# A Survey on Output Feedback Control of Robot Manipulators with an Application to PHANToM 1.5A Haptic Device

## TL;DR

This survey reviews velocity-free control schemes for robot manipulators, demonstrating their implementation on a simulated 3-DOF PHANToM 1.5A robot, comparing observer-based and approximate derivation methods with stability and robustness analyses.

## Contribution

It provides a comparative analysis of velocity-free control algorithms, highlighting the advantages of approximate derivation methods and their practical implementation on a haptic device.

## Key findings

- Approximate derivation controllers are more intuitive and easier to implement.
- These controllers are globally asymptotically stable.
- Simulation confirms robustness to disturbances and unmodeled dynamics.

## Abstract

This paper is aimed at presenting a short survey of velocity-free control schemes for robot manipulators. A salient feature of this work is the implementation of this control schemes on a simulation model of the 3-DOF industrial PHANToM 1.5 A robot. For both the regulation and tracking problems, two classes of control algorithms without velocity measurements are considered, namely, those based on observer-controller combination and those based on approximate derivation through an n-order filter. The latter was shown to be more advantageous from different aspects. First the controllers based on approximate derivation are very intuitive and easy to implement in practice. Moreover, these algorithms are proved to be globally asymptotically stable, while the observer-based controllers have only local stability results. We have also considered some algorithms that are robust to load disturbances and to unmodeled dynamics. Simulation results have confirmed the theoretical advantages and drawbacks of each algorithm.