Multi-DoF Time Domain Passivity Approach Based Drift Compensation for Telemanipulation

Abstract

When, in addition to passivity, position synchronization is also desired in bilateral teleoperation, Time Domain Passivity Approach (TDPA) alone might not be able to fulfill the desired objective. This is due to an undesired effect caused by admittance type passivity controllers, namely position drift. Previous works focused on developing TDPAbased drift compensation methods to solve this issue. It was shown that, in addition to reducing drift, one of the proposed methods was able to keep the force signals within their normal range, guaranteeing the safety of the task. However, no multi-DoF treatment of those approaches has been addressed. In that scope, this paper focuses on providing an extension of previous TDPA-based approaches to multi-DoF Cartesian-space teleoperation. An analysis of the convergence properties of the presented method is also provided. In addition, its applicability to multi-DoF devices is shown through hardware experiments and numerical simulation with round-trip time delays up to 700 ms.

Whole-Body Teleoperation and Shared Control of Redundant Robots with Applications to Aerial Manipulation

“…This paper extends our previous work, [12] and [13], in two directions. Firstly, it provides the extension of the multi-DoF drift compensator presented in [12] to compensate for the drift caused by TDPA in all subtasks, not only the main one, as shown in that paper.…”

“…This paper extends our previous work, [12] and [13], in two directions. Firstly, it provides the extension of the multi-DoF drift compensator presented in [12] to compensate for the drift caused by TDPA in all subtasks, not only the main one, as shown in that paper. In addition, the framework presented here can be seen as a generalization of the one presented in [13], where the following points were improved: the task selection logic, which allows the user to switch among tasks, was modified in order to make the system more robust to time delay and allow online switching among tasks; moreover, an analytical treatment of the effects of the coordinate transformation performed by the whole-body controller and its effects on the passivity of the system is presented.…”

“…In order to fulfill the passivity conditions from Eqs. 40 and 41, the slave-side PC can be applied as [12] λ…”

“…In case the coupling in λ and Γ d is not desired, the proposed approach could be transformed into its concatenated version [12], where each task would have a separate energy function, and the passivity of each task would be independently enforced.…”

Energy-Based Cooperative Control for Landing Fixed-Wing UAVs on Mobile Platforms Under Communication Delays

“…This operating point shift (subtraction of v land from the absolute velocity signals) allows for the distinction of inward and outward energy flows based on the sign of the power conjugated signal, as is usual in classical teleoperation setups [15]. Moreover, adding a current source to modify the desired velocity is a common practice in TDPA-based drift compensation [19], [20]. In fact, by having a part of the position synchronization controller before the passivity controller allows for automatic recovery of the drift caused by the PC.…”