INTELLIGENT MECHANISM TO SUPPORT DFX ABILITIES IN AUTOMATED DESIGNER'S ENVIRONMENT

The paper aims at providing a computerized design environment to support product design practically. The authors solved this problem by taking the product life-cycle issues into consideration as more as possible during the design process from the designer-oriented perspective of view. Design for X-abilities (DFX) is an effective approach to this philosophy. So the paper mainly presents the infrastructure of an intelligent DFX mechanism which is the essential part of the developed product design environment. At first the designer-oriented computer environment DesignerSpace is introduced for understanding the designer how to implement design activities and DFX method better. In order to integrate design knowledge from downstream aspects for the optimization and the design decision-making, an intelligent DFX mechanism is developed to incorporate knowledge base, algorithm-base and monitoring/debugging tools. DesignerSpace is implemented with DFX abilities and applied to the blisk design of aircraft engine and the further development is strongly intended.

INTELLIGENT CAD OF CRANE TRAVELLING MECHANISMS

Based on common characteristics in crane design, a new procedure of intelligent CAD for crane travelling mechanisms is proposed. The CAD used for crane travelling mechanisms is usually involved in choosing electrical motors.gear reducers,brakes and couplings, arranging travelling wheels and equilibrium beams.checking temperature increase of motors and slippage of driving wheels,estimating the time used for starting and stopping the cranes, drawing up the travelling mechanism.and so on. By enhancing the CAD, the related expert system and overall intelligent con trol are further developed here in treated as individual module. Accordingly,the intelligent CAD is constructed by combing the CAD with the two modules.

Editorial:Mechanics of intelligent materials and structures

Recently, intelligent or smart materials and structures have been received more and more attention due to their distinguished multi-field coupling properties and wide applications in aerospace, automobiles, civil structures, medical devices, information storage, energy harvesting and so on. It is of academic challenge to fully understand the complex multi-field coupling behaviors of various smart materials and structures, and of engineering sig- nificance to enhance the performance and reliability of these materials and structures in industrial applications. The papers in the special topic of Mechanics of Intelligent Materials and Structures focus on the understanding of the electromechanical, magneto-elastic, and magneto-rheological coupling behav- iors and properties of smart materials and structures for applications in vibration control, resonators, and various functional devices.

Fast determination of meso-level mechanical parameters of PFC models

To solve the problems of blindness and inefficiency existing in the determination of meso-level mechanical parameters of particle flow code (PFC) models, we firstly designed and numerically carried out orthogonal tests on rock samples to investigate the correlations between macro-and meso-level mechanical parameters of rock-like bonded granular materials. Then based on the artificial intelligent technology, the intelligent prediction systems for nine meso-level mechanical parameters of PFC models were obtained by creating, training and testing the prediction models with the set of data got from the orthogonal tests. Lastly the prediction systems were used to predict the meso-level mechanical parameters of one kind of sandy mudstone, and according to the predicted results the macroscopic properties of the rock were obtained by numerical tests. The maximum relative error between the numerical test results and real rock properties is 3.28% which satisfies the precision requirement in engineering. It shows that this paper provides a fast and accurate method for the determination of meso-level mechanical parameters of PFC models.

Effect of CF and RPP on the Mechanical and Electrical Properties of Smart Aggregate

By using redispersible polymer powder（RPP） and carbon fiber（CF） to adjust the flexibility and electrical properties of the smart aggregate, a new kind of smart aggregate with Z type structure was proposed. The study shows that Z type aggregate is more sensitive to the feedback of external force than the prism aggregate in the same loading environment, and it indicates that Z type aggregate is more suitable for the research and application of concrete health monitoring. Although the incorporation of RPP would cause the compressive strength of the aggregates and the elastic modulus of hardened cement mortar to reduce slightly within the dosage of RPP by 2.25% because of the polymer film formed in the internal system, this would improve the deformability of the aggregates. In the early loading stage（in the first 60 seconds）, the intelligent concrete specimens implanted with Z type smart aggregate do not show higher sensitivity as expected, although the resistance change rate changes a little bit more, the overall of it is still in balance. Adding RPP could improve the flexibility of smart aggregates exactly, and it plays an active role in prolonging the life of the smart aggregates. By implanting Z type aggregates the damage and failure of the concrete structure could be predicted accurately in this study. The results of this paper will help to promote further research and application of intelligent concrete.

Frontiers of collaborative intelligence systems

The development of information technology has propelled technological reform in artificial intelligence(AI).To address the needs of diversified and complex applications,AI has been increasingly trending towards intelligent,collaborative,and systematized development across different levels and tasks.Research on intelligent,collaborative and systematized AI can be divided into three levels:micro,meso,and macro.Firstly,the micro-level collaboration is illustrated through the introduction of swarm intelligence collaborative methods related to individuals collaboration and decision variables collaboration.Secondly,the meso-level collaboration is discussed in terms of multi-task collaboration and multi-party collaboration.Thirdly,the macro-level collaboration is primarily in the context of intelligent collaborative systems,such as terrestrial-satellite collaboration,space-air-ground collaboration,space-air-ground-air collaboration,vehicle-road-cloud collaboration and end-edge-cloud collaboration.Finally,this paper provides prospects on the future development of relevant fields from the perspectives of the micro,meso,and macro levels.

Anthropomorphic hand based on twisted-string-driven da Vinci’s mechanism for approaching human dexterity and power of grasp

Designing anthropomorphic prosthetic hands that approach human-level performance remains a great challenge.Commercial prosthetics are still inferior to human hands in several important properties, such as weight, size, fingertip force,grasp velocity, and active and passive dexterities. We present a novel design based on the under-actuated da Vinci’s mechanism driven by a flexible twisted string actuator(TSA). The distributed drive scheme allows structural optimization using a motion capture database to reproduce the natural movement of human hands while keeping adaptability to free-form objects. The application of TSA realizes a high conversion from motor torque to tendon contraction force while keeping the structure light,flexible, and compact. Our anthropomorphic prosthetic hand, consisting of six active and 15 passive degrees of freedom, has a weight of 280 g, approximately 70% of that of a human hand. It passed 30 of the 33 Feix grasp tests on objects in daily living and retained a loading capacity of 5 kg. This simple but intelligent mechanism leads to excellent stability and adaptability and renders feasible wide applications in prosthetics and in service robots.