Applied Mechanics and Materials Vols. 799-800

Abstract: The current article introduces a new method of construction of control systems for objects with uncertain parameters in the form of three-parameter structurally stable mappings from the theory of catastrophe, allowing to synthesize the highly effective control systems, which demonstrate the extremely wide range of robust stability. The research of robust stability of control systems is based on a new approach to post-rhenium of the A.M Lyapunov’s functions. The method of creation of control system with the increased potential of robust stability is stated. It could be concluded that the application of the suggested approach may assure asymptotically stable invariant states for the system in both negative and positive regions of variations of uncertain parameters.

Abstract: In this paper, we proposed a method for design of control systems with a high potential of robust stability in a class of two-parametric structurally stable mappings. Research of robust stability is based on the geometric interpretation of the second Lyapunov method, and also definition of system stability in the state space.We propose a method for construct the control system, designed in two-parametric class of structurally stable mappings, which will be sustained indefinitely in a wide range of uncertain parameters of the control object. This work presents novelty theoretical fundamental results assisting in analyzing of the behavior of control systems, meaning of robust stability.

Abstract: The extra-atmospheric aircraft model is established, and then the control system is designed. The control system consist of attitude control system and orbit control system, the attitude control system used PID controller and the orbit control system used augmented proportional navigation method. The traditional Proportional Navigation (PN) guidance law has higher accuracy. But for highly maneuvering targets, the accuracy of traditional PN guidance law is still not enough. An Augmented Proportional Navigation (APN) guidance law is designed, an acceleration compensation of the target is introduced on the basis of PN guidance law to overcome the effect of the acceleration on the guidance accuracy. And the engine control method is designed based on the fixed engine thrust. Simulation results indicated that, for homing against maneuverable targets, the APN guidance law is better than the PN guidance law in the following aspects: guidance accuracy is higher, miss distance is lower, interception time is shorter. And the new guidance law provides significant performance improvements over the commonly used classical proportional navigation law.

Abstract: The object-oriented class library designed for solving various optimization problems of resource allocation, including problems of cutting materials and any dimensional packing problems, is described in this paper. The class library enables obtaining of suboptimal solutions of NP-completed resource allocation problems using standard evolutionary and modified heuristic optimization algorithms. The developed class library can be used in creation of an applied software for a wide class of optimization problems, including problems of resource allocation in storage systems and logistics, problems of cutting materials on machine tools with numerical control, scheduling problems and a large set of other practical problems.

Abstract: To develop the numerical control program of mill-turn machine, the traditional method is to apply the computer-aided design and manufacture software to construct the geometric model, then to generate tool path and convert the path to NC program. For complex numerical control program of mill-turn machine, such as the multiple turret synchronized motion machining, because of the need to control time sequence, the NC program is highly required on using of dedicated software system. The objective of this paper is to establish a mill-turn machining system with window interface of via the language of Borland C++ Builder. The developed system can plan the machining path of simple mill-turn features, including turning shape, axial slot milling, and radial packet milling, and generate the corresponding NC program. For the milling functions, after the offset coordinates are calculated along the polygonal angle vector in the center point of cutters, the NC program is generated. For the turning functions, through importing the 2D DXF (Drawing Exchange Format) file and inputting related configurations, the entity coordinates can be retrieved and the corresponding NC program is then converted. By means of the solid cutting simulation software and practical cutting experiment for the generated numerical control program, the accuracy of the tool path generation algorithm is confirmed. Hence, the cost of purchasing commercial software can be saved and the time of generating program can also be decreased so that the working efficiency can be enhanced.

Abstract: The aim of this work is to investigate the performance of closed-loop impedance control in the case of a kinesthetic interface, more precisely to propose this control approach even for devices in which the natural dynamics of the system are relevant. This characteristic can be found in an industrial scenario where commercial components are generally used; hence the system can't be optimized as conversely occurs in a laboratory/ research environment where custom components are generally developed. It is shown that it is possible to guarantee a high dynamic accuracy using the closed-loop impedance control with force feedback and model feedforward. Therefore this approach is suggested as a valid alternative of the most diffused admittance control. The device implemented for the tests and the obtained results are described below.

Abstract: As an effective way for controlling emission of nitrogen oxide, EGR (Exhaust Gas Recirculation) has been widely used in automobiles. EVP (EGR valve position sensor) is a key component in EGR and functions as obtaining the accurate EGR valve opening position for governing the recirculation volume of exhaust gas. Its overall quality and working accuracy affect the performance of EGR directly and must be detected stringently before delivered from the factory. To solve the problems of labor intensity, low detecting efficiency, big deviation results with traditional EVP manual detection equipment in an automotive electronics company, an automatic detection system for EVP is developed based on PLC and industrial microcomputer. The working principle and structure of the system and design of EVP detection fixture are present, and hardware and software of its control system are developed in the paper. Three function modules, that are manual operation, automatic operation and data statistical analysis, are described in more detail. The practical application shows that the automatic detection system for EVP can achieve detection process flexibility, increase detection efficiency and accuracy greatly and solve the problems with traditional method effectively.

Abstract: The focus of this paper is to show a novel electromagnetic servo brake with ABS function. This electro-mechanical device is designed to be installed in mid-range commercial vehicles, and its operation is performed by the battery of the vehicle itself. A control system based on a linear controller was designed to regulate the electric current used by the servo brake. The device designed was constructed and experimentally validated using a test bench. The good agreement obtained from the experiments suggests that the servo brake with ABS function designed could be used in mid-range commercial vehicles in order to reduce the speed of the wheels while simultaneously preventing the wheels from locking safely.

Abstract: DC servo systems which are utilized in many industries require efficient and robust control strategies for achieving specific duties accurately. An integral sliding mode control (ISMC) is designed for position control of DC servo-driven conveyor system in this work. The ISMC which maintains the robustness, linearization and systematic design procedure of the conventional sliding modes is aimed to solve robust position control problem under load uncertainties. Performance and robustness of the ISMC are compared with the PID controller. Numerical and experimental results are presented to demonstrate the validity, feasibility and effectiveness of the designed control technique.

Abstract: The Tri-prism deployable structure is a complex mechanism which consists of six deployable structure units in series. All deployable structure units have the similar movements; the screw theory is used to establish the kinematic equation of each unit and the entire tri-prism deployable structure. Meanwhile, the motion stability, drive mode and mechanical design of the tri-prism deployable structure have been comprehensively researched. Finally, extensive simulations in ADAMS have been conducted to obtain the relationship between the motions of ends and inputs, which are further compared with theoretical results.