable value,…"
"It's startup from stand still. With normal ESC, you have to align the rotor and then start the rotation blindly, until you get enough feedback. With sensor, you know rotor position and can immediately start the motor with maximum power.
"Field oriented control, basicaly you have to know exact position of the rotor and then you apply such PWMs to all three phases that you get stator magnetic field that is perpendicular to rotor magnetic field = maximum torque. Also when the motor is…"
"Some day I might open source the code, but currently it is much too messy and there are a few tweaks I want to make before that :).
A "bit" better is Freescale's DSP 56f8037, but to be honest it could use a bit more power - it takes a lot of time to…"