Applied Mechanics and Materials Vols. 341-342

Abstract: This paper introduced a simple and rapid electrochemical method for determination of ascorbic acid (AA). A screen-printed carbon electrode modified by multilayer films containing multiwall carbon nanotubes (MWNTs) and redox polymer. The modified electrode exhibited good stability and high electrocatalytic activity towards AA in the presence of uric acid and dopamine even in the real samples. The response current revealed a good linear relationship with the concentration of AA in the range of 5×10^-7 M~7×10^-5 M and the detection limit was 3×10^-7 M.

Abstract: In this paper, in order to realize mechanical behavior analysis and friction disturbance accurate compensation. A measurement system of friction with accelerometer is designed. Principle and method of friction measurement are analyzed, and the system is built. The torque ripple has a huge impact on friction measurement. The digital filter is designed for filtering error which is caused by toque ripple, and the virtual value of friction torque can be acquired. The parameter of friction torque can be obtained using nonlinear least squares method. The experiment is carried out on the servo mount. This measurement system and method can effectively and accurately measure friction torque of servo mount, and be used in measurement of friction torque on other mount.

Abstract: In this paper, from the point of view of Man-machine system engineering, the evaluation method of the display and control system is studied based on fuzzy comprehensive evaluation. The determination of the factors system, the weighted value of the factors, the fuzzy evaluation matrixes and the method of overall evaluation is preliminarily expounded. At last, an example is given to show that the proposed method is effective and applicable. It provides a theoretic reference to the integrated display console interface of armored vehicle developing and designing.

Abstract: Based on the linear model of guidance instrument error separation, study on the separation accuracy affected by data sampling rate of inertial navigation equipment. First, theoretically proved that the higher data sampling rate is, the higher separation accuracy we can get. Second, a method for determining the optimal sampling rate is presented, whose idea is from the model itself. At last, the simulation results can verify the above two conclusions.

Abstract: This article introduces the system of DZN2 automatic soil moisture observation and its application in china. The system is mainly made up of automatic collecting device, wireless data transmission system and intelligent data analysis software, and it realizes the automatic collecting for soil moisture, remote wireless transmission, real-time analysis, automatic monitoring and decision support. Meanwhile, the installation of instrument is simple, the maintenance is convenient, the monitoring for soil moisture is continuous and the data precision is high. By these rich and practical functions, business service personnel can quickly analyze the variation trend of soil moisture content in the local area, make a scientific forecast of droughts, and provide technology support for decision-making service of government based on the real-timely collected soil moisture data.

Abstract: The introduction of the AQC boiler has complex effects on the temperature of Tertiary air, traditional PID is difficult to achieve the effective control. Combined the method of the conventional PID with the fuzzy control theory, a fuzzy self-tuning PID controller is designed. Compared with traditional PID, results of simulation show that the fuzzy PID controller improves not only the adaptability and robustness of the system, but also the system's static and dynamic performance.

Abstract: Describes briefly ultrasonic positioning system (UPS) and digital magnetic compass (DMC) heading measurement principle,analyzed the advantages and disadvantages of each option. To improve the accuracy of the heading measurement, As the theoretical basis of adaptive Kalman filter, designed a kind of ups and dmc integrated navigation system. Based on both real measurement data, made a simulation experiment and confirmed the feasibility of the navigation system.

Abstract: Driven by the interests of the construction unit, field workers illegal operations and other reasons, tower crane collapse accidents occur frequently, personal injury or death became common occurrence. According to the nationalGB12602-2010 lifting mechanical overload protection device security technical specifications, security and monitoring equipment must be installed on the tower crane. The GPRS and U disk storage tower crane control system has catered to the national security specified requirements. By the control system, the data can not only be recorded and inquired, well it can also be wireless remote transmitted. Supervisors who are in units can also monitor the construction site online. Meanwhile, the system can control the tower crane operations according to the specific situation of overrun. The system has a good promotional value.

Abstract: A switch function is presented to smooth control instructions and avoid system vibration during switch operating underwater vehicles with hybrid actuators. And a Modified S-plane Controller (MSC) is proposed by analyzing underwater vehicles dynamics and taking static force and coupling effects between the longitude velocity and other dimensions into account. Besides the advantages of S controller such as simple structure, MSC can solve the motion control of underwater vehicle at high speed which is difficult to control with S-plane controller. The stability of MSC is analyzed with Lyapunov function. Finally, MSC is applied to the motion control of an autonomous underwater vehicle controlled by rudders and thrusters. The feasibility of MSC is demonstrated by the results of velocity control, yaw control and depth control tests.

Abstract: An intelligence sliding mode controller for rotary steering drilling stabilized platform based on nonlinear disturbance observer is presented. Nonlinear disturbance observer which can converge exponentially with suitable design parameters is used to obs erve the uncertain disturbance of stabilized platform under work condition. Sliding mode controller is designed to guarantee the robustness of the closed-loop system. The adaptive rate of switching gain is designed and sign function is replaced by bipolar sigmoid function to weaken chattering. Finally, genetic algorithm is applied to search the optimal controller parameters, including switching function coefficient, switching gain adaptive coefficient, sigmoid function coefficient and observer coefficient. Simulation results show that nonlinear disturbance observer can observe the uncertain disturbance effectively, controller output is decreased and stabilized platform can get optimal control performance and robustness.