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2006 Vol. 32, No. 05

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Target identification of different task weight under multi-interface and multi-task
Zeng Qingxin, Zhuang Damin
2006, 32(05): 499-502.
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Target identification for weapon equipment in human machine interface design must to be settled through the research of experiments and assessments. A target identification experiment of multi-interface and multi-task was developed, according to tasks what pilot need to operate during flying. This work investigated how human identify target color, figure and location under different task weight by measuring response time and detection rate what participator react to main task to provide standards for target code in human machine interface design. Result indicates that green, red and triangle are the fit code for target in interface design and square and circular necessarily can be made as the target code under the need of attention allocation, no matter what task weight is; it is indispensable to take task weight into account in designing target location for human interface, as target identification of different location is affected by the task weight.
Bi-point/bi-objective optimization design of ailfoil using N-S equations
Wang Xiaolu, Zhu Ziqiang, Liu Zhou, Wu Zongcheng
2006, 32(05): 503-507.
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Based on the computation of N-S equations and the technique of wake integration method, the sharp of the airfoil was paramerically modeled, the bi-point(BP)/bi-objective(BO) optimization design of ailfoil was discussed with the comparison of single-point(SP)/single-objective(SO) and single-point(SP)/bi-objective(BO) optimization. Powell method and objective function combination method was integrated. Numerical results of given airfoils(RAE2822 and quasi-global hawk ailfoils) cases show that the BP/BO design method is compatible and effective for multiform design status and it is necessary and important to choose the objective function in the optimization method. The BP/BO optimal ailfoils have better pressure distribution to the original ones, which leads to higher coefficient of lift and lower coefficient of drag, thus results in better integral performance.The BP/BO optimal airfoils also have better integral performance to the SP/SO and the SP/BO ones.
Application of design sensitivity in aeroelastic genetic optimization
Wan Zhiqiang, Yang Chao
2006, 32(05): 508-512.
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A design study aimed to optimize a composite wing in an aeroelastic way was presented using genetic algorithm and genetic/sensitivity-based hybridalgorithm. In order to increase the search efficiency of the above-mentioned two algorithms, a set of methods was put forward to fix primary and secondary design variables followed by adjusting the design variable domain on the basis of design variable importance in terms of their sensitivity. Results demonstrate that the size of design variable domain had direct effects on the search efficiency of genetic algorithm and genetic/sensitivity-based hybrid algorithm, especially when the former was used. Therefore, the search space should be reduced to be as small as possible if an enough amount of excellent feasible solutions in design space could be ensured. Results indicate that the method to adjust the size of design variable domain on the basis of sensitivity has proved to be of fairly practical success, which can not only remarkably increase the search efficiency of genetic algorithm and genetic/sensitivity-based algorithm, but also strengthen the capability of the two algorithms to discriminate the feasible field.
Optimization of glide trajectory for a hypersonic vehicle
Zhou Hao, Chen Wanchun, Yin Xingliang
2006, 32(05): 513-517.
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According to hypersonic vehicle’s density model, dynamic model, areodynamic force models and the angle of attack considered as the input, the trajectory problem was cast as the optimal control problem and pontriaghin maximum principle was used to obtain first order necessary condition. A combined optimal approach including changing-region gene algorithm and nelder-mead simplex method and neighboring extrem method were proposed to explore two point boundary value problem. Firstly the gene algorithm and simplex method was used to get the goal optimal solution and then gained the fit initial value which is satisfied with strictly terminal constraints by neighboring extrem method. By optimizing a hypersonic vehicle case, optimal trajectory and the curve convergent was gained, and the result was compared with the flight scheme of maximizing the rate of lift and drag, the range obtaining by optimal control is longer than that by the flight scheme of maximizing the rate of lift and drag.
Quantitative measuring method of pilots’ attention allocation
Liu Zhongqi, Yuan Xiugan, Liu Wei, Kang Weiyong
2006, 32(05): 518-520.
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Subjects finished three different flight simulation tasks in a simulator in the laboratory. Eye movement data was recorded with eye tracking system. Visual information sources were divided into two AOIs (area of interest): IP (instrument panel) AOI and OV (out view) AOI. The three eye movement indices were analyzed and compared in the two AOIs. Results show that there are different scanning patterns through three tasks, and that there are more fixation points, longer dwell time and longer average fixation duration in OV AOI than that inside. It indicates that fighter pilots acquire information mostly from the OV in VFR (visual flight rules) condition and most of their visual attention is allocated to the outside world. Eye movement indices can objectively uncover the rules of pilots’ attention allocation and evaluate their workload. The research will be beneficial to cockpit display design of the fighter aircraft and pilots’ training.
