Linear Motor preview
Monday, 15 December 2014

Linear Motors Control

Linear Motor previewServotronix advanced control technology is the key to driving high precision, high performance linear motion applications.

Servotronix introduces advanced linear motor control capabilities at a competitive price. Sophisticated control algorithms in the CDHD actively suppress vibration and mechanical resonance, and produce optimal performance even with low cost motors. The CDHD servo drive can be paired with any type of linear motor, be it a brand name product, or a custom-developed motor. The CDHD is designed to achieve high performance, low acoustic noise, energy savings, and ultimately, a cost-effective system.

Advantages of Servotronix Advanced Linear Control Capabilities

Versatility in a single drive model

  • Controls any linear motor, including linear brushless and linear voice coil motors.
  •  Supports almost any feedback device, such as a digital incremental A-quad-B encoders (with or without Hall sensors) and analog sine/cosine encoders
    (with or without Hall sensors). Additional feedback options, such as serial encoders, are available upon request.
  • High level (14 bit) sine encoder interpolation is embedded in the drive, eliminating
    the need for an external sine-to-digital converter, thereby saving space and costs.

Advanced control algorithms ach1ieve fast dynamic response and acceleration, thus maximizing machine accuracy and throughput:

  • High current loop bandwidth (> 3 kHz)
  • Low tracking error
  • Fast settling time

An advanced standstill algorithm minimizes position error jitter in zero movement conditions.


Anti-vibration algorithms eliminate mechanical resonance by detecting and immediately dampening oscillations, significantly reducing the time it takes a heavy load or an end effector to reach its target position.



Harmonic compensation algorithms correct disturbances caused by mismatches between the phase and gain of the sine and cosine signals. Combined with magnet skewing, Servotronix algorithms also reduce cogging torque.

Harmonic Compensation Screenshot


Ease of Use:

  • Automatic motor setup identifies the motor’s electrical phase, and detects motor movement direction, Hall switches and index crossing, and sets parameters
    accordingly. The procedure takes just 30 seconds!
  •  Autotuning of the HD control loop sets parameters for minimizing position error during motion, and minimizing settling time at the end of motion.
  •  Automatic cogging compensation – available soon!
  • New motor wizard for easy setup of linear motor parameters



Servotronix advanced linear motor control capabilities provide excellent solutions for control in various types of applications:

  • Multi-axis CNC, laser cutting, and plasma cutting machines
  • Electronics assembly and wire-bonding machines requiring high accuracy and speed
  • High speed, servo driven printing machines. Proven Servotronix implementation- 5 times greater accuracy than with a ball screw solution
  • PCB drilling Proven Servotronix implementation- to 8 axes per machine


Why Linear Motors?

The demand for high accuracy, high speed linear motion systems is constantly growing. Conventional linear motion technologies, such as a ball screw drive and rotary servo motor, no longer provide the combination of speed and accuracy required by today’s linear motion applications.

While linear motor technology has been available for some time, it is the recent advancements in linear motion control that are resulting in improved machine performance, simplified operation, and cost-effectiveness.

Linear motors vs. rotary/ball screw drive mechanism.

  • Linear motors offer faster traverse speeds, higher precision, lower vibration, lower acoustical noise and lower maintenance costs.
  • High speed axis travel
  • High acceleration and deceleration
  • High accuracy and repeatability
  • Efficient use of power due to little energy loss and regenerative braking system
  • High stiffness: without mechanical transmission elements, such as ball screw, couplings or belts, there is no backlash, windup or lost motion.
  • Low maintenance and long life: with no contact between moving parts, there is no friction or wear, and no need for lubrication