Pub Date : 2020-07-01DOI: 10.23919/acc45564.2020.9147769
Doruk Aksoy, Efe C. Balta, D. Tilbury, K. Barton
Additive manufacturing (AM) is a digital manufacturing technology that manufactures a 3D object in a bottom-up and layer-by-layer fashion. Fused deposition modeling (FDM), also known as desktop 3D printing, is one of the most commonly used AM technologies with numerous applications in academia and industry. Some of the greatest challenges with FDM include poor repeatability and reliability of the process, leading to mid-process failures or out-of-spec final products. Closed-loop control applications for FDM have been proposed as a means of mitigating mid-process failures. However, no models currently exist to enable control of the bead cross-sectional dimensions for the extruded material. This work presents a control-oriented model describing the effect of process parameters on cross-sectional dimensions of the deposited beads in FDM. A geometric model is presented and a procedure to evaluate the unknown machine and material specific parameters in the model is provided by leveraging design of experiments. The proposed model is experimentally validated and the accuracy of the results is presented. The results show that the proposed model accurately represents the bead cross-sectional geometry and is suitable for closed-loop control applications.
{"title":"A Control-Oriented Model for Bead Cross-Sectional Geometry in Fused Deposition Modeling","authors":"Doruk Aksoy, Efe C. Balta, D. Tilbury, K. Barton","doi":"10.23919/acc45564.2020.9147769","DOIUrl":"https://doi.org/10.23919/acc45564.2020.9147769","url":null,"abstract":"Additive manufacturing (AM) is a digital manufacturing technology that manufactures a 3D object in a bottom-up and layer-by-layer fashion. Fused deposition modeling (FDM), also known as desktop 3D printing, is one of the most commonly used AM technologies with numerous applications in academia and industry. Some of the greatest challenges with FDM include poor repeatability and reliability of the process, leading to mid-process failures or out-of-spec final products. Closed-loop control applications for FDM have been proposed as a means of mitigating mid-process failures. However, no models currently exist to enable control of the bead cross-sectional dimensions for the extruded material. This work presents a control-oriented model describing the effect of process parameters on cross-sectional dimensions of the deposited beads in FDM. A geometric model is presented and a procedure to evaluate the unknown machine and material specific parameters in the model is provided by leveraging design of experiments. The proposed model is experimentally validated and the accuracy of the results is presented. The results show that the proposed model accurately represents the bead cross-sectional geometry and is suitable for closed-loop control applications.","PeriodicalId":288450,"journal":{"name":"2020 American Control Conference (ACC)","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133082587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.23919/ACC45564.2020.9147404
Z. Khalik, H. Bergveld, M. Donkers
In this paper, we utilize a Doyle-Fuller-Newman (DFN) model including capacity-loss side reactions to present a model-based design method for multi-stage charging protocols. This design method allows making a trade-off between charging time and battery ageing in a more systematic way. The results are leveraged by a highly efficient implementation of the DFN model, that has a short computation time. We show that by obtaining the Pareto front that describes the optimal trade-off between charging time and battery ageing for a single cycle, the results can be extended to the lifetime of the battery. Finally we show that the negative electrode over-potential is not always a good indicator for ageing, and that ageing will occur even when the battery operates in over-potential regions that are considered to not lead to ageing.
{"title":"Ageing-Aware Charging of Lithium-ion Batteries Using an Electrochemistry-Based Model with Capacity-Loss Side Reactions","authors":"Z. Khalik, H. Bergveld, M. Donkers","doi":"10.23919/ACC45564.2020.9147404","DOIUrl":"https://doi.org/10.23919/ACC45564.2020.9147404","url":null,"abstract":"In this paper, we utilize a Doyle-Fuller-Newman (DFN) model including capacity-loss side reactions to present a model-based design method for multi-stage charging protocols. This design method allows making a trade-off between charging time and battery ageing in a more systematic way. The results are leveraged by a highly efficient implementation of the DFN model, that has a short computation time. We show that by obtaining the Pareto front that describes the optimal trade-off between charging time and battery ageing for a single cycle, the results can be extended to the lifetime of the battery. Finally we show that the negative electrode over-potential is not always a good indicator for ageing, and that ageing will occur even when the battery operates in over-potential regions that are considered to not lead to ageing.","PeriodicalId":288450,"journal":{"name":"2020 American Control Conference (ACC)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133493577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.23919/ACC45564.2020.9147633
Suhak Lee, Youngki Kim
Diagnostic information of a battery allows for its maximum utilization while avoiding unfavorable or even dangerous operations. Model-based approaches have been proposed to identify the state of health (SOH) related parameters in lithium-ion (Li-ion) batteries; however, high computational cost for solving optimization-based parameter identification makes these approaches difficult to be implemented in onboard applications. To address this issue, this paper proposes a machine learning-based approach using a neural network (NN) model for identifying electrode-level degradation of Li-ion batteries. For the diagnosis of electrode-level degradation (i.e., loss of active material (LAM) for each electrode and loss of lithium inventory (LLI)), electrochemical features are extracted from both incremental capacity (IC) curve and differential voltage (DV) curve. The developed NN model trained with the proposed electrochemical features shows strong potential in identifying each degradation mode accurately: the RMSE of all degradation modes is less than 0.1.