Expert system of maintenance review board report based on CBR and RBR
Liu Ming, Zuo Hongfu, Geng Duanyang, Cai Jing
2006, 32(05): 521-525.
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According to the need of maintenance program development, a civil aircraft maintenance review board report (MRBR) development method was presented according as the latest maintenance steering group(MSG) ideals and the maintenance programs experiences of similar aircrafts. The method integrates case-based reasoning(CBR) with rule-based reasoning(RBR). A framework of civil aircraft MRBR expert system was constructed, and the critical technologies were discussed separately, including the case representation and structure, the case retrieval, the integration reasoning technology, case adaptation and storage. Case retrieval included two steps: firstly, searching the aircrafts in the case base as similar as possible, secondly, matching up to the most similar item from the similar aircrafts. The integrating reasoning was realized by the method that used CBR and RBR separately then compared their results to decision. The expert system was realized using object-oriented design, and the validity of the MRBR with hybrid CBR and RBR was demonstrated by applying the expert system to an aircraft in an airline.
Digital definition of aircraft structure product
Lu Hu, Fan Yuqing
2006, 32(05): 526-530.
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In order to meet the requirement of digital information system deployed in aircraft development, studying the aircraft structure product definition is very important. Based on anglicizing the method and process of aircraft development under the digital circumstance, the content and the form of aircraft structure product definition were summarized. The classes and the transformation principle of the axis and datum system were given for the digital aircraft design. The concept of the digital mockup and its usage were proposed, and the primary principle of the engineering drawings creation was discussed. The manufacture information and the quality control information were integrated into the digital definition to support engineering use. A way to manage all information integrated in the digital definition by layers and filters was introduced. The result consummates the concept of generalized digital definition and provides a reference instruction to implement digital system for aeronautical engineering.
Dynamic characteristic of squeeze film based on finite element method
Deng Yin, Lin Li, Shi Yajie, Hong Jie
2006, 32(05): 531-535.
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SFD(squeeze film dampers) designed to provide proper amounts of damping and stiffness to alleviate the problem of vibration are used extensively in almost all high-speed rotating machines, such as aeroengine. A squeeze film analysis based on finite element method was proposed for solving the steady state dynamic characteristic of the rotor system supported on squeeze film damper and elastic supports, but most closed form solutions of Reynolds’ equation assumed either a short bearing approximation or a long bearing approximation generally. The finite element model of damper was simulated by the variation of geometry within the flow path. In order to validate the results of theoretic analysis, the pressure distribution and equivalent film damping of typical SFD were calculated by using the finite element method. The effects of film inertia forces were also calculated. Comparison of calculational and experimental results show that the analysis and calculation methods and results of the rotor system dynamic characteristic can be used in engineering practice.
Game behaviors and efficiency analysis under Chinese pricing system of military aviation products
Gao Yuanyang, Qian Yonggang, Wang Wenjie
2006, 32(05): 536-539.
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According to the current pricing system and procedure of military aviation product in China, a theoretical analysis model was built, which was used to describe and analyse the game behaviors of players in the market and their effects on efficiency under the current pricing system based on cost. The research results show that under current pricing system, manufacturers have motivation to exaggerate their cost. The cost exaggerating behaviors of upriver manufacturers not only brought themselves the benefits, but also brought the profit contributions to downriver manufactures, which have motivation to connivance such behaviors of upriver manufacturers. The cost exaggerating behavior of upriver manufacturer has greater influence on the price of final product than downriver manufacture’s. Some suggestions were proposed to deal with these problems and improve the current pricing system.
Adaptive spectral estimation based acquisition for frequency hopping signals
Huang Dongwei, Shao Dingrong, Li Shujian
2006, 32(05): 540-543.
