Sun Xiaoyu, Rashid Mudassir, Askari Mohammad Reza, Cinar Ali
Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, 60616, IL, USA.
Department of Chemical and Biological Engineering, Illinois Institute of Technology, Chicago, 60616, IL, USA.
Control Eng Pract. 2023 Feb;131. doi: 10.1016/j.conengprac.2022.105386. Epub 2022 Nov 25.
This work considers the problem of adaptive prior-informed model predictive control (MPC) formulations that explicitly incorporate prior knowledge in the model development and is robust to missing data in the output measurements. The proposed prediction model is based on a latent variables model to extract glycemic dynamics from highly-correlated data and incorporates prior knowledge of exponential stability to improve the prediction ability. Missing data structures are formulated to enable model predictions when output measurements are missing for short periods of time. Based on the latent variables model, the MPC strategy and adaptive rules are developed to automatically tune the aggressiveness of the MPC. The adaptive prior-knowledge-informed MPC is evaluated with computer simulations for the control of blood glucose concentrations in people with Type 1 diabetes (T1D) using simulated virtual patients. Due to the variability among people with T1D, the hyperparameters of the prior-knowledge-informed model are personalized to individual subjects. The percentage of time spent in the target range is 76.48% when there are no missing data and 76.52% when there are missing data episodes lasting up to 30 mins (6 samples). Incorporating the adaptive rules further improves the percentage of time in target range to 84.58% and 84.88% for cases with no missing data and missing data, respectively. The proposed adaptive prior-informed MPC formulation provides robust, effective, and safe regulation of glucose concentration in T1D despite disturbances and missing measurements.
这项工作考虑了自适应先验知识驱动的模型预测控制(MPC)公式化问题,该公式化在模型开发中明确纳入先验知识,并且对输出测量中的数据缺失具有鲁棒性。所提出的预测模型基于一个潜变量模型,用于从高度相关的数据中提取血糖动态,并纳入指数稳定性的先验知识以提高预测能力。制定了缺失数据结构,以便在输出测量短时间缺失时进行模型预测。基于潜变量模型,开发了MPC策略和自适应规则,以自动调整MPC的激进程度。使用模拟虚拟患者,通过计算机模拟对自适应先验知识驱动的MPC进行评估,以控制1型糖尿病(T1D)患者的血糖浓度。由于T1D患者之间存在变异性,先验知识驱动模型的超参数针对个体受试者进行了个性化设置。在无数据缺失时,处于目标范围内的时间百分比为76.48%;当存在持续长达30分钟(6个样本)的数据缺失情况时,该百分比为76.52%。对于无数据缺失和有数据缺失的情况,纳入自适应规则后,处于目标范围内的时间百分比分别进一步提高到84.58%和84.88%。所提出的自适应先验知识驱动的MPC公式化方法,尽管存在干扰和测量缺失,仍能对T1D患者的血糖浓度提供稳健、有效且安全的调节。