Leo Steenson

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Steven Pinker

Harvard University

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Vrije Universiteit Brussel

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University of Saskatchewan

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Knox College

Armando Marques-Guedes

UNL - New University of Lisbon

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Dublin Institute of Technology

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Nepal College of Information Technology

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Graduate Center of the City University of New York

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Papers by Leo Steenson

Automated ESP-Lifted Well Startup Using Model Predictive Control: Introduction of the Algorithm and Field Tests Results

Day 3 Thu, August 25, 2022

The start of an electric submersible pump (ESP) is the most dynamic event in the life of the ESP,... more The start of an electric submersible pump (ESP) is the most dynamic event in the life of the ESP, and one that has been shown to be the main contributor to the premature failure of the ESP; yet it is clearly unavoidable. This article introduces an algorithm comprising of a model-predictive controller and a moving horizon estimator for automating the well startup. Objectives and constraints related to the startup are considered for the whole well system, including the reservoir, the ESP, the tubing etc. A lumped-parameter model is established to model the fluid dynamics in the system. The estimator recalibrates the model and provides estimates (virtual measurements) in lieu of unavailable physical measurements. The operating sequences for the ESP and choke are then updated step-by-step by the controller, considering the model of the system, the startup objectives and constraints, and the measured feedback information from the wellbore gauges. The startup algorithm was implemented on ...

Experimentally verified model predictive control of a hover-capable AUV

This work presents the development of control systems that enable a hover-capable AUV to operate ... more This work presents the development of control systems that enable a hover-capable AUV to operate throughout a wide speed range. The Delphin2 AUV was built as part of this project and is used to experimentally verify the prototype control systems. This vehicle is over-actuated with; four through-body tunnel thrusters, four independently-actuated control surfaces and a rear propeller. The large actuator set allows the Delphin2 to operate at low speeds, using the through-body tunnel thrusters, and at high speeds, using the rear propeller and control surfaces. There lies a region between slow and high speed where neither the control surfaces nor tunnel thrusters are operating optimally. To maintain depth stability, both actuator sets are required to operate simultaneously. The model predictive control (MPC) algorithm is used to control the vehicle given its ability to handle multiple inputs and outputs along with system uncertainties. The basis of MPC is a mathematical model of the syst...

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Delphin2: An Over Actuated Autonomous Underwater Vehicle for Manoeuvring Research

International Journal of Maritime Engineering, 2013

Delphin2 is a hover capable torpedo style Autonomous Underwater Vehicle (AUV), developed at the U... more Delphin2 is a hover capable torpedo style Autonomous Underwater Vehicle (AUV), developed at the University of Southampton to provide a test bed for research in marine robotics, primarily to enhance the manoeuvring capability of AUVs. This paper describes the mechanical design of the vehicle and its software architecture. The performance of the vehicle is presented as well as preliminary findings from the vehicles first fully autonomous video survey missions in Lough Erne, Northern Ireland. It is interesting to note that the low-cost of the vehicle and its development using a succession of MEng and PhD students has provided an excellent training environment for specialists in the growing area of marine autonomous vehicles.

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Experimental Verification of a Depth Controller using Model Predictive Control with Constraints onboard a Thruster Actuated AUV

IFAC Proceedings Volumes, 2012

When referring to this work, full bibliographic details including the author, title, awarding ins... more

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Experimentally Verified Depth Regulation for AUVs Using Constrained Model Predictive Control

Proceedings of the 19th IFAC World Congress, 2014

In the application of an autonomous underwater vehicle a critical requirement is to keep the leve... more In the application of an autonomous underwater vehicle a critical requirement is to keep the level of the actuation signals within operational limits to avoid, for example, actuator nonlinearities and reduce peak power consumption. The most common approach to this problem for AUVs that have been deployed is, if required, to trade-off performance in order to keep the actuation signals and power required within the operational limits. This paper addresses depth control of an AUV using model predictive control with constraints on the both the amplitude and rate of change of the entries in the control vector. The model predictive control algorithm is designed by solving a quadratic programming problem in real-time when implemented on an AUV prototype. Experimental test results for depth control are also given and demonstrate that physically relevant constraints on the thrust and actuation power, critical factors for the use of these vehicles, can be achieved. Moreover, there is agreement between the control action used and the underlying physics of a body moving in water.

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Effect of measurement noise on the performance of a depth and pitch controller using the model predictive control method

2012 IEEE/OES Autonomous Underwater Vehicles (AUV), 2012

In this paper a depth and pitch controller for a hover-capable AUV is designed and implemented in... more In this paper a depth and pitch controller for a hover-capable AUV is designed and implemented in simulation. The effect on controller performance of random Gaussian noise on the feedback signals is evaluated. It has been shown that very small levels of measurement noise will result in the controller performance degrading substantially and behaving in an erratic fashion. A polynomial type filter has been proposed and integrated into the model predictive control algorithm. This modification reduces the effect of the measurement noise substantially and improves controller performance.

