Increasing stability in model-mediated teleoperation approach by reducing model jump effect

Abstract

Model-mediated teleoperation is a predictive control approach for controlling haptic teleoperation systems whereby the environment force is virtually located on master side in order to increase the stability and transparency of the system. This promising approach, however, results in new challenges. One pivotal challenge is the model jump effect, which stems from the delay in correct creation of the virtual environment. Previous works have endeavored to reduce this effect; however, they either led to transparency decrease or assumed simplified environment models. In this paper, we propose a control approach for this aim based on the idea of decoupling. This means that when a new environment has been identified, the operation is interrupted and no signal is transmitted between master and slave sides. During this time, both sides are controlled by their own sliding mode controllers until the system reaches stability. The main advantage of this method is its independence from environment type, which makes it usable for different kinds of applications. To verify the effectiveness of the proposed approach simulation tests are conducted. The results show the system is stable in interaction with hard and soft environments in presence of large time delays in communication channels.

QoS Provisioning: Key Drivers and Enablers Toward the Tactile Internet in Beyond 5G Era

“…Similarly, the study in [184] proposed a model-based control design that decoupled master and slave during state transitions to ensure system stability and high transparency. The authors overcame model jumping effects causing a mismatch period, i.e., an interval when the master-side local model is not informed about the new environment parameters.…”

L1 impedance control for bilateral teleoperation containing model uncertainty

“…A linear viscoelastic environment dynamics, generally known as Kelvin–Voigt, is a proper representation in many real-life cases (Cortesão et al, 2006; Yazdankhoo and Beigzadeh, 2019), which can be written down as…”

“…Impedance control has primarily been applied to master side in teleoperation systems so as to render the haptic feel to the operator (Tabatabaei et al, 2019; Yazdankhoo and Beigzadeh, 2019, Zhang et al, 2018). Nevertheless, safe behavior in the presence of environment force on the slave side can be attained in light of impedance control, as well.…”

Position synchronization for an uncertain teleoperation system with time delays using L1 theory

“…Predictive control has been another widely used approach in recent years [9]. It has been applied to both sides of a teleoperation system: to the operator side as model-mediated teleoperation [10] and to the teleoperator side to predict the human motion before/after transmitting it through communication channel, with either constant known time delays [11] or both constant and variable but unknown time delays [12].…”