Below are the basic steps required to run a motor in Open Loop by using its SSI sensors. Only the necessary information to run the motor will be provided, so for a more detailed explanations please refer to the Roboteq Controllers User Manual.


To run the motor in open loop with SSI follow the below steps:

 

1. Configure at General configurations the Molex Input to “SSI Sensors”

 



2. Configure the number of “Pole Pairs”

 

Pole pairs parameter is essential for the sinusoidal commutation and for the speed calculation

 

3. Configure the switching mode to sinusoidal


SSI sensor can only be used for sinusoidal commutation


4. Configure the Reference seek power to the rated current of the motor


The reference seek power is the current that will be provided to the motor during the motor/sensor setup. If the reference current is too low or too high the motor/sensor setup might not be performed correctly




5. Configure the sinusoidal angle sensor to SSI Sensor


 

6. Configure the SSI sensor resolution


The resolution of the sensor equals 2 ^ number of sensor bits. To ensure the sensor compatibility make sure that the sensor data is pure angle and does not have any additional information like start/stop bits, error check, etc. Consult Roboteq if you have any doubts for the sensor compatibility. Different SSI resolutions are supported in different firmware versions.



7. Configure the FOC Flux Gains

 

These PI gains are used to optimize the sinusoidal commutation. The motor can turn with the default values, but the response might not be the optimal. For more information about the FOC tuning refer to the Roboteq Controllers User Manual, in the chapter about Brushless FOC.

 

 

8. Configure the Amp Limit

 

The controller will prevent the current from exceeding the amp limit value by reducing its power. Please make sure the amp limit value is below the peak current of the motor and that is higher than the reference seek power parameter

 

 

9. Configure the Operating Mode to “Open Loop”

 

 

 

10. Now go to the Diagnostics tab and run the Motor/Sensor Setup process.

The controller should turn for some degrees in CW and CCW direction by consuming a current that is equal to the reference seek power parameter. In the chart verify the following: 

 

  • The Sin parameter has the SSI angle. The angle value increase is linear and does not have any “steps”
  • The Sensor Angle is almost linear
  • The Motor Amps are equal to the Reference seek power

 

 

 

 

11. Now the motor is ready to Run in Open Loop / Sinusoidal with SSI sensor!

      

  To assess the performance of the motor, do the following:


  • Turn the motor without load in both directions and verify that the motor current is not beyond the “no load current” and symmetrical in both directions. You can monitor the controller working parameters on the Run tab of the Roborun+ Utility.
  • Verify that the Motor flux amps parameter has a small fluctuation and is kept close to zero. 
  • Verify that the FOC angle correction parameter is stable or that it stabilizes in satisfying time by changing the motor load/speed.
  • Verify that the Internal Sensor RPM parameter has a positive value by giving a positive motor command. If the measured speed is reverse, you can fix it by inverting the pole pairs parameter sign. Note that is important to have a speed of the correct sign, otherwise the motor will not be controller properly in Closed Loop.