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We offer EC Motors, both physical and Virtual Prototypes, which
includes 3D printed slotless (Wide Airgap) BLDC motors, slotless permanent magnet BLDC motors,
and traditional torque motors of the BLDC type with a complete range of electronic
controls/drivers. Although, we now prefer to supply "apps" that embody Virtual Prototypes which allow modist tailoring of the design characteristcs for applications adjustments without expensive modification and retooling of physical machines. The Virtual Prototype represents a huge investment savings over machined physical devices.
Jackson Research EC motors meet or exceed EU Commission
Regulation (EC) No 640/2009 regarding ecodesign requirements. |
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Transverse Flux motors and generators
are the object of considerable alternate energy research. One of
the newest incarnations is an inside out version which only achieves
approximately 50% of its potential and suffers complete demagnetization.
Jackson Research has developed and constructed machines that overcome
those deficiencies achieving efficiencies over 90%. These inside
out machines are proprietary.
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We use sensored drives
exclusively to achieve continuous stall torque. And, it is the only
means to achieve precision profiling. The computer on a chip and
proprietary PID closed loop operation coupled with precision optical
encoders or our proprietary resolver technology provides the ultimate
in precision motion and positioning.
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Jackson Research
encoder technologies are interchangeable devices with choices
of pole counts and shaft hole sizes. They can be furnished
in several grades of precision. All units are designed for
harsh environments. Specialized permanent magnets provide stable
accurate reliable operation over the entire temperature range.
Simple encoder winding alignment during assembly is achieved
by rotation of the encoder housing with the encoder magnet
fixed to the shaft.
Features include:
- Phase Angle Resolution to +/- 0.01 Degrees
- Typical Bandwidths to 10KHz
- Interchangeable Housings
- Neutralized Flutter
- Thermally compensated
- Near and Far Field Shielding
- Submersible
These proprietary devices are fully solid state.
No sine wave inputs are necessary. Demodulation is no longer
required. All Synchro/Resolvers outputs are pure sine waves
in real time. Any latency or phase delays are within the device
resolution and are not measureable. |
Resolution can never be better than the A/D converters used in the DSP MCU. |
Resolution
N in Bits |
2N |
LSB as % of
Full Scale |
Degrees
per Bit |
Minutes
per Bit |
Radians
per Bit |
8 |
256 |
0.39062500 |
1.4062500 |
84.37500 |
0.02454369 |
9 |
512 |
0.19531250 |
0.7031250 |
42.18750 |
0.01227185 |
10 |
1,024 |
0.09765625 |
0.3515625 |
21.09375 |
0.00613592 |
11 |
2,048 |
0.04882813 |
0.1757813 |
10.54688 |
0.00306796 |
12 |
4,096 |
0.02441406 |
0.0878906 |
5.27344 |
0.00153398 |
13 |
8,192 |
0.01220703 |
0.0439453 |
2.63682 |
0.00076699 |
14 |
16,384 |
0.00610352 |
0.0219727 |
1.31836 |
0.00038350 |
15 |
32,768 |
0.00305176 |
0.0109863 |
0.65918 |
0.00019175 |
16 |
65,536 |
0.00152588 |
0.0054932 |
0.32959 |
0.00009587 |
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While PID controllers
are applicable to many control problems, and often perform satisfactorily
without any improvements or even tuning, they can perform poorly
in some applications, and do not in general provide optimal control.
The fundamental difficulty with PID control is that it is a feedback
system, with constant parameters, and no direct knowledge of
the process, and thus overall performance is reactive and a compromise
– while PID control is the best controller with no model
of the process, better performance can be obtained by incorporating
a model of the process.
Typical Configurations |
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The control system performance can be
improved by combining the feedback (or closed-loop) control of a PID
controller with feed-forward (or open-loop) control. Knowledge about
the system (such as the desired acceleration and inertia) can be fed
forward and combined with the PID output to improve the overall system
performance. The feed-forward value alone can often provide the major
portion of the controller output. The PID controller can be used primarily
to respond to whatever difference or error remains between the setpoint
(SP) and the actual value of the process variable (PV). Since the feed-forward
output is not affected by the process feedback, it can never cause
the control system to oscillate, thus improving the system response
and stability. |
The combination of a motion controller,
drive and actuator is called an axis. When there is more than one drive
and actuator the system is said to have multiple axes. Complex motion
control systems such as computer controlled milling machines (CNC)
and robots have 3 to 6 axes which must be moved in coordination. |
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Moving a system from one steady position
to another (point-to-point motion) following the fastest possible
motion within an allowed maximum value for speed, acceleration, and
jerk, will result in a third-order motion profile as illustrated
in this image:
The motion profile consists of up to 7 segments
defined by the following:
- acceleration build-up, with maximum positive
jerk
- constant acceleration (zero jerk)
- acceleration ramp-down, approaching the desired
maximum velocity, with maximum negative jerk
- constant speed (zero jerk, zero acceleration)
- deceleration build-up, approaching the desired
deceleration, with maximum negative jerk
- constant deceleration (zero jerk)
- deceleration ramp-down, approaching the desired
position at zero velocity, with maximum positive jerk
If the initial and final positions are sufficiently
close together, the maximum acceleration or maximum velocity may
never be reached. |
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- "Testing a Low-Influence Spindle Drive Motor, L.C. Hale", T.A. Wulff, J.C. Sedgewick, Lawrence Livermore National Laboratory, UCRL-JRNL-200853, March 5, 2004.
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