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In this paper, a general evasion strategy for the cruise phase of the air-breathing hypersonic vehicle is derived by game theory. With the speed advantage over pursuer, the evasion strategy of hypersonic vehicle should be a game of ability rather than traditional trajectory planning method. Different from the traditional evasion methods which try to maximize the miss distance, a lower bound for the miss distance of successful evasion is set up. For pursuer with any guidance laws, the concept of evasion window is introduced and an evasion strategy with minimum effort is proposed in this paper. The simulation results show that the evasion strategy proposed in this paper can achieve minimum effort evasion within the window given by norm differential game.

To solve the problem of multiple missiles attacking a maneuverable target simultaneously, a novel finite-time cooperative guidance law with line-of-sight angle constraint is proposed based on sliding-mode control method. The multiple missiles cooperative guidance model is constructed based on in-plane missiles-target relative motion equations and the process of design including two stages. In the first stage, a distributed finite time cooperative guidance law in the line-of-sight direction is designed based on the adaptive super-twisting and integral sliding mode control theory. Secondly, the acceleration command on the normal direction of the line-of-sight is developed. Mathematical simulation of time cooperation of multiple missiles is carried out for maneuverable target to ensure the missile's line-of-sight angle converges to its desired value in finite time. The proposed guidance law guarantees the attacking of target, and the attack time cooperation of multiple missiles is realized as well.

In this paper, the attitude tracking control problem is investigated for a rigid spacecraft. Robust controllers based on the quaternion model are proposed to solve this problem with external perturbations. An exponential reaching law-based sliding mode control approach is proposed for the problem. The controller guarantees the convergence of attitude tracking errors in finite time, where the settling time can be set in advance, for spacecraft attitude tracking problem. Finally, simulation results are given to demonstrate the efficiency of the proposed methods.

Purpose – A multi-disciplinary robust design optimization method for micro Mars entry probe (no more than 0.8 m in diameter) is proposed. The purpose of this paper is to design a Mars entry probe, not only the geometric configuration, but the trajectory and thermal protection system (TPS). In the design optimization, the uncertainties of atmospheric and aerodynamic parameters are taken into account. The probability distribution information of the uncertainties are supposed to be unknown in the design. To ensure accuracy levels, time-consuming numerical models are coupled in the optimization. Multi-fidelity approach is designed for model management to balance the computational cost and accuracy. Design/methodology/approach – Uncertainties which cannot defined by usual Gaussian probability distribution are modeled with degree of belief, and optimized through with multiple-objective optimization method. The optimization objectives are set to be the thermal performance of the probe TPS and the corresponding b...

In this paper, considering the normal temperature continuous transonic wind tunnel is a typical complex system, we utilize predictive control algorithm based on its state space description to control this system. Meanwhile, optimize the error weighting coefficient matrix Q and control weighting coefficient matrix R by genetic algorithm. Through simulation experiments show that applying the control algorithm makes the wind tunnel system own the characteristic of fast response and good steady performance.

An approach is proposed to avoid model structure determination in system identification using NARMAX (nonlinear auto-regressive moving average with exogenous inputs) model. Identification procedure is formulated as an optimization procedure of a special class of Hopfield network in the proposed approach. The particular structure of these Hopfield networks can avoid the local optimum problem. Training of these Hopfield network achieves model structure determination and parameter estimation. Convergence of Hopfield networks guarantees that a NARMAX model of random initial state will approach a valid identification model with accurate state parameters. Results of two simulation examples illustrate that this approach is efficient and simple.

With the development of modern industry, sheet-metal parts in mass production have been widely applied in mechanical, communication, electronics, and light industries in recent decades; but the advances in sheet-metal part design and manufacturing remain too slow compared with the increasing importance of sheet-metal parts in modern industry. This paper proposes a method for automatically extracting features from an arbitrary solid model of sheet-metal parts; whose characteristics are used for classification and graph-based representation of the sheet-metal features to extract the features embodied in a sheet-metal part. The extracting feature process can be divided for valid checking of the model geometry, feature matching, and feature relationship. Since the extracted features include abundant geometry and engineering information, they will be effective for downstream application such as feature rebuilding and stamping process planning.

