I have a geared MAC hub motor & some Hyperion RC motors. Do you need some sample motors to test your controller design on?
Just wondering what you want to do for the next test phase
Are you intending to offer this as a kit or product or for ES members
Well, it would be very nice indeed to try the system out on all kinds of motors. I imagine
that if you're handy with the soldering iron I can send you a schematic and a programmed IC.
It's not an expensive system and it would be possible to take a typical Xie Controller and
do a conversion. I once saw a schematic of a EB206 (?), if they're all build like this then
a conversion should be no problem.
What I have consists of a 30F4011 MCU/DSP. The input signals it needs are the 3 hall sensors (for sensored
start-up) and 2 current sensors to measure the motors phase currents (it is meant for the Allegro current
sensors). The outputs are 6 PWM signals which switch the high/low side FET transistors.
To come back to the EB206 schematic I saw, this is setup in a similar way (3 hall sensors to
a u-controller which then supplies signals to the 6 FET drivers). All it would need is a check to
make sure the 5V supply can deliver the 200 mA the 30F needs and then you just take out the
Infineon chip and substite wire in the 30F. Add 2 current sensors and that's it. For a throttle
anything that gives out 0 to 5 V can be used. The hardware side of my controller is nothing special.
The cost should not be high. A 30F4011 cost around $5 to $10 here in Switzerland, a current
sensor costs $2 to $20 dependent on how crazy large you want the current to be.
There will be some pins on the 30F that can bring the chip in certain modes. It has a ascii (RS232)
menu driven system for what I call 'calibration'. During calibration it will ask you a few times to
spin the motor, the 30F will then learn the relationship between all the hall signals and the motor
phases. This takes away all the guessing of which hall/phase combinations to use, the 30F will
'learn' this during calibration. Hall and motor phase signals can be outputted in table format for
copy-paste in a spreadsheet program, in this way you can look at the signals. It has a menu for chosing
the PWM frequency and dead-time to be flexible enough to use a low-cost output stage (EB206) or a
faster more advanced optical output stage (as I use). The parameters of the sensorless and throttle
(current) control loop can be chosen, as well as how fast the control loop executes (upto
around 80 kHz, so 80000 measurements and phase/amplitude updates a second). The motors resistance
and inductance do not need to be known. After you've gone through the setup everthing can
be saved to the 30F 's internal EEPROM . Calibration is a one-time deal, except of course for when you want
to play around and try all kinds of stuff. The RS232 interface can be used during motor operation to
real-time observe internal variables like motor current, e-phase etc etc (like in the video I posted earlier).
Throttle wise, I will put in a calibration for this, it will ask you to close and fully open the throttle
and measure the associated voltages. Still thinking about putting in a choise between linear/logarithmic
throttle curves. Or you can use the CAN bus for this, good for connecting multiple motor controllers
in parallel for when you have a motor in each wheel or a double stator motor. It's a current based throttle,
this means that you control the torque the motor delivers (much like with a petrol engine).
Basically I have everything except for the throttle interface (working on this now) and I still need to
add some 'fluff', some more menus for the calibration phase and things like this.
I've only tried it with my motor so it would be fun to try on others
I hope that during the upcoming
Christmas week I'll get the throttle done so I can start with some tests under load. 'Under load' is relative by
the way, I only have a 150 Watt power supply so I cannot try it out with dozens of amps. But everything is
relative, I mean, the algorithm doesn't care whether you have a 10 Amp or 200 Amp current sensor installed
or whether you use 6 or 30 FETs, or if your battery is 36 or 150 Volt. The 30F is sitting nicely in it's 5V world, so...
If you want to try it out, PM me