{"title":"Li-ion Battery Electrode Health Diagnostics using Machine Learning","authors":"Suhak Lee, Youngki Kim","doi":"10.23919/ACC45564.2020.9147633","DOIUrl":"https://doi.org/10.23919/ACC45564.2020.9147633","url":null,"abstract":"Diagnostic information of a battery allows for its maximum utilization while avoiding unfavorable or even dangerous operations. Model-based approaches have been proposed to identify the state of health (SOH) related parameters in lithium-ion (Li-ion) batteries; however, high computational cost for solving optimization-based parameter identification makes these approaches difficult to be implemented in onboard applications. To address this issue, this paper proposes a machine learning-based approach using a neural network (NN) model for identifying electrode-level degradation of Li-ion batteries. For the diagnosis of electrode-level degradation (i.e., loss of active material (LAM) for each electrode and loss of lithium inventory (LLI)), electrochemical features are extracted from both incremental capacity (IC) curve and differential voltage (DV) curve. The developed NN model trained with the proposed electrochemical features shows strong potential in identifying each degradation mode accurately: the RMSE of all degradation modes is less than 0.1.","PeriodicalId":288450,"journal":{"name":"2020 American Control Conference (ACC)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127798938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.23919/ACC45564.2020.9147210
Karthik Chikmagalur, Bassam Bamieh
Periodically time-varying models are found across nature and engineered systems, from fluid dynamics, structures and MEMS devices to quantum mechanics and astrophysics. Such systems are known to exhibit parametric resonance, a kind of instability caused by fluctuating model parameters. Under conditions of instability, they can also be vibrationally stabilized with the right forcing. The question of interest here is variation in behavior within these two stable regimes, and whether certain parameter configurations are preferred from a design perspective. This motivation leads us to consider Mathieu’s equation with harmonic forcing as a canonical model. To address these questions, we use a lifting based approach to obtain a representation of the frequency response operator that is amenable to methods from LTI systems. We study the poles of the system as a function of its parameters, and obtain a description of the free response of Mathieu’s equation as the product of two simple functions. We also investigate the dependence of the ${mathcal{H}_2}$ norm of Mathieu’s equation on its parameters. A considerable difference in ${mathcal{H}_2}$ norm between the two regimes is found, as well as interesting behavior within each domain.
{"title":"Frequency Response Analysis of Parametric Resonance and Vibrational Stabilization","authors":"Karthik Chikmagalur, Bassam Bamieh","doi":"10.23919/ACC45564.2020.9147210","DOIUrl":"https://doi.org/10.23919/ACC45564.2020.9147210","url":null,"abstract":"Periodically time-varying models are found across nature and engineered systems, from fluid dynamics, structures and MEMS devices to quantum mechanics and astrophysics. Such systems are known to exhibit parametric resonance, a kind of instability caused by fluctuating model parameters. Under conditions of instability, they can also be vibrationally stabilized with the right forcing. The question of interest here is variation in behavior within these two stable regimes, and whether certain parameter configurations are preferred from a design perspective. This motivation leads us to consider Mathieu’s equation with harmonic forcing as a canonical model. To address these questions, we use a lifting based approach to obtain a representation of the frequency response operator that is amenable to methods from LTI systems. We study the poles of the system as a function of its parameters, and obtain a description of the free response of Mathieu’s equation as the product of two simple functions. We also investigate the dependence of the ${mathcal{H}_2}$ norm of Mathieu’s equation on its parameters. A considerable difference in ${mathcal{H}_2}$ norm between the two regimes is found, as well as interesting behavior within each domain.","PeriodicalId":288450,"journal":{"name":"2020 American Control Conference (ACC)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133806209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.23919/ACC45564.2020.9147381
Yixuan Lin, Shripad Gade, Romeil Sandhu, Ji Liu
This paper considers a distributed reinforcement learning problem in the presence of Byzantine agents. The system consists of a central coordinating authority called "master agent" and multiple computational entities called "worker agents". The master agent is assumed to be reliable, while, a small fraction of the workers can be Byzantine (malicious) adversaries. The workers are interested in cooperatively maximize a convex combination of the honest (non-malicious) worker agents’ long-term returns through communication between the master agent and worker agents. A distributed actor-critic algorithm is studied which makes use of entry-wise trimmed mean. The algorithm’s communication-efficiency is improved by allowing the worker agents to send only a scalar-valued variable to the master agent, instead of the entire parameter vector, at each iteration. The improved algorithm involves computing a trimmed mean over only the received scalar-valued variable. It is shown that both algorithms converge almost surely.
