• Comparison of control strategies for a 2 DOF helicopter 

      Sharma, Roshan; Pfeiffer, Carlos Fernando (Journal article; Peer reviewed, 2017)
      The two degrees of freedom (2-DOF) helicopter is an openloop unstable multi-variable process. Various control strategies can be applied to stabilize the system for tracking and regulation problems but not all control methods ...
    • Covering the Gap Between Advanced Control Theory Design and Real Time Implementation Using Simulink 

      Pfeiffer, Carlos Fernando; Sharma, Roshan (Journal article; Peer reviewed, 2017)
      New developments in sensor technology and control actuators make it viable to monitor and regulate more process variables, providing an opportunity to apply advanced multivariable control techniques. Although modern control ...
    • Enhanced Power Capability of Generator Units for Increased Operational Security using NMPC 

      Øyvang, Thomas; Nøland, Jonas Kristiansen; Sharma, Roshan; Hegglid, Gunne John; Lie, Bernt (Peer reviewed; Journal article, 2019)
      The ever-increasing penetration of intermittent energy sources introduces new demanding operating regimes for the bulk power generation in the power grid. During a worst-case power system disturbance scenario, the generator ...
    • Flood Management of Lake Toke: MPC Operation under Uncertainty 

      Menchacatorre, Itsaso; Sharma, Roshan; Furenes, Beathe; Lie, Bernt (Peer reviewed; Journal article, 2019)
      A deterministic reference tracking model predictive control (MPC) is in use at Skagerak Kraft for flood management of Lake Toke in Norway. An operational inflow estimate is used to predict the optimal gate opening at Dalsfos ...
    • Model based control for run-of-river system. Part 1: Model implementation and tuning 

      Vytvytskyi, Liubomyr; Sharma, Roshan; Lie, Bernt (Journal article; Peer reviewed, 2015)
      Optimal operation and control of a run-of-river hydro power plant depends on good knowledge of the elements of the plant in the form of models. River reaches are often considered shallow channels with free surfaces. A ...
    • Model based control for run-of-river system. Part 2: Comparison of control structures 

      Vytvytskyi, Liubomyr; Sharma, Roshan; Lie, Bernt (Journal article; Peer reviewed, 2015)
      Optimal operation and control of a run-of-river hydro power plant depend on good knowledge of the elements of the plant in the form of models. Both the control architecture of the system, i.e. the choice of inputs and ...
    • Model based flow measurement using venturi umes for return flow during drilling 

      Pirir, Ivan; Jinasena, Asanthi; Sharma, Roshan (Journal article; Peer reviewed, 2017)
      In an oil well drilling operation, a proper knowledge of the return fluid flowrate is necessary both for the stabilization of the bottom hole pressure of the well and also as a primary indication of a kick or loss. In ...
    • Modeling and Analysis of Fluid Flow through A Non-Prismatic Open Channel with Application to Drilling 

      Jinasena, Asanthi; Ghaderi, Ali; Sharma, Roshan (Journal article; Peer reviewed, 2018)
      This paper presents the development and validation of a simplified dynamic model of a Venturi channel. The existing dynamic models on open channels are based on the open channel flow principles, which are the shallow water ...
    • Modeling and Simulation of Triclosan Kinetics and Distribution in Humans Using a PBPK Model 

      Maharjan, Samee; Sharma, Roshan; Husøy, Trine; Dirven, Hubert; Andreassen, Monica; Lie, Bernt (Conference object; Peer reviewed, 2015-11-25)
      Personal care products (PCPs) such as soaps, perfumes, toothpastes, lotions, etc. contain various chemicals. Triclosan (TCS) is widely used as an antibacterial additive in PCPs. Traces of TCS are found in human plasma and ...
    • Modeling for control of run-of-river power plant Grønvollsfoss 

      Vytvytskyi, Liubomyr; Sharma, Roshan; Granstrøm, Ingunn; Lie, Bernt (Conference object; Peer reviewed, 2015-11-25)
      Design of optimal operation and control of a run-of-river hydro power plant depends on good models for the elements of the plant. River reaches are often considered to be shallow channels with free surface flow. A typical ...
    • Nonlinear observer for hydropower system 

