Applied Mechanics and Materials Vols. 644-650

Abstract: DC microgrid can effectively play to the value and benefits of the distributed power supply, communication than micro grid-connected have the ability to stronger more flexible refactoring and therefore become a new trend micro grid-connected technology research. Based on photovoltaic DC microgrid as example, this paper aimed at the DC microgrid voltage stability problem, proposes a layered coordination control DC bus voltage, the method is based on the detection and control of DC bus voltage variation to coordinate photovoltaic battery energy storage interface, net side interface and the interface converter works, ensure that under different conditions can keep the grid-connected in active power balance. Using Matlab/Simulink simulation and experimental verification, the results verified the effectiveness and feasibility of the method.

Abstract: A method of minimum resolution adjustment based on the control of PWM is proposed. In the first part, the principle of PIC16F877 is analyzed and the signal period and the pulse width is calculated. the Two buttons on PIC16F877 are used to precise control the increment and decrement of output of PWM. The procedure of control of PWM is introduced at the last part. Using the method, the speed of rotation of the direct current motor can be precise controlled.

Abstract: This paper proposed a numerical model to investigate the characteristics of solar energy collected by the UAV’s surface in different flight conditions. The novel model consists of a solar radiation model and a solar-powered aircraft model. The solar radiation model describes the process of the sunlight (including visible and infrared light) reaching the surface of the panels, and key effective factors are included. The solar-powered aircraft model describes a conventional layout fixed wing aircraft model with solar panels on the upper surface of the wing. The whole model was solved numerically by a computer program developed with C language to calculate the total power that the panels absorbed under different conditions. The visual and numerical results were presented and discussed in details.

Abstract: Integrating the merits of wheeled and tracked mechanism, a robot’s mobile mechanism may have more adaptability in field environments. A kind of metamorphic mechanism with three configurations was proposed, which configuration transformation was analyzed and metamorphic equations on configuration transformations were put forward. Based on them, a wheel-tracked robot’s mobile mechanism was brought forward. The key component of the structure, locomotion-mode-changing unit, was synthesized. The robot’s prototype was made and the principle test was finished. The result shows that the built prototype can run by wheels or tracks, and transform itself successfully.

Abstract: Based on synthesizing the robot’s chassis mechanism,a transformable chassis is presented to adapt to the conflictive requirements of complex fields. A transformable wheel-legged robot has been designed with the applied chassis. As a variable topology mechanism, the robot has many changeable configurations. Finally the structure implementation of the robot was discussed.

Abstract: This paper establishes the kinematics model of humanoid robot arm, the arm forward kinematics equations were built and solved, based on the advantages of CCD (Cyclic Coordinate Descent) and BFS (Broyden-Fletcher-Shanno) algorithm to solve the inverse kinematics of humanoid robot arm. In the joint space, using cubic polynomial and quintic polynomial interpolation method respectively for each joint angle interpolation. Cubic polynomial trajectory planning can meet the point-to-point movement in general, but can not guarantee the continuity of acceleration of each point; Quintic polynomial trajectory planning can ensure that each point is continuous of the joint angle, angular velocity, and angular acceleration, so this polynomial method can meet the movement of the humanoid robot arm.

Abstract: The quality of the turbocharger is made up of parts material and the machining precision of parts and assembly precision, etc. Turbocharger manufacturing areas concentrated production and standardization is the foundation of product scale and diversification. Parts of standardized production is a key link in the process to ensure product quality. The relationship between the parts production enterprises is parallel relationship. Key parts machining and parts material is the main content of the core enterprise research. Sharing of technical information between enterprises and the market demand information. The core enterprise to assembly as the main mode of production. Parts machining accuracy control is done by manufacturing companies. The core enterprise in the processing of parts to participate in the inspection and supervision. Process control into the whole process of quality control.

Abstract: Hydraulic excavator is due to the effects of vibration and shock may cause structural damage, and in view of this, we need to study its dynamic characteristics, so as to avoid or reduce this impact on when the machine is running. In this paper, using UG as modeling tool we built a small hydraulic excavator boom’s 3-D simulation model and under UG’s advanced simulation environment we called ANSYS as solver and after modal analysis of the boom, we extracted the first 15 modals and vibration modes, which provides the basis as do dynamic optimization excavator boom design.

Abstract: Vibration appears in the main drive system of the six-roller cold rolling mill of one plant. The oscillation frequency is 2.5 Hz. The oscillation cycle is 0.4 second. The oscillation period has nothing to do with the speed. Using the finite element software ANSYS, the low natural frequency is got through the modal analysis and harmonic response analysis based on the measured vibration data from the field. Horizontal vibration is the main vibration mode and it is the electromechanical coupling vibration. Main motor is controlled by IEGT inverter of TEMIC and the low frequency harmonic component is difficult to eliminate. AC drive trap filter is designed to dodge the 2.5 Hz frequency. The solution has achieved the recognition by the TEMIC company. The problem was solved and good results were obtained.

Abstract: The positioning accuracy of tracked mobile robot is low because of sliding in steering process. Taking the micro-tracked mobile robot as the platform, the interface force between tracks and ground was analyzed, and the motor model, kinematic model and dynamic model were established further. A tracking error controller was built based on the tracking error equations, and the co-simulation of mechanical and control system was applied to predict the robot’s trajectory. That controller was applied on a small tracked mobile robot designed by the authors’ laboratory, and the path tracking experiments with and without obstacles had been done. The results show that the robot can accurately track the given path, whether there are obstacles or not.