A high-performance digital servo system built on the platform of a field programmable gate array (FPGA),a fully digitized hardware design scheme of a direct torque control (DTC) and a low speed permanent magnet synchr...A high-performance digital servo system built on the platform of a field programmable gate array (FPGA),a fully digitized hardware design scheme of a direct torque control (DTC) and a low speed permanent magnet synchronous motor (PMSM) is proposed. The DTC strategy of PMSM is described with Verilog hardware description language and is employed on-chip FPGA in accordance with the electronic design automation design methodology. Due to large torque ripples in low speed PMSM,the hysteresis controller in a conventional PMSM DTC was replaced by a fuzzy controller. This FPGA scheme integrates the direct torque controller strategy,the time speed measurement algorithm,the fuzzy regulating technique and the space vector pulse width modulation principle. Experimental results indicate the fuzzy controller can provide a controllable speed at 20 r min-1 and torque at 330 N m with satisfactory dynamic and static performance. Furthermore,the results show that this new control strategy decreases the torque ripple drastically and enhances control performance.展开更多
An innovation is conducted on a K190πK rail auto welding machine because of its poor stability in quality of welding joints. A new control system based on a programmable controller is designed to replace the old o...An innovation is conducted on a K190πK rail auto welding machine because of its poor stability in quality of welding joints. A new control system based on a programmable controller is designed to replace the old one. The new control system is of higher accuracy in controlling sequence and good ability in anti disturbance, and is convenient to operate. The comparison tests are carried out. The experimental results show that the quality of welded joints is greatly increased by the improved welding mechine.展开更多
To solve the problems of mechanical cam, tracking in an automatic welding machine, a new method of programmable logic controller ( PLC) tracking is presented. Based on analyzing the forming of welding tracking, a math...To solve the problems of mechanical cam, tracking in an automatic welding machine, a new method of programmable logic controller ( PLC) tracking is presented. Based on analyzing the forming of welding tracking, a mathematical model of position control is set up. The experiments show that using a modified machine, PLC makes little welding positional error and can meet the product requirements.展开更多
利用SIEMENS公司S7-200系列PLC作为控制器,凭借其强大的PID指令和较强的浮点数计算能力,实现复杂过程控制实验的设计与研究,并使用SIEMENS公司软件系统Win CC(Windows Control Center)进行上位机监控和过程控制数据的保存。本文对S7-20...利用SIEMENS公司S7-200系列PLC作为控制器,凭借其强大的PID指令和较强的浮点数计算能力,实现复杂过程控制实验的设计与研究,并使用SIEMENS公司软件系统Win CC(Windows Control Center)进行上位机监控和过程控制数据的保存。本文对S7-200系列PLC的PID应用进行了分析,根据过程控制系统提出的总体要求和技术指标,对液位、压力、流量、温度等过程控制实验曲线进行分析,阐述PID算法各个环节的作用,总结PID的实验整定方法,以及PID整定方法选用的原则。展开更多
基金the Natural Science Foundation of Hubei Province (No.2005ABA301)
文摘A high-performance digital servo system built on the platform of a field programmable gate array (FPGA),a fully digitized hardware design scheme of a direct torque control (DTC) and a low speed permanent magnet synchronous motor (PMSM) is proposed. The DTC strategy of PMSM is described with Verilog hardware description language and is employed on-chip FPGA in accordance with the electronic design automation design methodology. Due to large torque ripples in low speed PMSM,the hysteresis controller in a conventional PMSM DTC was replaced by a fuzzy controller. This FPGA scheme integrates the direct torque controller strategy,the time speed measurement algorithm,the fuzzy regulating technique and the space vector pulse width modulation principle. Experimental results indicate the fuzzy controller can provide a controllable speed at 20 r min-1 and torque at 330 N m with satisfactory dynamic and static performance. Furthermore,the results show that this new control strategy decreases the torque ripple drastically and enhances control performance.
文摘An innovation is conducted on a K190πK rail auto welding machine because of its poor stability in quality of welding joints. A new control system based on a programmable controller is designed to replace the old one. The new control system is of higher accuracy in controlling sequence and good ability in anti disturbance, and is convenient to operate. The comparison tests are carried out. The experimental results show that the quality of welded joints is greatly increased by the improved welding mechine.
文摘To solve the problems of mechanical cam, tracking in an automatic welding machine, a new method of programmable logic controller ( PLC) tracking is presented. Based on analyzing the forming of welding tracking, a mathematical model of position control is set up. The experiments show that using a modified machine, PLC makes little welding positional error and can meet the product requirements.
文摘利用SIEMENS公司S7-200系列PLC作为控制器,凭借其强大的PID指令和较强的浮点数计算能力,实现复杂过程控制实验的设计与研究,并使用SIEMENS公司软件系统Win CC(Windows Control Center)进行上位机监控和过程控制数据的保存。本文对S7-200系列PLC的PID应用进行了分析,根据过程控制系统提出的总体要求和技术指标,对液位、压力、流量、温度等过程控制实验曲线进行分析,阐述PID算法各个环节的作用,总结PID的实验整定方法,以及PID整定方法选用的原则。
