A Review on Haptic Bilateral Teleoperation Systems

In the haptic human-robot interaction systems, stability and transparency factors are critical but conflicting with one another. Ensuring safety and accuracy of bilateral haptic teleoperation systems is always an important tradeoff to be carefully balanced. Attaining a reasonable operating point for less painful compensation between stability and transparency has been the main concern when designing haptic human-robot systems. Some important works discussed in the paper include model-based control approaches like wave-variable transformation and scattering, time domain passivity/wave prediction with energy regulation, model mediated teleoperation approaches, along with model-free control approaches like neural networks and fuzzy control approaches. The objective to obtain a better agreement between stability and transparency criteria, along with a comprehensive review of these methods and a newly proposed technique attracted most interests of the paper. Earlier solutions tried to achieve a decent tradeoff but were limited to varying time delay and data loss encountered during transmission in the communication channels. The comparison of these methods demonstrates their performance, by illustrating their respective outlines, viability, and limitations, which can aid in the identification of compensation among the state-of-the-art methods and inspire novel ideas. The hardware platforms developed in literature are also summarized here to show the physical implementation of such systems. The paper concludes by suggesting the need of a hybrid method inclusive of an Active Disturbance Rejection Controller (ADRC), towards an even better operating point for the tradeoff between the transparency and stability of haptic human-robot systems.