Pub Date : 2024-07-30DOI: 10.1109/TCST.2024.3430708
Shuang Feng;Ricardo de Castro;Iman Ebrahimi
This article proposes a control barrier function (CBF) approach for fast charging and discharging of batteries under temperature, state of charge (SoC), and terminal voltage constraints. To improve numerical efficiency, we derive a cascade CBF formulation, which divides this safety problem into multiple layers that are easier to formulate and implement. The proposed algorithm exhibits a computational speed that is seven times faster than the model predictive control (MPC) and 3.6 times faster than the traditional single-layer (central) CBF. In the charging scenario, experimental results indicate that the proposed algorithm reduces charging time by 20% in comparison to traditional constant current, constant voltage (CC-CV) methods without violating electro-thermal safety constraints. The discharging experiment illustrates that the cascade CBF effectively limits the battery’s performance to ensure compliance with safety constraints.
{"title":"Safe Battery Control Using Cascade-Control-Barrier Functions","authors":"Shuang Feng;Ricardo de Castro;Iman Ebrahimi","doi":"10.1109/TCST.2024.3430708","DOIUrl":"10.1109/TCST.2024.3430708","url":null,"abstract":"This article proposes a control barrier function (CBF) approach for fast charging and discharging of batteries under temperature, state of charge (SoC), and terminal voltage constraints. To improve numerical efficiency, we derive a cascade CBF formulation, which divides this safety problem into multiple layers that are easier to formulate and implement. The proposed algorithm exhibits a computational speed that is seven times faster than the model predictive control (MPC) and 3.6 times faster than the traditional single-layer (central) CBF. In the charging scenario, experimental results indicate that the proposed algorithm reduces charging time by 20% in comparison to traditional constant current, constant voltage (CC-CV) methods without violating electro-thermal safety constraints. The discharging experiment illustrates that the cascade CBF effectively limits the battery’s performance to ensure compliance with safety constraints.","PeriodicalId":13103,"journal":{"name":"IEEE Transactions on Control Systems Technology","volume":"32 6","pages":"2344-2358"},"PeriodicalIF":4.9,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-30DOI: 10.1109/TCST.2024.3429908
Jianping Lin;Gray C. Thomas;Nikhil V. Divekar;Vamsi Peddinti;Robert D. Gregg
Various backdrivable lower limb exoskeletons have demonstrated the electromechanical capability to assist volitional motions of able-bodied users and people with mild to moderate gait disorders, but there does not exist a control framework that can be deployed on any joint(s) to assist any activity of daily life in a provably stable manner. This article presents the modular, multitask optimal energy shaping (M-TOES) framework, which uses a convex, data-driven optimization to train an analytical control model to instantaneously determine assistive joint torques across activities for any lower limb exoskeleton joint configuration. The presented modular energy basis is sufficiently descriptive to fit normative human joint torques (given normative feedback from signals available to a given joint configuration) across sit-stand transitions, stair ascent/descent, ramp ascent/descent, and level walking at different speeds. We evaluated controllers for four joint configurations (unilateral/bilateral and hip/knee) of the modular backdrivable lower limb unloading exoskeleton (M-BLUE) exoskeleton on eight able-bodied users navigating a multiactivity circuit. The two unilateral conditions significantly lowered overall muscle activation across all tasks and subjects (p $mathbf {lt }$