Applied Mechanics and Materials Vols. 462-463

Abstract: Based on introduction of the fluid diffusion energy, the model for path planning is presented. The adaptive mesh is used to solve the equation model for path planning. Based on the dynamic model and kinematic constraints of the nonholonomic mobile robot, a trajectory tracking controller is designed. Theory and calculation results prove that, as a new method for mobile robot path planning, the equation of the fluid diffusion energy for nonholonomic mobile robot path planning is feasible and effective.

Abstract: Based on analyzing the mathematical model of brushless DC motor and shortcomings of the traditional PID control, combining with the intelligent algorithm and the conventional PID, the paper gives a improved algorithm and simulations in MATLAB environment. A brushless DC motor PWM speed regulation system is designed based on high-performance MCU. The improved algorithm and the conventional algorithm control effects were analyzed and compared in the experiment.

Abstract: Ccording to the running speed of ultrasonic motor instability, design a motor testing system, the closed-loop controller embedded improved neural networkalgorithm, to suppress chaos. In open-loop state, input constant parameters to the motor, the motor rotating speed detection, the test data is chaotic analysis,found the speed has chaotic characteristics; in the closed-loop state, the feedback signal through the controller for processing, effectively inhibited theultrasonic motor speed jitter phenomenon, so as to improve the smoothness of motion motor. Experimental results show that, the neural network controller design not only significantly inhibited motor chaotic jitter phenomenon, but also has good anti-interference ability.

Abstract: A novel intelligent driver based on digital signal controller (DSC) has been put forward for magneto-rheological (MR) damper. The working principles of MR damper were described, as well as the hardware circuit scheme of signal condition and MR damper driver etc. on account of TMS320F28335 DSC. A hierarchical control algorithm was designed and the studies for the performance of the driver were conducted. The results suggest that the driver could provide accurate drive current for MR damper, and meanwhile the respond time is less than 2ms, which can meet the drive requirements of MR damper.

Abstract: This paper present a hybrid, hierarchical control architecture for mission re-planning and plan repair of autonomous underwater vehicle (AUV) navigating in dynamic and uncertain marine environment. The proposal carries out a component-oriented part-based control architecture structured in three parts: situation reasoning, re-planning trigger and hierarchical re-planning layer. Situation reasoning using the unstructured real-word information obtained by sorts of sensor detectes and recognizes uncertain event. According the event types and influence degree, the re-planning trigger decides the re-planning level. Hierarchical re-planning layer contains mission re-planning, task re-planning and behavior re-planning. Different re-planning level depends on the result of re-planning trigger. Preliminary versions of the architecture have been integrated and tested in a marine simulation environment.

Abstract: Maglev train operation process can be affected by a variety of disturbance force. The system stiffness should be improved in order to strengthen the train's anti-disturbance ability. The electromagnet input voltage will saturate when the system is disturbed by a large force. Since the electromagnet input voltage can only change in the range of the vehicle power grid voltage, the system performance is unable to be further improved by increasing the proportional feedback coefficient. Therefore an appropriate vehicle power grid voltage should be selected in consideration of the disturbance force the train may meet. In this paper, the mathematical model of magnetic suspension system was established according to the dynamics and electromagnetism theory. Then the working principle of the digital chopper and the linear generator was analyzed. Finally the relationship between the vehicle power grid voltage and the system anti-disturbance ability was explored. Gap changes of systems with different vehicle power grid voltage are compared in consideration of several common disturbing forces. The simulation results show that the higher the power grid voltage is, the stronger the system resistance ability to impact interference is. The existed 440 V vehicle power grid voltage can guarantee the stability of maglev train under 20 kN impact interference. But under more than 20 kN impact, train may crash the track. By selecting 500 V power grid voltage, the trains' gap change will be less than 5 mm, under 20 kN impact interference.The gap overshoot volume is reduced by 35.2% compared with that with 440 V power grid voltage.

Abstract: In this paper, an NC milling Machine transformation scheme based on SINUMERIK 802D sl system is introduced. This transformation aims to fulfill the needs of both production practice and NC teaching, the electrical system and PLC control system are particularly designed for this object. It is validated that the transformed NC milling machine has perfect functions and high reliability, providing useful reference for the transformation of this type of machine tools.

Abstract: A Multiple Independently Targeted Reentry Vehicle (MIRV) is a ballistic missile payload containing several warheads each capable of hitting one of a group of targets. In the process of missile flight control, the release of warheads brings about coupling to the missile attitude control system which will lower the flight stability. In order to solve this problem, a missile attitude controller, which combined the α-order integral inverse system with internal model principle, was presented. Firstly, determine the Post Boost Vehicle (PBV) attitude dynamics model. Then, combine the linearization of attitude dynamics equation with feed-forward decoupling method to implement the attitude decoupling. Finally, a two-degree of freedom (TOF) multivariable internal model controller was set up to optimize the control system performance. Simulation results show that the coupling of attitude control system has been eliminated. Compared with the original system, the internal model controller provides the control system better input-tracking performance, robust stability and interference suppression capacity.

Abstract: Servo Precision Drive system is mainly composed of servo motor, mechanical transmission parts and control parts. Because of mutual coupling between various parts, particularly transmission system in mechanical coupling vibration in non-smooth transition, it will be of great harm to safe operation of the system. This paper is mainly from the perspective of backlash nonlinear characteristic and with simulation tool of Matlab/Simulink to analyze the influence of backlash on the precision of servo system, do hope the work above will have certain reference significance to actual engineering application.

Abstract: Currently, cutting umbilical (root) process of dehydrated garlic slice processing plant has not been realized mechanization in China, and mostly completed by manual. Cutting umbilical (root) efficiency is low and the quality is difficult to guarantee. In this paper based on image processing, the demarcation line between garlic umbilical and garlic meat is measured, and then the measured data is transmitted to MCU control system of garlic umbilical (root) cutting machine through serial port communication technology. MCU system controls the gear motor to drive ball screw moving accurately and cutting garlic umbilical. The cutting error is less than 0.5 mm. This system adopts image processing technology and electromechanical integration technology, realizes the automation cutting of garlic umbilical (root).