Wave-Variable-Based Passivity Control of Four-Channel Nonlinear Bilateral Teleoperation System Under Time Delays

Abstract

An innovative wave-based Time Domain Passivity Approach (TDPA) applied to a four-channel (4-CH) nonlinear teleoperation system is proposed. The primary objective of this approach is to enhance system transparency while maintaining stability in the presence of random time delays. The system stability for different scenarios of human and environment condition is analyzed. The method is validated through experimental work based on a 3-DOF bilateral teleoperation system. The experimental results show that the proposed control algorithm can robustly guarantee the system stability and simultaneously provide better performance than methods developed in previous work.

Time domain passivity control of time-delayed bilateral telerobotics with prescribed performance

“…where is a constant p-dimensional vector of inertia parameters and ( ,̇,̈) ∈ × is the matrix of known functions of the generalized coordinates and their higher derivatives [20]. P4: For the robots with revolute joints, there exists a positive bounding the Coriolis/centrifugal matrix as:…”

“…From (30), only when the passivity of the master, the communication channels and the slave are simultaneously maintained, can the overall system's passivity be guaranteed. In this paper, the passivity of communication channels can be guaranteed by using the wave-based TDPA proposed by the authors in [20]. The wave-based TDPA has the following advantages compared with previous approaches: 1) wave-based TDPA can accurately observe the power flow in the communication channels and provide higher transparency than traditional TDPA to the teleoperation system.…”

“…However, although the above TDPA-based system can guarantee system stability under time-varying delays, transparency degradation is their main drawback, even in the presence of small constant or no time delay. In [20], we design a new wave-based TDPA to significantly enhance the system transparency compared with the previous approaches in the presence of arbitrary time delays. However, our wave-based TDPA in [20] is only proposed to guarantee the passivity of communication channels.…”

“…In [20], we design a new wave-based TDPA to significantly enhance the system transparency compared with the previous approaches in the presence of arbitrary time delays. However, our wave-based TDPA in [20] is only proposed to guarantee the passivity of communication channels. In practice, the control algorithms in the master side and the slave sides can also insert extra energy into the system especially when the measured external force signals are involved, to the extent that the overall system's passivity may still be easily jeopardized without proper control parameters.…”

“…To our best knowledge, PPC has not been deployed into achieve force tracking forces in bilateral teleoperation systems. The contributions of this paper are list as follows: 1) Unlike the previous system in [20] in which the TDPA is used to guarantee the passivity of communication channels, the new designed TDPA is able to guarantee the passivity of the whole system. 2) The previous TDPA system in [20] has a main drawback.…”