Model predictive control of a hybrid autonomous underwater vehicle with experimental verification

Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment, 2014

In this work, model predictive control is used to provide transit and hover capabilities for an a... more In this work, model predictive control is used to provide transit and hover capabilities for an autonomous underwater vehicle where the description of the system dynamics used include terms measured experimentally. The resulting controller manoeuvres the vehicle in the presence of constraints on the actuators and results obtained from the deployment of the vehicle in an inland lake for the study of the zebra mussel, an invasive species, are also given.

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Maneuvering of an over-actuated autonomous underwater vehicle using both through-body tunnel thrusters and control surfaces

The maneuvering performance of an over-actuated AUV (2m long, 254mm diameter) has been tested ope... more The maneuvering performance of an over-actuated AUV (2m long, 254mm diameter) has been tested operating on the free surface (97% displacement submerged). Straight line speed tests and turning circle tests have been performed. Both rear control surfaces and through-body tunnel thrusters were used to maneuver the vehicle. The turning circle diameter, turning rate and forward velocity data is presented with rudder, thruster and hybrid tests. The rudder actuated turning diameters (TD) reduced as forward speed increased. The thruster actuated TD are smaller than the rudder actuated and the TD for thruster actuated increases with forward speed. For the smallest TD, a hybrid system using both the rudders and thrusters were used. An inverse open loop control algorithm is presented that delegates actuator set-points for a given propeller set-point and TD

Control of an auv from thruster actuated hover to control surface actuated flight

An autonomous underwater vehicle (AUV) capable of both low speed hovering and high speed flight-s... more An autonomous underwater vehicle (AUV) capable of both low speed hovering and high speed flight-style operation is introduced. To have this capability the AUV is over-actuated with a rear propeller, four control surfaces and four through-body tunnel thrusters. In this work the actuators are modelled and the non-linearities and uncertainties are identified and discussed with specific regard to operation at different speeds. A thruster-actuated depth control algorithm and a flight-style control-surface actuated depth controller are presented. These controllers are then coupled using model reference feedback to enable transition between the two controllers to enable vehicle stability throughout the speed range. Results from 3 degrees-of-freedom simulations of the AUV using the new controller are presented, showing that the controller works well to smoothly transition between controllers. The performance of the depth controller appears asymmetric with better performance whilst diving than ascending.

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The performance of vertical tunnel thrusters on an autonomous underwater vehicle operating near the free surface in waves

Underwater vehicles operating near the free surface in waves can experience large forces acting o... more Underwater vehicles operating near the free surface in waves can experience large forces acting on the body which can cause the vehicle to move undesirably. To overcome these forces, and keep station with minimal disturbance, actuators fitted to the vehicle are used. To develop a suitable controller, the performance of the actuators used must be known. This paper shows that as a vertical tunnel thruster approaches the free surface, the thrust generated decreases. Experimental data is presented and reasons for the reduction in total effective thrust discussed. Further to this, the performance of the Delphin2 AUV (Phillips et al 2010) operating in waves is analysed and suggestions made for improving performance.

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Preliminary results of a hover capable auv attempting transitional flight

The actuators of an over-actuated AUV have been modeled and this information used to design a con... more The actuators of an over-actuated AUV have been modeled and this information used to design a control algorithm that enables an vehicle to operate throughout a wide range of forward velocities. Both experimental and simulation results are presented for the performance of the through-body vertical tunnel thrusters, four independent control surfaces, and the interaction between the vehicle hull and actuators. The control algorithm has been tested and shown to work adequately well provided the vehicle acceleration is constrained

Model-Predictive Control of a Compliant Hydraulic System

2018 UKACC 12th International Conference on Control (CONTROL), 2018

Automatic operation of hydraulic systems poses a challenging control problem. Factors contributin... more Automatic operation of hydraulic systems poses a challenging control problem. Factors contributing to this include nonlinear system dynamics along with highly nonlinear actuator dynamics. This altogether necessitates the control design to be carefully thought through to achieve a good behaviour and minimise the risk of damaging events, such as a rapid closure of a valve that could create a pressure wave travelling back and forth through the system known as the water hammer effect. A real-life example of a hydraulic system is an oilfield production system in which various pumps and valves are used for control. The aim of the actuation in an oil production system is to produce the oil mixture from the reservoir through the well to the surface subject to operational constraints.

Inverse Model of an AUV Actuator Unit

Automated ESP-Lifted Well Startup Using Model Predictive Control: Introduction of the Algorithm and Field Tests Results

Day 3 Thu, August 25, 2022