{"title":"Toward Resilient Multi-Agent Actor-Critic Algorithms for Distributed Reinforcement Learning","authors":"Yixuan Lin, Shripad Gade, Romeil Sandhu, Ji Liu","doi":"10.23919/ACC45564.2020.9147381","DOIUrl":"https://doi.org/10.23919/ACC45564.2020.9147381","url":null,"abstract":"This paper considers a distributed reinforcement learning problem in the presence of Byzantine agents. The system consists of a central coordinating authority called \"master agent\" and multiple computational entities called \"worker agents\". The master agent is assumed to be reliable, while, a small fraction of the workers can be Byzantine (malicious) adversaries. The workers are interested in cooperatively maximize a convex combination of the honest (non-malicious) worker agents’ long-term returns through communication between the master agent and worker agents. A distributed actor-critic algorithm is studied which makes use of entry-wise trimmed mean. The algorithm’s communication-efficiency is improved by allowing the worker agents to send only a scalar-valued variable to the master agent, instead of the entire parameter vector, at each iteration. The improved algorithm involves computing a trimmed mean over only the received scalar-valued variable. It is shown that both algorithms converge almost surely.","PeriodicalId":288450,"journal":{"name":"2020 American Control Conference (ACC)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133721104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.23919/acc45564.2020.9147495
Xu Zhang, Wei Lin
The problem of global stabilization by delay-free output feedback is considered for a class of time-delay nonlinear systems with uncertainty in both output and state equations. The nonlinear perturbations with time-delay in the state equation are allowed to satisfy a linear growth condition with a polynomial output-dependent rate, while the uncertain parameter in the system output is assumed to be located in a known compact set. By constructing appropriate LyapunovKrasovskii functionals, we present a recursive algorithm for the design of a delay-independent, estimator-based controller that consists of an estimator with a dynamic gain and an estimator-based feedback law, capable of dealing with simultaneously the uncertainty in the output and polynomial nonlinearities in the state dynamics.
{"title":"Robust Control of Time-Delay Uncertain Systems by Delay-Free Output Feedback","authors":"Xu Zhang, Wei Lin","doi":"10.23919/acc45564.2020.9147495","DOIUrl":"https://doi.org/10.23919/acc45564.2020.9147495","url":null,"abstract":"The problem of global stabilization by delay-free output feedback is considered for a class of time-delay nonlinear systems with uncertainty in both output and state equations. The nonlinear perturbations with time-delay in the state equation are allowed to satisfy a linear growth condition with a polynomial output-dependent rate, while the uncertain parameter in the system output is assumed to be located in a known compact set. By constructing appropriate LyapunovKrasovskii functionals, we present a recursive algorithm for the design of a delay-independent, estimator-based controller that consists of an estimator with a dynamic gain and an estimator-based feedback law, capable of dealing with simultaneously the uncertainty in the output and polynomial nonlinearities in the state dynamics.","PeriodicalId":288450,"journal":{"name":"2020 American Control Conference (ACC)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114599518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.23919/acc45564.2020.9147921
P. Dower, W. McEneaney
By exploiting min-plus linearity, semiconcavity, and semigroup properties of dynamic programming, a fundamental solution semigroup for a class of approximate finite horizon linear infinite dimensional optimal control problems is constructed. Elements of this fundamental solution semigroup are parameterized by the time horizon, and can be used to approximate the solution of the corresponding finite horizon optimal control problem for any terminal cost. They can also be composed to compute approximations on longer horizons. The value function approximation provided takes the form of a min-plus convolution of a kernel with the terminal cost. A general construction for this kernel is provided, along with a spectral representation for a restricted class of sub-problems.
