Technosoft IDM240-5EI - Scaling Factors; Position Units; Brushless; DC Brushed Motor with Quadrature Encoder on Motor; DC Brushed Motor with Quadrature Encoder on Load and Tacho on Motor

© Technosoft 2011 77 IDMx40 Technical Reference
6. Scaling Factors
Technosoft drives work with parameters and variables represented in the drive internal units (IU).
These correspond to various signal types: position, speed, current, voltage, etc. Each type of
signal has its own internal representation in IU and a specific scaling factor. This chapter presents
the drive internal units and their relation with the international standard units (SI).
In order to easily identify them, each internal unit has been named after its associated signal. For
example the position units are the internal units for position, the speed units are the internal
units for speed, etc.
6.1. Position units
6.1.1. Brushless / DC brushed motor with quadrature encoder on motor
The internal position units are encoder counts. The correspondence with the load position in SI
units
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is:
For rotary motors:
]IU[Position_Motor
Trlines_encoder_No
]SI[Position_Load ×
××
π×
=
4
2
For linear motors:
]IU[Position_Motor
Tr
accuracy_Encoder
]SI[Position_Load ×=
where:
No_encoder_lines – is the rotary encoder number of lines per revolution
Encoder_accuracy – is the linear encoder accuracy i.e. distance in [m] between 2 pulses
Tr – transmission ratio between the motor displacement in SI units and load displacement
in SI units
6.1.2. DC brushed motor with quadrature encoder on load and tacho on motor
The internal position units are encoder counts. The motor is rotary and the transmission is rotary-
to-rotary. The correspondence with the load position in SI units is:
]IU[Position_Load
lines_encoder_No
]rad[Position_Load ×
×
π×
=
4
2
where:
No_encoder_lines – is the encoder number of lines per revolution
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SI units for position are: [rad] for a rotary movement, [m] for a linear movement