Abstract: This paper takes a new-type 3-TPT 3-DOF parallel machine tool as the object of study, established the positive and negative solution of kinematic equations of the machine, and derived the Jacobian matrix and Jacobian inverse matrix of the machine tool. On this basis, the singularity and stationarity of the machine tool were researched by using Matlab and got the expression of the absolute value of Jacobian matrix determinant of the machine tool. The velocity distribution curves of telescopic driving rods of the machine tool were simulated, too. The results show that the machine tool has advantages such as good stationarity and no singularity and so on. The study provides certain theoretical basis for the structural optimum design and performance analysis of parallel machine tool.
Abstract: Vector control is one of the most popular control techniques of induction motors. Owing to its simplicity, the indirect vector control gains increasing popularity. This paper proposes a speed sensor-less indirect vector control system of induction motors based on a novel sliding mode control (SMC) speed observer. The observer uses the stator current difference of the estimated value and the actual value to calculate the rotor speed. The simulation results show that the method has a fast response and high accuracy, and it robust to parameter variations.
Abstract: This paper gives the structure and principle, design method, function characteristics and transformer test platform of a new automatic instrument transformer calibrator based on the conception of virtual instrument. The design project of the errors testing and the optimizing automatic voltage regulation controlling are proposed in details, introducing several applications of anti-jamming technology as well. This optimized design makes the transformer testing and measuring resolution fast, steady and accurate.
Abstract: Aiming at the liquid-level control of double water-tank, this paper discusses the application of fuzzy control theory in liquid-level control system and a cascade control method based on fuzzy self- tuning PID controller is proposed. The design method of this fuzzy self- tuning PID controller is put forward. The fuzzy self- tuning PID controller is designed and the control effect of three kinds control methods, the single loop PID control system, the cascade control system and the cascade control system based on fuzzy self- tuning PID are simulated with Simulink. The analysis and simulation results indicate that the overshoot, the adjusting time and the capacity of anti- disturbance of the liquid-level cascade control system based on fuzzy self- tuning PID controller are superior to those of the general single loop PID control and cascade control.
Abstract: To implement the remote and real-time monitoring of surface water pollution, a design scheme of water quality monitoring system based on GPRS technology is put forward, which is composed of monitoring terminal, monitoring center and communication network. The various parameters of surface water are acquired using water quality detection sensor terminal and uploaded to the remote monitoring center via GPRS module by monitoring, and then the water quality parameters acquisition, processing and wireless transmission are realized. Water quality parameters are received through the internet network by the monitoring center, to realize its remote monitoring and management. According to the practice result, the system has materialized functions on GPRS service platform, such as real-time water quality parameters acquisition, procession, wireless transmission, remote monitoring and management, which is suitable for surface water pollution continuous monitoring and has the good application in the future.
Abstract: The bolt support is one of the effective support means to stable the surrounding rocks in underground projects. To determine the ultimate shear strength parameter between the surrounding rocks and bolting mass interface would have important project value to the bolt support design. In order to easy and accurately determine the shear strength of the bolting layer in the bolt design, based on elastic-plastic theory, a theoretical model under the bolt pulling function was established. The load transmission function during the bolt function process was derived. The theoretical relationship between the limit shear strength parameter of the bolting layer interface and the bolt pulling test curve was obtain. The shear strength parameter between the resin anchoring agent of the bolt support in mine roadway and the coal rock mass was determined. The results show that with the bolt pulling test curves, the cohesive strength of the bolting layer and the shearing rigidity coefficient of the bolting layer interface could be easily obtained and could provide the references to the bolt support design.
Abstract: Induced polarization method is one of common methods for electrical prospecting of geophysical. The paper is to analyses and research application of embedded technology for induced polarization instrument and design multifunctional transceiver instrument. The paper is to realize hardware part of induced polarization instrument by regarding ARM processor as hardware core by combination of current intelligent power module (IPM), induced polarization analog signal processing and 24-digit △-∑ high-precision A/D conversion chip (CS5532), etc. It can transplant embedded operation system (uClinux) on embedded ARM processor and formulate drive program which matches hardware circuit and application program to fulfils various functions including data acquisition, data processing & display, data storage & transmission required by induced polarization instrument under uClinux system management.
Abstract: In this paper, a new method based on modal analysis and CPF method devoting to designing of generation adjusting plan which can alleviate stressful voltage condition considering energy saving is proposed. The voltage stability condition has relation with the generation and load distribution modes, usually only adjustment of load distribution modes has been noticed when there is a need to alleviate stressful voltage condition. Noticing that properly modification of the generation mode under stressful voltage stability condition can also reduce the power loss of power system and enlarge the voltage stability margin, a fast generation adjusting strategy designing algorithm is proposed. In the mean time, coal consumption of each generator is also considered. Participation elements is employed in this method to select the generators which are effective in adjusting process, continuous power flow calculation algorithm is used to trace the variation of power loss in power system. The simulation result on IEEE 39 system show that the method proposed by this paper can modify the voltage stability condition and enlarge stability margin to certain extent.
Abstract: The control system of automatic clutch is based on the manual gearbox instead of the clutch pedal. It realizes automated clutch and manual shifting. The essence of automatic clutch is how to control the motor drive unit to achieve the implementation of the automatic clutch separation and bonding, and thus automatic speed technology of motor is the key. In this paper, combining the characteristics of micro-car, a double-loop automatic motor speed control system is designed. The design is proved reasonable and feasible through simulation based on MATLAB.
Abstract: Pressure-rate deconvolution method based on the newly robust solution algorithm is applied to low permeability reservoirs, and deconvolution codes were developed for the study based on Schreoter deconvolution algorithm in this paper. The application of this method in a low permeability oilfield shows that deconvolution can provide much more information than the conventional well test interpretation methods, and this deconvolution method can interpret the whole test sequence but doesn’t be limited in pressure build-up period. It is proved that the pressure-rate deconvolution algorithm works well in well test interpretation of low permeability reservoirs.