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A FH(frequency hopping) signal acquisition technology based on frequency estimation was introduced. An adaptive spectral-estimation model was established, and the frequency estimation was implemented by autoregressive and adaptive algorithm. However, for a fading and AWGN (additive-white Gaussian noise) channel, frequency estimation errors might occur. To achieve more accurate and robust acquisition, a new acquisition logic was developed, which would prevent the acquisition scheme from making a wrong decision and leading to the false tracking. The acquisition scheme using multiple antennas was also addressed to combat the fading effect. Numerical results for the probability of the MSB (most significant bit) error and the corresponding mean acquisition time were illustrated for the performance evaluation under unfading and Rayleigh-fading channel conditions. Simulation results indicate that the FH signal frequency can be precisely estimated, and quick acquisition for the frequency-hopping signal is implemented.
Fault diagnosis of control electric component based on RBF neural network
Yuan Haiwen, Lü Hong, Yuan Haibin
2006, 32(05): 544-547.
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Based on nonlinear mapping relationship between fault symptom and fault type in control electric component, RBFNN(radial basis function neural network) approach was presented for fault diagnosis. Fault mechanism and failure behavior of control electric component was analyzed, then featured fault types were extracted from control electric component failures and the extracted features were regarded as fault symptom eigenvector. The process of fault diagnosis principal, fault diagnosis model and fault diagnosis algorithm was given using RBFNN with enough fault feature information. Trained RBFNN was used for fault vector recognition and diagnosis to verify the proposed fault diagnosis model effectiveness and rationality. Simulated result shows that RBFNN can overcome the limitation of local infinitesimal during fault diagnosis process, and the requirement for fast diagnosis rate and high diagnosis precision can be met.
Design and realization of high reliability tri-redundancy digital actuator controller
Jin Hongtao, Jiao Zongxia, Wang Shaoping, Han Pengxiao
2006, 32(05): 548-552.
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To attain a high reliability, controller of the servo actuating system was developed with tri-redundancy. CCDL(cross channel data link), synchronization between different channels, setting voting/monitoring plane and other key technologies of redundancy were presented. A method of self-monitoring of one channel by the inter-monitoring of two controllers was presented. By comparison monitoring, self-monitoring and cross-monitoring, two failures-operation and three failures-safety of the tri-redundancy system were realized effectively. The redundancy scheme is simplified while the basic reliability is higher compared with other redundancy schemes. The tri-redundancy digital actuator controller was developed based on the technologies of high-speed DSP(digital signal processor) and CAN(controller area network) bus. Taking into account of coverage percentage of one fault and two faults, reliability of the controller was analyzed based on the Markov model, analysis shows that the system has a high reliability.
EHA controller design based quantitative feedback theory
Ma Jiming, Fu Yongling, Gao Bo
2006, 32(05): 553-557.
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QFT (quantitative feedback theory) is a robust controller design method. It has good practicability and has been widely used in hydraulic servo control system. After creating the EHA(electrical hydrostatic actuator)’s model, the inner and outer loop controllers were designed based on QFT. Inner loop controlled motor’s rotate speed and ensured that it had good response time. Outer loop controlled the position of flight surface and ensured that it had good robust stability, tracking capability and disturb restraining ability. Design process considered the parameters’ uncertainty of electronic and hydraulic system, and aero load changing under all flight conditions. Performance bounds defining took all the inner and outer loop requirements into account. Simulation results show that this control system has good robust stability and can restrain the output disturbance efficiently, which can fully utilize some strongpoint of integrated EHA like high torque and power density, easiness to maintain and modularize. It can greatly improve the performance of flight control system.
Computation of microwave RCS of various bodies
Pan Shunkang, Lü Shanwei, Feng Keming, Wang Wei
2006, 32(05): 558-560.
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The moment method was used to calculate the RCS (radar cross section) of cell of great metal various body which has two-dimension periodic configuration．Then antenna array technology was used to compute the RCS of whole various body．The method could both ensure the precision of calculation and solve the difficult problem of large computation and coupling．Related mathematics formulas were deducted. On the condition of incidence of linear polarized plane wave, the example of calculation RCS of various metal pyramid was illustrated accordingly．The results are consistent with the conclusion which was obtained by using software HFSS(high frequency structure simulator),but the time taken to compute was much less than the time taken in the computation by using HFSS．The method is feasible to engineering.
Comparison between adaptive algorithms using in GPS receiver
Mohamed E A, Wang Yongfang, Tan Zhanzhong
2006, 32(05): 561-565.
