In drilling field, stick-slip vibrations of the drill-string are the main reason for the failure of the drilling system. To suppress the undesired stick-slip vibrations, an observer-based state feedback control method...In drilling field, stick-slip vibrations of the drill-string are the main reason for the failure of the drilling system. To suppress the undesired stick-slip vibrations, an observer-based state feedback control method is proposed. The drilling system is described by a lumped parameter model including a Karnopp friction torque model. A state observer is designed to estimate the bit velocity in bottom hole and a state feedback controller is proposed to control the top drive velocity. By simulation, the performance of the control algorithm is demonstrated. Based on the control algorithm, a stick-slip vibration control system is developed. Test results show that the control system can effectively eliminate stick-slip vibrations of the drill-string and can be applied to the drilling field.展开更多
In developing distributed systems, conformance testing is required to determine whether an implementation under test （IUT） conforms to its specification. With distributed test architectures involving multiple remote...In developing distributed systems, conformance testing is required to determine whether an implementation under test （IUT） conforms to its specification. With distributed test architectures involving multiple remote testers, testing approaches may become more complicated because of issues known as controllability and observability problems. Based on a finite state machine （FSM） representation of the system＇s specification, this paper proposes a new method to generate a test sequence utilizing multiple UIO sequences. The method is essentially guided by the way of minimizing the use of external coordination messages and input/output operations. Experiments are given to evaluate the proposed method.展开更多
针对航空发动机高空环境模拟过渡态试验对高空舱进气环境压力模拟系统提出的强抗扰性、强鲁棒性等控制综合品质要求,设计了一种基于鲁棒模型预测控制(Robust Model Predictive Control,RMPC)的高空舱进气环境压力控制方法。RMPC采用滚...针对航空发动机高空环境模拟过渡态试验对高空舱进气环境压力模拟系统提出的强抗扰性、强鲁棒性等控制综合品质要求,设计了一种基于鲁棒模型预测控制(Robust Model Predictive Control,RMPC)的高空舱进气环境压力控制方法。RMPC采用滚动时域优化和扰动反馈补偿的方法,在预测控制框架内处理模型的不确定性。通过建立进气环境压力模拟系统设备特性模型,设计了基于RMPC的进气环境压力控制策略,搭建了仿真平台,与线性自抗扰控制(Linear Active Disturbance Rejection Control,LADRC)方法进行了对比分析。仿真结果表明,应用RMPC技术后,动态调节时间由7.68 s缩短至3.91 s,最大瞬时波动量由0.94%减小至0.25%,该技术能够大幅提高发动机高空环境模拟过渡态试验中进气环境压力模拟的动态响应速度、控制精度和抗扰能力。展开更多
文摘In drilling field, stick-slip vibrations of the drill-string are the main reason for the failure of the drilling system. To suppress the undesired stick-slip vibrations, an observer-based state feedback control method is proposed. The drilling system is described by a lumped parameter model including a Karnopp friction torque model. A state observer is designed to estimate the bit velocity in bottom hole and a state feedback controller is proposed to control the top drive velocity. By simulation, the performance of the control algorithm is demonstrated. Based on the control algorithm, a stick-slip vibration control system is developed. Test results show that the control system can effectively eliminate stick-slip vibrations of the drill-string and can be applied to the drilling field.
基金Project supported by the National Natural Science Foundation of China （Grant No.60673115）, and the Open Foundation of State Key Laboratory of Software Engineering （Grant No.SKLSE05-13）
文摘In developing distributed systems, conformance testing is required to determine whether an implementation under test （IUT） conforms to its specification. With distributed test architectures involving multiple remote testers, testing approaches may become more complicated because of issues known as controllability and observability problems. Based on a finite state machine （FSM） representation of the system＇s specification, this paper proposes a new method to generate a test sequence utilizing multiple UIO sequences. The method is essentially guided by the way of minimizing the use of external coordination messages and input/output operations. Experiments are given to evaluate the proposed method.
文摘针对航空发动机高空环境模拟过渡态试验对高空舱进气环境压力模拟系统提出的强抗扰性、强鲁棒性等控制综合品质要求,设计了一种基于鲁棒模型预测控制(Robust Model Predictive Control,RMPC)的高空舱进气环境压力控制方法。RMPC采用滚动时域优化和扰动反馈补偿的方法,在预测控制框架内处理模型的不确定性。通过建立进气环境压力模拟系统设备特性模型,设计了基于RMPC的进气环境压力控制策略,搭建了仿真平台,与线性自抗扰控制(Linear Active Disturbance Rejection Control,LADRC)方法进行了对比分析。仿真结果表明,应用RMPC技术后,动态调节时间由7.68 s缩短至3.91 s,最大瞬时波动量由0.94%减小至0.25%,该技术能够大幅提高发动机高空环境模拟过渡态试验中进气环境压力模拟的动态响应速度、控制精度和抗扰能力。
