Hi everybody!
When the gimbal motor runs slowly in ControlType::velocity_openloop with velocity 0.5 rad/s, it stops running after about 14 minutes and 10 seconds.
This is my setup:
- SimpleFOClibrary version : 2.0,
- motor : gimbal T-Motor GB2208
- board : F446RE
- motor driver : simpleFOCshield
- Controll mode : ControlType::velocity_openloop
- speed : 0.5 rad/s
- main motor voltage : 12 V
There is still power at the motor, as the motor keeps being hot and has cogging torque, but no more movement.
The L6234 is still cold on the simpleFOCshield.
When I adjust the speed higher to 20 rad/s, the motor moves again.
If I reduce the speed then to 0.5 rad/s, the motor stops again.
If I reload the program from the ARDUINO IDE to the F446RE, the motor starts running immediately at at 0.5 rad/s.
It seems, that the problem is not located at the motor or the F446RE board (as I can still change the speed over the console), but inside the software.
Tried already to raise the motor.voltage_limit in order to get higher torques, but unfortunately the motor got very hot.
Therefore, I still use motor.voltage_limit = 3 and driver.voltage_power_supply = 12, using 12V dc for the motor.
Even with motor.voltage_limit = 3, the motor becomes very hot after a minute or so.
Since I am using ControlType::velocity_openloop, I don’t think I can use ControlType::voltage as David_Gonzalez suggested, because I don’t have an encoder for this motor.
If I am wrong, please let me know, and I will check.
Below I enclose the ARDUINO source code of the example I am using.
Cheers,
Juergen
######################################
// Open loop motor control example
#include <SimpleFOC.h>
// motor instance
// BLDCMotor( phA, phB, phC, pp, (en optional))
// BLDCMotor motor = BLDCMotor(9, 10, 6, 7, 8);
// BLDCMotor motor = BLDCMotor(3, 5, 11, 7, 7);
BLDCMotor motor = BLDCMotor(7); // just pole pairs
BLDCDriver3PWM driver = BLDCDriver3PWM(3,5,11,7); // all the hardware pins
void setup()
{
// power supply voltage - default 12V
driver.voltage_power_supply = 12;
driver.init();
motor.linkDriver(&driver);
// limiting motor movements
motor.voltage_limit = 3; // rad/s - default 3
motor.velocity_limit = 100; // rad/s - default 20 (60rpm = 6.2832rad/sek)
// open loop control config
motor.controller = ControlType::velocity_openloop;
// default modulation is SinePWM
motor.foc_modulation = FOCModulationType::SinePWM;
// or
//motor.foc_modulation = FOCModulationType::SpaceVectorPWM;
// init motor hardware
motor.init();
Serial.begin(115200);
Serial.println("Motor ready!");
_delay(1000);
}
float target_velocity = 0.5; // rad/s
void loop()
{
// open loop velocity movement
// using motor.voltage_limit and motor.velocity_limit
motor.move(target_velocity);
// receive the used commands from serial
serialReceiveUserCommand();
}
// utility function enabling serial communication with the user to set the target values
// this function can be implemented in serialEvent function as well
void serialReceiveUserCommand()
{
// a string to hold incoming data
static String received_chars;
while (Serial.available()) {
// get the new byte:
char inChar = (char)Serial.read();
// add it to the string buffer:
received_chars += inChar;
// end of user input
if (inChar == '\n') {
// change the motor target
target_velocity = received_chars.toFloat();
Serial.print("Target velocity ");
Serial.println(target_velocity);
// reset the command buffer
received_chars = "";
}
}
}
.