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To compare the adaptive algorithms performance, such as power inversion (PI),multiple signal classification (MUSIC),and min-norm algorithms, the algorithms principle was analysed. In computer simulation, the algorithms were adopted in uniform linear array, the antenna gain in the useful signal and interference directions were compared. Power inversion, multiple signal classification, and min-norm algorithms were compared in case of using GPS signal with power -160 dBW as a useful signal and a varying power for the interference of the same frequency coming from different directions. The simulation result indicates that the three algorithms can be used for GPS receiver to achieve anti-jammer. The power inversion algorithm gives a bad result when dealing with low power interference, MUSIC algorithm can cancel the low power interference but introduces a lot of false nulls, but min-norm algorithm can cancel the low power interference and also do not introduce false nulls.
Stability of time-delay fault tolerant control systems with markovian parameters
Gao Fei, Zhang Hongyue
2006, 32(05): 566-570.
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FDI (fault detection and isolation) is a crucial part in AFTCS (active fault tolerant control system), so how to model the FDI process and evaluate its influence upon the system is very important. Considering constant networked-induced time delay between sensor and controller in the transmission, two homogeneous Markov stochastic processes with different state spaces were defined: one represented system components failures and the other represented the decisions of the FDI process upon which the state feedback control law was reconfigured. Further, the stability of the control system with state feedback was discussed. A delay-independent sufficient condition based on Kronecker product approachfor checking the mean square stochastic stability of this class of systems was established. Simulation examples were given to demonstrate the theoretical results. Simulation results gave the relation of time-delay, false alarm rate and missed detection rate to guarantee the system stability.
Hydraulic simulator outer gimbal FNN controller design and simulation
Wang Kai, Wang Zhanlin, Qiu Lihua, Fu Yongling
2006, 32(05): 571-574.
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Taking hydraulic simulator outer gimbal as controlled object, direct adaptive fuzzy controller(DAFC) and synchronizing fuzzy controller(SFC) for outer gimbal to resolve disturbance from load and synchronizing drive of dual hydraulic motors, which are primary factors affected on the performance of hydraulic simulator outer gimbal, were presented, based on employing fuzzy control theory. Adaptive fuzzy controller was combined with PID controller to compose parallel control system, which was aimed at reducing static error and suppressing dynamic disturbance of the whole system. Since the deficiency of poor ability of self-learning of fuzzy controller, fuzzy neural net(FNN) controllers for multi-input multi-output(MIMO) system were induced to the above two fuzzy controllers to resolve these problems. Simulation results of FNN controllers show that the proposed approach can achieve high displacement tracking accuracy and dynamic performance when the loads of the simulator are changeable or two hydraulic motors’ rotate speeds are different greatly.
Steel bar real-time recognition and tracking method
Zhang Yusheng, Fu Yongling
2006, 32(05): 575-579.
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Feature extraction and pattern matching are the key problems in recognition and tracking system of multiple objects. In order to extract the features of stacked steel bars in real production environment, a method was proposed, which consisted of connected objects segmentation and multiple objects recognition. Median filter and morphological filter were applied in the steel bars image to remove the noise. Adaptive thresholding and watershed transform were used to segment the connected bar objects. Object centroid as the features was computed by means of regional statistics, parameter recognition, noise region removal and cluster analysis. For the image sequence of steel bars, the object tracking chain was established with template matching, near displacement matching and Kalman filtering. Target tracking was updated with inserting, deleting and refreshing of tracking chain nodes. The potential missing objects and false incremental ones were corrected in the counting result. At the production line 100 frames of sequential images were captured, and the tracking and counting method get the accuracy of 96.2%.
Local interference identification of multi-point machining
Wang Ruiqiu, Chen Wuyi, Jin Man
2006, 32(05): 580-584.
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In order to get rid of the local interference of the tool positions calculated using multi-point machining algorithm, the discriminant of local interference was derived after the analysis on the geometric match between the disc cutter with a concave end and the desired surface. The ratio of curvature radius of intersection curve of the disc cutter and the desired surface at the first contact point to the radius of the cutter, which was belonged to tool position calculated using multi-point machining method, was derived with differential geometry analysis. Combined with the discriminant of local interference, the solution areas of multi-point machining constraint immune to local interference were deduced. Results show that no matter what kind of surface was machined, the tool positions calculated using multi-point machining method would not be interferential with the desired surface locally if the second tangent contact point was selected in the solution areas of multi-point machining constraint, where the corresponding principle direction had larger surface curvature.
