Delay-Dependent Stability Analysis of Haptic Systems via an Auxiliary Function-Based Integral Inequality

In this paper, the delay-dependent stability of haptic systems is studied by developing a new stability criterion. Firstly, the haptic system inevitably introduces time delays by using communication networks to transmit information between the controller and the haptic device. When discussing the stability of the haptic system near its operating point, the original nonlinear system is modeled as a linear system with the time delay mentioned above. In addition, a suitable augmented Lyapunov–Krasovskii functional (LKF) with more integral forms is constructed and an auxiliary function-based integral inequality is applied to estimate the derivative of the proposed LKF. Then, a less conservative delay-dependent criterion in terms of the linear matrix inequality (LMI) is derived to calculate the delay margin for the haptic system. Finally, case studies are carried out based on a one degree of freedom haptic system. The results show that, compared with criteria in existing works, the proposed criterion can obtain more accurate results and require less calculation complexity, and, with the increase in virtual damping in a certain range, the stable upper bound of the haptic system increases at first and then decreases.

Development of a Human-Display Interface with Vibrotactile Feedback for Real-World Assistive Applications

It is important to operate devices with control panels and touch screens assisted by haptic feedback in mobile environments such as driving automobiles and electric power wheelchairs. A lot of consideration is needed to give accurate haptic feedback, especially, presenting clear touch feedback to the elderly and people with reduced sensation is a very critical issue from healthcare and safety perspectives. In this study, we aimed to identify the perceptual characteristics for the frequency and direction of haptic vibration on the touch screen with vehicle-driving vibration and to propose an efficient haptic system based on these characteristics. As a result, we demonstrated that the detection threshold shift decreased at frequencies above 210 Hz due to the contact pressure during active touch, but the detection threshold shift increased at below 210 Hz. We found that the detection thresholds were 0.30–0.45 gpeak with similar sensitivity in the 80–270 Hz range. The haptic system implemented by reflecting the experimental results achieved characteristics suitable for use scenarios in automobiles. Ultimately, it could provide practical guidelines for the development of touch screens to give accurate touch feedback in the real-world environment.

Corpi annidati

We are bodies start from other bodies. Yet, we rarely consider how our bodies extend into our surroundings. Discusses our body schema, peripersonal and extra personal space. Considers buildings as extensions of our bodies and minds and develops the con-cept of nested bodies that engage the senses, spatial cognition and a sense of place, audi-tory system and acoustic architecture, the haptic system and texture, tasting, smelling and the imagination, visual perception and chronobiology, atmospheric space.

Kompetenzentwicklung in der hybriden Montage/Design of system interaction for competence development in hybrid assembly systems

Für eine Kompetenzentwicklung im Wertschöpfungsprozess müssen Schnittstellen für die Interaktion mit dem System lernförderlich gestaltet sein. In der Mensch-Roboter-Kollaboration, zum Beispiel in der Montage, kann eine lernförderliche Gestaltung der visuellen, auditiven und haptischen Systeminteraktion die Informationsakquisition unterstützen. Hierzu wurden Gestaltungskriterien für die Systeminteraktion erstellt und auf einen Mensch-Roboter-Arbeitsplatzes angewandt.   To develop competence in the value-adding process, interfaces for interaction with the system must be designed to promote learning. In human-robot collaboration, e.g. in assembly, a design for visual, auditory and haptic system interaction that is conducive to learning can support information acquisition. For this purpose, design criteria for system interaction were developed and applied to the design of a human-robot workstation.

Optimal interface controller design for haptic system

Haptic technology is the future oriented technology having wide applications in various field from medical, military and pilot training to video games and smartphones. In medical, it can prove a major asset for training the surgeon. The key performance issues in a haptic system are stability and transparency. This paper presents the design of haptic interface controller (HIC) for a 1-DOF haptic system designed to be used by surgical practitioners. The designed controller emphasizes on stability and transparency under the presence of uncertainty and delay. The optimal parameter of HIC has been selected using Genetic Algorithm (GA) and modified Particle Swarm Optimization (m-PSO). The performance of the designed controller is evaluated in terms of performance measure and compared with the conventional tuning method.

Novel m-PSO-SVM based Interface Controller Design for Haptic System

The haptic system has two key performance issues: stability and transparency. A haptic interface controller (HIC) is designed to address these issues. Addressing these issues becomes a complex problem as both are complementary to each other. Here, when transparency of the system is increased, its stability degrades and vice-versa. To overcome this problem, intelligent optimized solutions are used in this paper to design a HIC controller for the haptic system. SVM and NN techniques have been employed to identify the performance of the controller, ensuring stability and transparency both. The disadvantages of NN in terms of the number of neurons and hidden layers are overcome by SVM. Further, the performance of SVM is highly dependent upon the selection of free parameters. So, further, a modified PSO technique is employed for the optimal selection of these parameters to enhance the performance of SVM. Hence, this novel proposed hybrid technique of m-PSO optimized SVM is applied for the optimal design of the HIC to find out an optimal solution between trade-off the transparency and stability of the haptic device simultaneously. To appreciate the efficacy of the proposed technique, the result obtained with this is compared with HIC design using neural network and conventional ZN method also. This designed controller ensures stability as well as transparency, even under the presence of uncertainty, delay, and quantization error.