SPRACO3 October   2019 INA240 , LMG5200 , TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1 , TMS320F280040-Q1 , TMS320F280040C-Q1 , TMS320F280041 , TMS320F280041-Q1 , TMS320F280041C , TMS320F280041C-Q1 , TMS320F280045 , TMS320F280048-Q1 , TMS320F280048C-Q1 , TMS320F280049 , TMS320F280049-Q1 , TMS320F280049C , TMS320F280049C-Q1 , TMS320F28374D , TMS320F28374S , TMS320F28375D , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376D , TMS320F28376S , TMS320F28377D , TMS320F28377D-EP , TMS320F28377D-Q1 , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378D , TMS320F28378S , TMS320F28379D , TMS320F28379D-Q1 , TMS320F28379S

 

  1.   Dual-Axis Motor Control Using FCL and SFRA On a Single C2000 MCU
    1.     Trademarks
    2. 1 Introduction
      1. 1.1 Acronyms and Descriptions
    3. 2 Benefits of the C2000 for High-Bandwidth Current Loop
    4. 3 Current Loops in Servo Drives
    5. 4 PWM Update Latency for Dual Motor
    6. 5 Outline of the Fast Current Loop Library
    7. 6 Evaluation Platform Setup
      1. 6.1 Hardware
        1. 6.1.1 LAUNCHXL-F28379D or LAUNCHXL-F280049C
          1. 6.1.1.1 DACs
          2. 6.1.1.2 QEPs
        2. 6.1.2 Inverter BoosterPack - GaN + INA240
        3. 6.1.3 Two Motor Dyno
        4. 6.1.4 System Hardware Connections
        5. 6.1.5 Powering Up the Setup
      2. 6.2 Software
        1. 6.2.1 Incremental Build
        2. 6.2.2 Software Setup for Dual-Axis Servo Drive Projects
    8. 7 System Software Integration and Testing
      1. 7.1 Incremental Build Level 1
        1. 7.1.1 SVGEN Test
        2. 7.1.2 Testing SVGEN With DACs
        3. 7.1.3 Inverter Functionality Verification
      2. 7.2 Incremental Build Level 2
        1. 7.2.1 Connecting motor to INVs
        2. 7.2.2 Testing the Motors and INVs
        3. 7.2.3 Setting Over-current Limit in the Software
        4. 7.2.4 Setting Current Regulator Limits
        5. 7.2.5 Position Encoder Feedback
      3. 7.3 Incremental Build Level 3
        1. 7.3.1 Observation One – Latency
      4. 7.4 Incremental Build Level 4
        1. 7.4.1 Observation
        2. 7.4.2 Dual Motor Run With Speed Loop
      5. 7.5 Incremental Build Level 5
        1. 7.5.1 Dual Motor Run with Position Loop
      6. 7.6 Incremental Build Level 6
        1. 7.6.1 Integrating SFRA Library
        2. 7.6.2 Initial Setup Before Starting SFRA
        3. 7.6.3 SFRA GUIs
        4. 7.6.4 Setting Up the GUIs to Connect to Target Platform
        5. 7.6.5 Running the SFRA GUIs
        6. 7.6.6 Influence of Current Feedback SNR
        7. 7.6.7 Inferences
        8. 7.6.8 Phase Margin vs Gain Crossover Frequency
    9. 8 Summary
    10. 9 References

7.6.2 Initial Setup Before Starting SFRA

The setting up involves co-ordination between the debug environment and the SFRA GUI. Until getting familiar with connecting the SFRA GUI to the target platform, it is a good idea to turn off the power supply input to the inverter board.

  1. Open ’dual_axis_servo_drive_settings.h’ and select level 6 incremental build option by setting the BUILDLEVEL to FCL_LEVEL6 (#define BUILDLEVEL FCL_LEVEL6) . Also, in this file, watch out for the definitions:
    1. SFRA_FREQ_START
    2. SFRA_FREQ_LENGTH
    3. FREQ_STEP_MULTIPLY

      4. These definitions inform the GUI about the starting value of noise frequency, number of different noise frequencies to sweep and the ratio between successive sweep frequencies, respectively. More information is available in the C2000™ Software Frequency Response Analyzer (SFRA) Library and Compensation Designer User's Guide associated with SFRA. In the context of this evaluation project, it is important to know and appreciate these parameters to tweak them for further repeat tests.

      The default setting of the code is that SFRA will be performed on motor1. To do SFRA on motor 2, call the SFRA functions with the motor 2 handle (or pointer) by setting the SFRA_MOTOR to MOTOR_2 (#define SFRA_MOTOR MOTOR_2) in "dual_axis_servo_drive_settings.h".

      In this motor control project, there are three different loops such as the speed loop, D axis current loop and Q axis current loop. Any of these loops could be analyzed for frequency response. Technically, this could be performed on position loop as well, but is not included in this project scope.

  2. Right click on the project name and click Rebuild Project.
  3. Once the build is complete click on debug button, reset CPU, restart, enable real time mode and run.
  4. Add the following variable in the Expressions window:
    1. sfraTestLoop : for selecting the control loop on which to evaluate SFRA, letting you choose between the following settings.
      1. SFRA_TEST_D_AXIS - D axis current loop
      2. SFRA_TEST_Q_AXIS - Q axis current loop
      3. SFRA_TEST_SPEEDLOOP - speed loop
  5. Set 'enableFlag' to 1 in the watch window. The variable named 'motorVars[0].isrTicker' and 'motorVars[1].isrTicker' will be incrementally increased as seen in watch windows to confirm the interrupt working properly.
  6. The SCI initialization needed to communicate with the GUIs should be complete by now.
  7. Further steps with the debug window will follow after setting up the GUI to connect to target platform.