In order to restrain the high pumping voltage of braking procedure which is harmful to the system of electric armored vehicle. Based on the analysis of pumping voltage of the braking procedure, the relation between pu...In order to restrain the high pumping voltage of braking procedure which is harmful to the system of electric armored vehicle. Based on the analysis of pumping voltage of the braking procedure, the relation between pumping voltage and PWM ratio is derived and a new digital control method to restrain the pumping voltage by changing PWM ratio is put forward. Because the capacitance is decreased effectively, the volume of controller is reduced and the performance to price ratio is improved. The results of computer simulation and experiment proved that this method is feasible and valid.展开更多
针对精密电机数控领域中16位位宽的坐标旋转数字计算机(coordinate rotation digital computer,CORDTC)算法存在输出时延长、运算精度低、稳定性差等问题,提出高精度双向同步旋转CORDIC算法,通过角度预处理和区间折叠扩大收敛区间,迭代...针对精密电机数控领域中16位位宽的坐标旋转数字计算机(coordinate rotation digital computer,CORDTC)算法存在输出时延长、运算精度低、稳定性差等问题,提出高精度双向同步旋转CORDIC算法,通过角度预处理和区间折叠扩大收敛区间,迭代过程中采用双向同步旋转与误差均衡来提升算法的精度以及健壮性,最后根据区间结果进行还原输出.结果表明:在硬件实现上,相比传统算法,本算法的运算精度分别提高了76.3%,最大输出时延降低了71.4%,具有高精度、低延时以及稳定等优点.展开更多
A CO2 laser die-cutting system, which does not need die board any more, is a new technique for manufac-turing packing box. Two optical paths, the galvanometer scanning system and the flying optical system, are used to...A CO2 laser die-cutting system, which does not need die board any more, is a new technique for manufac-turing packing box. Two optical paths, the galvanometer scanning system and the flying optical system, are used to satisfy different processing needs. The scanning system is composed of galvanometer scanning mirrors and F-θ lens. And the flying optical system is driven by two servo motors. This paper presents the software and hardware design of the laser die-cutting system, the difference between the two optical paths, as well as the relationship among the cutting speed, thickness of wrapping paper and laser power. The cutting speed and thickness of wrapping paper are linearly increased by the incremental laser power, while the cutting speed is hyperbolically decreased by the incremental thickness of wrapping paper when the laser power is constant. The amount of incision is reduced by 20% and the processing time by 40% when tested by a low power RF CO2 laser die-cutting system using the optimized program. This tech- nique is also used for the reference of other rapid laser processing systems.展开更多
As an important branch in the field of servo control, multi-motor coordination motion control applications are increasingly widespread.For open CNC system requirement, taking DSP as master core, combing with specific ...As an important branch in the field of servo control, multi-motor coordination motion control applications are increasingly widespread.For open CNC system requirement, taking DSP as master core, combing with specific integrated stepper motor driver chip LMDI8201T, this designed a serial communication-based new collaborative multi-motor control system, which has characters of highly integrated, good stability, real-time, convenient man-machine interface.The test results show that the system fully meet performance requirements and achieved the motion control functions.展开更多
A simulation model of an electronically controlled two solenoid valve fuel injection system for a diesel engine is established in the AMESim environment.The accuracy of the model is validated through comparison with e...A simulation model of an electronically controlled two solenoid valve fuel injection system for a diesel engine is established in the AMESim environment.The accuracy of the model is validated through comparison with experimental data.The influence of pre-injection control parameters on main-injection quantity under different control modes is analyzed.In the spill control valve mode,main-injection fuel quantity decreases gradually and then reaches a stable level because of the increase in multi-injection dwell time.In the needle control valve mode,main-injection fuel quantity increases with rising multi-injection dwell time;this effect becomes more obvious at high-speed revolutions and large main-injection pulse widths.Pre-injection pulse width has no obvious influence on main-injection quantity under the two control modes;the variation in main-injection quantity is in the range of 1 mm3.展开更多
In this paper, eddy current sensors and thermocouple sensors were employed to measure the thermal field and thermal deformation of a spindle of a telescopic CNC boring-milling machine tool, respectively. A linear regr...In this paper, eddy current sensors and thermocouple sensors were employed to measure the thermal field and thermal deformation of a spindle of a telescopic CNC boring-milling machine tool, respectively. A linear regression method was proposed to establish the thermal error model. Furthermore, two compensation methods were implemented based on the SIEMENS 840D system by using the feed shaft of z direction and telescopic spindle respectively. Experimental results showed that the thermal error could be reduced by 73.79% when using the second compensation method, and the thermal error could be eliminated by using the two compensation methods effectively.展开更多
