Goto

Collaborating Authors

 process control


Application of Soft Actor-Critic Algorithms in Optimizing Wastewater Treatment with Time Delays Integration

Mohammadi, Esmaeel, Ortiz-Arroyo, Daniel, Hansen, Aviaja Anna, Stokholm-Bjerregaard, Mikkel, Gros, Sebastien, Anand, Akhil S, Durdevic, Petar

arXiv.org Artificial Intelligence

Wastewater treatment plants face unique challenges for process control due to their complex dynamics, slow time constants, and stochastic delays in observations and actions. These characteristics make conventional control methods, such as Proportional-Integral-Derivative controllers, suboptimal for achieving efficient phosphorus removal, a critical component of wastewater treatment to ensure environmental sustainability. This study addresses these challenges using a novel deep reinforcement learning approach based on the Soft Actor-Critic algorithm, integrated with a custom simulator designed to model the delayed feedback inherent in wastewater treatment plants. The simulator incorporates Long Short-Term Memory networks for accurate multi-step state predictions, enabling realistic training scenarios. To account for the stochastic nature of delays, agents were trained under three delay scenarios: no delay, constant delay, and random delay. The results demonstrate that incorporating random delays into the reinforcement learning framework significantly improves phosphorus removal efficiency while reducing operational costs. Specifically, the delay-aware agent achieved 36% reduction in phosphorus emissions, 55% higher reward, 77% lower target deviation from the regulatory limit, and 9% lower total costs than traditional control methods in the simulated environment. These findings underscore the potential of reinforcement learning to overcome the limitations of conventional control strategies in wastewater treatment, providing an adaptive and cost-effective solution for phosphorus removal.


Neurofeedback-Driven 6-DOF Robotic Arm: Integration of Brain-Computer Interface with Arduino for Advanced Control

Satam, Ihab A., Szabolcsi, Róbert

arXiv.org Artificial Intelligence

Brain computer interface (BCI) applications in robotics are becoming more famous and famous. People with disabilities are facing a real-time problem of doing simple activities such as grasping, handshaking etc. in order to aid with this problem, the use of brain signals to control actuators is showing a great importance. The Emotive Insight, a Brain-Computer Interface (BCI) device, is utilized in this project to collect brain signals and transform them into commands for controlling a robotic arm using an Arduino controller. The Emotive Insight captures brain signals, which are subsequently analyzed using Emotive software and connected with Arduino code. The HITI Brain software integrates these devices, allowing for smooth communication between brain activity and the robotic arm. This system demonstrates how brain impulses may be utilized to control external devices directly. The results showed that the system is applicable efficiently to robotic arms and also for prosthetic arms with Multi Degree of Freedom. In addition to that, the system can be used for other actuators such as bikes, mobile robots, wheelchairs etc.


Towards Hypermedia Environments for Adaptive Coordination in Industrial Automation

Ramanathan, Ganesh, Mayer, Simon, Ciortea, Andrei

arXiv.org Artificial Intelligence

Electromechanical systems manage physical processes through a network of inter-connected components. Today, programming the interactions required for coordinating these components is largely a manual process. This process is time-consuming and requires manual adaptation when system features change. To overcome this issue, we use autonomous software agents that process semantic descriptions of the system to determine coordination requirements and constraints; on this basis, they then interact with one another to control the system in a decentralized and coordinated manner.Our core insight is that coordination requirements between individual components are, ultimately, largely due to underlying physical interdependencies between the components, which can be (and, in many cases, already are) semantically modeled in automation projects. Agents then use hypermedia to discover, at run time, the plans and protocols required for enacting the coordination. A key novelty of our approach is the use of hypermedia-driven interaction: it reduces coupling in the system and enables its run-time adaptation as features change.


Facilitating Reinforcement Learning for Process Control Using Transfer Learning: Perspectives

Lin, Runze, Chen, Junghui, Xie, Lei, Su, Hongye, Huang, Biao

arXiv.org Artificial Intelligence

This paper provides insights into deep reinforcement learning (DRL) for process control from the perspective of transfer learning. We analyze the challenges of applying DRL in the field of process industries and the necessity of introducing transfer learning. Furthermore, recommendations and prospects are provided for future research directions on how transfer learning can be integrated with DRL to empower process control.


Tensor-based process control and monitoring for semiconductor manufacturing with unstable disturbances

Li, Yanrong, Du, Juan, Tsung, Fugee, Jiang, Wei

arXiv.org Artificial Intelligence

With the development and popularity of sensors installed in manufacturing systems, complex data are collected during manufacturing processes, which brings challenges for traditional process control methods. This paper proposes a novel process control and monitoring method for the complex structure of high-dimensional image-based overlay errors (modeled in tensor form), which are collected in semiconductor manufacturing processes. The proposed method aims to reduce overlay errors using limited control recipes. We first build a high-dimensional process model and propose different tensor-on-vector regression algorithms to estimate parameters in the model to alleviate the curse of dimensionality. Then, based on the estimate of tensor parameters, the exponentially weighted moving average (EWMA) controller for tensor data is designed whose stability is theoretically guaranteed. Considering the fact that low-dimensional control recipes cannot compensate for all high-dimensional disturbances on the image, control residuals are monitored to prevent significant drifts of uncontrollable high-dimensional disturbances. Through extensive simulations and real case studies, the performances of parameter estimation algorithms and the EWMA controller in tensor space are evaluated. Compared with existing image-based feedback controllers, the superiority of our method is verified especially when disturbances are not stable.


