Arlo1 wrote:6.99k erpm max??? Thats only 699rpm for colossus....
Lebowski wrote:Arlo1 wrote:6.99k erpm max??? Thats only 699rpm for colossus....
These numbers are for my own motor, you can type whatever you want here. This
particular entry I think goes up to 255.99k and is not limited by the controller algorithm
but by the computation which takes the number you enter and transforms it into the
16 bits integer the algorithm uses. Is there a need to go higher than 256 k-erpm ?
Farfle wrote:The joby motors are some insane E-rpm iirc, but I cant find it.
whatever wrote:seems controllers with reverse also limit the max speed in reverse...more complexity
This sounds perfect.Lebowski wrote:What I can do maybe is that when the direction switch is thrown the controller
automatically jumps to a preset regen level to shed the energy of the motor
before reversing it. As a user you would be able to stay on the throttle while
this automatic process happens....
Miles wrote:In the case of using reverse to change gear, most parts of the transmission are freewheeling until the load is retaken in the opposite direction. The bulk of the inertia to overcome is in the rotor of the motor.
Is a pause needed before reversal?
If the throttle is going to be held, it might be good to have a temporary torque limit after reversing, until the load is retaken..
Alan B wrote:Motor controllers often have a reversal input. A good controller will reverse at high power.
I would think to reverse quickly you would set PWM to zero, reverse the phasing of the commutation, and ramp the PWM back up. Clearly during this ramping the power is going to buck the motor EMF, but just like other situations the PWM is used to control the current to a safe level. Applying bucking power is the fastest way to reverse the motor while keeping voltages and currents at a safe level.
Miles wrote:Some sensorless controllers seem to need a pause of at least 100 milliseconds at zero rpm, before restarting in reverse.
Lebowski wrote:In the end how fast it will be able to reverse depends on the setup, all variables influencing this process
are accessible to the user. You can set the regen current during slow down and the rpm below which
the reversal is made. You can try to make the reversal as fast as possible with these but it won't allow you to
violate certain current limits like phase wire current and battery regen current (though you can also change
these as well but you have to be sure your FETs/battery can take it).