Panasonic MINAS A6 Series, Technical Reference

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4.5Full-closed control
4-19
4.5 Full-closed control
Full-closed control is where the position of the unit being controlled is controlled by direct feedback of
the detected position using an externally located scale (external scale).
This allows, for example, control that is not affected by ball screw errors or position variation from
temperature. Configuring a full-closed control system will enable the achievement of high-precision
positioning of sub-micrometer order.
Full-closed control mode is works in position control mode (profile position control [pp], cyclic position
control [csp], homing [hm]). Interpolated position control (ip) is not supported.
If 6060h (Modes of operation) is set to 3 (pv), 4 (tq), 9 (csv), and 10 (cst) under full-closed control,
Err88.1 (Control mode setting error protection) occurs.
It is not possible that switching to velocity control mode (profile velocity control [pv], cyclic velocity
control [csv]) or torque control mode (profile torque control [tq], cyclic torque control [cst]) under full-closed
control.
This section describes the setting of external scale ratio and the setting of excessive hybrid deviation in
the initial setting for full-closed control.

One command pulse(one command unit) of when the command division/multiplication
ratio is 1:1 becomes as one pulse of external scale.With the full-closed control, the velocity
control is implemented by the encoder feedback, and the position control by the external
scale feedback.

Make sure to set Pr3.28 "Hybrid deviation excess setup" and Pr3.29 "Hybrid deviation clear
setup" to appropriate values.When the hybrid deviation excess range is set excessively
wide, detection becomes delayed, and the effects of error detection become lost. Please
refer to "4.5.3 Setting of hybrid deviation excess" for details.
Also, if set excessively narrow the torsion between motor and equipment in normal
operation may be detected as an abnormal.

The external scale of 1/40 ≤ External scale ratio ≤ 125200 is recommended.When the
external scale rate is set at the value smaller than 50/position loop gain (Hz), control by the
unit of 1 pulse in external scale may not become possible.If the external scale ratio is
increased, the operating noise may become louder.

When a wrong external scale division ratio is set, even if the external scale and motor
position agree with each other, the Err25.0 "Hybrid deviation excess error protection" may
occur especially when the stroke distance is long with the movement. In that case, use with
the external scale division ratio set to a value that is as close as possible, and the hybrid
deviation excess range expanded.

Full-closed control cannot be used in 0.250 ms and 0.125 ms of communication cycles. If
0.250 ms and 0.125 ms of communication cycles are set under full-closed control, Err91.1
(Command error protection) occurs.