Technical data
28
───
Version: 1.0
eXtended Transport System
Below you will find definitions of terms, environmental conditions
and operating specifications as well as technical data.
4.1
Definition
All details relate to an ambient temperature of 40 °C. The data can
have a tolerance of +/- 10%.
4.1.1
Technical terms
Nominal force F
0
[N]
Nominal force that a mover can continuously apply.
Force constant K
F
[N/A]
Specification of how much force in N the mover generates with a
certain mover current.
The equation is F
0
= I
0Mover
x K
F
Voltage constant K
E
[Vs/m]
Induced motor EMF related to 1 m/s as a peak sine value on a mo-
tor coil.
Thermal time constant tTH [min]
Specification of the heating time of the cold module when loaded
with the nominal force until 63% of the maximum overtemperature is
reached. This temperature rise happens in a much shorter time
when the motor is loaded with the peak current.
Absolute accuracy [mm]
Specification of the difference between an expected set position and
the mean value of the actual position resulting from approaching the
set position from different directions (multi-directional). The absolute
accuracy is valid within a module and is defined as the difference
between the set position and the actual position of the positioning
system.
Standstill repeatability [mm]
Specification of how accurately the system positions when ap-
proaching a position from the same direction (unidirectional). The
standstill repeatability is to be evaluated as the average difference
between the actual position and the set position and is the most im-
portant measure for the assessment of a positioning system. It de-
fines the variance around the mean value with a large number of po-
sitionings.
The variance of the positions is illustrated by the Gauss distribution
or normal distribution. The standstill repeatability is defined by three
standard deviations (3σ) with a probability of 99.74%.
Synchronization accuracy [mm]
Specification of the fluctuations that the system exhibits in the posi-
tion / following error during a position-controlled movement at a con-
stant set velocity. The synchronization accuracy depends on the
mechanical rigidity, the applied load on the movers, the controller
settings, the set velocity and also any mechanical offset between
the modules.
