Search found 299 matches

by pf26
20 Aug 2018, 09:37
Forum: FOC
Topic: FOC RPM control keeps reversing direction
Replies: 7
Views: 2738

Re: FOC RPM control keeps reversing direction

I think the speed control based on motor current is very hard to achieve with a PID, especially when your motor has strong load variations and little inertia. The strong currents required for high loading will cause very high acceleration should the load cease. A voltage based speed regulation is mu...
by pf26
16 Aug 2018, 12:09
Forum: FOC
Topic: FOC settings configuration
Replies: 1
Views: 56

Re: FOC settings configuration

With a 1amp current, I fear you have too much noise in the measurements, so the results are unreliable.
You probably should try with the higher current that still gives a result for lambda.
What are the values found for R and L ? Do they seem to correspond to your motor specs ?
by pf26
23 Jul 2018, 08:48
Forum: FOC
Topic: Direct CAN velocity control
Replies: 3
Views: 283

Re: Direct CAN velocity control

Having CAN signals through sliprings seems a bit scary to me for long term reliability.. I would have used sliprings for power, and wireless (802.15.4) for control. If you use CAN through sliprings, maybe using some small capacitors (47pF ?) between 0V and both CANH and CANL, can help filter the pos...
by pf26
15 Jul 2018, 16:06
Forum: Related Hardware
Topic: Battery overvoltage protection - dump load
Replies: 13
Views: 617

Re: Battery overvoltage protection - dumb load

Did you have a look at this one: http://vedder.se/forums/viewtopic.php?f=15&t=586 ? (dump, not dumb..)
by pf26
12 Jul 2018, 14:38
Forum: Related Hardware
Topic: Battery overvoltage protection - dump load
Replies: 13
Views: 617

Re: Battery overvoltage protection - dumb load

I doubt you scheme will work. When the dump load is switched on, the internal resistance of the battery will cause the main voltage to drop, and depending upon the hysteresis of your comparator, will switch off the load or not. Anyway, you need some capacitance somewhere to have your dump load switc...
by pf26
21 Jun 2018, 16:49
Forum: Custom Applications
Topic: Dual motor setup over CAN with UART
Replies: 2
Views: 197

Re: Dual motor setup over CAN with UART

To send commands to the master VESC (ID=1), I think you better send the command directly, and not use the Forward command : i.e. remove these 2 lines when ID=1 payload[index++] = COMM_FORWARD_CAN ; payload[index++] = address ; I checked your CRC calculation. and it seems correct. Maybe you should ma...
by pf26
14 Jun 2018, 09:25
Forum: General
Topic: Freezing during PID Positional Control (with encoder)
Replies: 2
Views: 224

Re: Freezing during PID Positional Control (with encoder)

Possibly the motor startup currents interfere with your hardware. You could try to improve your routing (wiring away from power cables), or lower the motor max current, or use separate power sources for VESC and your hardware (if not already the case). You should be able to transmit position referen...
by pf26
04 Jun 2018, 09:04
Forum: FOC
Topic: FOC on eBike - cuts in acceleration
Replies: 5
Views: 654

Re: FOC on eBike - cuts in acceleration

You could try to reduce the FOC current controller parameters (Ki and Kp), say by 20%, and see if it helps.
It is also possible to adjust manually the R and L of the motor, but I do not know in which direction to go.
by pf26
02 Jun 2018, 06:03
Forum: FOC
Topic: FOC on eBike - cuts in acceleration
Replies: 5
Views: 654

Re: FOC on eBike - cuts in acceleration

In BLDCTOOLS, motor configuration/Motor/Current limits, you could set a higher "Absolute Max" parameter. This will reduce your "ABS_OVER_CURR" faults, at the expense of a greater risk to blow your VESC. Reason is the current control is not perfect, and setting too little margin b...
by pf26
01 Jun 2018, 08:26
Forum: General
Topic: Vesc constant speed control in code?
Replies: 1
Views: 199

Re: Vesc constant speed control in code?

You don't need to change the code. You can add a little application to the firmware. You can create a file like this: // Settings #define SpeedReference 3000 #include "ch.h" // ChibiOS #include "hal.h" // ChibiOS HAL #include "mc_interface.h" // Motor control functions ...

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