Introduction

In high-performance motion control, tuning controllers is often a balancing act. A fixed set of PID or PI gains may work well at certain speeds or positions, but as operating conditions change, the same tuning can cause instability, overshoot, or sluggish response.

This is where gain scheduling comes into play. Technosoft drives provide advanced gain scheduling capabilities, allowing users to dynamically adjust control parameters in real time, ensuring optimal performance across the entire motion profile.

What Is Gain Scheduling?

Gain scheduling is a control strategy that allows multiple sets of controller parameters (PID/PI gains and integral limits) to be pre-configured and automatically applied depending on specific conditions.

Instead of a “one-size-fits-all” controller, gain scheduling adapts the controller dynamically, based on conditions such as Speed (reference or measured value), Position (reference or measured value), Motion phase (best settling) or even Manual selection.

With Technosoft drives, up to 64 controller sets can be defined, each with its own tuning values, and applied at the right time according to defined trigger conditions.

This flexibility is critical in applications where a single tuning set cannot deliver both fast response and stable settling, or where operating conditions vary widely during the motion cycle.

Why Use Gain Scheduling?

The Limitation of Fixed Gains

A conventional PID controller forces the engineer to compromise between:

• Fast rise time vs. overshoot
• Responsiveness vs. stability
• High precision vs. robustness

This compromise often results in suboptimal performance: too aggressive in one phase of motion, too sluggish in another.

The Advantage of Dynamic Gains

With gain scheduling, Technosoft drives can:

• Use high proportional gain (Kp) during acceleration to minimize rise time.
• Switch to lower Kp and optimized Ki near target position to avoid overshoot.
• Apply different settings for standing, settling, and in-motion phases.

This ensures smooth transitions, better accuracy, and faster cycle times without instability.

Gain Scheduling Methods in Technosoft Drives

Technosoft drives support multiple scheduling methods. Each method has unique advantages and application scenarios.

1. By Speed Reference

• Triggered by the commanded speed
• Best suited for applications where load dynamics vary with commanded speed
• Example: Packaging machines running both low-speed setup movements and high-speed production cycles

2. By Actual Speed

• Uses the measured motor speed instead of the reference
• Ensures adaptation to real-world variations, including load disturbances or speed drops
• Example: Conveyor systems with variable load inertia

3. By Position Reference

• Based on the commanded target position
• Useful in applications where control requirements change depending on position along the trajectory
• Example: Robotic arm movement that goes from horizontal to vertical

4. By Actual Position

• Uses actual measured position from the encoder
• Ensures precise control in systems where load mechanics vary depending on actual location
• Example: Printing heads or inspection equipment with mechanical tolerances at certain regions

5. Best Settling

• A fixed 3-phase strategy:
  1. In motion → aggressive tuning for fast response
  2. Settling → softer tuning to reduce overshoot
  3. Standing → stable tuning to minimize steady-state error
• Example: Robotics, CNC, pick-and-place machines

6. Manual Selection

• Gives complete control to the user
• Multiple gain sets can be saved to the drive’s non-volatile memory and be selected on the fly from the master controller.
• Gain sets are chosen via the “GS_INDEX” global parameter
• Best for advanced users who want full control over gain switching

When Should You Use Gain Scheduling?

Gain scheduling is ideal when system dynamics vary significantly during motion, such as:

• Multi-stage trajectories in robotics or CNC systems
• Load changes or varying speeds
• Applications demanding high precision with minimal overshoot
• Scenarios where mechanical compliance or backlash may affect performance

By leveraging gain scheduling, users can achieve rapid response without sacrificing stability, a key advantage over traditional PID control.

Conclusion

Gain scheduling in Technosoft drives transforms motion control from a compromise into an optimization. By adjusting control parameters in real time, it delivers faster response, smoother settling, and higher precision—without the instability associated with fixed-gain controllers.

With support for multiple scheduling strategies, intuitive setup in EasyMotion Studio II, and compatibility with a wide range of motor types, gain scheduling ensures that Technosoft drives can be tuned for the highest performance in the most demanding applications.

Contact our team today!