Approach to process improvement based on process failure knowledge and its implementation
Wei Li, Zheng Lianyu, Liu Rihui
2006, 32(05): 585-589.
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Process planning is a continued improving and optimizing process, and reverse process knowledge, namely process failure knowledge which is experience of process improving measures where process quality problems occur in production, is quite effective to improve and optimize process solution. A process improvement approach based on process failure knowledge was proposed, it includes eight steps: identifying potential failure mode, analyzing potential failure cause, counting risk priority number N, proposing improvement action, counting risk priority number N’ after improvement, tradeoff improvement action, accepting improvement action and saving process improvement data. On the basis of Web-based process failure knowledge management system (process FMEA, failure mode and effect analysis), the relationships between process failure knowledge and product and process information was established so as to implement the information and process integration between process FMEA and CAPP(computer aided process planning), and achieve effective process improvement. An airplane structural part(main girder) was used to validate process improvement utilizing process failure knowledge. This approach provides an effective measure to actively other than passively improve process solution during process planning.
Method of stiffness equivalence for calculating three-layer thin shells
Guan Shiwei
2006, 32(05): 590-593.
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A relatively simple method for calculating three-layer shells was proposed for the complex problem of three-layer shell calculation, named as the method of stiffness equivalence, which was based on the research achievement of general thin-shell theory and could directly use those theoretical formulas. Itcould not only cut down the labor resource, but also reserve the precision of the calculation by using this method. After analyzing the characteristics of those adopted formulas and using the principle of stiffness equivalence, the calculating process was given out; the formulas of the equivalent elastic module and the equivalent thickness were deduced. In the following example, The equivalent elastic module and the equivalent thickness were taken into the formulas of the general thin-shell theory, and the result of the three-layer column shell based on the elastic condition was obtained, which was further verified by numerical calculation. The calculating results show that the method of stiffness equivalence can be used for the calculation of three-layer thin shells.
Mechanical model of two-dimensional cellular materials with negative Poisson’s ratio
Lu Zixing, Zhao Yabin
2006, 32(05): 594-597.
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Cellular materials with negative Poisson’s ratio have unique mechanical performance and a promising prospect of applications. A mechanical model of two-dimensional cellular materials with negative Poisson’s ratio, composed of partly re-entrant and partly regular hexagons, was proposed based on rotation mechanism. The relationships of both Poisson’s ratio and sitiffness coefficients with the angles were predicted. The shear strain of the model was obtained. Energy method was used to develop the elastic constitutive equations. Results show that the mechanical model gave rise to not only a negative Poisson’s ratio, but also a positive one greater than 1 and performed a characteristic of negative stiffness. The stiffness coefficients of the model could be altered by adjusting the ratio of the cell ribs length and the characteristic angle. The results are useful for designing the microstructures of two-dimensional cellular materials.
Wavelet image compression based on support vector machines
Li Yuancheng, Jiao Runhai, Li Bo
2006, 32(05): 598-602.
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A novel image compression algorithm that combined SVM(support vector machines) regression and wavelet transform was presented. SVM regression could learn dependency from training data and realized compression by using fewer training point (support vectors) to represent the original data. Thus, wavelet coefficients could be compressed based on this feature. Image was decomposed into subbands of different scales in using wavelet transform. The lowest subband was coded using DPCM for its great importance, and the other coarser subbands were compressed by SVM. Since the characteristic of the wavelet coefficients was various in different scales and directions, it was a key problem to design the appropriate organization method of the coefficients. Effective entropy coding technique was also studied to encode the support vectors and the corresponding weights. Experiment results demonstrate the coding efficiency of the proposed algorithm.
Implicit mapping mechanism in pen-based three-dimensional modeling system
Gong Yingkui, Fan Yuqing, Wu Zhifang
2006, 32(05): 603-606.