The vector control algorithm based on vector space decomposition (VSD) transformation method has a more flexible control freedom, which can control the fundamental and harmonic subspace separately. To this end, a cu...The vector control algorithm based on vector space decomposition (VSD) transformation method has a more flexible control freedom, which can control the fundamental and harmonic subspace separately. To this end, a current vector decoupling control algorithm for six-phase permanent magnet synchronous motor (PMSM) is designed. Using the proposed synchronous rotating coordinate transformation matrix, the fundamental and harmonic components in d-q subspace are changed into direct current (DC) component, only using the traditional proportional integral (PI) controller can meet the non-static difference adjustment, and the controller parameter design method is given by employing intemal model principle. In addition, in order to remove the 5th and 7th harmonic components of stator current, the current PI controller parallel with resonant controller is employed in x-y subspace to realize the specific harmonic component compensation. Simulation results verify the effectiveness of current decoupling vector controller.展开更多
This paper introduces a design to improve the radiotherapy accuracy of gamma knife. In this design, sensor is used to collect respiratory parameters and tumor displacement (caused by human respiration) model is establ...This paper introduces a design to improve the radiotherapy accuracy of gamma knife. In this design, sensor is used to collect respiratory parameters and tumor displacement (caused by human respiration) model is established through optimization modeling. At the same time, data are transferred to single chip microcomputer (SCM) system by pressure sensor and then stepping motor is controlled by SCM. Finally, the intelligent positioning bed is under the control of stepping motor. As a result, the intelligent positioning bed can move reverse to respiratory law. The experimental results showed that this method can reduce the influence of respiration on tumor displacement, improving the accuracy of intelligent positioning bed with simple circuit and low cost at the same time.展开更多
the system to DC voltage source as the core, AT89C52 MCU as the main controller, the output voltage to set the DC power supply through the keyboard, with a step function voltage to reality, the actual output value. Th...the system to DC voltage source as the core, AT89C52 MCU as the main controller, the output voltage to set the DC power supply through the keyboard, with a step function voltage to reality, the actual output value. This design is divided into four modules: SCM control and display module, digital to analog (D/A) conversion module, a constant voltage source module, output module. MCU control module as the core, the input signal is converted to digital quantity output; constant current source module voltage D/A conversion to analog conversion into constant pressure through a constant voltage circuit. The system has good reliability, high precision.展开更多
The paper deals with the comparison of three different digital devices used for the computing of permanent magnet synchronous motor (PMSM) model. Model is used for virtual high frequency injection method (VHFIM) s...The paper deals with the comparison of three different digital devices used for the computing of permanent magnet synchronous motor (PMSM) model. Model is used for virtual high frequency injection method (VHFIM) sensorless control, where injection and acting voltages are virtual ones. For computing the whole PMSM model, differential equations are used. The paper is focused on performance analysis of computing speed and accuracy of field-programmable gate array (FPGA) device, digital signal controller and Power PC microcontroller and results are compared.展开更多
The power system controllers normally have more than one parameter.The distinguishability analysis of the controller parameters is to identify whether the optimal set of the parameters of the controllers is unique.It ...The power system controllers normally have more than one parameter.The distinguishability analysis of the controller parameters is to identify whether the optimal set of the parameters of the controllers is unique.It is difficult to obtain the analytic relationship between the objective of the optimization and the controller parameters,which means that the analytical method is not suitable for the distinguishability analysis.Therefore,a trajectory sensitivity based numerical method for the distinguishability analysis of the controller parameters is proposed in this paper.The relationship between the distinguishability and the sensitivities of the parameters is built.The magnitudes of the sensitivities are used to identify the key parameters,while the phase angles of the sensitivities are used to analyze the distinguishability of the key parameters.The distinguishability of the controller parameters of wind turbine with DFIG is studied using the proposed method,and dynamic simulations are performed to verify the results of the distinguishability analysis.展开更多
文摘In order to restrain the high pumping voltage of braking procedure which is harmful to the system of electric armored vehicle. Based on the analysis of pumping voltage of the braking procedure, the relation between pumping voltage and PWM ratio is derived and a new digital control method to restrain the pumping voltage by changing PWM ratio is put forward. Because the capacitance is decreased effectively, the volume of controller is reduced and the performance to price ratio is improved. The results of computer simulation and experiment proved that this method is feasible and valid.
