Abstract: A novel technique for power electronic switch current detection is introduced in this paper, in which the current-sensor is replaced by electronics circuit. According to the principle that the magnitude of the switch current is proportional to its turned-on voltage drop, the proposed technique utilizes the method of grasping the turned-on voltage drop of the MOSFET to reproduce its current waveform. The appearances of voltage drop of the MOSFET are analyzed and the current reconstruction principles are introduced. Experimental results are given to validate the proposed technique. It has the characteristics of simplicity and inexpensiveness and is worthy of adoption.
Abstract: Based on Tooth Contact Analysis (TCA), a feasible approach for Transmission Error (TE) of planetary gear train is proposed in this paper. With a view to getting the total TE curve of the planetary gear train, a specific analysis of the TE from the planetary gear train with only one planet should be proceed firstly, the second step is to calculate each phase difference of planets in the gear train. The applicable conditions for the simplified calculation are spur gear or involute gear pairs in the gear train. Due to equal space between them, planets have the same phase angle.
Abstract: For the low status of straw utilization, in order to improve the mass production rate and reduce energy consumption, according to the classification principle and the idea of “first cut ,second crush”, a set of cutting, screening, crushing, and re-screening as one of the universal closed type straw cutting mill was designed. Design plan was set, the structure diagram of the process of cutting and screening was given, major working parts such as the feeding body, cutting body, shattered body were designed and calculated, the cutting and crushing productivities was 0.29t/h and 0.32t/h respectively, matching power was 10KW. It plays an important role on the richness variety of straw processing equipments, increase straw utilization, and reduction energy consumption.
Abstract: A numerical parameter match approach for harmonic retrieval is presented to improve the demerits of harmonic retrieval methods, such as complicated calculation, low precision and false frequency appearance. The theory deduction and computer simulation are given to show the validity of the approach, and the implementary steps are offered. Based on the characteristics of the motor vibration fault signals exhibiting cyclostation and harmonic information, the numerical harmonic retrieval method can not only search fixed frequency but also match fault characteristic frequency. By the amplitude modulation fault examples, the degrees of modulation variation are employed to validate the availability of the approach in rotating machinery fault diagnosis.
Abstract: Through theoretical analysis and simulation, a practical structural and design method of rotary non-contact electric power transmission (RNEPT) device for ultrasonic vibration internal grinding (UVG) system were proposed, experiments about the prototype of the RNEPT device for UVG system were studied, the feasibility of the optimum design methods was verified.
Abstract: Direct torque control (DTC) method for permanent magnet synchronous motor (PMSM) used as Integrated Starter/Generator (ISG) in PHEV was analyzed. The DTC PMSM model, with PI produced a voltage space vector based on torque PI regulator and flux linkage PI regulator, was built up based on Matlab /Simulink and all simulation blocks were discussed. The results showed that this scheme was simple and effective, also had a good robustness. It is easy to realize in PHEV application, while to keep the fast torque response and little flux linkage and torque fluctuation.
Abstract: When a relative motion occurring between liquid and solid, electric charges with opposite signs come out separately on each side by friction which phenomena is called flow electrification. As the amount of charge generated by flow electrification is small, and part of which neutralize each other at the same time, the test method of flow electrification becomes one of discussion topics for scientists of all countries. This paper introduces an experimental measurement method of flow electrification, which is a comparative method by inserting electrodes in pipelines, and acquisition amplifier circuit, with high resolution and strong anti-jamming ability. Experiments show that the measurement method could be applied to system testing for flow electrification.
Abstract: In view of characteristics of large time delay, multi-interference and strong coupling in temperature and humidity control system, an adaptive decoupling strategy based on generalized predictive control (GPC) and multi-model control is proposed in this paper. The proposed strategy mainly contains muti-model control, GPC decoupling control and adaptive algorithm. In multi-model control, multi-model sets are established to prevent the model mismatch in different working conditions. Meanwhile, this paper designs adaptive dynamic decoupling algorithms based on the principle of GPC. In actual experiments, temperature and humidity achieve precision of ±0.2°C and ±0.5% respectively.
Abstract: Presently for single function and high cost of the phototherapy equipments, this paper introduces a kind of Double-Wave-Bands therapeutic apparatus, which fully utilizes the principle of near-infrared wavelengths treating various pains and UVC sterilizing. This apparatus uses two different kinds of wave bands by selecting different light sources, but a set of control system. Because of a machine with multi-purpose and less cost, this apparatus can treat all forms of disease safely and effectively through using output light of the optical system by various forms of curing probes to be helpful for a promotion.
Abstract: In view of repeated impact condition, developed a repeated impact test machine. This study focuses on using MCU (Micro Controller Unit) to control output of electromagnetic valve what is the core of the machine. The square wave signal , what is issued by AT89s52 and whose cycle and duty cycle can be adjusted, is used to control relay, thereby to control electromagnetic valve of the machine, and ultimately to realize multi-frequency repeated impact under the control of MCU system. A MCU control circuit system is designed at the aim of relay response, including control circuit of hardware, process design of software and anti-jamming design.