Difference between revisions of "Argon user guide/Drive parameterization"

Revision as of 21:40, 1 September 2013

This article will describe how to set-up Argon parameters with Granity to make motor operational and ready for servo tuning.

Preparations and connection

As the goal is to parameterize and make motor operational, we should have:

1. The drive and motor fully wired. However it's not required to have controller (to J5 port) or braking resistor connected at this point.
2. Be familiar with the operation and parameters of Granity. Make sure you have read Granity user guide.
3. Granity connection working. See Making the first Granity connection

Walk-through of initial parameterization

In this chapter we walk-trough all Granity tabs and modify the parameter needed. This guide assumes that the drive is in factory defaults state (not configured before). Restore drive to factory state can be done by uploading a firmware file to the drive.

Connect tab

No other actions than connect to drive needed on this tab. Once connection successful, proceed to the next tab.

Goals tab

The factory defaults (torque control as control mode and serial only as setpoint) as well as the other defaults are the correct ones for beginning.

Machine tab

In this tab we configure the motor and its feedback device.

Axis mechanics

Axis type, units and scale parameters AXT and AXS affect only on the unit conversion of Granity parameters (such as acceleration/velocity limit unit conversions) and has no effect on drive operation.

Choose your axis type and scale, or leave them as defaults.

Motor

Find motor parameters from the motor data sheet/manufacturer specifications.

1. Choose motor type from the drowndown list MT
2. Set motor pole count MPC (non-brush DC motors only). If unsure, see Determining motor pole count.
3. Set maximum rated speed MMS of the motor, or alternatively the maximum allowed motor speed in the target application
4. Set motor continuous MMC and peak MMC current values. If non-brush DC motor type has been selected, then these are measured as the peak value of sine.
5. Set coil resistance MR and inductance ML, these values are measured Phase-to-phase. If unavailable, perform Tuning torque controller manually after initial parameters are set.
6. Set thermal time constant MTC. Motor thermal time constant value in seconds, used for thermal modeling of motor to avoid motor overheating with peak current MMC. If not available, use formula 200*motor_weight (kg) as approximate, so a 2 kg motor would get a 400 second time constant. There is no guarantee of accuracy of this method.

As torque is directly proportional to motor current, it is advisable to set current limits lower at the beginning of testing. I.e. 50% of motor's rated current will produce 50% of motor's rated torque.

Feedback device

1. Choose feedback device type from the dropdown FBD
2. Set feedback device resolution. If FBD is quadrature encoder, then manufacturers typically give resolution as pulses per revolution (PPR) or lines per revolution (LPR) which are the same thing and shall be entered directly into FBR field. Some manufactures also call PPR as CPR.
3. Configure the polarity of feedback device counting direction by FBI parameter. Motor and feedback device must have same electrical positive rotation direction to make a stable servo system. If your system shows no stability (instant following error after a motor "jump"), try changing this setting.
4. Leave the Hall sensors Off FBH during initial setup. Enable later if necessary (see when).