Applied Mechanics and Materials Vol. 740

Abstract: Parallel welded steel truss component is widely used in construction, tower, bridges, aerospace and other fields. And the welding residual stress is distributed complicatedly in many areas and directions, which will definitely deform the welded steel truss or even crack it. So, it is necessary to do aging treatment to avoid such thing happened, as well as improve the accuracy and reliability. Vibratory stress relief (VSR) is a new kind of technology which may eliminate the residual stress in metal component with high efficiency, energy-saving, environment protection and low cost compared with thermal stress relief (TSR). But its technical effects vary with the vibration parameters. To the parallel steel truss structures, the excitation parameter of VSR is determined by welding residual stress distribution and the natural mode of vibration. The residual stress concentration areas can get enough vibration, if the parallel steel truss component vibrates with different kinds of natural mode of vibration, which will obtain good effect of eliminating stress. Firstly, the inherent vibration mode of parallel welded steel truss component is measured by the modal analysis technology. Secondly, multiple intrinsic modes are chosen according to principle of making all the welding residual stress concentration regions and directions get enough vibration and then main technical parameters are determined such as excitation frequency, excitation point and support point. In this paper, two examples are given out: the specimen 1is treated with the transverse bending vibration mode and torsion vibration mode respectively according to the above method. As for specimen 2, it is treated with 3 exciting frequencies which are located automatically by the vibration aging machine. The residual stresses of the two specimens are measured before and after their vibrations with blind holes method. Results show that after vibration aging, the welding residual stress peak figure of the Specimen 1 is reduced by an average of 48.65% and the mean value of that dropped by an average of 32.50%. Correspondingly, the residual stress peak value of the Specimen 2 shows a decline of 3.38%, its average fell by an average of 2.55%.

Abstract: In this paper, based on the honeycomb floor damper of high-speed train, the finite element analysis was carried out on the floor damper, and we compared the experimental results with the physical model experiments. The results show that: when correction factor γ = 0.5, there is the minimum incremental error of vertical deformation, and the value of the damper parameters is the best at this time.

Abstract: Based on the emus' VIP test of floor shock absorber, the parameter optimizations are conducted. Through the experimental comparison and analysis of low stiffness with high damping, stiffness damping and the original car shock absorber, it proved that the high stiffness damping vibration damping performance is better than another two kinds of shock absorber.

Abstract: Organization is an organization with a parameter independent degrees of freedom movement, mechanical design and analysis of important concepts, the degree of freedom for the agency when analyzing problems illustrate the organization's scope of application and freedom of formula should pay attention to the issue, and based on this proposed the Reflections, in order to better use and master.

Abstract: Piston is one of important parts of engine. It is meaningful to modify piston machining. The motion characteristics of shaped-piston cylindrical surface and profile were analyzed. A fitting transition curve method for the piston skirt cylindrical profile was proposed, which could satisfy requirements of smooth and non-impact, especially at the starting point and the ending point. And the machining profile data were generated by interpolating in Matlab. This result provides references for the piston design.

Abstract: This paper is concerned with the design and implementation of a ZigBee based wireless sensor and actuator networks, which has been applied in our service robot intelligent space successfully. Firstly, an overview of ZigBee protocol is given, and then the design and implementation of hardware module and software stack of ZigBee based wireless sensor and actuator networks are addressed in detail. Some representative devices are described, including environmental sensors for environmental perception, home devices controllers for device control, IMU module for abnormal behaviors detection, locating system for node localization and laser robot control for service robot navigation. Application example is described to demonstrate how the devices in ZigBee based wireless sensor and actuator networks to provide service cooperatively. Finally, we conclude this paper and discuss the future directions.

Abstract: Intelligent Ground Vehicle needs real-time communication system and a better architecture to handle a variety of sensors. This paper presents a fast communication and efficient architecture for intelligent vehicle (FCEA-IV). The vehicle contains three control centers, communicating with each other based on real-time control system. And also it has a hybrid mode. In auto driving mode, it will go under the better path, calculated by considering comprehensive environmental factors. While in active control mode, the vehicle will be controlled by remote commands. First of all, we will discuss RCS (real-time control system) and why we choose it. Then the overview of system, including architecture and control structure will be discussed. Further some communication message and work flow will be studied in detail. At last we share some experiments to test the efficiency of the communication system.

Abstract: The theory of gait is one of walking ways which is efficient, fast and stable in a variety of industrial robots, offering a structure of climbing robots in a way of gait and climbing with the gait motion in paper. Through the results of analysis by various industrial software, the presented structure of climbing robots which is composed of two terminal parts and two robot arms that is the part of pedestal and climbing mechanism. In the process of climbing, realizing gripping, Swing work, turning work, an orderly motion and get to the aimed place finally through alternate between the upper and lower part of the body by the control of SCM. The presented method has not only improved many problems like complicated climbing structure, controlling rough, slow-motion and unable thronging obstacles, but also accomplished the subsequent operations like tools delivering, pole testing, clearing, maintenance work, furthermore, there has more comprehensive benefits.

Abstract: With the maturing of in-wheel motor technology, Control on vehicle longitudinal and lateral stability have a rapid development, vehicle with in-wheel motor have also made considerable progress. The paper conducts a study on control strategy of electric vehicle with two in-wheel motors mounted on rear wheels. Yaw moment adopt target following algorithm based on two degrees of model of monorail and study the allocation of torque on two driving wheels. The study indicates that ESP control strategy in which yaw moment of left and right wheel is different and the way of allocating torque based on utilization adhesion can improve vehicle handling ability.

Abstract: The electro-mechanical braking system of In-Wheel-Motor vehicle is analyzed by applying vehicle braking stability theory. Considering the properties of composite lectro-mechanical braking system, a regenerative braking system control strategy with ABS function for In-Wheel-Motor vehicle is proposed. In the strategy, the ABS function is achieved by adjust the motor torque. With using the new strategy, simulations are conducted on an in-wheel-motor vehicle model, and the road adhesion coefficient in the simulation is 0.2 and 0.8 respectively. The result shows that the control strategy proposed enhances the braking stability of In-Wheel-Motor vehicle.