【作者】 吴迪；

【导师】 万会雄；

【作者基本信息】 武汉理工大学 ， 机械设计及理论， 2007， 硕士

【摘要】 本文以钢带纠偏系统为实际参考模型，运用现代理论并结合仿真技术，研究了脉宽调制式电液伺服系统。在此基础上，进行了仿真研究与试验，提出了有关数字阀电磁铁结构优化和电液系统性能改进的措施。对脉宽调制式电液伺服系统中所使用的高速开关数字阀进行了研究，由于数字阀对电磁推力有一定要求，在传统电磁阀的电磁铁基础上进行了设计改进，并通过有限元仿真分析对电磁铁结构作了优化。对PWM控制的电液系统进行了理论研究，并以钢带纠偏系统为实际模型，对数字控制的电液系统进行了仿真分析，研究了一些控制参数如PWM控制信号占空比、脉冲信号频率、数字阀电磁铁推力与纠偏精度之间的关系。PWM信号占空比过大或过小，都将影响钢带纠偏系统的纠偏精度，甚至引起执行机构的误操作；纠偏精度在一定范围内随PWM控制信号脉冲频率增大而提高，但随着控制信号脉冲频率增加，系统响应特性明显改善，但过高的频率也带来了问题，由于每个PWM信号周期内的流量过小，使得系统响应时间增大；纠偏系统对数字阀电磁铁的推力有一定要求，系统的油压越大，所需电磁推力也相应增大，但超过动作所需推力的临界值之后，电磁铁推力的增加对系统纠偏精度的提高没有明显效果。与实践相结合，通过实验对系统的仿真结果进行了验证。与传统采用伺服阀的纠偏系统相比，采用数字阀的电液系统拥有更好的性能。作为一种很适合于轧钢生产的新型电液伺服系统，其所具有的响应速度快、工作稳定可靠、抗污染能力强以及价格优势等许多优点，拥有广阔的前景。更多还原

【Abstract】 In this paper, study the Electronic-Hydraulic Servo System based on PWM control, which use the modem theory and simulation technology. And use the Strip Steel Rectifying Control System for reference model. Make optimize design and experiences for the system, bring some methods to improve the structure of the electromagnetic iron and the capability of the Electronic-Hydraulic System.Study the high speed on/off value which used in the Electronic-Hydraulic System based on PWM control, Because there are some requests of the digital valve such as magnetic force, it needs to redesign the structure of the electromagnetic iron which used in the digital valve. It is optimized through the finite element analysis. Study the PWM control theory, perform the Electronic-Hydraulic System simulation, found some relationship between the rectifying precision and duty cycle frequency of the PWM signal magnetic force.Too much or too less of the duty cycle will cause the decrease of the rectifying precision; If the frequency of the PWM signal increase, the rectifying precision will also increase. But there exist a critical point. If past this point, the response time will increase. Similar to frequency of the PWM signal, the Strip Steel Rectifying Control System have particular need with the magnetic force. But when the magnetic force value is strong enough, increased of the force value will useless for improvement of the system.In practice, confirm the results of the analysis and simulation through experiences. Compared with the Rectifying Control System using servo value, it is better for the Rectifying Control System using digital value. High response stabilities anti-pollution and lower prices, will make this new kind of Electronic-Hydraulic System using PWM control more and more popular.更多还原