ElmoMC CANopen DSP 402 Implementation Guide - Manual (Page 70)

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
10.1 General 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 * 10 9 regardless of the
DSP 402 maximum range.