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The pen-based three-dimensional modeling system supports the user to sketch freely based on pen-paper metaphor so as to express three-dimensional models, and carries out corresponding three-dimensional modeling according to the user’s interaction intention. A kind of implicit mapping mechanism was proposed according to the characteristics of pen-based three-dimensional modeling technology. Two virtual projecting planes, which were vertical reciprocally, were constructed dynamically through analyzing the two-dimensional stroke and the interaction context so as to transform the two-dimensional stroke to three-dimensional spatial information smoothly. A method of coordinate increment replacement was proposed to dissolve the problems of mapping in ultimate positions. As a result, not only the problems of coordinate mapping from two-dimensional stroke tothree-dimensional spatial information in ultimate positions were settled, but also the user could sketch more freely to express much more complicated three-dimensional models. The user could be free from fussy and complicated operations by implicit mapping mechanism and concentrate on expressing his creative inspiration. It has been validated in a prototype system, PenSketch3D, with promising effect.
Novel scheme to locate software fault by aggregate analysis of program behaviors
Jia Xiaoxia, Wu Ji, Jin Maozhong, Liu Yongpo
2006, 32(05): 607-611.
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It is an interesting and noteworthy issue to locate rapidly and effectively the fault according to the input and the program behavior in case of software failure. A drill-down framework for fault localization was proposed, based on which the fault localization problem was expressed in a step-by-step procedure with multi-hierarchy. Proposed and analyzed is a novel scheme of fault-locating method on input level using aggregate analysis of the program behavior. Statistical model of the fault-locating approach on input level was established and the corresponding solution were presented and discussed. To validate the proposal, an experiment was conducted, involving 5 software, 4 of which are injected with faults deliberately and the rest one is actual software in use. The results show that an average precision of 0.803 and an average recall of 0.697 are obtained. Finally, the application of aggregate analysis of the program behavior into the fault-locating method on module level was discussed.
Design of an infrared-imaging homing head simulator
Deng Ke, Hu Kai, Hu Jianping, Lu Xuerong
2006, 32(05): 612-616.
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The design and research of an advanced infrared-imaging homing head simulator were introduced, and its architecture,major performance parameter,track arithmetic and experiment results were provided. Based on succeed designedimaging identify and track circuit which contain two parallel microcomputers, corresponding different ground goals, developed different track arithmetic and noise generated arithmetic program. The system can simulate manifold homing head. It could be installed in the helicopter to search, capture and trace multi-objectives, to verify the fact of bad climate, smog and changing space resolution that will effect imaging identify and track. It can also make many interfere experiments to verify interfere effect. The results of experiments show that the system can achieve expected application effects. These tests offer a great deal of originality materials for simulated experiment, also provide important data to design and use infrared-imaging homing system.
Fast motion estimation algorithm for H.264 with multi-references
Pu Juhua, Xiong Zhang, Liu Yongli
2006, 32(05): 617-620.
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H.264, in spite of its high quality, is very time-consuming due to its complex motion estimation. A fast motion estimation (FME) algorithm called valid-region-based FME (VRF) was proposed by exploring the motion continuity property in multiple reference frames (RFs). VRF used 3-step search(3SS) FME in the first RF and restricts 3SS FME in other RFs to select the best RF. Due to motion continuity, it employed full search in the best RF only in a much smaller area, called valid region. Experiments were done to justify the motion continuity property. Results show that, compared with H.264 full search, VRF reduced the number of search pixels for motion estimation up to 82% while it decreased peak signal to noise ratio(PSNR)0.24 dB and increased bit-rate 8.81% averagely. Compared with another FME, VRF reduced the number of search pixels for motion estimation up to 39% and bit-rate 5.17%, with the PSNR decreased 0.08 dB averagely.
Incremental recognition method for pen-based sketch
Gong Yingkui, Fan Yuqing, Wu Zhifang
2006, 32(05): 621-624.
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A method of two-dimensional sketch recognition based on incremental mode was proposed according to the characteristics of gesture interaction inpen-based three-dimensional modeling technology. The sketch recognition includes: on-line stroke recognition and conversion, automatic constraint catching and appending, two-dimensional combined entity recognition and rectification, feature gesture recognition and three-dimensional feature modeling. Three-dimensional feature modeling thinking and intelligent reasoning technology based on context-aware were used to the recognition. Feature information for three-dimensional modeling was distilled step-by-step from disorganized and inaccurate two-dimensional sketch. The complexity and accumulative uncertainty are reduced effectively by the method. Feature gesture was mapped into three-dimensional space according to implicit mapping mechanism to finish three-dimensional modeling in real time. Asa result, two-dimensional freehand sketch and three-dimensional accurate modeling are integrated effectively. It has been validated in a prototype system, PenSketch3D, with promising effect.

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