{"title":"A min-plus fundamental solution semigroup for a class of approximate infinite dimensional optimal control problems","authors":"P. Dower, W. McEneaney","doi":"10.23919/acc45564.2020.9147921","DOIUrl":"https://doi.org/10.23919/acc45564.2020.9147921","url":null,"abstract":"By exploiting min-plus linearity, semiconcavity, and semigroup properties of dynamic programming, a fundamental solution semigroup for a class of approximate finite horizon linear infinite dimensional optimal control problems is constructed. Elements of this fundamental solution semigroup are parameterized by the time horizon, and can be used to approximate the solution of the corresponding finite horizon optimal control problem for any terminal cost. They can also be composed to compute approximations on longer horizons. The value function approximation provided takes the form of a min-plus convolution of a kernel with the terminal cost. A general construction for this kernel is provided, along with a spectral representation for a restricted class of sub-problems.","PeriodicalId":288450,"journal":{"name":"2020 American Control Conference (ACC)","volume":"191 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114858097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.23919/ACC45564.2020.9147504
Prasad Vilas Chanekar, J. Cortés
Due to recent technological advances, performance enhancement of complex networked control systems by edge modification done according to their importance in the network is becoming increasingly feasible. Unlike the nodal case, edge characterization with respect to a given performance metric is a rather unexplored research area. In this work, we seek to address this problem by proposing a novel Gramian-based edge centrality matrix which characterizes all the possible edges in the network with respect to physically realizable energy-based performance metrics. We rigorously prove the relationship of the various edge centrality matrix for different performance metrics with the gradient of the controllability Gramian with respect to edge weights. Notable feature of our proposed edge characterization is that it exhibits the contribution of individual inputs. We then analyze the edge centrality matrix for directed ring and line networks. Finally, through numerical examples, we validate a structural property of proposed edge centrality matrix and demonstrate its utility in network edge modification.
{"title":"Edge Centrality Matrix: Impact of Network Modification on Gramian Controllability Metrics","authors":"Prasad Vilas Chanekar, J. Cortés","doi":"10.23919/ACC45564.2020.9147504","DOIUrl":"https://doi.org/10.23919/ACC45564.2020.9147504","url":null,"abstract":"Due to recent technological advances, performance enhancement of complex networked control systems by edge modification done according to their importance in the network is becoming increasingly feasible. Unlike the nodal case, edge characterization with respect to a given performance metric is a rather unexplored research area. In this work, we seek to address this problem by proposing a novel Gramian-based edge centrality matrix which characterizes all the possible edges in the network with respect to physically realizable energy-based performance metrics. We rigorously prove the relationship of the various edge centrality matrix for different performance metrics with the gradient of the controllability Gramian with respect to edge weights. Notable feature of our proposed edge characterization is that it exhibits the contribution of individual inputs. We then analyze the edge centrality matrix for directed ring and line networks. Finally, through numerical examples, we validate a structural property of proposed edge centrality matrix and demonstrate its utility in network edge modification.","PeriodicalId":288450,"journal":{"name":"2020 American Control Conference (ACC)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114888074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-01DOI: 10.23919/acc45564.2020.9147325
Francesco Saverio Tedesco, A. Casavola
This work presents a novel distributed supervision architecture for reference signals management of dynamically coupled constrained linear systems where the dynamic interconnection among them can vary on-line to accomplish different operative scenarios. The strategy is based on non-iterative distributed command governor ideas that are here specialized to properly schedule modification on the couplings involving more than one subsystem. The main feature of the approach concerns the capability to avoid constraints violation regardless of any configuration change occurring on-line in the global plant/constraint structure. To this end, formal conditions to guarantee safe system configuration switchings are investigated by involving also graph colorability concepts. Simulation results on a water network are presented to illustrate the effectiveness of the proposed strategy.
{"title":"Turn-Based Command Governor Strategies for Interconnected Dynamical Systems with Time-Varying Couplings","authors":"Francesco Saverio Tedesco, A. Casavola","doi":"10.23919/acc45564.2020.9147325","DOIUrl":"https://doi.org/10.23919/acc45564.2020.9147325","url":null,"abstract":"This work presents a novel distributed supervision architecture for reference signals management of dynamically coupled constrained linear systems where the dynamic interconnection among them can vary on-line to accomplish different operative scenarios. The strategy is based on non-iterative distributed command governor ideas that are here specialized to properly schedule modification on the couplings involving more than one subsystem. The main feature of the approach concerns the capability to avoid constraints violation regardless of any configuration change occurring on-line in the global plant/constraint structure. To this end, formal conditions to guarantee safe system configuration switchings are investigated by involving also graph colorability concepts. Simulation results on a water network are presented to illustrate the effectiveness of the proposed strategy.","PeriodicalId":288450,"journal":{"name":"2020 American Control Conference (ACC)","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115031197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：