      Vytvytskyi, Liubomyr; Sharma, Roshan; Lie, Bernt (Peer reviewed; Journal article, 2019)
      Estimation of unmeasured states plays an essential role in the design of control systems as well as for monitoring of hydropower plants. The standard Kalman filter gives the optimum state estimates for linear systems. ...
    • Optimal control strategies with nonlinear optimization for an Electric Submersible Pump lifted oil field 

      Sharma, Roshan; Glemmestad, Bjørn (Journal article; Peer reviewed, 2013)
      In an Electric Submersible Pump (ESP) lifted oil field, the ESP of each oil well should be operated inside its operating window. The total power consumed by the ESPs in the oil field should be minimized. The speed of the ...
    • Optimal Operation of the Peat Drying Process in Steam Tube Dryers 

      Kulakovsky, Leonid; Rosen, Victor; Sharma, Roshan; Pfeiffer, Carlos Fernando; Lie, Bernt (Conference object; Peer reviewed, 2015-11-25)
      Ukraine is an energy-dependent country and aims to reduce the import of natural gas, heat, and power in general. This implies extracting fuel from her own natural resources; one relevant and readily available energy carrier ...
    • Optimization of lift gas allocation in a gas lifted oil field as non-linear optimization problem. 

      Sharma, Roshan; Fjalestad, Kjetil; Glemmestad, Bjørn (Journal article; Peer reviewed, 2012)
      Proper allocation and distribution of lift gas is necessary for maximizing total oil production from a field with gas lifted oil wells. When the supply of the lift gas is limited, the total available gas should be optimally ...
    • Parameter estimation for externally simulated thermal network models 

      Brastein, Ole Magnus; Lie, Bernt; Sharma, Roshan; Skeie, Nils-Olav (Peer reviewed; Journal article, 2019)
      Obtaining accurate dynamic models of building thermal behaviour requires a statistically solid foundation for estimating unknown parameters. This is especially important for thermal network grey-box models, since all their ...
    • Second Order KP Scheme for the Solution of flow in a Venturi Channel 

      Dissanayake, Susantha; Sharma, Roshan; Lie, Bernt (Journal article; Peer reviewed, 2018)
      In many different applications, a Venturi channel is used as a tool to compute fluid flow rates. The Saint-Venant equation is a hyperbolic type Partial Differential Equation (PDE) which can be used to model fluid flows ...
    • Second order scheme for open channel flow 

      Sharma, Roshan (Preprint, 2015-08-26)
      In the search for a numerical scheme which: (i) is semi-descrete in nature (only space discritization) so that built-in ODE solvers in MATLAB or Modelica can be used, (ii) can handle dry bed conditions (island or dry ...
    • Semi Discrete Scheme for the Solution of Flow in River Tinnelva 

      Dissanayake, Susantha; Sharma, Roshan; Lie, Bernt (Chapter; Peer reviewed, 2016)
      The Saint-Venant equation is a mathematical model which could be used to study water flow in an open channel, river etc. The Kurganov-Petrova (KP) method, which is a second order scheme, is used to solve the Saint-Venant ...
    • Sensor placement and parameter identifiability in grey-box models of building thermal behaviour 

      Brastein, Ole Magnus; Sharma, Roshan; Skeie, Nils-Olav (Journal article; Peer reviewed, 2019)
      Building energy management systems can reduce energy consumption for space heating in existing buildings, by utilising Model Predictive Control. In such applications, good models of building thermal behaviour is important. ...
    • Third Order Reconstruction of the KP Scheme for Model of River Tinneselva 

      Dissanayake, Susantha; Sharma, Roshan; Lie, Bernt (Journal article; Peer reviewed, 2017)
      The Saint-Venant equation/Shallow Water Equation is used to simulate ow of river, ow of liquid in an open channel, tsunami etc. The Kurganov-Petrova (KP) scheme which was developed based on the local speed of discontinuity ...