• CN:11-2187/TH
  • ISSN:0577-6686

›› 2014, Vol. 50 ›› Issue (8): 197-204.

• 论文 • 上一篇    下一篇

模模型与条件PID补偿的永磁伺服电动机驱动液压源流量控制

贾永峰;谷立臣   

  1. 西安建筑科技大学机电工程学院;陕西交通职业技术学院
  • 出版日期:2014-04-20 发布日期:2014-04-20

Model and Conditional PID Compensation Control on Flow of Hydraulic Source Driven by Permanent Magnet Servo Motor

JIA Yongfeng; GU Lichen   

  1. School of Mechanical and Electronic Engineering, Xi’an University of Architecture & Technology;Shanxi College of Communication Technology
  • Online:2014-04-20 Published:2014-04-20

摘要: 针对变频异步电动机驱动液压源在实际应用中存在响应速度慢、控制精度差、控制参数不易掌握等缺陷,提出永磁伺服电动机驱动定量泵液压源的流量控制策略,将永磁伺服电动机动态特性好、控制精度高、节能等优点与定量泵结构简单、可靠性好、抗污染能力强等特点相结合,根据定量泵的转速、流量、压力特性关系和油液温度、黏度、弹性模量等相关参数建立电动机转速模型控制和条件比例积分微分(Proportion,integration,differentiation,PID)补偿控制,通过较易控制的电动机转速信号实现对定量泵输出流量的快速准确调节。控制系统充分利用模型开环控制的稳定性、及时性,快速接近目标流量,克服传统流量控制中实测流量信号延迟对系统响应造成严重迟滞的不良影响;通过条件阈值开启PID补偿控制,进一步消除流量偏差,提高系统精度;通过条件限幅限制系统超调量。仿真结果表明模型控制和条件PID补偿控制的可行性,试验结果证明,模型控制的系统响应接近于电动机转速开环控制,优于转速估算流量闭环控制,大幅领先于涡轮流量计实测流量反馈控制,并且具有很好的抗负载扰动能力;条件PID补偿控制能够完全消除由于系统参数非线性变化和模型简化带来的稳态误差,能够无误差地跟随目标流量斜坡响应。

关键词: 液压源;伺服驱动;模型控制;条件补偿;流量控制

Abstract: In view of the existed defects of hydraulic source driven by variable frequency induction motor in practical applications, such as slow response, low control accuracy and difficult to master control parameters, a flow control strategy of permanent magnet servo motor driven constant pump hydraulic power unit is presented. This strategy mixes merits of permanent magnet servo motor, such as good dynamic characteristics, high control precision, and saving energy, and characteristics of constant pump, such as simple structure, good reliability and strong ability to fight pollution, etc. According to the relationship between speed, flow and pressure of constant pump, and oil temperature, viscosity, elastic modulus and other related parameters, model and conditional compensation proportion, integration, differentiation(PID) control on motor speed is proposed, through which the rapidity and accuracy of control on the output flow of constant pump are realized easily. The control system makes full use of the stability and timeliness of the open-loop model control to approaching target flow, overcoming the adverse effect that the measured flow signal delay brings serious hysteresis influence on system response in the traditional flow control system. In addition, the conditional PID compensation control, through the comparison with the conditional threshold value to open, can further eliminate flow deviation and improve the precision of the system. Simulation results show that the feasibility of the model control and the conditional PID compensation control. Experimental results show that the response of model control is close to motor speed open-loop control, which is better than indirect measurement flow feedback control, and significantly ahead of the turbine flowmeters measured flow feedback control. The control system has good resistance to load disturbance ability; the conditional PID compensation control can completely eliminate the steady-state error caused by the system parameter nonlinear change and simplified model, and can follow target flow at slope response without error.

Key words: hydraulic unit;servo drive;model control;conditional compensation;flow control

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