# Model-free Friction Observers for Flexible Joint Robots with Torque Measurements

arXiv: https://arxiv.org/abs/1907.00553 · HTML: https://mlsanity.com/paper/1907.00553/

## Key facts

- Cited by 3 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 1 Jul 2019.

## Built on by (most cited first, 3 of 3)

- [COMBO-Grasp: Learning Constraint-Based Manipulation for Bimanual Occluded Grasping](https://mlsanity.com/paper/2502.08054/) (2025)
- [Enhancing Goal Inference via Correction Timing](https://mlsanity.com/paper/2602.18603/) (2026)
- [CDM: Contact Diffusion Model for Multi-Contact Point Localization](https://mlsanity.com/paper/2502.06109/) (2025)

## Abstract (arXiv)

This paper tackles a friction compensation problem without using a friction model. The unique feature of the proposed friction observer is that the nominal motor-side signal is fed back into the controller instead of the measured signal. By doing so, asymptotic stability and passivity of the controller are maintained. Another advantage of the proposed observer is that it provides a clear understanding for the stiction compensation which is hard to be captured in model-free approaches. This allows to design observers that do not overcompensate for the stiction. The proposed scheme is validated through simulations and experiments.