An adaptive control scheme is presented,which can simultaneously realize vibration suppression and compliance control for flexible joint robot(FJR).The proposed control scheme provides a unified formulation for both v...An adaptive control scheme is presented,which can simultaneously realize vibration suppression and compliance control for flexible joint robot(FJR).The proposed control scheme provides a unified formulation for both vibration suppression mode,where FJR tracks the desired position with little vibration,and compliance mode,in which FJR presents passive.Instead of designing multiple controllers and switching between them,both modes are integrated into a single controller,and the transition between two modes is smooth and stable.The stability of the closed-loop system is theoretically proven via the Lyapunov method,with the considering the dynamics uncertainties in both link side and motor side.Simulation results are presented to illustrate good performances of the proposed control scheme.展开更多
A new impedance controller based on the dynamic surface control-backstepping technique to actualize the anticipant dynamic relationship between the motion of end-effector and the external torques was presented. Compar...A new impedance controller based on the dynamic surface control-backstepping technique to actualize the anticipant dynamic relationship between the motion of end-effector and the external torques was presented. Comparing with the traditional backstepping method that has ＂explosion of terms＂ problem, the new proposed control system is a combination of the dynamic surface control technique and the backstepping. The dynamic surface control （DSC） technique can resolve the ＂explosion of terms＂ problem that is caused by differential coefficient calculation in the model, and the problem can bring a complexity that will cause the backstepping method hardly to be applied to the practical application, especially to the multi-joint robot. Finally, the validity of the method was proved in the laboratory environment that was set up on the 5-DOF （degree of freedom） flexible joint robot. Tracking errors of DSC-backstepping impedance control that were 2.0 and 1.5 mm are better than those of backstepping impedance control which were 3.5 and 2.5 mm in directions X, Y in free space, respectively. And the anticipant Cartesian impedance behavior and compliant behavior were nchieved successfully as depicted theoretically.展开更多
With the growing trend toward using cloud storage,the problem of efficiently checking and proving data integrity needs more consideration.Many cryptography and security schemes,such as PDP(Provable Data Possession) an...With the growing trend toward using cloud storage,the problem of efficiently checking and proving data integrity needs more consideration.Many cryptography and security schemes,such as PDP(Provable Data Possession) and POR(Proofs of Retrievability) were proposed for this problem.Although many efficient schemes for static data have been constructed,only a few dynamic schemes exist,such as DPDP(Dynamic Provable Data Possession).But the DPDP scheme falls short when updates are not proportional to a fixed block size.The FlexList-based Dynamic Provable Data Possession(FlexDPDP) was an optimized scheme for DPDP.However,the update operations(insertion,remove,modification)in Flex DPDP scheme only apply to single node at a time,while multiple consecutive nodes operation is more common in practice.To solve this problem,we propose optimized algorithms for multiple consecutive nodes,which including MultiNodes Insert and Verification,MultiNodes Remove and Verification,MultiNodes Modify and Verification.The cost of our optimized algorithms is also analyzed.For m consecutive nodes,an insertion takes O(m) + O(log N) + O(log m),where N is the number of leaf nodes of FlexList,a remove takes O(log/V),and a modification is the same as the original algorithm.Finally,we compare the optimized algorithms with original FlexList through experiences,and the results show that our scheme has the higher efficiency of time and space.展开更多
To verify the therapeutic effects of the method of softening and lubricating the joints,and calming the endogenous wind in case of rheumatoid arthritis (RA) with the syndrome of channel blockage due to yin deficiency,...To verify the therapeutic effects of the method of softening and lubricating the joints,and calming the endogenous wind in case of rheumatoid arthritis (RA) with the syndrome of channel blockage due to yin deficiency,60 RA patients with the syndrome of channel blockage due to yin deficiency were randomly divided into a treatment group (40 cases) and a control group (20 cases) and treated respectively by the above method for the former and with Zheng Qing Feng Tong Ning Tablets (正清风痛宁片) for the latter. The result turned out to be that the effect in the treatment group was very satisfying.The treatment group obtained a better result in the accumulated points of syndrome and RA,morning rigidity of the joints,grip strength,20m walking time and erythrocyte sedimentation rate (ESR) (P<0.01 or P<0.05).The above indicates that channel blockage due to yin deficiency is an important pathogenesis of RA,and calming the endogenous wind is a method of choice for treating RA.展开更多
文摘旋转导向钻井系统代表了当前井眼轨迹控制技术的最高水平,是一种能够在复杂工作环境中运行的高尖端技术产品.实际应用过程中,国外公司一方面利用井下振动监测装置来控制带旋转导向工具的底部钻具组合的振动,起到保护旋转导向工具和确保井下测量数据的准确性的作用,另一方面通过优化该组合的结构,尽可能减少因振动问题而造成的作业参数调整次数.文章针对具有超长细比特征的带旋转导向工具的底部钻具组合,运用有限元结点迭代方法,研究不同结构的带旋转导向工具的底部钻具组合的动力学特性,并对实际工程中使用的带旋转导向工具的底部钻具组合结构进行优化.计算结果表明,合理安放稳定器和柔性短节能够有效地减少振动频率和应力峰值；对于现在实际使用的带旋转导向工具的底部钻具组合,柔性短节的合理安装位置为距离钻头6～8 m.
