Key Engineering Materials Vol. 620

Abstract: Traditional electric heating boilers have disadvantages, such as low purity of the heating resistor, low electric conversion efficiency, poor stability, high acquisition, maintenance costs and so on. This paper, on the one hand, analyzed the basic rationale of the current electric heating boilers, and on the other hand, the advantages of nanomaterials. Based on the combination of the basic rationale and the advantages mentioned above, this paper then designed a new type of electric heating boilers, including the relevant control system, which used nanoelectric membranes as the heating component. This new nanoelectric boiler adopts a brand-new heating method, and it does not get heat by the combustion of chemical energy. On the contrary, the electrical energy is directly converted into heat. This new nanoelectric boiler is equipped with the intelligent control system, and uses computers to realize complete automation. It has excellent physical stability, high electric conversion efficiency and power factor as well as a large power density, and low-carbon environment. Compared with the conventional products of the same electric power, this new type of electric heating boilers can save 30% to 50% of energy. Besides, it is environmental-friendly and functional.

Abstract: Considering the efficient use of energy and environmental pollution, people's lives tend to energy saving and environmental protection, and energy saving electric vehicles has gradually been widely used. Through combining theoretical analysis, numerical simulation, system design and experimental validation, based on studying electric vehicle body design principles, the experiment optimized electric vehicle body design, and reduced the weight of the vehicle effectively. Its performance becomes more advanced, and the application becomes more economical and safe. By using Solidworks software, lightweight electric vehicle body structure of two-dimensional design and three-dimensional modeling was built to reach practical requirements. The body structure design is original and simple, which has good practical value.

Abstract: Current domestic and international for the experimental apparatus been associated asynchronous motor design generally used hand horseshoe magnet rotates to drive the rotor rotates, While it is possible to achieve, the apparatus is too simple, and the effect is not in great satisfaction. To further improve the experimental results, a new type of asynchronous motor experimental device is designed, whose working mechanism is a DC motor as a driving source, driven by a reduction gear mechanism to produce a rotating magnetic field, the control circuit can be achieved by utilizing the rotational speed and adjust direction. By apparatus of the stator, rotor apparatus, the related motor control and display device design can make the operation more stable, more easily observed. The experimental apparatus can enhance students' awareness and understanding of asynchronous motor, so that the original abstract theory becomes boring incomprehensible gusto, to stimulate students' desire for knowledge, strengthen students' practical knowledge and ability, with higher practical significance. The apparatus simple shaped, with simple and safe operation, is able to facilitate teaching, with better promote the use of value.

Abstract: Magnetorheological fluid as an important branch of the emerging intelligent material, its excellent characteristics make it widely used in electrical system and mechanical system. Common MRF system environment is limited to a uniform magnetic field, the practical application process to the vast of magneto rheological characteristics devices has shown the phenomenon, which does not match the uniform magnetic field theory, the reason is that the actual work environment is the non-uniform magnetic [1-2]. To study the characteristics of MRF shear stress in a non-uniform magnetic field, this paper established a non-uniform field magneto-rheological fluid shear stress measurement device. Comparing the experimental shear stress curves with the uniform magnetic field measured shear stress curves, we found that the non-uniform magnetic field strength of the environmental equivalent shear stress values ​​compared with the uniform magnetic field data have large deviation, this indicates that the existing uniform magnetic field theory is not well to explain non-uniform magnetic field shear properties of MRF, we need to build the introduction of non-uniform magnetic field theory.

Abstract: This is companion paper with “Diamond-bead Wire Classification and Spectrum with POS Part I: Classification with Process and Subject”. The current study continued to collected and analyzed systematically a series of patterns of diamond-bead wires from the diamond-bead wire manufacturers throughout the globe and went insight into the essential elements of the wire, including the overall layout, shape characteristics, technological processes, cutting and grinding object, and studied in classification for the spectrum characteristics, with respect to the features of structure, process and the sawing object. The stress was on the method of classification with POS with respect to the structural characteristics, and a trial spectrum has been drawn on the POS classification for diamond–bead wires. Such subject was discussed and presented in two parts, and here is the second part for classification with structure and spectrum with POS.

