Applied Mechanics and Materials Vols. 670-671

Abstract: A kind of small cylinder crochet galloon machine was designed; the technical features, principle and structure characteristics of the equipment were introduced, and the functions of major mechanisms such as cylinder crocheting and winding and their design were expounded. Practice indicates that small cylinder crochet galloon machine designed is a kind of excellent fancy yarn production equipment with simple structure, convenient operation and varieties replacement.

Abstract: There exist overfrequency issues of airframe vibration, instable fight conditions, inefficient airframe survivability and undeveloped cockpit’s eject-ability insides multi-rotor aircraft flights. This paper focuses on four-rotor aircraft researches via gathering inherent rotor attitudes with the inertial motion capture device. Based-on the resulting data analyses, the relations between flight attitudes and rotor performances are clearly figured out. This research also advances multi-rotor aircraft works, such as: drawing frameworks, evaluating simulations, designing control systems, and optimizing safety and stability properties.

Abstract: For a class of T-S fuzzy time-delay systems, the problem of designing a static output feedback controller is considered via the parallel distributed compensation (PDC) approach. Namely, when one controller can not assure the stability of system, a controller switching strategy in certain set of controllers may stabilize the system. Moreover the adoption of this strategy often improves the performance of system even in the case that a single controller can stabilize the system. By defining multiple Lyapunov functions, the sufficient condition for the existence of the static out put feedback controller is presented in terms of linear matrix inequality (LMI), which guarantees the stability of the close-loop system for the switching cases. The simulation results demonstrate the effectiveness of the proposed method.

Abstract: Robust stabilization of a class of uncertain fuzzy systems is considered in this paper. The fuzzy systems not only exit disturbances which do not satisfy the so-called matching condition and contain uncertainties in the input channel, but have uncertainties in the state matrix. By using Lyapunov function, the robust state-feedback controllers are constructed. The controllers guarantee that the states of systems are robust stabilization. A numerical example is given to show the effectiveness of our method.

Abstract: The electric valve cutting off or connecting pipeline of nuclear equipment is an essential component of nuclear facilities for safe operation, whose reliability directly determines working performance of entire nuclear device. Based on function analysis, module partition and structure analysis of valve have been carried out in the paper, and the direct correspondence between common faults and structural modularization of valve has been established. Furthermore, the proper methods and procedures of fault diagnosis for nuclear valve are put forward, which can guarantee safe operation of nuclear facilities.

Abstract: In order to improve the ability of independent planning for AUV (Autonomous Underwater Vehicle), a new method of motion planning based on SBMPC (Sampling Based Model Predictive Control) is proposed, which is combined with model predictive control theory. Input sampling is directly made in control variable space, and sampling data is substituted into the predictive model of AUV motion. Then surge velocity and yaw angular rate in next sampling time are obtained through calculations. If predictive states are evaluated according to the performance index previously defined, optimal prediction of AUV states in next sampling can be used to realize motion planning optimization. Effects of three sampling methods (viz. uniform sampling, Halton sampling and CVT sampling) on motion planning performance are also compared in simulations. Statistical analysis demonstrates that CVT sampling points has the most uniform coverage in two-dimensional plane when amount of sampling points is the same for three methods. Simulation results show that it is effective and feasible to plan a route for AUV by using CVT sampling and rolling optimization of MPC (Model Predictive Control).

Abstract: Classical linear PID controllers have such disadvantages as the derivative signal unable to be used owing to the noise amplification effect, and the contradiction between the more swiftness and less overshoot. We develop a practical nonlinear PID controller based on a tracking differentiator (TD) in the high precision servo system of the three-axis flight simulator, which could eliminate above disadvantages. The nonlinear PID controller adopts the tracking differentiator to arrange the response process and produce the ideal derivative signal of the reference signal. We use a nonlinear combination function of the error proportional, integral and derivative item in the PID controller. The simulation results in Matlab Simulink demonstrate that the nonlinear PID controller makes the flight simulator servo system with the friction disturbance realize the higher position tracking precision and velocity tracking precision. The nonlinear PID controller with the TD is superior to the classical PID one in control performance.

Abstract: This paper presents a novel design of multi dof and multifunctional manipulator arm control system. It uses 32 bit microcontroller STM32 as the core control unit, by controlling the pulse width modulation to control the manipulator arm of the steering gear. It consists of a mechanical model, the control core module, operation module, power supply module. The manipulator arm can greatly improve labor productivity, accelerate the realization of industrial production mechanization and automation, it can replace human labor in order to realize the mechanization and automation of production, and protect the personal safety in harmful environment. It has the advantages of light weight, simple operation, and low production cost etc.

Abstract: The complex geographical environment put forward grand challenge to most current detecting robot on the problem of communication control and moving obstacle avoidance.This paper proposed a crawler robot for complex environment detecting.Information acquisition was achieved by Labview programming,the collected sensor information was debugged by fusing and displaying in the Labview interface , in order to realize the stability of the system.The positioning part adopted wireless location technology of ZigBee networks,which can support a large number of network nodes, fast, and reliable security etc.In addition, the upper part of the robot body was equipped with camera and mechanical arm to achieve target capture, carrying something and other tasks. According to the situation of accident, remote control terminal through wireless control function can control the further action of the robot. Through experimental tests, this paper proposes this kind of detection robot had great advantages in detection, search and rescue, it can complete the search under complex and dangerous environment.

Abstract: A three-arm robot is designed according to the needs of space operations. Four kinds of climbing are analyzed and the kinematics parameters of the robot are derived. Based on ADAMS virtual prototyping technology, robot modal is established and the climbing process of the robot on a pole is simulated for four kinds of gait, respectively. The force curves and effect factors are obtained so as to offer the design references for the robot.