QRTL Overshoots home position

During landing, my quadplane overshoots the home position, then “reverses” for it to start descending. Initially I thought I should increase q_loit_acc_max but even with a 50% increase (120 to 180) I don’t see any improvement.

What parameter should I change to ensure the quadplane does not overshoot home position.
@tridge

The most likely cause is your Q_TRANS_DECEL is too high. Posting a log also helps.

Thank you Tridge
Below is the log file showing the overshoot.

https://drive.google.com/file/d/14_f_qbalYil_SAXTxL_OK2xlTFezgA9-/view?usp=sharing


image showing the overshoot (about 30m past home) in QRTL

In addition, I also find my sink rate is very low (less than 1) during RTL but during guided mode or auto, I am able to achieve sink rates of up to 5.

This is a quadplane of 40kgs with a wingspan of about 4.5m.

the Q_TRANS_DECEL is indeed way too high. The current value is 2.0. I suggest changing it to 1.0 to start with, and lower it some more if you still get overshoot
I’d also suggest you look at this tuning guide:
https://ardupilot.org/plane/docs/quadplane-vtol-tuning-process.html
you seem to have skipped some of the basic tuning steps

the TECS.hdem and TECS.h do track each other nicely in RTL mode:

Thank you Tridge,
Let me test this. Will post how it goes.

I settled on Q_TRANS_DECEL value of 0.8 and I no longer have overshoots on landing.

Thank you.