Abstract: In order to solve the hobbing machining data calculation and hobbing simulation of non-circular gear with various shapes, the piecewise cubic spline fit method has been adopted to unify the polar coordinate expression of non-circular pitch curve. The method to generate hobbing machining data was deduced based on hobbing linkage mathematical model, and the machining data error caused by piecewise cubic spline fitting method was analyzed. The three-dimension software has been used as simulation tool to make secondary development, and then non-circular gear hobbing simulation was realized based on machining data, which can verify the validity of machining data and the relevant design drawbacks of non-circular gear. The work of this paper lay a good foundation for design parameters optimization and hobbing of non-circular gear.

Abstract: In this paper, theory analysis, the MATLAB research and experimental verification about feedforward fuzzy PID control have been performed by combining the characteristics of the PID, feedforward control and fuzzy control. Simulation results show that the feedforward fuzzy PID control could improve the response speed of the system and reduce the tracking error of the system which shows the obvious superiority compared with the PID, feedforward PID, and fuzzy PID. Load experiment for such four kinds of control modes is done on the linear motor platform, and the experimental results show that the accuracy of the feedforward fuzzy PID control is obviously higher than the other three kinds of control modes and the feedforward fuzzy PID control is easier to be implemented. The position error of feedforward fuzzy PID control is changeless during the load change, and the change of the speed tracking error is small, which proves that the feedforward fuzzy PID control is suitable for the condition of load change or the great disturbance.

Abstract: Aiming at the deficiencies of single signal of electrical resistivity imaging instrument, poor anti-interference, fixed electrode arrangement and low-sampling accuracy, etc, this paper designs a new type of high-density exploring ground instrument. Based on MCU as controller, the transmitter uses MOSFET tube driving H bridge circuit to transmit any digital code current signal. Based on FPGA as master controller, the receiver uses 24 bit ADC chip to sample the data, designs the key circuit such as reference source, clock and single-ended to differential, accomplishes high precision data acquisition. Distributed intelligent electrode conversion device uses low power relay, so it is very small and low power consumption. We did the noise test and repeated measurement experiments on pure resistance on this instrument. The experimental results show that the transmitting signal is stable, waveform is standard, resistance curve tested by collecting system and actual curve are coherent, the precision is high and the stabilization is good.

Abstract: As plants of lowbush blueberry are widely cultivated, picking of blueberry has become an important link in the chain of blueberry industry. At present, research of domestic machinery of blueberry picking is still in early stages. Mechanical and automation level of blueberry picking are enriched, through research of picking machine of lowbush blueberry. The research has the vital significance to the development of blueberry industry. To improve picking efficiency and reduce total loss rate of green fruit, mechanism of picking is analyzed. Fruit, which has certain representativeness in the variety, is researched. Picking force and vibration frequency of plants are obtained and work principle is determined. Structures of vibrating picking and fruit collection and the body of the machine are designed. Parameters of structure size and working are determined, with which the machine is manufactured. Plan of experiment is designed and experiment of picking is done in the season blueberries are most ripe. Result indicates structure of blueberry picking machine is reasonable. Picking force and vibration frequency are effective. Compared with that of manual picking, efficiency of mechanical picking is high, which meets technical requirements of blueberry machinery.

Abstract: In order to study the kinematic characteristics of the tree transplanter and the hydraulic cylinder, this paper established the model of the tree transplanter with the Cero2.0 software and analyzed kinematic characteristics of the hydraulic cylinder and the tree spade when the tree spade was driven by the hydraulic cylinder with the analytical method. The dynamic simulation curves of the angular velocity and the angular acceleration of the hydraulic cylinder can be obtained with the Matlab software. Then the appropriate format model file was imported into Adams software, and the angular velocity and the angular acceleration of the hydraulic cylinder were analyzed and simulated in Adams. The obtained curves in Adams software were compared with the curves obtained with the Matlab using the analytical method. The result revealed that the trends of the two ways simulation curves were consistent. The comparison showed the analytical method of kinematic characteristics of the tree transplanter and hydraulic cylinder was correct.