What is a servo press?

A servo press uses servo motors for precise force and position control during forming operations.

How do I calculate servo press tonnage?

Use our free tonnage calculator at servopress.club/tonnage-calculator.html

Servo Drive Parameter Tuning: Reducing Overshoot on High-Speed Strokes

admin

Position overshoot on a servo press can damage tooling and trigger safety faults.

## Why Overshoot Happens

Overshoot occurs when the drive commands deceleration too late or when position loop gain is too high relative to velocity loop bandwidth. Variable load and mechanical compliance in the drive train make this worse on a press.

## Tuning Sequence

### 1. Velocity Loop First

Set KVP to 50% of default, KVI to 20ms. Command a 10% speed step and observe response. Increase KVP until slight oscillation then back off 20%. Target bandwidth: 80-150 Hz for a 200-ton press.

### 2. Position Loop Gain

Start at KPP = 30 rad/s, increase in steps of 5. Target: position error under 0.05mm during forming. Acceptable overshoot at TDC: under 0.1mm.

### 3. Enable Feed-Forward

Velocity feed-forward KFF: start at 80%, increase until following error during acceleration is minimized. With proper feed-forward you can reduce KPP by 30% while achieving better tracking.

### 4. Adjust the Motion Profile

Increase deceleration ramp length approaching BDC. Add a creep phase of 5-10mm at 10% speed before forming contact. Use S-curve profiles instead of trapezoidal.

## Validation

Empty stroke at max SPM: position error under 0.1mm. Full load at 50% SPM: check for increased following error. Run 30 minutes at production speed for thermal test. 100-stroke repeatability test: BDC variation target under 0.02mm.

anna_controls

Overshoot tuning is an art. Start by reducing position loop gain (Kp) by 20% from default. If overshoot improves but settling time gets worse, increase velocity loop gain instead. The goal is to get the velocity loop tight enough that the position loop doesn't have to work as hard. On Yaskawa, Pn100 and Pn101 are your main knobs.

jim_applications

One thing that causes overshoot that isn't a tuning issue: mechanical backlash. If the gearbox or ball screw has backlash, no amount of tuning will eliminate overshoot completely. Check mechanical play first before spending hours tweaking parameters. I've seen shops tune for days when the real problem was 0.05mm of backlash in the reducer.