Technosoft iPOS4808 BX-CAN, Technical Reference

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Technosoft 2015 94 iPOS4808 BX-CAN Technical Reference
6.4. Jerk units
The internal jerk units are internal position units / (slow loop sampling period) 3 i.e. the acceleration
variation over one slow loop sampling period.
6.4.1. Brushless / DC brushed motor with quadrature encoder on motor
The internal jerk units are encoder counts / (slow loop sampling period)
3
. The correspondence with
the load jerk in SI units
1
is:
] IU [ Jerk _ Motor
T Tr lines _ encoder _ No
] SI [ Jerk _ Load
×
× × ×
π ×
=
3
4
2
where:
No_encoder_lines – is the rotary encoder number of lines per revolution
Tr – transmission ratio between the motor displacement in SI units and load displacement in SI
units
T – is the slow loop sampling period expressed in [s]. You can read this value in the “Advanced”
dialogue, which can be opened from the “Drive Setup”
6.4.2. Brushless motor with linear Hall signals
The internal jerk units are counts / (slow loop sampling period)
3
. The motor is rotary. The position
resolution i.e. number of counts per revolution is programmable as a power of 2 between 512 and
8192. By default it is set at 2048 counts per turn. The correspondence with the load acceleration in
SI units is:
For rotary motors: ] IU [ Jerk _ Motor
T Tr resolution
] SI [ Jerk _ Load
×
× ×
π ×
=
3
2
For linear motors:
3
Pole_Pitch
Load_Jerk[SI] = ×Motor_Jerk[IU]
resolution× Tr × T
where:
resolution – is the motor position resolution
Tr – transmission ratio between the motor displacement in SI units and load displacement in SI
units
T – is the slow loop sampling period expressed in [s]. You can read this value in the “Advanced”
dialogue, which can be opened from the “Drive Setup”
Pole_Pitch – is the magnetic pole pitch NN (distance expressed in [m])
1
SI units for jerk are [rad/s
3
] for a rotary movement, [m/s
3
] for a linear movement