Side-window detection technology is adopted by the kinetic kill vehicle (KKV) to solve the problem of aerodynamic heat induced by the high speed. A new side-window orientation algorithm is proposed to adjust the KKV attitude angles according to the line-of-sight (LOS) angles to achieve stable and accurate tracking of the target. The time-scale separation methodology is adopted to implement the side window algorithm. The attitude thrusters are activated in pulse mode, and the pulse-width pulse-frequency (PWPF) modulation is adopted to control the thrusters firing. PWPF modulation is a control method that provides pseudo-linear operation for an on-off thruster. PWPF modulator holds several advantages over classical bang-bang controllers such as close to linear operation, high accuracy, and reduced propellant consumption. A modified PWPF modulator with threshold limitation is adopted in this paper to reduce the number of thruster firings and fuel consumption at a possible cost of control accuracy. The control scheme is verified using computer simulation. The results have been proven the potential of this scheme.

A popular version of optimal control problems is discussed and a nonlinear two point boundary value problem embedded in the optimal control problem is then converted into an initial-value problem according to the boundary value sensitivity differential equations. An integration method for matrix differential equations is also presented. In this novel way, the exact solutions are obtained for the linear optimal control problems. Two illustrative numerical examples are given to show the power and efficiency.

The H(+)-ATPase from reticulocyte endosomes was purified and reconstituted into liposomes, and protein-dependent iron transport was observed. Reconstitution of the H(+)-ATPase into liposomes was performed by sonicating a lipid mixture, with a composition similar to the reticulocyte plasma membrane, in a buffer containing ferric citrate. The nonencapsulated iron:citrate was removed by gel filtration and the proteoliposomes diluted into 1 mM FerroZine. Upon addition of ascorbate, an initial efflux of 2.9 +/- 0.3 x 10(-2) mumol of iron/mg of ATPase/min and 56 +/-7% of total internal Fe(II) was detected by formation of the Fe(II)-FerroZine complex with an absorbance at 562 nm or radioactivity of 59Fe(II)-FerroZine following separation using gel filtration. Both thiosulfate and ferrocyanide could substitute for ascorbate. Citrate or EGTA could substitute for FerroZine. The initial rate of Fe(II) efflux was decreased by 41 or 17% using 100 microM of the cation channel inhibitor N,N'-dicyclohexylcarbodiimide or 70 microM of the ATP hydrolysis inhibitor N-ethylmaleimide, respectively, but was unaffected by the presence of ATP. The amount of iron transported was decreased 51 or 39% by 100 microM N,N'-dicyclohexylcarbodiimide or 70 microM of the ATPase inhibitor 7-chloro-4-nitrobenz-2-oxa-1,3-diazole. The amount of Fe(III) transport was 80% lower than Fe(II) when reductants were not present internally or externally although the apparent rate constants were identical when ascorbate was externally present. These results suggest that this vacuolar H(+)-ATPase may transport iron.

Fuzzy disturbance observer and feedback linearization method are adopted to solve the attitude control problem for the rigid spacecraft driven by three orthogonal reaction flywheels. Since the spacecraft model is nonlinear and strongly coupled, it is difficult to design the controller directly. Differential geometry theory based feedback linearization technique is used to convert the original model to the linear decoupled SISO system models, which greatly simplifies the controller design. The fuzzy disturbance observer based on fuzzy basis function vector is used to observe the disturbance torque. The estimated value of disturbance torque is converted to equivalent control by the gain adjustment part. The equivalent control along with the control obtained by feedback linearization are then used as the input to the reaction flywheels. Simulation results show that the proposed method can counteract the effect of the disturbance torque, and achieve accurate tracking of attitude.

We present a novel architecture description language - OPNADL. The domain specific software architecture based on OPNADL is employed to guide the large-scale software development. OPNADL (object-oriented Petri nets architecture description language) is a graphical and mathematical modeling language, which can be used to describe static and dynamic semantics, and analyze the dynamic behavior of software system. The overall and individual characteristics of a system can be visually and intuitively depicted with the proposed OPNADL. Software architecture is conveniently constructed, refined and verified by OPNADL.

Based on microscopic traffic models, the object-oriented method and visualization technology are applied to the microscopic simulation of urban traffic systems, and a concise and flexible traffic simulator is developed. For an urban traffic network with 3 by 3 intersections, simulation results show that the vehicle behaviors in the traffic network accord with human traffic experience, and the movement curves of vehicles reflect the response of drivers to many traffic events. The fixed time signal control scheme is also compared with the fuzzy logic one in the simulation. The proposed approach can be adopted to study general large-scale traffic networks.

