This paper investigates the adaptive optimal tracking control(AOTC)for underactuated surface vessels(USVs).Compared to the majority of existing studies,the control strategy in this paper innovatively combines an exten...This paper investigates the adaptive optimal tracking control(AOTC)for underactuated surface vessels(USVs).Compared to the majority of existing studies,the control strategy in this paper innovatively combines an extended state observer(ESO)with reinforcement learning(RL).The designed ESO has high estimation accuracy and robust disturbance rejection capabilities for the unmeasurable information for USVs.To obtain the AOTC,the actor–critic(AC)networks based on RL are constructed to solve the Hamilton–Jacobi–Bellman(HJB)equations.Due to the uncertainties,it is challenging to obtain the optimal controller by directly solving the HJB equations.To address this issue,this paper employs neural networks(NNs)to approximate the uncertainties and solves the optimal controller via AC-RL and ESO.In addition,the adaptive parameters of the optimal controller is trained in parallel with AC networks,which can ensure that the trained networks can further improve tracking performance.The boundedness of AOTC for USVs is shown by Lyapunov stability theorem.Finally,simulation results demonstrate the effectiveness of the proposed algorithm.展开更多
In alloy bar rolling process, the component of alloyed steel influenced the spread coefficient greatly, therefore, the component influence coefficient m of different alloyed steel has been determined firstly to calcul...In alloy bar rolling process, the component of alloyed steel influenced the spread coefficient greatly, therefore, the component influence coefficient m of different alloyed steel has been determined firstly to calculate the maximum spread. Then the curvature radius of stress free surface and the ＂critical point on the contact boundary＂ have been solved, the surface profile of outgoing workpiece has been obtained. Furthermore, the formula of the equivalent contact section area has been proposed and the mean roll radius has been calculated. The bar rolling experiment and the rigid-plastic FEM （finite element method） simulation have been carried out to verify the novel approach. Compared with experimental data and simulation results, the novel approach can be used in setting processing parameter and design of finishing groove.展开更多
In this paper we aimed to determine the surface tension of traditional Chinese medicine (TCM) tablet and tried to provide a key reference parameter to control tablet film coating quality. Using contact angle tester, t...In this paper we aimed to determine the surface tension of traditional Chinese medicine (TCM) tablet and tried to provide a key reference parameter to control tablet film coating quality. Using contact angle tester, the Chinese medicine tablet, a famous Fufang Danshen tablet CP as a model example, was determined by Zisman critical surface tension method. Our study showed that the critical surface tension of Fufang Danshen tablet CP was determined to be 18.00 dyne/cm. The Zisman method, hence, can determine successfully the critical surface tension of Chinese medicine tablet and will become an effective manner to control tablet film coating quality.展开更多
目的优化半夏桃红颗粒湿法制粒成型工艺。方法以半夏桃红颗粒的成型率、吸湿率和休止角的综合评分为指标,采用AHP-CRITIC混合加权法结合Box-Behnken设计-响应面法建立半夏桃红颗粒成型的关键工艺参数(critical process parameter,CPP)...目的优化半夏桃红颗粒湿法制粒成型工艺。方法以半夏桃红颗粒的成型率、吸湿率和休止角的综合评分为指标,采用AHP-CRITIC混合加权法结合Box-Behnken设计-响应面法建立半夏桃红颗粒成型的关键工艺参数(critical process parameter,CPP)和关键质量属性(critical quality attribute,CQA)的数学模型,构建工艺设计空间并验证。结果半夏桃红颗粒成型工艺参数为:以可溶性淀粉作为辅料,辅药质量比为0.30:1~0.47:1,以95%乙醇为润湿剂,乙醇用量为35.0%~38.5%,于60℃干燥2 h。在此范围内工艺参数均可满足目标要求。结论通过AHP-CRITIC混合加权法结合Box-Behnken设计优选的半夏桃红颗粒成型工艺稳定性好,可为该复方制剂的工业化生产提供支持。展开更多
基金supported by the National Natural Science Foundation of China under Grants 62203338,62173259 and U1913602Zhejiang Provincial Natural Science Foundation of China under Grant LZ24F0390006the Postdoctoral Science Foundation of China under Grant 2022M722485.
文摘This paper investigates the adaptive optimal tracking control(AOTC)for underactuated surface vessels(USVs).Compared to the majority of existing studies,the control strategy in this paper innovatively combines an extended state observer(ESO)with reinforcement learning(RL).The designed ESO has high estimation accuracy and robust disturbance rejection capabilities for the unmeasurable information for USVs.To obtain the AOTC,the actor–critic(AC)networks based on RL are constructed to solve the Hamilton–Jacobi–Bellman(HJB)equations.Due to the uncertainties,it is challenging to obtain the optimal controller by directly solving the HJB equations.To address this issue,this paper employs neural networks(NNs)to approximate the uncertainties and solves the optimal controller via AC-RL and ESO.In addition,the adaptive parameters of the optimal controller is trained in parallel with AC networks,which can ensure that the trained networks can further improve tracking performance.The boundedness of AOTC for USVs is shown by Lyapunov stability theorem.Finally,simulation results demonstrate the effectiveness of the proposed algorithm.
文摘In alloy bar rolling process, the component of alloyed steel influenced the spread coefficient greatly, therefore, the component influence coefficient m of different alloyed steel has been determined firstly to calculate the maximum spread. Then the curvature radius of stress free surface and the ＂critical point on the contact boundary＂ have been solved, the surface profile of outgoing workpiece has been obtained. Furthermore, the formula of the equivalent contact section area has been proposed and the mean roll radius has been calculated. The bar rolling experiment and the rigid-plastic FEM （finite element method） simulation have been carried out to verify the novel approach. Compared with experimental data and simulation results, the novel approach can be used in setting processing parameter and design of finishing groove.
文摘In this paper we aimed to determine the surface tension of traditional Chinese medicine (TCM) tablet and tried to provide a key reference parameter to control tablet film coating quality. Using contact angle tester, the Chinese medicine tablet, a famous Fufang Danshen tablet CP as a model example, was determined by Zisman critical surface tension method. Our study showed that the critical surface tension of Fufang Danshen tablet CP was determined to be 18.00 dyne/cm. The Zisman method, hence, can determine successfully the critical surface tension of Chinese medicine tablet and will become an effective manner to control tablet film coating quality.
