24 research outputs found
Robust global fast terminal sliding mode controller for rigid robotic manipulators
No full textA global fast terminal sliding mode controller (GFTSMC) is proposed for a-link rigid robot manipulators by employing the fast terminal sliding mode control concept" in both the reaching phase and the sliding phase. Under the control, the system states will reach the terminal sliding manifold in a desired finite time and then converge to the origin along the sliding manifold in a specified finite time, resulting in reduced steady tracking error in comparison with the linear sliding mode controller. The proposed sliding mode controller is continuous and therefore is chattering-free. An example is shown to demonstratethe effectiveness of the controller
P-Expert : implementation and deployment of large scale fuzzy expert advisory system
No full textThis paper discusses the problem of parthenium weed infestation in Queensland and describes P-Expert, an expert advisory system designed to provide expert knowledge in control and management strategies of partheniurn weed. P-Expert is fundamentally a hybrid fuzzy expert system incorporating technologies from fuzzy logic, relational database and multimedia systems. The primary topic of this paper will be a description of the framework of P-Expert, focussing on three main areas: (1) Layered component architecture - each component of the expert advisory systern is designed as modules to facilitate maintenance, adaptability and flexibility, (2) Discourse semantics (explanatory capabilities) - provision for explanation and justifying outputs given by the expert advisory system, (3) Metaconsequent - mapping final aggregated output from a fuzzy If-Then rule onto a finite database, and (4) Deployment of large scale advisory expert system
Applying an evolutionary algorithm to web search: The methodology of Evagent
No full textAn evolutionary algorithm is introduced to find authoritative resources on the Web. The problem of Web search is considered as an optimisation problem within hyperlinked space. We aim to find information that is both relevant andrecent so as to cope with the dynamic nature of the Web. Theoretical studies have been made on problem-specific search space, fitness functions and generic operators. The search space is constructed in the direction so the optimum driven by the reproduction operator with good hubs as a clue. Fitness functions combine text-based and link-based analysis. The (u+7) evolution strategy just implements the selection scheme of elitism. The mutation operator helps to prevent search from trapping in local optimisation by introducing multiple domains. Experiments have been performed to study algorithms performance. The algorithm has been implemented as a kernel component of an intelligent Web agent Evagent
Continuous finite-time control for robotic manipulators with terminal sliding modes
No full textA new continuous finite-time control scheme (or trajectory-tracking problem ofrobotic manipulators is proposed using terminal sliding mode (TSM). The finite-time convergence property of TSM is applied in both the reaching phase and the sliding phase ofthe sliding mode control system. As a result; the closed-loop system is globally finite-time stable and the trajectory-tracking objective is achieved in finite time. The resulting control law is continuous therefore chattering-free. Furthermore. it overcomes the common singularity problem in TSM Theoretical analysis shows that the proposed control strategy has stronger robustness and disturbance-attenuation ability compared with the conventional boundary-layer method. Simulation results are given to illustrate the effectiveness ofthe proposed algorithm
Phase-to-phase wave parameters measurement of distribution lines based on BP networks
No full textAbstrac
