Key Engineering Materials Vol. 621

Abstract: This article describes the elastic element of the servo valve, elaborates the definition of the stiffness of elastic element, analyzes the characteristics of existing rigidity measurement system, points out the limitations of the existing rigidity measurement system when it measures the large-stiffiness elastic element, utilizes a new measuring principle based on the existing stiffness test systems, uses the more accurate laser displacement measurement method to overcome the weaknesses of the existing stiffness test system, improves the measurement accuracy, makes stiffness measurements more accurate and promotes the stiffness measurement technology of the servo valve elastic element.

Abstract: As a key component of heavy five-axis linkage CNC machine tools, the existing mechanical biaxial rotary milling heads are usually driven by worm gear, timing belt, or multi-stage gears. Worm gear is inefficiency to transmit motion, hard to maintain the accuracy and difficult to eliminate all clearance; Timing belt can be seriously worn and cannot maintain good accuracy; and multi-stage gears transmission has defects such as long chain, low transmission stiffness. This paper aims at designing a biaxial rotary milling head with large output torque of 3000Nm, high precision and high rigidity. So a new design for biaxial rotary milling head with mechanical spindle, gear transmission and swinging fork structure is proposed. An integral supporting axis is applied to increase the rigidity of A-axis; through the closed numerical loop control based on precise encoder and the decoupling technology of feed motion of A/C axis, the contradiction between large reduction ratio and high precision transmission is solved, and then the requirement of high positioning accuracy (10") is met. Theoretical calculation and simulated analysis shown, the new design not only can guarantee transmission accuracy and dynamic characteristics of biaxial rotary milling head, but also can improve its structural stiffness and meet the high demands of large torque, high precision and high rigidity.

Abstract: Increasing demands regarding the light-weight, high-torque and high-precision actuator are inducing the need for new actuators and new drive principles. This paper introduces a novel principle for transforming the linear motion of high performance piezoelectric actuators into continuous rotation is implemented by two piezoelectric actuators acting on a driving gear covering a driven gear with a slightly smaller diameter. By driving the piezoelectric actuators, the driving gear is energized to move on a circular trajectory around the driven gear which is thereby slowly rotated. Firstly, the structure and driving mechanism is introduced. Secondly, transmission ratio, the demand driving force and displacement are analyzed theoretically and by the means of simulation analysis. Finally, the bottlenecks of mechanism design and machining are presented. Some instructive reference for the structure design of Piezo/Gear compound drive is provided.

Abstract: Traditional orthogonal pattern is ordinarily employed in stiffener configurations of plates in engineering. Layout optimization design of the stiffeners can realize the win-win situation of structure lightweight and bearing property. The existing methods generally transform the challenge into strengthening regional distribution, and the resulting vague regions need identification by post-processing technology. Structure similarity exists between dicotyledonous venation pattern and irregular stiffener distribution. The paper extracted some mechanical factors from the topology regularity and morphogenesis theory of dicotyledonous venation, and static bionic mechanical model was constructed for bionic rib pattern. A new venation growth method with hierarchical veins was proposed based on it. Then typical plate example was designed for proper stiffener distribution, and compared through static experiment.

Abstract: With the development of computer technology, communication technology, electronic technology and automatic control technology, computer control technology widespread application, has been widely used in iron and steel, petroleum, chemical, electric power, building materials, machinery manufacturing, automotive, textile, transportation and other industries. Controlled by computer, we can realize the control of high reliability, process visualization, remote monitoring, data storage and processing. The simulation of PID control algorithm, and focuses on the study and analysis of the digital PID control algorithm, the marine gear lube oil temperature control system model, the three parameters of digital PID: proportional coefficient, integral constant, differential constant on the control system performance was also analyzed.

Abstract: Signal of PLC controller by PID operation after the output of numerical simulation between 0~1, and solid state relay can receive only signal, digital or switched on or off. Only connected the two, temperature control system can be realized. The experimental approach is to learn from PWM pulse width modulation technology, the numerical analog PID controller output into the heating time in a cycle, namely, solid state relay on time. By this method, the indirect control heating rod of equivalent power, the power output of the heating rod according to the control signal of controller output, so as to realize marine gear oil temperature PID regulation. This paper designs the control system used in the experiment. The temperature control experiment system; design of the electrical schematic diagram of the temperature control system, including two parts electrical schematic diagram of control circuit and main circuit of temperature control system design process. At the same time, the experimental scheme is designed. Analysis of the mechanism of temperature balance control object, and focus on the temperature within the experimental results are analyzed.

Abstract: ^{: In this paper, I designed a differential planetary gear for flip climbing transmission system which was applied to the star-climbing wheelchair. According to space limitation and the stair climbing per formance requirements, distributing the number of teeth for each gear under transmission ratio requirements. Furthermore, modifying tooth profile parameters on each gear for improving the quality of the transmission. Using SolidWorks software established t he three-dimensional model. Then impact and contact simulated analysis is studied based on the SolidWorks Motion Plugins to get transmission and meshing condition. At the same time, gave the SolidWorks Motion output data as a result of the input data to t h e SolidWorks Simulation. Through the simulation results validate the output center gear tooth can meet the carrying capacity requirements. On the other hand, it also provides theoretical basis for further improve the structure design.}

Abstract: This paper studies the automatic test system of bus dashboard EOL (end of line) based on machine vision. Based on machine vision theory, Identification and detection algorithm of panel signal indicator elements and tachometer pointer readings was studied combining single-frame still images and real-time processing of color video image, the automatic parallel detection of multiple dashboard was realized by distributed network architecture. This paper first describes the function requirements, the overall composition and working principle of automatic test system. Then, it proposes an automatic identification and detection algorithm of dashboard symbol sheets and pointer position. Finally, it shows the designing of automatic test software with a self-learning and auto-detection function, and describes the working process of the software. The tests prove that the system is capable of realizing fast and accurate auto-test of bus dashboard functions based on the non-contact of machine vision, which improves the overall efficiency of the bus dashboard line.

Abstract: The mechanism of longitudinal-torsional vibration (LTV) realized by using converter with multiple diagonal slits (MDS) was analyzed based on the acoustic wave propagation when acoustic wave enters obliquely from steel to air. The influences of geometrical parameters of the stepped compound horn with multiple diagonal slits on natural frequencies of LTV were studied with finite element analysis (FEA). The design procedure of stepped compound horn with LTV was provided. The vibration characteristics of actual horn were analyzed with simulation and test. The FEA results show that LTV of the output end of the stepped compound horn may be realized when the input end is excited by longitudinal vibration at certain natural frequency if suitable geometrical dimensions are selected, and the amplitude of the horn is periodical; the trajectory of the particle in the output end is helical curve. The test results indicate that LTV may be realized by stepped compound horn under single acoustic excitation, and the vibration frequency is close to the simulation result, and its vibration properties are good. This method may be applied to design the acoustics system of ultrasonic machining with LTV under single acoustic excitation.

Abstract: Electrical energy directly converted into mechanical energy of linear motion by linear force motor, greatly enhancedthe rapid response ability and control precision of the feed system. The product quality of linear force motor can be effectively improved by design a performance test system of linear force motor. The paper designed a performance test system of linear force motor based on the Labview virtual instrument platform, and test project of linear force motor has been planned, the test method, the structure of the test device, power drive module, step motor load part, data acquisition and the software system all have been completed. The test system realized automatic and manual two different kinds of test methods, data acquisition and management and processing function and the good human-machine interface, the linear force motor dynamic and static parameter, including input current, output force and output displacement and the relationships between them have been tested.