Abstract: The clearances, which universally exist in the joint parts of mechanical systems, are a main cause of various operation deteriorating problems, including noises generating, material wearing, even the early fatigue of members. In this paper, a new method to determine the clearance magnitude in the beam support is proposed with the description of a numerical example. The growing clearance will increase the vibration period of realistic system, and the accurateness of measurement is relevant to the frequency resolution of the instrument. Through the time series of the midpoint response of a simply supported beam, the period of the first modal free vibration can be obtained using the FFT Algorithm. Only two responses from different initial conditions are needed to identify the magnitude of the clearance. It is estimated the accurateness could be below 15%. The investigation also suggests this free vibration period approach may be adapted to handle the energy losses situations with the damping ratio considered in the formulas.
Abstract: According to the principle of manganese powder forming, a battery online weighing system with PLC-based PID-Fuzzy control algorithm was designed. In this paper, we focus on the need for a detailed description of hardware and software and matlab simulation of the system. The system uses touch screen for realization of human-machine interaction with high stability, and double closed-loop controls overcome the disadvantages of the traditional offline open-loop control, those greatly improve the efficiency and accuracy of manganese ring weighing.
Abstract: A robust dense 3D feature map is built only with monocular vision and odometry. Monocular vision mounted on the robot front-end tracks the 3D natural landmarks, which are structured with matching Scale Invariant Feature Transform (SIFT) feature matching pairs. SIFT features are highly distinctive and invariant to image scaling, rotation, and change in 3D viewpoints. A fast SIFT feature matching algorithm is implemented with the KD-Tree based nearest search approach in the time cost of O(log2N), and matches with large error are eliminated by epipolar line restriction. A map building algorithm based on 3D spatial SIFT landmarks is designed and implemented. Experiment results on Pioneer mobile robot in a real indoor environment show the superior performance of our proposed method.
Abstract: Hydrogenated nanocrystalline silicon (nc-Si:H) ﬁlms were deposited on glass substrates using Radio frequency plasma-enhanced chemical vapor deposition(RF-PECVD)from a B2H6/SiH4/H2 gas mixtures. In this paper, we mainly changed the Borane-Silane flow rate ratio (β), while other parameters were kept constant. Raman spectrum and X-ray diffraction were employed to investigate the micro-structure of the films, and the indentations were used to measure the mechanical characters (the Young’s modulus (E) and hardness (H)). The Raman spectrum showed that, withβincreasing the crystalline fraction decreased, which indicated that more boron doped might not be propitious to the formation of crystalline of the thin films. XRD spectrum revealed that the films have a remarkably preferential orientation. The analysis of the Young’s modulus and hardness by TriboIndenter nano system suggested that the increase inβhad concernful effects in the decrease of E and H values, so we can control the mechanical characters of the thin films by means of changing the doped concentrations. In view of these results, it may be concluded that the use of lowβconditions might lead to growth of nc-Si:H ﬁlms with high crystallinity, and as well high Young’s modulus and hardness.
Abstract: An electronically controlled air suspension system has been introduced to improve the ride performance of a vehicle. A fuzzy controller is designed on the basis of fuzzy logic control strategy which is applied to control the air suspension system. The vibration reduction of a coach with the suspension system is achieved by controlling the stiffness of the air spring and the damping of a switchable damper. A nonlinear dynamic model of a half-vehicle is used to simulate traditional air suspension and the one with fuzzy controller for ride performance respectively on road input. The results indicate that implementing a control strategy can improve the ride performance of the coach on the condition of normal road.
Abstract: Through the study on fuzzy control in the vehicle speed control, the intelligent fuzzy controller with intelligent integral and differential is proposed. In this paper, we take diesel vehicle control system as an example, and the vehicle speed control system’s simulation has been completed. Simulation results show that the intelligent fuzzy controller could adapt to the model whose parameters are non-linear, time-varying, and this controller can also effectively inhibit the environmental interference, so the system with intelligent fuzzy controller has strong robustness, good reliability and higher control precision.
Abstract: An on-line system which based on acoustic resonance employed digital signal processer (DSP) as its core device for eggshell crack detection. The system consists of the IR trigger for detecting the egg’s coming, the motor drive for driving the DC motor, the signal conditioning circuit for signal amplification and filter and DSP for control and signal processing. Based on the analysis of response signal of eggshell which excited with a light mechanical, four featured descriptors were exacted for discriminating intact and cracked eggs. By using the on-line system for detection of cracked eggs, the identification rates of intact eggs and cracked eggs were 93.75% and 96.25%, respectively. This system can detect 5 eggs within one second, it completely meet the needs of on-line detection.
Abstract: The purpose of the work is to accurately calculate the forces acting on the working mechanism of wheel loader when excavating granulated material. In order to examine mobile machines movement processes, MSC.ADAMS is used to carry out multi-body system simulation and hydraulics sub-system simulation. Because the flexibility of the component of the working mechanism of wheel loader can not be neglected, ANSYS is used to compute the data describing the behaviour of the flexible component of working mechanism of wheel loader. Based on the Fundamental Earthmoving Equation, this paper describes a methodology and basic formulations of forces between the tool and the material to be moved as well as the internal forces in the pile to be dug from. The method has been implemented in an MSC.ADAMS model of a working mechanism wheel loader. The numerical simulation test on LCM(Linyi Construction Machinery) Wheel Loaders under various position of working equipment will be done to predict the forces acting on the machines during digging cycles.
Abstract: Based on the Chinese medical massage manipulation of rolling, pressing, kneading and pushing, the serial mechanical arm with six rotational joints and the end actuator with 3-DOF parallel mechanism are selected, and a new type of hybrid massage robot is proposed. The type synthesis of this massage arm is designed from two aspects, the arm and the wrist. 6R serial joint massage arm is adopted. Using Denavit-Hartenberg coordinate system, the kinematics model of this massage robot is established and the direct kinematic problem is solved by homogeneous coordinate transformation. The workspace of this Chinese medical massage arm is analyzed by the graphical approach. It shows that the length of upper arm and forearm of this kind of Chinese medical massage arm should be equal to make the work section largest. The workspace of this Chinese medical massage arm is also portrayed based on the Monte Carlo principle through programming on MATLAB. It indicates that the working points in the workspace of the manipulator are distributed compactly and uniformly, which can satisfy the Chinese medical massage requirements with high efficiency.
Abstract: With the minimum mass of steel structure for bodywork as the object, beam sections and location topologies as design variables, and the stress and displacement as constraints, the optimum model is established. With the method of killing or activating elements, a high level technique in MSC. Marc, by Genetic Algorithms, a new scheme of researching structure topology optimization is proposed and the calculation procedure system is programmed. Applied the system, a steel structure of bodywork is optimized successfully. The validity and practicability of the system are certified.