Elmo DSP 402 Position Control Function, 10.1General Information, 6064h Position actual value

CANopen DSP 402 Implementation Guide

MAN-CAN402IG (Ver. 1.2)

64

10: Position Control Function

6062h: Position demand value in position units

6063h: Position actual value in increments

6064h: Position actual value

6065h: Following error window

6067h: Position window

6068h: Position window time out

60F4h: Following error actual value

60FAh: Position control effort

60FCh: Position demand value in increments

10.1General Information

This chapter describes all parameters required for closed-loop position control. The control loop is fed with the position demand value as one of the outputs of the trajectory generator and with the output of the position detection unit (position actual value) as input parameters. The behavior of the control is influenced by the control parameters. Position control parameters (PI/P) may be set using the Composer Wizard during setup.

To ensure that the physical limits of a drive are not exceeded, an absolute limit function is implemented for the position control effort. The Elmo drive implements a cascaded control loop in which the position control effort is a velocity demand value for the velocity control loop. For further information about tuning the position loop and using the Composer Wizard, refer to the SimplIQ Composer User Manual and the SimplIQ Software Manual.

The following terms are used in this chapter:

Following error:

A position actual value outside the allowed range of the following error window around a position demand value for longer than the following error timeout results in setting bit 13, following error, in the statusword.

The position following error calculates each cycle of the position control. The position demand value must be set lower than the setup value of the drive following error ER[3]. When the position following error exceeds ER[3], the motion aborts.

Position reached:

This function provides the option of defining a position range around a position demand value to be regarded as valid. If a drive position is within this area for a specified time — the position window time — the related control bit 10 target reached in the statusword is set. Bit 10 is reset to 0 when the motor is off.

The position range in the Elmo servo drive is limited to ±1 * 109 regardless of the DSP 402 maximum range.