Applied Mechanics and Materials Vols. 602-605

Abstract: Due to the ability of the strong anti-interference and directly digital controlling, digital valve has great applications and developing potential in the filed of high frequency response digital servo valve. Base on the rotating structure, a novel high frequency digital valve which can be rotated and controlled in differential parallel way is designed, and the frequency characteristic of electrical signals converting into rotation signals is developed through differential and parallel control of valve spool and valve sleeve. Meanwhile, the hydraulic natural frequency of servo-screw mechanism is further enhanced by the control way of hydraulic half-bridge type A in both chambers of valve spool, and corresponding mathematical model and control block diagram are built. Theoretical analysis concludes that the frequency response characteristic of digital valve is developed significantly. In addition, the multi-gain of rotation angle and axial displacement of valve spool is realized through milling the spiral grooves with different helix angles in the inside of valve sleeve, which improves the flow adaptability of high frequency digital valve effectively. Compared to traditional rotary digital valve, the designed novel digital valve that can be controlled by rotating differentially and parallel has greater advantages in high frequency response and flow adaptability, it provides a new scheme for engineering applications of high frequency digital valve.

Abstract: Executable UML is one of development directions of Model Driven Architecture (MDA). Executable UML is committed to the automatic code generation from UML model. The simulation and testing of the model is realized either by compiling the model or by executing the code it generate. For solving the problem that how to confirm the correctness of executable model, this paper researches the mechanism of executable UML model and explore a verification method based on executable UML. Finally, researches how to apply the executable mechanism of Executable UML to the design and verification of Armored Vehicle Information System (AVIS) through an imaginary combat mission scenario.

Abstract: The characteristic of unit coordinated control in thermal power plants having complex, nonlinear, larger time delay, and establishing mathematical models are very difficult. In the paper establish mathematical models of using fuzzy neural network system, make full use of the ability of fuzzy logic reasoning and neural network self-learning; using multivariable generalized predictive control strategy, Simulation results show that the use of fuzzy neural network generalized predictive control for good stability of main steam pressure , strong effectiveness of tracking the power grid load, and little fluctuation of different load conversion.

Abstract: With full rotation articulated ABB-IBR140-M2000 robot with six degrees of freedom used as welding robot, the exploring of efficient complete coverage of welding position flock is an important way of improving the performance of welding robot. Making use of improved genetic algorithm, in which the best father generation is saved and using ordered cross and reverse ordered mutation to constitute filial generation, and this method makes sure that the algorithms is convergent. The complete coverage of welding position optimization mathematic model whose objective is the minimum distance is established, making use of the improved genetic algorithm to solve the problem, an example is analyzed in detail, and the result shows that the algorithms is convergent and efficient.

Abstract: Based on object oriented timed place Petri net (OOTPN) model, the study on the loading and unloading schedule of automatic Storage/Retrieval System is given. The OOTPN model is established through dividing the model into six sub models according to the class of AS/RS elements, that is: In-Buffer model, In-Plant model, In-Elevator model, Out-Elevator model, Out-Plant model and Out-Buffer model. The six sub models. Furthermore, the deadlock analysis problem of the process is also discussed, and the maximally permissive feedback control strategies for deadlock avoidance are finally proposed.

Abstract: In this paper, a vacuum suction cup robot is introduced, which is used in drill bolt welding machine to add silver brazing sheets. This paper briefly discusses the application of vacuum power on the device. Then through the selection of the degree of vacuum and a vacuum generator, the selection and calculation of the chuck size specify the design process of the vacuum power system. Finally, through the working process of the manipulator and the structural design of the silver brazing box briefly introduce the movement of the vacuum suction manipulator.

Abstract: This paper designs a ship rudder system simulation device in order to serve the research of ship control better with the proportion of a real marine hydraulic rudder system, which can complete closed-loop experiments in the lab with the steering system. The rudder system simulation device mainly includes two parts, electric control system which uses PLC as core control unit, hydraulic system, and it can achieve both manual and automatic operation control mode.

Abstract: According to micro UAV is susceptible to wind environmental impact during the flight, this paper puts forward a kind of ergodicity track strategy for return path re planning. By adding coverage flight and sacrificing path to achieve safe recovery of voyage. A genetic algorithm is used to solve the problem, and introducing dynamic penalty function to improve the fitness function, effectively reduce the search space. The simulation results show that the method can generate safely track, and satisfy the path constraints.

Abstract: This paper proposes a new method of 6-DOF serial robot’s trajectory planning. Ensuring to satisfy the physical constraints of space conditions, the robot’s trajectory is interpolated in the Cartesian coordinate system, and using quaternion interpolation to solve the multiple solution problem in RPY interpolation. Meanwhile, the interpolated position information is transformed into the angular displacement information of the joint coordinate system, and the joint space trajectory planning is achieved using the genetic algorithms integrated velocity, acceleration, jerk and torque and other important kinematic and dynamic constraints. In robot safety and stability, the method is better than the general approach, and it has both the ideal trajectory parameters of the global search ability and performance planning.

Abstract: The temperature control model of an intelligent sand casting and gas forming tester is introduced in this paper. The thermostatic fuzzy control of the tester is simulated by the fuzzy control kit in Matlab. The result of the simulation indicates that the control method of the research has a intelligentized degree, which is more precise than conventional control method.