www.fastech-motions.com - 7
Traditional servo motor drives overshoot their position
and try to correct overshooting by moving the opposite
direction, especially in high gain applications. This is
called null hunt and is especially prevalent in systems
that the break away or static friction is significantly
higher than the running friction. The cure is lowering
the gain, which affects accuracy or using Ezi-SERVO
Motion Control System. Ezi-SERVO utilizes the unique
characteristics of stepping motors and locks itself
into the desired target position, eliminating Null Hunt.
This feature is especially useful in applications such
as nanotech manufacturing, semiconductor fabrication,
vision systems and ink jet printing in which system
oscillation and vibration could be a problem.
No Hunting
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Ezi-SERVO boosts the voltage supplied to the motor
to increase the torque at high speed. In the case that
motor speed is increased, Back-EMF will be increased
accordingly and it cause the reduction of motor torque
at high speed. Since Ezi-SERVO has the function to
increase the voltage supplied to the motor to compensate
the torque reduction, the torque of motor at high speed
can be imrpoved about 30%.
※ The torque at high speed is improved about 30%
Measured Condition : Drive = Ezi-SERVO-ST-56L
Motor Voltage = 40VDC
Input Voltage = 24VDC
Torque
[N.m]
Speed
[rpm] × 100
1.6
0.4
0.6
0.8
1.0
1.2
1.4
0.2
0
0.1 1 2 3 4 5 6 7 8 9 10 12 14 16 18 20 22 24 26 28 30
Motor Voltage:
40V
Motor Voltage:
24V
Torque increase due to
higher motor voltage
Torque Improvement
(Motor Voltage Increasing)
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Similar to conventional stepping motors, Ezi-SERVO
instantly synchronizes with command pulses providing
fast positional response. Ezi-SERVO is the optimum
choice when zero-speed stability and rapid motions
within a short distance are required. Traditional servo
motor systems have a natural delay called settling time
between the command input signals and the resultant
motion because of the constant monitoring of the current
position.
Fast Response
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Ezi-SERVO is a high-precision servo drive, using a
high-resolution encoder with 32,000 pulses/revolution.
Unlike a conventional Microstep drive, the on-board
high performance MCU (Micro Controller Unit) performs
vector control and filtering, producing a smooth rotational
control with minimum ripples.
Smooth and Accurate
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The unit of the position command can be divided
precisely. (Max. 32,000 pulses/revolution)
High Resolution
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