文摘针对精密电机数控领域中16位位宽的坐标旋转数字计算机(coordinate rotation digital computer,CORDTC)算法存在输出时延长、运算精度低、稳定性差等问题,提出高精度双向同步旋转CORDIC算法,通过角度预处理和区间折叠扩大收敛区间,迭代过程中采用双向同步旋转与误差均衡来提升算法的精度以及健壮性,最后根据区间结果进行还原输出.结果表明:在硬件实现上,相比传统算法,本算法的运算精度分别提高了76.3%,最大输出时延降低了71.4%,具有高精度、低延时以及稳定等优点.
基金Supported by by Major State Basic Research Development Program of China ("973" Program, No. 2010CB327800)
文摘A CO2 laser die-cutting system, which does not need die board any more, is a new technique for manufac-turing packing box. Two optical paths, the galvanometer scanning system and the flying optical system, are used to satisfy different processing needs. The scanning system is composed of galvanometer scanning mirrors and F-θ lens. And the flying optical system is driven by two servo motors. This paper presents the software and hardware design of the laser die-cutting system, the difference between the two optical paths, as well as the relationship among the cutting speed, thickness of wrapping paper and laser power. The cutting speed and thickness of wrapping paper are linearly increased by the incremental laser power, while the cutting speed is hyperbolically decreased by the incremental thickness of wrapping paper when the laser power is constant. The amount of incision is reduced by 20% and the processing time by 40% when tested by a low power RF CO2 laser die-cutting system using the optimized program. This tech- nique is also used for the reference of other rapid laser processing systems.
文摘As an important branch in the field of servo control, multi-motor coordination motion control applications are increasingly widespread.For open CNC system requirement, taking DSP as master core, combing with specific integrated stepper motor driver chip LMDI8201T, this designed a serial communication-based new collaborative multi-motor control system, which has characters of highly integrated, good stability, real-time, convenient man-machine interface.The test results show that the system fully meet performance requirements and achieved the motion control functions.
基金Supported by the Program for New Century Excellent Talents in University(NECT-11-0826) the National Natural Science Foundation of China(NSFC 51279037)+1 种基金 the Fundamental Research Funds for the Central Universities(HEUCFZ13) the Postdoctoral Science-research Developmental Foundation of Heilongjiang Province(LBH-Q12126)Acknowledgement The authors gratefully acknowledge vice Professor Yong Shi and Jun Sun's help in fuel injection experiment.
文摘A simulation model of an electronically controlled two solenoid valve fuel injection system for a diesel engine is established in the AMESim environment.The accuracy of the model is validated through comparison with experimental data.The influence of pre-injection control parameters on main-injection quantity under different control modes is analyzed.In the spill control valve mode,main-injection fuel quantity decreases gradually and then reaches a stable level because of the increase in multi-injection dwell time.In the needle control valve mode,main-injection fuel quantity increases with rising multi-injection dwell time;this effect becomes more obvious at high-speed revolutions and large main-injection pulse widths.Pre-injection pulse width has no obvious influence on main-injection quantity under the two control modes;the variation in main-injection quantity is in the range of 1 mm3.