基金supported by the National Key R&D Program of China(No.2017YFB1300400)the National Natural Science Foundation of China(No. 51805107)
文摘An adaptive control scheme is presented,which can simultaneously realize vibration suppression and compliance control for flexible joint robot(FJR).The proposed control scheme provides a unified formulation for both vibration suppression mode,where FJR tracks the desired position with little vibration,and compliance mode,in which FJR presents passive.Instead of designing multiple controllers and switching between them,both modes are integrated into a single controller,and the transition between two modes is smooth and stable.The stability of the closed-loop system is theoretically proven via the Lyapunov method,with the considering the dynamics uncertainties in both link side and motor side.Simulation results are presented to illustrate good performances of the proposed control scheme.
基金Project(2006AA04Z228) supported by the National High-Tech Research and Development Program of ChinaProject(PCSIRT) supported by Program for Changjiang Scholars and Innovative Research Team in University
文摘A new impedance controller based on the dynamic surface control-backstepping technique to actualize the anticipant dynamic relationship between the motion of end-effector and the external torques was presented. Comparing with the traditional backstepping method that has ＂explosion of terms＂ problem, the new proposed control system is a combination of the dynamic surface control technique and the backstepping. The dynamic surface control （DSC） technique can resolve the ＂explosion of terms＂ problem that is caused by differential coefficient calculation in the model, and the problem can bring a complexity that will cause the backstepping method hardly to be applied to the practical application, especially to the multi-joint robot. Finally, the validity of the method was proved in the laboratory environment that was set up on the 5-DOF （degree of freedom） flexible joint robot. Tracking errors of DSC-backstepping impedance control that were 2.0 and 1.5 mm are better than those of backstepping impedance control which were 3.5 and 2.5 mm in directions X, Y in free space, respectively. And the anticipant Cartesian impedance behavior and compliant behavior were nchieved successfully as depicted theoretically.
基金supported in part by the National Natural Science Foundation of China under Grant No.61440014&&No.61300196the Liaoning Province Doctor Startup Fundunder Grant No.20141012+2 种基金the Liaoning Province Science and Technology Projects under Grant No.2013217004the Shenyang Province Science and Technology Projects under Grant Nothe Fundamental Research Funds for the Central Universities under Grant No.N130317002 and No.N130317003
文摘With the growing trend toward using cloud storage,the problem of efficiently checking and proving data integrity needs more consideration.Many cryptography and security schemes,such as PDP(Provable Data Possession) and POR(Proofs of Retrievability) were proposed for this problem.Although many efficient schemes for static data have been constructed,only a few dynamic schemes exist,such as DPDP(Dynamic Provable Data Possession).But the DPDP scheme falls short when updates are not proportional to a fixed block size.The FlexList-based Dynamic Provable Data Possession(FlexDPDP) was an optimized scheme for DPDP.However,the update operations(insertion,remove,modification)in Flex DPDP scheme only apply to single node at a time,while multiple consecutive nodes operation is more common in practice.To solve this problem,we propose optimized algorithms for multiple consecutive nodes,which including MultiNodes Insert and Verification,MultiNodes Remove and Verification,MultiNodes Modify and Verification.The cost of our optimized algorithms is also analyzed.For m consecutive nodes,an insertion takes O(m) + O(log N) + O(log m),where N is the number of leaf nodes of FlexList,a remove takes O(log/V),and a modification is the same as the original algorithm.Finally,we compare the optimized algorithms with original FlexList through experiences,and the results show that our scheme has the higher efficiency of time and space.
文摘To verify the therapeutic effects of the method of softening and lubricating the joints,and calming the endogenous wind in case of rheumatoid arthritis (RA) with the syndrome of channel blockage due to yin deficiency,60 RA patients with the syndrome of channel blockage due to yin deficiency were randomly divided into a treatment group (40 cases) and a control group (20 cases) and treated respectively by the above method for the former and with Zheng Qing Feng Tong Ning Tablets (正清风痛宁片) for the latter. The result turned out to be that the effect in the treatment group was very satisfying.The treatment group obtained a better result in the accumulated points of syndrome and RA,morning rigidity of the joints,grip strength,20m walking time and erythrocyte sedimentation rate (ESR) (P<0.01 or P<0.05).The above indicates that channel blockage due to yin deficiency is an important pathogenesis of RA,and calming the endogenous wind is a method of choice for treating RA.
