Re: Motor
Hi.
Well controlling 6 BCLD motors requires lot of computing power. (When I say control I mean, a closed loop system: read the encoder, compare the position with the set point, solve the controlller equaton, and generate the PWM).
A MCU capable of controlling 1 BLDC needs 6pwm outputs, a couple of timers to decode quadrature (or a integrated quadrature decoder), I/Os for hall sensors, and some analog ports for current and temp monitoring.
Another important Aspect for any control system you need a resonable proccessing time, to maintain the sample period small enough. So you will have 6 controller running in the same loop.
Maybe you could use a big 32bit mcu from freescale and six OMC506 (irf) (these are integrated BLDC speed controllers, they have an internal speed closed loop), with this you could worry to cascade your position controller from the speed loop.
I will encourange you to divide you proyects into diferent modules. remember: divide and conquer. You can develop a simple BLDC controller for one motor (I've used for this purpose the PIC18F4431 and the dsPIC30F3011, I like them because they include the quadrature decoder). When this is working fine you can repeat it 6 times, and conected through the integrated UART's and coordinate your system. Industrial systems work like this, you have different drives, one for each motor.
I've made something similar for 3 dc servos, I used a central MCU to send trayectories to the controllers, and works fine.
Good luck
hope this helps
Alex