文摘In this paper, eddy current sensors and thermocouple sensors were employed to measure the thermal field and thermal deformation of a spindle of a telescopic CNC boring-milling machine tool, respectively. A linear regression method was proposed to establish the thermal error model. Furthermore, two compensation methods were implemented based on the SIEMENS 840D system by using the feed shaft of z direction and telescopic spindle respectively. Experimental results showed that the thermal error could be reduced by 73.79% when using the second compensation method, and the thermal error could be eliminated by using the two compensation methods effectively.
基金Project(51507188)supported by the National Natural Science Foundation of China
文摘The vector control algorithm based on vector space decomposition (VSD) transformation method has a more flexible control freedom, which can control the fundamental and harmonic subspace separately. To this end, a current vector decoupling control algorithm for six-phase permanent magnet synchronous motor (PMSM) is designed. Using the proposed synchronous rotating coordinate transformation matrix, the fundamental and harmonic components in d-q subspace are changed into direct current (DC) component, only using the traditional proportional integral (PI) controller can meet the non-static difference adjustment, and the controller parameter design method is given by employing intemal model principle. In addition, in order to remove the 5th and 7th harmonic components of stator current, the current PI controller parallel with resonant controller is employed in x-y subspace to realize the specific harmonic component compensation. Simulation results verify the effectiveness of current decoupling vector controller.
文摘This paper introduces a design to improve the radiotherapy accuracy of gamma knife. In this design, sensor is used to collect respiratory parameters and tumor displacement (caused by human respiration) model is established through optimization modeling. At the same time, data are transferred to single chip microcomputer (SCM) system by pressure sensor and then stepping motor is controlled by SCM. Finally, the intelligent positioning bed is under the control of stepping motor. As a result, the intelligent positioning bed can move reverse to respiratory law. The experimental results showed that this method can reduce the influence of respiration on tumor displacement, improving the accuracy of intelligent positioning bed with simple circuit and low cost at the same time.
文摘the system to DC voltage source as the core, AT89C52 MCU as the main controller, the output voltage to set the DC power supply through the keyboard, with a step function voltage to reality, the actual output value. This design is divided into four modules: SCM control and display module, digital to analog (D/A) conversion module, a constant voltage source module, output module. MCU control module as the core, the input signal is converted to digital quantity output; constant current source module voltage D/A conversion to analog conversion into constant pressure through a constant voltage circuit. The system has good reliability, high precision.
文摘The paper deals with the comparison of three different digital devices used for the computing of permanent magnet synchronous motor (PMSM) model. Model is used for virtual high frequency injection method (VHFIM) sensorless control, where injection and acting voltages are virtual ones. For computing the whole PMSM model, differential equations are used. The paper is focused on performance analysis of computing speed and accuracy of field-programmable gate array (FPGA) device, digital signal controller and Power PC microcontroller and results are compared.
基金supported by the National Natural Science Foundation of China(Grant Nos.51137002,51190102)Natural Science Foundation of Jiangsu Province(Grant No.BK2011026)
文摘The power system controllers normally have more than one parameter.The distinguishability analysis of the controller parameters is to identify whether the optimal set of the parameters of the controllers is unique.It is difficult to obtain the analytic relationship between the objective of the optimization and the controller parameters,which means that the analytical method is not suitable for the distinguishability analysis.Therefore,a trajectory sensitivity based numerical method for the distinguishability analysis of the controller parameters is proposed in this paper.The relationship between the distinguishability and the sensitivities of the parameters is built.The magnitudes of the sensitivities are used to identify the key parameters,while the phase angles of the sensitivities are used to analyze the distinguishability of the key parameters.The distinguishability of the controller parameters of wind turbine with DFIG is studied using the proposed method,and dynamic simulations are performed to verify the results of the distinguishability analysis.