摘要：Structural bionic design lacks mature and scientific theories, and the excellent structural characteristics of natural organisms sometimes cannot be transferred into engineering structures effectively. Aiming at overcoming the existing problems, this paper summarizes three related theories: similarity theory, fuzzy evaluation theory and optimization theory. Based on the related theories, a method of structural bionic design is introduced, which includes four steps: selecting the most useful structural characteristic of natural organism; analyzing the structural characteristic finally chosen for engineering problem; completing the structural bionic design for engineering structure; and verifying the structural bionic design. Similarity theory and fuzzy evaluation theory are employed to achieve Step 1. In Step 2 and Step 3, optimization theory is employed to analyze the parameters of structures. Together with the thoughts of simplification and grouping, optimization theory can reveal the relationship between organism structure and engineering structure, providing a way to structural bionic design. A general evaluation criterion is proposed in Step 4, which is feasible to evaluate the performance of different structures. Finally, based on the method, a structural bionic design of thin-walled cylindrical shell is introduced.

摘要：Optimal layout of rectangular stock cutting is still in great demand from industry for diversified applications. This paper introduces four basic solution methods to the problem linear programming, dynamic programming, tree search and heuristic approach. A prototype of application software is developed to verify the pros and cons of various approaches

摘要：Electrorheological (ER) fluids, or suspensions, as one kind of smart materials, have very important and potential applications in electromechanical control due to their attractive features of rapid (with ms order), reversible, and controllable changes in rheological properties upon the application of an external electric field with kV/mm order[1～3]. Once ER fluids have met the engineering targets, they will bring revolution in several areas of industry and technology such as mechanics, trans portation, hydraulics and so on[4].

摘要：This paper concerns the exponential attitude-orbit coordinated control problems for gravitational-wave detection formation spacecraft ***,the large-scale communication delays resulting from oversized inter-satellite distance of space-based laser interferometers are first *** to the delayed communication behaviors,a new delay-dependent attitude-orbit coordinated controller is ***,by reconstructing the less conservative Lyapunov-Krasovskii functional and free-weight matrices,sufficient criteria are derived to ensure the exponential stability of the closed-loop relative translation and attitude error ***,a simulation example is employed to illustrate the numerical validity of the proposed controller for in-orbit detection missions.

摘要：This paper describes a novel design for the carrier mechanism of a pipe-inspection micro robot Based on this mechanism, a new micro robot for the pipes with diameter of 20mm has been developed. It can travel through both vertical pipes and curved pipes to make possible inspection that would be difficult with conventional endoscopes. This mechanism is composed of three units, two novel micro mechanisms called as a planetary wheel mechanism for robot drive, two micro electromagnetic motors and a flexible coupler.

摘要：Aiming at the problems of difficult deployment and access of surveillance system server,as well as high operation and maintenance cost,a remote surveillance camera is designed based on RK3566 chip,which is controlled and transmits data via email ***,to address the impact of environmental factors such as weather and light on image quality,a deep neural network(DNN)image exposure correction network is employed to rectify images with abnormal ***,a back propagation(BP)neural network is utilized to fit a curve relating the brightness difference to the gamma value of images before and after exposure correction,thereby adjusting the gamma value of the ***,to enhance the precision of YOLOv5 algorithm in differentiating between anomalies in nighttime imagery,infrared image data are employed,and a context-aware light-weight label assignment head and coordinate attention mechanism are incorporated into the model to augment the model’s detection accuracy and recall rate for small ***,to meet the demand for reporting of abnormal situations in unattended environments,an automatic target identification and reporting process has been designed which combines YOLOv5 algorithm with the frame-difference motion detection *** camera has been tested for compatibility with the current mainstream commercial email *** mean time required for transmitting a single image file via the email platform is less than 10 s,while the mean time for transmitting a short video is less than 60 *** BP network’s average training loss is 0.015,and the average testing loss is 0.013,which basically meets the precision requirements for gamma *** improved YOLOv5 algorithm achieved an mAP@0.5 of 91.5%and a recall rate of 85.5%,effectively enhancing the accuracy of small object detection.

摘要：The bioinert nature of polyether ether ketone(PEEK)material limits the widespread clinical application of PEEK *** the porous structure is considered to improve osseointegration of PEEK implants,it is hardly used due to its mechanical *** study investigated the combined influence of the porous structure and in vivo mechanical stimulation on implantation safety and bone growth based on finite element analysis of the biomechanical behavior of the implantation *** combined control of pore size and screw preloads allows the porous PEEK implant to achieve good osseointegration while maintaining a relatively high safety level.A pore size of 600μm and a preload of 0.05 N·m are the optimal combination for the long-term stability of the implant,with which the safety factor of the implant is>2,and the predicted percentage of effective bone growth area of the bone-implant interface reaches 97%.For further clinical application,PEEK implants were fabricated with fused filament fabrication(FFF)three-dimensional(3D)printing,and clinical outcomes demonstrated better bone repair efficacy and long-term stability of porous PEEK implants compared to solid PEEK ***,good osteointegration performance of 3D-printed porous PEEK implants was observed,with an average bone volume fraction>40%three months after *** conclusion,3D-printed porous PEEK implants have great potential for clinical application,with validated implantation safety and good osseointegration.

摘要：Bifurcation analysis and stability design for aircraft longitudinal motion are investigated when the nonlinearity in flight dynamics takes place severely at high angle of attack regime. To predict the special nonlinear flight phenomena, bifurcation theory and continuation method are employed to systematically analyze the nonlinear motions. With the refinement of the flight dynamics for F-8 Crusader longitudinal motion, a framework is derived to identify the stationary bifurcation and dynamic bifurcation for high-dimensional system. Case study shows that the F-8longitudinal motion undergoes saddle node bifurcation, Hopf bifurcation, Zero-Hopf bifurcation and branch point bifurcation under certain conditions. Moreover, the Hopf bifurcation renders series of multiple frequency pitch oscillation phenomena, which deteriorate the flight control stability severely. To relieve the adverse effects of these phenomena, a stabilization control based on gain scheduling and polynomial fitting for F-8 longitudinal motion is presented to enlarge the flight envelope. Simulation results validate the effectiveness of the proposed scheme.

摘要：This paper investigates a consensus design problem for continuous-time first-order multiagent systems with uniform constant communication *** that the agent dynamic is unstable and the diagraph is undirected,sufficient conditions are derived to guarantee *** key technique is the adoption of historical input information in the ***,when agent's own historical input information is used in the protocol design,the consensus condition is constructed in terms of agent dynamic,communication delay,and the eigenratio of the network *** result is presented to validate the effectiveness of the theoretical result.

摘要：Robust control design is presented for a general class of uncertain non-affine nonlinear systems. The design employs feedback linearization, coupled with two high-gain observers: the first to estimate the feedback linearization error based on the full state information and the second to estimate the unmeasured states of the system when only the system output is available for feedback. All the signals in the closed loop are guaranteed to be uniformly ultimately bounded(UUB) and the output of the system is proven to converge to a small neighborhood of the origin. The proposed approach not only handles the difficulty in controlling non-affine nonlinear systems but also simplifies the stability analysis of the closed loop due to its linear control structure. Simulation results show the effectiveness of the approach.