The significance of the H(+)-ATPase in iron absorption by rabbit reticulocytes is explored using isolated endosomes, effects of inhibitors, and the purified proton pump. We have recently reported H(+)-ATPase-mediated iron transfer across a liposomal membrane (Li et al., 1994). In this report, the effect of H(+)-ATPase inhibitors on iron mobilization is investigated at pH 6.0 in the presence of 15 microM FCCP in order to dissociate 59Fe(III) from transferrin and eliminate the kinetic effects of acidification by the ATPase. Iron transport by isolated endosomes is decreased 50% by the cation pore inhibitor dicyclohexylcarbodiimide (DCCD) for ascorbate-mediated iron mobilization and increased by 40-50% when NADH and ferrocyanide are used as electron donors. In contrast, the ATPase hydrolysis inhibitors N-methylmaleimide (NEM) and 7-chloro-4-nitrobenz-2-oxa-1,3-diazole (NBD) increase iron mobilization when NADH and ferrocyanide are used as reductants but have negligible effects for ascorbate. The differential inhibition or enhancement by DCCD, NEM, and NBD with respect to the reductants used for mobilization indicates that the H(+)-ATPase may be involved in the multiple pathways or iron transport found in isolated rabbit reticulocyte endosomes. Effects of inhibitors of ATP hydrolysis suggest significant structural interactions between the proton pump and sites for iron binding and/or reduction. The isolated H(+)-ATPase binds iron as revealed by using nondenaturing electrophoretic and chromatographic methods. One class of iron binding sites is suggested to be the 17.5 kDa proton pore subunits of the H(+)-ATPase which also covalently react with DCCD.(ABSTRACT TRUNCATED AT 250 WORDS)

The reductant dependence of iron mobilization from isolated rabbit reticulocyte endosomes containing diferric transferrin is reported. The kinetic effects of acidification by a H(+)-ATPase are eliminated by incubating the endosomes at pH 6.0 in the presence of 15 microM FCCP to acidify the intravesicular milieu and to dissociate 59Fe(III) from transferrin. In the absence of reductants, iron is not released from the vesicles, and iron leakage is negligible. The second-order dependence of rate constants and amounts of 59Fe mobilized from endosomes using ascorbate, ferrocyanide, or NADH are consistent with reversible mechanisms. The estimated apparent first-order rate constant for mobilization by ascorbate is (2.7 +/- 0.4) x 10(-3) s-1 in contrast to (3.2 +/- 0.1) x 10(-4) s-1 for NADH and (3.5 +/- 0.6) x 10(-4) s-1 for ferrocyanide. These results support models where multiple reactions are involved in complex processes leading to iron transfer and membrane translocation. A type II NADH dehydrogenase (diaphorase) is present on the endosome outer membrane. The kinetics of extravesicular ferricyanide reduction indicate a bimolecular-bimolecular steady-state mechanism with substrate inhibition. Ferricyanide inhibition of 59Fe mobilization is not detected. Significant differences between mobilization and ferricyanide reduction kinetics indicate that the diaphorase is not involved in 59Fe(III) reduction. Sequential additions of NADH followed by ascorbate or vice versa indicate a minimum of two sites of 59Fe(III) residence; one site available to reducing equivalents from ascorbate and a different site available to NADH. Sequential additions using ferrocyanide and the other reductants suggest interactions among sites available for reduction. Inhibition of ascorbate-mediated mobilization by DCCD and enhancement of ferrocyanide and NADH-mediated mobilization suggest a role for a moiety with characteristics of a proton pore similar to that of the H(+)-ATPase. These data provide significant constraints on models of iron reduction, translocation, and mobilization by endocytic vesicles.

Support vector regression (SVR) is an effective method for the predication of chaotic time-series, which is a fundamental topic of nonlinear dynamics. Through analyzing the possible variation of support vector sets after new samples are inserted to the training set, a novel SVR algorithm is proposed; thus an online learning algorithm is set up. In connection with the specific characteristics of chaotic signals, a wavelet kernel satisfying wavelet frames is also presented. The wavelet kernel can approximate arbitrary functions, and is especially suitable for local processing; hence the generalization ability of SVR is improved. To illustrate the good performance of the online wavelet SVR, a benchmark problem, i.e. the online prediction of chaotic Mackey-Glass time-series, is considered. The simulation results indicate that the online wavelet SVR algorithm outperforms the existing algorithms in higher efficiency of learning as well as better accuracy of prediction.