The design of iterative learning controller(ILC) requires to store the system input, output or control parameters of previous trials for generating the input of the current trial. In order to apply the iterative learn...The design of iterative learning controller(ILC) requires to store the system input, output or control parameters of previous trials for generating the input of the current trial. In order to apply the iterative learning controller for a real application and reduce the memory size for implementation, a current error based sampled-data proportional-derivative(PD) type iterative learning controller is proposed for control systems with initial resetting error, input disturbance and output measurement noise in this paper.The proposed iterative learning controller is simple and effective. The first contribution in this paper is to prove the learning error convergence via a rigorous technical analysis. It is shown that the learning error will converge to a residual set if a forgetting factor is introduced in the controller. All the theoretical results are also shown by computer simulations. The second main contribution is to realize the iterative learning controller by a digital circuit using a field programmable gate array(FPGA) chip applied to repetitive position tracking control of direct current(DC) motors. The feasibility and effectiveness of the proposed current error based sampleddata iterative learning controller are demonstrated by the experiment results. Finally, the relationship between learning performance and design parameters are also discussed extensively.展开更多
This paper presents a new method for soft error detection using software redundancy (SEDSR) that is able to detect transient faults. Soft errors damage the control flow and data of programs and designers usually use h...This paper presents a new method for soft error detection using software redundancy (SEDSR) that is able to detect transient faults. Soft errors damage the control flow and data of programs and designers usually use hardware-based solutions to handle them. Software-based techniques for soft error detection force less cost and delay to systems and do not change their configuration. Therefore, these kinds of methods are appropriate alternatives for hardware-based techniques. SEDSR has two separate parts for data and control flow errors detection. Fault injection method is used to compare SEDSR with previous methods of this field based on the new parameter of “Evaluation Factor” that takes in account fault coverage, memory and performance overheads. These parameters are important in real time safety critical applications. Experimental results on SPEC2000 and some traditional benchmarks of this field show that SEDSR is much better than previous methods of this field. SEDSR’s evaluation factor is about 50% better than other methods of this field. These results show its success in satisfaction of the existing tradeoff between fault coverage, performance and memory overheads.展开更多
如何有效降低WSN(Wiretess Sensor Net work)网内数据传输量,延长WSN的寿命,是WSN领域的研究热点.在分簇WSN基础上,实现了一种误差实时可控的数据融合算法.通过该算法,节点可自行根据近期采集的历史数据实时调整传输阈值,不同节点可保...如何有效降低WSN(Wiretess Sensor Net work)网内数据传输量,延长WSN的寿命,是WSN领域的研究热点.在分簇WSN基础上,实现了一种误差实时可控的数据融合算法.通过该算法,节点可自行根据近期采集的历史数据实时调整传输阈值,不同节点可保持接近的数据传输率,实现均匀耗电;自适应的阈值可以有效控制数据融合的误差.理论分析与仿真实验表明,该算法能够保证不同节点数据传输的公平性;在数据传输率相同的情况下,其求和查询及均值查询的平均绝对误差均远低于当前优秀的基于伯努利采样的数据融合方法.此算法无需先验知识,在多种WSN应用场景中具有较强的可用性与适应性.展开更多
基金supported by National Science Council,Taiwan,China(No.NSC102-2221-E-211-011)National Nature Science Foundation of China(No.61374102)
文摘The design of iterative learning controller(ILC) requires to store the system input, output or control parameters of previous trials for generating the input of the current trial. In order to apply the iterative learning controller for a real application and reduce the memory size for implementation, a current error based sampled-data proportional-derivative(PD) type iterative learning controller is proposed for control systems with initial resetting error, input disturbance and output measurement noise in this paper.The proposed iterative learning controller is simple and effective. The first contribution in this paper is to prove the learning error convergence via a rigorous technical analysis. It is shown that the learning error will converge to a residual set if a forgetting factor is introduced in the controller. All the theoretical results are also shown by computer simulations. The second main contribution is to realize the iterative learning controller by a digital circuit using a field programmable gate array(FPGA) chip applied to repetitive position tracking control of direct current(DC) motors. The feasibility and effectiveness of the proposed current error based sampleddata iterative learning controller are demonstrated by the experiment results. Finally, the relationship between learning performance and design parameters are also discussed extensively.
文摘This paper presents a new method for soft error detection using software redundancy (SEDSR) that is able to detect transient faults. Soft errors damage the control flow and data of programs and designers usually use hardware-based solutions to handle them. Software-based techniques for soft error detection force less cost and delay to systems and do not change their configuration. Therefore, these kinds of methods are appropriate alternatives for hardware-based techniques. SEDSR has two separate parts for data and control flow errors detection. Fault injection method is used to compare SEDSR with previous methods of this field based on the new parameter of “Evaluation Factor” that takes in account fault coverage, memory and performance overheads. These parameters are important in real time safety critical applications. Experimental results on SPEC2000 and some traditional benchmarks of this field show that SEDSR is much better than previous methods of this field. SEDSR’s evaluation factor is about 50% better than other methods of this field. These results show its success in satisfaction of the existing tradeoff between fault coverage, performance and memory overheads.
文摘如何有效降低WSN(Wiretess Sensor Net work)网内数据传输量,延长WSN的寿命,是WSN领域的研究热点.在分簇WSN基础上,实现了一种误差实时可控的数据融合算法.通过该算法,节点可自行根据近期采集的历史数据实时调整传输阈值,不同节点可保持接近的数据传输率,实现均匀耗电;自适应的阈值可以有效控制数据融合的误差.理论分析与仿真实验表明,该算法能够保证不同节点数据传输的公平性;在数据传输率相同的情况下,其求和查询及均值查询的平均绝对误差均远低于当前优秀的基于伯努利采样的数据融合方法.此算法无需先验知识,在多种WSN应用场景中具有较强的可用性与适应性.
