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IntelligentMagnetics™ Motion Control
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Designs by the inventor of the Slotless Wide Airgap Motor
Embedded Motion Controls
Integrated Control DriverEC Motor Control

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.

EC Motion ControlsKW Motion Control System
PID
PID Controls 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
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.
Motion Profile
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.

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:

  1. acceleration build-up, with maximum positive jerk
  2. constant acceleration (zero jerk)
  3. acceleration ramp-down, approaching the desired maximum velocity, with maximum negative jerk
  4. constant speed (zero jerk, zero acceleration)
  5. deceleration build-up, approaching the desired deceleration, with maximum negative jerk
  6. constant deceleration (zero jerk)
  7. 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.

Motion Profiler