• An exact penalty-function approach to proactive fault-tolerant economic MPC 

      Knudsen, Brage Rugstad; Brusevold, Jon Håman; Foss, Bjarne Anton (Chapter; Conference object; Peer reviewed, 2017)
      This paper presents a fault-tolerant economic model predictive control scheme for proactive handling of incipient actuator faults. The scheme applies an L1 exact penalty function with a set of switching rules in order to ...
    • Dynamic optimization of control setpoints for an integrated heating and cooling system with thermal energy storages 

      Rohde, Daniel; Knudsen, Brage Rugstad; Andresen, Trond; Nord, Natasa (Journal article; Peer reviewed, 2019)
      Energy systems for buildings and neighborhoods are expected to become more complex and flexible. Advanced control strategies are required to exploit the full potential of this flexibility and are especially important for ...
    • Global Optimisation of Multi-Plant Manganese Alloy Production 

      Digernes, Martin Naterstad; Rudi, Lars; Andersson, Henrik; Stålhane, Magnus; Wasbø, Stein O.; Knudsen, Brage Rugstad (Journal article; Peer reviewed, 2017)
      This paper studies the problem of multi-plant manganese alloy production. The problem consists of finding the optimal furnace feed of ores, fluxes, coke, and slag that yields output products which meet customer specifications, ...
    • Incipient Actuator Fault Handling in Nonlinear Model Predictive Control 

      Knudsen, Brage Rugstad; Faulwasser, Timm; Jones, Colin N.; Foss, Bjarne Anton (Journal article; Peer reviewed, 2017)
      This paper presents a reconfigurable nonlinear model predictive control (NMPC) scheme for handling of incipient actuator faults in nonlinear plants. The scheme seeks to ensure recoverability from an incipient actuator fault ...
    • Mathematical programming formulations for piecewise polynomial functions 

      Grimstad, Bjarne Andre; Knudsen, Brage Rugstad (Journal article; Peer reviewed, 2020)
      This paper studies mathematical programming formulations for solving optimization problems with piecewise polynomial (PWP) constraints. We elaborate on suitable polynomial bases as a means of efficiently representing PWPs ...
    • Mixed-Integer Nonlinear Programming Heuristics Applied to a Shale Gas Production Optimization Problem 

      Sharma, Shaurya (Master thesis, 2013)
      Mixed-Integer nonlinear programs(MINLPs) are a general class of nonlinear optimization problems that have a wide array of real-world applications. These problems are in general notoriously difficult to solve, and it is ...
    • Model Predictive Control of District Heating Systems 

      Rene, Anders Svenheim (Master thesis, 2016)
      A district heating system is a network of pipelines where heating is delivered to a number of customers from a centralized heating station. For the operators of these systems, the ideal operating scenario is to deliver ...
    • A nonlinear model predictive control scheme for sensor fault tolerance in observation processes 

      Knudsen, Brage Rugstad; Alessandretti, Andrea; Jones, Colin N.; Foss, Bjarne Anton (Peer reviewed; Journal article, 2020)
      This article addresses the problem of designing a sensor fault‐tolerant controller for an observation process where a primary, controlled system observes, through a set of measurements, an exogenous system to estimate the ...
    • On Shut-In Based Production Optimization of Shale-Gas Systems 

      Knudsen, Brage Rugstad (Doktoravhandlinger ved NTNU, 1503-8181; 2014:285, Doctoral thesis, 2014)
      The use of shale gas as an energy resource has increased extensively over the last decade, with emerging new technologies causing shale gas to become the largest source of growth in the US natural-gas supply. Ecient ...
    • Optimizing the Capacity of Thermal Energy Storage in Industrial Clusters 

      Thombre, Mandar; Prakash, Sandeep; Knudsen, Brage Rugstad; Jäschke, Johannes (Chapter, 2020)
      A key factor for energy-efficient industrial clusters is the recovery of waste heat. To this end, thermal energy storage (TES) is an appealing technology that facilitates dynamic heat integration between supplier and ...
    • Penalty Function Approaches for Proactive Fault-Tolerant Model Predictive Control 

      Brusevold, Jon Håman (Master thesis, 2015)
      In the event of actuator faults in systems, standard control algorithms might not be sufficient for stabilizing the system and keeping the performance at an accept- able level. Because of this, fault-tolerant control methods ...
    • Petroleum production optimization - A static or dynamic problem? 

      Foss, Bjarne Anton; Knudsen, Brage Rugstad; Grimstad, Bjarne André (Journal article; Peer reviewed, 2018)
      This paper considers the upstream oil and gas domain, or more precisely the daily production optimization problem in which production engineers aim to utilize the production systems as efficiently as possible by for instance ...
    • Proactive Actuator Fault-Tolerance in Economic MPC for Nonlinear Process Plants 

      Knudsen, Brage Rugstad (Journal article; Peer reviewed, 2016)
      This paper presents a scheme for proactive accommodation of incipient actuator faults in nonlinear process plants operated with economic model predictive control (EMPC). The control scheme implements a switching from nominal ...
    • Production Optimization in Shale Gas Reservoirs 

      Knudsen, Brage Rugstad (Master thesis, 2010)
      Natural gas from organic rich shales has become an important part of the supply of natural gas in the United States. Modern drilling and stimulation techniques have increased the potential and profitability of shale gas ...
    • Seasonal storage and demand side management in district heating systems with demand uncertainty. 

      Egging-Bratseth, Ruud; Kauko, Hanne; Knudsen, Brage Rugstad; Bakke, Sara Angell; Ettayebi, Amina; Haufe, Ina Renate (Peer reviewed; Journal article, 2021)
      District heating is an under-researched part of the energy system, notwithstanding its enormous potential to contribute to Greenhouse Gas emission reductions. Low-temperature district heating is a key technology for ...
    • Sensor fault tolerance in output feedback nonlinear model predictive control 

      Knudsen, Brage Rugstad; Alessandretti, Andrea; Jones, Colin N. (Conference object; Journal article; Peer reviewed, 2016)
      This paper presents an active output feedback fault-tolerant model predictive control (MPC) scheme for systems with sensor faults. The proposed control scheme actively steers the system in order to prevent loss of observability ...
    • Shale-gas wells as virtual storage for supporting intermittent renewables 

      Knudsen, Brage Rugstad; Foss, Bjarne Anton (Journal article; Peer reviewed, 2016)
      Mature shale-gas wells possess a property that enables cyclic production and shut-in without incurring revenue losses. Based on this property, we suggest that fields with mature shale-gas wells may act as virtual gas storage ...