Aiming at the low mechanical property of existing self-lubricating ceramic cutting tool material, a new Al2O3 based nano-micro composite gradient self-lubricating ceramic tool material was developed by applying the de...
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Aiming at the low mechanical property of existing self-lubricating ceramic cutting tool material, a new Al2O3 based nano-micro composite gradient self-lubricating ceramic tool material was developed by applying the design concept of nano-micro composite. The self-lubricating ceramics was composed of ceramic matrix and self-lubricating component, and was prepared by hot pressing technology at a hot-pressing temperature of 1650℃, pressure of 30MPa, and duration of 15min. The model of gradient ceramic tool material is symmetrical composition distribution, and the compositional distribution n and layer number are 1.8 and 7, respectively. The result shows that the interfaces between layers are bonded well and no cracks or defects can be observed. Compare with the homogeneous material, the flexural strength, hardness and fracture toughness of Al2O3 based graded material increase by 74%, 5.2% and 3.9%, respectively.
The observer-based H∞ control problem for discrete-time networked systems where the output measurements are subject to random time delays is considered in this paper. With the proposed measurement model, an observer-...
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The influence of friction on microforming increased dramatically than macroforming with the miniature of the forming parts. The factors which have great impact on friction coefficient in microsheet forming were studie...
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It is necessary to study the dynamic characteristics of the structure of processing shaft cascade in high speed and high precision PCB drilling machine because of its great impact on the drilling precision. As a basic...
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A method to shape the incident laser beam into a concentric multi-ring pattern with different intensity distribution is presented based on geometrical transform method and energy conservation. The output two and three...
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A method to shape the incident laser beam into a concentric multi-ring pattern with different intensity distribution is presented based on geometrical transform method and energy conservation. The output two and three rings are designed as examples to verify the validity of the method. The real shaped rings are produced by the spatial light modulation （SLM） and the experimental results show that the shaped laser beam can satisfy the design requirements.
This paper is concerned with the observer-based H∞ control problem for discrete-time networked systems subject to random communication time delays. Under the assumption that the measurements are not time stamped, a n...
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ISBN:
(纸本)9781467355339
This paper is concerned with the observer-based H∞ control problem for discrete-time networked systems subject to random communication time delays. Under the assumption that the measurements are not time stamped, a new measurement model is presented to describe the measured data subject to random delays which are caused by the transmission between the sensor and the observer. Then the observer-based controller is designed by solving a linear matrix inequality. Our design guarantees the exponentially mean-square stability of the closed-loop system and satisfies the prescribed H ∞ performance. A simulation example is given to illustrate the effectiveness of the proposed method.
This paper investigates an H∞ filtering problem for discrete-time networked systems with random delays. Under the assumption of no packet dropout, a new measurement model is presented to describe the measured data su...
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ISBN:
(纸本)9781467355339
This paper investigates an H∞ filtering problem for discrete-time networked systems with random delays. Under the assumption of no packet dropout, a new measurement model is presented to describe the measured data subject to random delays which are caused by the transmission between the sensor and the state estimator. Based on this model, a sufficient condition for the existence of the estimator is given in terms of the feasibility of a linear matrix inequality (LMI). The designed estimator guarantees the exponentially mean-square stability of the state estimation error system and satisfies the prescribed H∞ performance. Finally, a numerical example is given to illustrate the effectiveness of the proposed approach.
This paper is concerned with the stochastic bounded consensus tracking problems of leader-follower multi-agent systems, where the control input of an agent can only use the information measured at the sampling instant...
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This paper is concerned with the stochastic bounded consensus tracking problems of leader-follower multi-agent systems, where the control input of an agent can only use the information measured at the sampling instants from its neighbours or the virtual leader with a time-varying reference state, and the measurements are corrupted by random noises. The probability limit theory and the algebra graph theory are employed to derive the necessary and sufficient conditions guaranteeing the mean square bounded consensus tracking. It is shown that the maximum allowable upper boundary of the sampling period simultaneously depends on the constant feedback gains and the network topology. Furthermore, the effects of the sampling period on the tracking performance are analysed. It turns out that from the view point of the sampling period, there is a trade-off between the tracking speed and the static tracking error. Simulations are provided to demonstrate the effectiveness of the theoretical results.
For the vehicle, lightweight means low fuel consumption. and small quantity of exhausted gas. In this paper by using the finite element method, the author established the model of the truck side framework. After meshi...
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