Machine learning for industrial sensing and control: A survey and practical perspective

Lawrence, Nathan P., Damarla, Seshu Kumar, Kim, Jong Woo, Tulsyan, Aditya, Amjad, Faraz, Wang, Kai, Chachuat, Benoit, Lee, Jong Min, Huang, Biao, Gopaluni, R. Bhushan

arXiv.org Artificial Intelligence

With the rise of deep learning, there has been renewed interest within the process industries to utilize data on large-scale nonlinear sensing and control problems. We identify key statistical and machine learning techniques that have seen practical success in the process industries. To do so, we start with hybrid modeling to provide a methodological framework underlying core application areas: soft sensing, process optimization, and control. Soft sensing contains a wealth of industrial applications of statistical and machine learning methods. We quantitatively identify research trends, allowing insight into the most successful techniques in practice. We consider two distinct flavors for data-driven optimization and control: hybrid modeling in conjunction with mathematical programming techniques and reinforcement learning. Throughout these application areas, we discuss their respective industrial requirements and challenges. A common challenge is the interpretability and efficiency of purely data-driven methods. This suggests a need to carefully balance deep learning techniques with domain knowledge. As a result, we highlight ways prior knowledge may be integrated into industrial machine learning applications. The treatment of methods, problems, and applications presented here is poised to inform and inspire practitioners and researchers to develop impactful data-driven sensing, optimization, and control solutions in the process industries.


Real-time Autonomous Control of a Continuous Macroscopic Process as Demonstrated by Plastic Forming

Muroga, Shun, Honda, Takashi, Miki, Yasuaki, Nakajima, Hideaki, Futaba, Don N., Hata, Kenji

arXiv.org Artificial Intelligence

To meet the demands for more adaptable and expedient approaches to augment both research and manufacturing, we report an autonomous system using real-time in-situ characterization and an autonomous, decision-making processer based on an active learning algorithm. This system was applied to a plastic film forming system to highlight its efficiency and accuracy in determining the process conditions for specified target film dimensions, importantly, without any human intervention. Application of this system towards nine distinct film dimensions demonstrated the system ability to quickly determine the appropriate and stable process conditions (average 11 characterization-adjustment iterations, 19 minutes) and the ability to avoid traps, such as repetitive over-correction. Furthermore, comparison of the achieved film dimensions to the target values showed a high accuracy (R2 = 0.87, 0.90) for film width and thickness, respectively. In addition, the use of an active learning algorithm afforded our system to proceed optimization with zero initial training data, which was unavailable due to the complex relationships between the control factors (material supply rate, applied force, material viscosity) within the plastic forming process. As our system is intrinsically general and can be applied to any most material processes, these results have significant implications in accelerating both research and industrial processes.


Control invariant set enhanced reinforcement learning for process control: improved sampling efficiency and guaranteed stability

Bo, Song, Yin, Xunyuan, Liu, Jinfeng

arXiv.org Artificial Intelligence

Reinforcement learning (RL) is an area of significant research interest, and safe RL in particular is attracting attention due to its ability to handle safety-driven constraints that are crucial for real-world applications of RL algorithms. This work proposes a novel approach to RL training, called control invariant set (CIS) enhanced RL, which leverages the benefits of CIS to improve stability guarantees and sampling efficiency. The approach consists of two learning stages: offline and online. In the offline stage, CIS is incorporated into the reward design, initial state sampling, and state reset procedures. In the online stage, RL is retrained whenever the state is outside of CIS, which serves as a stability criterion. A backup table that utilizes the explicit form of CIS is obtained to ensure the online stability. To evaluate the proposed approach, we apply it to a simulated chemical reactor. The results show a significant improvement in sampling efficiency during offline training and closed-loop stability in the online implementation.


Data Quality Over Quantity: Pitfalls and Guidelines for Process Analytics

Siang, Lim C., Elnawawi, Shams, Rippon, Lee D., O'Connor, Daniel L., Gopaluni, R. Bhushan

arXiv.org Artificial Intelligence

A significant portion of the effort involved in advanced process control, process analytics, and machine learning involves acquiring and preparing data. Literature often emphasizes increasingly complex modelling techniques with incremental performance improvements. However, when industrial case studies are published they often lack important details on data acquisition and preparation. Although data pre-processing is unfairly maligned as trivial and technically uninteresting, in practice it has an out-sized influence on the success of real-world artificial intelligence applications. This work describes best practices for acquiring and preparing operating data to pursue data-driven modelling and control opportunities in industrial processes. We present practical considerations for pre-processing industrial time series data to inform the efficient development of reliable soft sensors that provide valuable process insights.


Industrial Data Science for Batch Manufacturing Processes

Arzac-Garmendia, Imanol, Vallerio, Mattia, Perez-Galvan, Carlos, Navarro-Brull, Francisco J.

arXiv.org Artificial Intelligence

Batch processes show several sources of variability, from raw materials' properties to initial and evolving conditions that change during the different events in the manufacturing process. In this chapter, we will illustrate with an industrial example how to use machine learning to reduce this apparent excess of data while maintaining the relevant information for process engineers. Two common use cases will be presented: 1) AutoML analysis to quickly find correlations in batch process data, and 2) trajectory analysis to monitor and identify anomalous batches leading to process control improvements.