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Adaptive Tuning

1. Concept
To simplify tuning while still allowing highest versatility and control over servo behaviour, we have developed Adaptive Tuning technology, meaning relative to the inertia load, the servo adapts a wide margin of permissible parameters that will ensure stable control. This allows to easily select the settings for smoothest motion, and fastest response.

The margin of stability being adaptive is critical for many applications. For example, in machine tool, the dynamic load inertia can drastically change. The load inertia ratio is different at acceleration/deceleration, constant traverse and workpiece processing. The same is true for robotic applications. By maintaining a wide region of stability, the DMM adaptive tuning provides seamless performance transition between these events. Even with the same parameter settings, as the load inertia ratio change, the servo is still well within the stable region.

Second generation tuning algorithm further improves smoothing with wider frequency range leading to wider domain of inertia load capability.

2. Features
  • Optimal servo control topology based on the Encoder Feedback and Position Command. Ensures the closed-loop servo has maximum stability margin
  • Smallest number of adjustable servo parameters. Very easy to tune servo for different load inertia and required servo stiffness
  • The closed-loop servo has more performance capability over larger inertia load variance

3. Application Functionality
The user is able to adjust the 3 gain parameters very quickly according to their unique load and inertia specifications. From the factory default settings, a trial-and-error process should be used until the servo motor is within stable range. Within the range of stability, the user has further options to tune the behaviour according to application. For example, CNC applications requires the servo motor to be more rigid, so the gain parameters can be biased higher. Printing or feeding applications requires the servo motor to be more soft, so the parameters can be biased lower. The overall tuning procedure can be completed within minutes.

Servo Tune Up: Functions for Main Gain, Speed Gain, Integration Gain, Torque Filter

Main Gain: As load inertia increases, Main Gain should be increased correspondingly to make sure the servo has higher stability, increased stiffness and faster response. If set too high, high frequency noise is introduced because control loop frequency domain conflicts with torque servo loop. If set too low, servo loop may become unstable - low frequency oscillations introduced.

Speed Gain: As load inertia further increases, Speed Gain should be correspondingly increased to increase the servo stability. Speed Gain also has the effect of smoothing servo motor's motion. If set too high relative to load, servo response may become slower, high frequency noise may be introduced.

Integration Gain: Used to increase the servo stiffness and keeping servo accuracy. Generally should be lowered as load inertia increase as larger loads should not have high dynamic ability (rapid acceleration/deceleration). Higher integration gain will decrease the servo stability. For large inertia loads, integration should be decreased.

Torque Filter Constant: When the servo is operating in speed or torque servo mode, this filter is used for torque command smoothing/ramping. Should be set to 127 (filter off) in position servo mode.

Applicable Products

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