为了解决永磁直线同步电机(permanent magnet linear synchronous motor,PMLSM)运行过程中对系统参数扰动及端部效应等不确定因素敏感的问题,提出了一种PMLSM的非线性鲁棒控制方法。利用反馈线性化的思想,对PMLSM数学模型进行变换得到...为了解决永磁直线同步电机(permanent magnet linear synchronous motor,PMLSM)运行过程中对系统参数扰动及端部效应等不确定因素敏感的问题,提出了一种PMLSM的非线性鲁棒控制方法。利用反馈线性化的思想,对PMLSM数学模型进行变换得到包含不确定因素的准线性化且解耦的模型。采用msat函数的思想方法,设计了固定边界层滑模控制器,确保系统鲁棒性。同时给出了力观测器的设计方法估计新模型中未知的负载力。不需要知道系统参数的精确数值,通过确定其范围就可以使控制器得到良好的鲁棒性。仿真与实验结果均验证了文中所提出方法的正确性和控制策略的有效性。展开更多
国际学生评估项目(Program for International Student Assessment,PISA)于2018年开始引入多阶段自适应测验(Multistage Adaptive Test,MSAT)技术,来测量学生的阅读素养水平。在此背景下,文章首先阐释了MSAT的核心概念,随后介绍了MSAT...国际学生评估项目(Program for International Student Assessment,PISA)于2018年开始引入多阶段自适应测验(Multistage Adaptive Test,MSAT)技术,来测量学生的阅读素养水平。在此背景下,文章首先阐释了MSAT的核心概念,随后介绍了MSAT的实施过程,最后在综合考虑MSAT设计、实施和结果反馈等的基础上,总结出MSAT对我国教育质量监测的启示,即收集多模态交互数据、因地制宜地使用不同测验方式、综合使用多种题目类型以及增加可修改答案的功能等。文章旨在帮助教育工作者加深对MSAT的了解和认识,以促进MSAT技术在教育质量监测中的应用。展开更多
The advantages of permanent magnet linear synchronous motors （PMLSM） include high speed and good motion precision compared with rotary motors. However, PMLSM are sensitive to uncertainties such as the parameter pert...The advantages of permanent magnet linear synchronous motors （PMLSM） include high speed and good motion precision compared with rotary motors. However, PMLSM are sensitive to uncertainties such as the parameter perturbations and end effect etc. A new nonlinear robust scheme of PMLSM is proposed to overcome this trouble. First, a quasi-linearized and deeoupled model with uncertainties is derived from the mathematical model of PMLSM by using the conception of feedback linearization. Then a fixed-boundary-layer sliding mode controller using the m sat function is designed to guarantee the robustness. Design of a force observer is given to estimate the load force unknown in the new model. Finally, the validity of the proposed strategy compared with the conventional PID control scheme is proved by the DSpobased experimental results.展开更多
文摘为了解决永磁直线同步电机(permanent magnet linear synchronous motor,PMLSM)运行过程中对系统参数扰动及端部效应等不确定因素敏感的问题,提出了一种PMLSM的非线性鲁棒控制方法。利用反馈线性化的思想,对PMLSM数学模型进行变换得到包含不确定因素的准线性化且解耦的模型。采用msat函数的思想方法,设计了固定边界层滑模控制器,确保系统鲁棒性。同时给出了力观测器的设计方法估计新模型中未知的负载力。不需要知道系统参数的精确数值,通过确定其范围就可以使控制器得到良好的鲁棒性。仿真与实验结果均验证了文中所提出方法的正确性和控制策略的有效性。
文摘国际学生评估项目(Program for International Student Assessment,PISA)于2018年开始引入多阶段自适应测验(Multistage Adaptive Test,MSAT)技术,来测量学生的阅读素养水平。在此背景下,文章首先阐释了MSAT的核心概念,随后介绍了MSAT的实施过程,最后在综合考虑MSAT设计、实施和结果反馈等的基础上,总结出MSAT对我国教育质量监测的启示,即收集多模态交互数据、因地制宜地使用不同测验方式、综合使用多种题目类型以及增加可修改答案的功能等。文章旨在帮助教育工作者加深对MSAT的了解和认识,以促进MSAT技术在教育质量监测中的应用。
文摘The advantages of permanent magnet linear synchronous motors （PMLSM） include high speed and good motion precision compared with rotary motors. However, PMLSM are sensitive to uncertainties such as the parameter perturbations and end effect etc. A new nonlinear robust scheme of PMLSM is proposed to overcome this trouble. First, a quasi-linearized and deeoupled model with uncertainties is derived from the mathematical model of PMLSM by using the conception of feedback linearization. Then a fixed-boundary-layer sliding mode controller using the m sat function is designed to guarantee the robustness. Design of a force observer is given to estimate the load force unknown in the new model. Finally, the validity of the proposed strategy compared with the conventional PID control scheme is proved by the DSpobased experimental results.
