Applied Mechanics and Materials Vols. 543-547

Abstract: The effect of the mechanical properties and geometric parameters on the crack density of a multi-layered thin film structure under residual tensile stress is investigated theoretically. The numerical results show that the crack density of the thin film decreases with the increase of the thickness of the thin film and (or) the fracture strength of the thin film. These results can help us more deeply understand the fracture behavior of the multi-layered thin film structure under residual tensile stress.

Abstract: A new thin cross type rotary ultrasonic motor has been proposed for further study of this type motors characteristics. As a stator, eight semi-circular piezoelectric ceramics were attached on the upper and bottom sides of a thin hollow cross brass plate. The stator was excited by two sinusoidal voltages with a phase difference of 90° and elliptical trajectories were generated at the contact points to drive a shaft rotor. The driving principle of the motor was illustrated by degenerating two orthogonal in plane vibration modes. Based on FEM analysis, the vibration shapes and frequencies of operation modes were simulated and the relationships between the maximum displacements of the contact points and various motor parameters were obtained. A prototype was fabricated and characteristics of the motor were measured. The relationship among rotation speed, pre-pressure and voltage are no-linear. The maximum rotation speed with no load was 22.9 rpm. The merits and shortcomings of the thin cross type rotary ultrasonic motor were discussed.

Abstract: This paper proposed an online direction classifying method for constructing an intuitive tactile communication during human-robot cooperation. The proposed approach abstracts a suitable feature set from a tactile array sensor equipped on a hand-bar. This lower computation feature extraction method analyze the weighting values concerned with oriental information from principle component analysis (PCA), together with support vector machines (SVM) classifier for direction classification and recognition. Experimental results showed an average accuracy of 96.3% and a low costs of 512μs with respect to different handle gestures of the 6 touch directions, which is practicable utilized for human-robot cooperation based on tactile recognition.

Abstract: To meet the test requirements of a certain kind missile, the general test system based on the PXI bus and test adapters is designed, The generality of the system is achieved by designing corresponding adapter for different types of missiles, the framework based on the function interface and the method of the test tasks handle dynamic management are used in the software, the expert systemthe database theory and other theories are used in the intelligence faults diagnosis system. The practical application results indicated that the system has many advantages such as better generality, high automatization and more convenience.

Abstract: It is of great importance to accomplish identifying the non-cooperative targets inertial parameters for capturing and controlling it. This paper adopts an identification method utilizing the tactile and vision to establish the identification equations based on the principle of conservation of momentum. In order to solve the equations precisely and rapidly, two of the most widely used methods: the least square method and the recursive least-square method (RLS) are employed for simulation and calculation utilizing ADAMS and MATLAB, and the limitation of each method is pointed out. Then the paper proposes a new method named the recursive method based on the least square solution. This method provides the identification equation a new solving thought and realizes fast identification of the targets inertial parameters at high accuracy. The simulation results verify the validity and feasibility of the proposed approach.

Abstract: This paper investigates a special case for scheduling of the multi-crane operations in batch annealing process in an iron and steel enterprise so that the completion time of the last annealed coil (makespan) is minimized. Additional no-delay and no-buffer constraints for taking fully advantage of machines are considered. No-delay constraints for machine unloading means technological requires fixed heating time and cooling time that once the heating (cooling) is completed, the furnace (cooler) must be unloaded immediately without any delay by crane. No-buffer constraints for machine unloading means the time gap between the unloading time of one machine for one job and its start time on the next job is exactly equal to the corresponding transportation time. We prove that this problem can be solved optimally in polynomial time where the starting time and ending time of every possible crane movement are formulated.

Abstract: We consider a multi-crane scheduling problem commonly encountered in real warehouse operations in steel enterprises. Given some demanded coils, if a demanded coil is in upper level or in lower level without being blocked, it can be picked up directly to designated place; else, the blocking coils need to be picked up to another position first. Unlike previous literatures in which both operations have been considered to be scheduled separately, our problem schedules transportation operation and shuffling operation coordinately. The objective is to minimize the last demanded coil transported to its designated place which is consistent with the earliest possible completion time of one crane. We propose a heuristic algorithm for solving this demonstrated strongly NP-hard.

Abstract: Network intrusion is highly destructive and uncontrollable. Current networks are all closed-loop feedback control systems, therefore conflicts, instability, limit data bandwidth and other uncontrollable factors occur after networks intrusion. The traditional stability control methods have better control to the pre-intrusion. Once after intrusion, the volatility of networks will beyond the control and the control threshold cannot play the role of optimal control. On the foundation of feedback rules of random and long-time unstable network control system states, this paper proposes a stability and stabilization method for network volatility caused by intrusion. Finally, a numerical example is used to verify the validity of the conclusions.

Abstract: Cyber-Physical Systems (CPS) are integrations of computation with physical processes. This paper develops a precision agriculture architecture based on CPS technology, including three layers: the physical layer, the network layer and the decision layer. Every layer is analyzed in detail. This paper helps the exploration of CPS in precision agriculture.

Abstract: In this paper, the degradation problem of digital Logistic map is investigated. Chen chaotic system is applied to anti-control the digital Logistic map and a controller that combines an external state control along with a modular function is designed. Results of the experiments show that the external control can greatly improve the dynamical and statistical properties. Thus, it can be used in cryptography applications.