As friction, intrinsic steady-state nonlinearity poses a challenging dilemma to the control system of 3-DOF （three degree of freedom） flight simulator, a novel hybrid control strategy of nonlinear PID （proportional...As friction, intrinsic steady-state nonlinearity poses a challenging dilemma to the control system of 3-DOF （three degree of freedom） flight simulator, a novel hybrid control strategy of nonlinear PID （proportionalintegral-derivative） with additional FFC （feed-forward controller） is proposed, and the hardware-in-the-loop simulation results are also given. Based on the description of 3-DOF flight simulator, a novel nonlinear PID theory is well introduced. Then a nonlinear PID controller with additional FFC is designed. Subsequently, the loop structure of 3-DOF flight simulator is also designed. Finally, a series of hardware-in-the-loop simulation experiments are undertaken to verify the feasibility and effectiveness of the proposed nonlinear PID controller with additional FFC for 3-DOF flight simulator.展开更多
A controllable hydrostatic thrust bearing was presented to improve rigidity. The bearing worktable poses were controlled by coupling oilfilm thickness of four controllable chambers. The chamber flow can be regulated b...A controllable hydrostatic thrust bearing was presented to improve rigidity. The bearing worktable poses were controlled by coupling oilfilm thickness of four controllable chambers. The chamber flow can be regulated by electro hydraulic servo valve-control variable pump according to the surface roughness, load, cutting force, and thermal effects of worktable. The mathematical models of the controllable chamber flow, servo variable mechanism and controller were built. The pose control model was established, which contained the kinematics positive and negative solution and control strategy of feedforward and hydraulic cylinder position feedback. Hardware-in-loop simulation experiment was carried out on the electro hydraulic servo test bench by means of the non-linear relation of film thickness and hydraulic cylinder displacement. Hardware-in-loop simulation experiment results show that the controllable bearings exhibit high oilfilm rigidity, the rising time is 0.24 s and the maximum overshoot is 2.23%, and can be applied in high precision heavy machine tool.展开更多
基于软件实现的多核系统模拟器执行计算密集/数据密集任务的时效性极差,且存在模拟精度和性能评估准确性差的不足,限制其在多核系统结构优化探索中的应用。文章提出一种周期精确的软硬件协同多核系统模拟器(cycle accurate hardware-sof...基于软件实现的多核系统模拟器执行计算密集/数据密集任务的时效性极差,且存在模拟精度和性能评估准确性差的不足,限制其在多核系统结构优化探索中的应用。文章提出一种周期精确的软硬件协同多核系统模拟器(cycle accurate hardware-software co-simulator,CAHSCS),通过在传统模拟器架构中引入硬件计算和存储模块,CAHSCS能有效改善全系统的模拟速度、精度,提高性能评估的准确性。复杂真实任务加载实验结果表明,CAHSCS将大规模复杂数据的运算效率提高了10倍,显著加快了系统设计收敛速度。展开更多
基金the National Natural Science Foundation of China (60604009)Aeronautical Science Foundationof China(2006ZC51039)Beijing NOVA Program (2007A017).
文摘As friction, intrinsic steady-state nonlinearity poses a challenging dilemma to the control system of 3-DOF （three degree of freedom） flight simulator, a novel hybrid control strategy of nonlinear PID （proportionalintegral-derivative） with additional FFC （feed-forward controller） is proposed, and the hardware-in-the-loop simulation results are also given. Based on the description of 3-DOF flight simulator, a novel nonlinear PID theory is well introduced. Then a nonlinear PID controller with additional FFC is designed. Subsequently, the loop structure of 3-DOF flight simulator is also designed. Finally, a series of hardware-in-the-loop simulation experiments are undertaken to verify the feasibility and effectiveness of the proposed nonlinear PID controller with additional FFC for 3-DOF flight simulator.
基金Project(20050214001) supported by Doctor Foundation of Education Ministry of ChinaProject(GC05A512) and supported by the Program of Heilongjiang Province Science and Technology, ChinaProject(zjg0702-01) supported by the Natural Science Foundation of Heilongjiang Province, China
文摘A controllable hydrostatic thrust bearing was presented to improve rigidity. The bearing worktable poses were controlled by coupling oilfilm thickness of four controllable chambers. The chamber flow can be regulated by electro hydraulic servo valve-control variable pump according to the surface roughness, load, cutting force, and thermal effects of worktable. The mathematical models of the controllable chamber flow, servo variable mechanism and controller were built. The pose control model was established, which contained the kinematics positive and negative solution and control strategy of feedforward and hydraulic cylinder position feedback. Hardware-in-loop simulation experiment was carried out on the electro hydraulic servo test bench by means of the non-linear relation of film thickness and hydraulic cylinder displacement. Hardware-in-loop simulation experiment results show that the controllable bearings exhibit high oilfilm rigidity, the rising time is 0.24 s and the maximum overshoot is 2.23%, and can be applied in high precision heavy machine tool.
基金National Nature Science Foundation of China(61104085)Natural Science Foundation of Jiangsu Province(BK20130744)sponsored by Jiangsu Qing Lan Project,and the Jiangsu Government Scholarship for Overseas Studies(JS-2012-051)
文摘基于软件实现的多核系统模拟器执行计算密集/数据密集任务的时效性极差,且存在模拟精度和性能评估准确性差的不足,限制其在多核系统结构优化探索中的应用。文章提出一种周期精确的软硬件协同多核系统模拟器(cycle accurate hardware-software co-simulator,CAHSCS),通过在传统模拟器架构中引入硬件计算和存储模块,CAHSCS能有效改善全系统的模拟速度、精度,提高性能评估的准确性。复杂真实任务加载实验结果表明,CAHSCS将大规模复杂数据的运算效率提高了10倍,显著加快了系统设计收敛速度。
