MCSDK: behavior of sequential ramps

[B0bbyR4y]

Hi,

I wonder how the motor control unit should behave if a speed ramp is programmed right after a torque ramp?

Following code snippet shows this setup:

// Set Torque/Iq limit
MC_ProgramTorqueRampMotor1(iqLimit, 0);
// Programm speed ramp
MC_ProgramSpeedRampMotor1(speed, 500);
// Start motor
MC_StartMotor1();

Do I understand correctly that this code should lead to the following behavior?

• the motor starts in speed mode

• if the load driven by the motor increases the speed will decrease

• if the load increases further the motor will run with decreasing speed until it reaches the torque/iq limit set by  the MC_ProgramTorqueRampMotor1() function

• the motor will stop and deliver a constant torque - the torque programmed with MC_ProgramTorqueRampMotor1()

Best regards

B0bbyR4y

[STuser2 · Accepted solution]

If one command execution is in progress it will not execute the next command. Refer the below documentation in the code 

/**
  * @brief  Returns information about the state of the last buffered command.
  * @PAram  pHandle Pointer on the component instance to work on.
  * @retval The state of the last buffered command
  *
  * The state returned by this function can be one of the following codes:
  * - #MCI_BUFFER_EMPTY if no buffered command has been called.
  * - #MCI_COMMAND_NOT_ALREADY_EXECUTED if the buffered command
  * condition has not already occurred.
  * - #MCI_COMMAND_EXECUTED_SUCCESSFULLY if the buffered command has
  * been executed successfully. In this case calling this function resets
  * the command state to #MCI_BUFFER_EMPTY.
  * - #MCI_COMMAND_EXECUTED_UNSUCCESSFULLY if the buffered command has
  * been executed unsuccessfully. In this case calling this function
  * resets the command state to #MCI_BUFFER_EMPTY.
  */
__weak MCI_CommandState_t MCI_IsCommandAcknowledged(MCI_Handle_t *pHandle)

 This function is in the mc_interface.c file

and also refer

/**
  * @brief Programs a torque ramp for Motor 1 for later or immediate execution.
  *
  *  A torque ramp is a linear change from the current torque reference to the @p hFinalTorque
  * target torque reference in the given @p hDurationms time.
  *
  *  Invoking the MC_ProgramTorqueRampMotor1() function programs a new torque ramp
  * with the provided parameters. The programmed ramp is executed immediately if
  * Motor 1's state machine is in the #RUN states. Otherwise, the ramp is buffered
  * and will be executed when the state machine reaches any of the aforementioned state.
  *
  *  The Application can check the status of the command with the MC_GetCommandStateMotor1()
  * to know whether the last command was executed immediately or not.
  *
  * Only one command can be buffered at any given time. If another ramp - whether a
  * torque or a speed one - or if another buffered command is programmed before the
  * current one has completed, the latter replaces the former.

in mc_api.c file.