1 From academia to industry Commercializing research on propulsion and hydrodynamics Øyvind Smogeli Chief Operating Officer
2 Motivation Demand for vessels to conduct allyear operation in harsh environment and extreme conditions There is a trend towards physical and functional integration between the power and automation s DP must be robust to any single failure Severe consequences if a blackout occurs High positioning accuracy required, calling for accurate thrust production Thrusters are the main power consumers Mechanical wear and tear leads to costly repairs and vessel down-time
3 DP Overview Environment Waves Wind Current Thrust forces Vessel Motion Motion Guidance and navigation Sensors Measurements Vessel observer High-level controller Filtered & reconstructed signals Setpoint/path generator Setpoint Waves Current Propulsion Thrust setpoints Thrust allocation Desired thrust vector DP controller Q a Load torque Propulsion unit Thrust force T a Propeller hydrodynamics n Shaft dynamics Shaft speed Q m Motor dynamics Q c Motor torque Low-level thruster controller T r Thrust setpoint Waves Current Vessel motion
4 Why thruster control? Thrusters affected by waves, current and vessel motion: Rapidly changing operating conditions and loss effects Load fluctuations Inaccurate thrust production Feasible improvements: More accurate thrust force with faster response Increased station-keeping capability Reduced oscillations and transients in motor and propeller torque Less mechanical wear and tear Reduced oscillations in power Reduced danger of blackout and reduced need for spinning power reserve, i.e. reduced fuel consumption
5 Thruster control, an overview Normal operating conditions: moderate seas, small thrust losses Shaft speed control Keep the shaft speed constant Torque control Keep the motor torque constant Power control Keep the motor power constant Combined controllers
6 Experimental results in waves T a [N] 95 90 85 Controller comparison in waves Torque Power Shaft speed Propeller thrust Q a [Nm] 3.6 3.4 Propeller torque n [1/s] 7 6.8 Shaft Speed Q m [Nm] P m [W] 6.6 5 4.8 4.6 215 210 205 200 0 1 2 3 4 5 6 7 Time [s] Motor Torque Motor Power
7 Normal conditions, a summary Torque and power control gives: More accurate thrust production Reduced wear and tear More predictable power consumption Improved station-keeping capability Reduced maintenance cost Reduced vessel down-time Reduced fuel consumption Reduced risk of black-out What about extreme conditions?
8 Extreme conditions Large waves Large vessel motions High thrust demand Danger of ventilation and water exits
9 Ventilation experimental results A sudden loss of thrust and load torque may occur when operating with high propeller loading close to the surface. Thrust for J = 0.2
10 Solution: Anti-spin thruster control Inspired by anti-spin/abs s on cars Main challenges: How to detect ventilation? Propeller observer What is the appropriate action to take when ventilation is detected? 1) Take control of the shaft speed 2) Reduce the shaft speed
11 Proposed anti-spin control scheme - Facilitates use of torque and power control in all conditions
12 Thruster control, an overview Normal operating conditions: moderate seas, small thrust losses Shaft speed control Keep the shaft speed constant Torque control Keep the motor torque constant Power control Keep the motor power constant Combined controllers Extreme operating conditions: high seas, severe thrust losses Shaft speed control Torque/Power/Combined control with Anti-spin
13 Recap: Motivation Demand for vessels to conduct all-year operation in harsh environment and extreme conditions There is a trend towards physical and functional integration between the power and automation s DP must be robust to any single failure Severe consequences if a blackout occurs High positioning accuracy required
14 Recap: DP Overview Environment Waves Wind Current Thrust forces Vessel Motion Motion Guidance and navigation Sensors Measurements Vessel observer High-level controller Filtered & reconstructed signals Setpoint/path generator Setpoint Waves Current Propulsion Thrust setpoints Thrust allocation Desired thrust vector DP controller Q a Load torque Propulsion unit Thrust force T a Propeller hydrodynamics n Shaft dynamics Shaft speed Q m Motor dynamics Q c Motor torque Low-level thruster controller T r Thrust setpoint Waves Current Vessel motion
15 www.marinecontrol.org
CONTROL SYSTEMS Rapid development from mechanical to computer-controlled s Software drives both safety- and operational critical s Systems from different vendors must work together as an integrated whole 2012 Marine Cybernetics www.marinecyb.com
CONTROL SYSTEM INTERDEPENDENCIES Crane control Drill floor control Well control s Power management Dynamic positioning Testing and verification of SW had not kept pace with the development Thruster control Integrated automation Emergency shutdown Diving control Offloading BOP control Ballast control 2012 Marine Cybernetics www.marinecyb.com
MARINE CYBERNETICS AS A spin-off from NTNU. Founded in December 2002 Vision To be established as the leading and most profitable niche company in independent testing and verification of control s Business Idea To improve safety and profitability for our customers by developing and applying Hardware-In-the-Loop (HIL) solutions for independent testing of software in control s on ships and offshore installations Planning Specification Design HIL testing Certification Operation 18 2012 Marine Cybernetics www.marinecyb.com
CONCEPT OF HARDWARE IN THE LOOP TESTING Control Real world 2012 Marine Cybernetics www.marinecyb.com
HARDWARE IN THE LOOP TESTING IS VIRTUAL REALITY FOR THE CONTROL SYSTEMS Control Simulated world = HIL Simulator 2012 Marine Cybernetics www.marinecyb.com
HEADCOUNT AND EXPANSION 80 70 July 2010 / April 2011: Houston office opened / US legal entity established 68 75 60 50 January 2011 / May 2011: Rio de Janeiro office opened / Brasil legal entity established 45 40 30 28 32 36 20 16 10 4 7,25 7,25 7,25 0 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2012 Marine Cybernetics www.marinecyb.com
PRODUCTS AND SERVICES DP s Drilling s DP Computer Systems (DP HIL) Power Management Systems (PMS HIL) Steering, Propulsion, Thrusters (STP HIL) Integration Testing Drill Floor (Drill HIL) Intelligent drilling HIL: MPD, AWC, DGD, +++ Blow-out preventers (BOP HIL) Integration Testing Other automation s Crane s Emergency shutdown s (ESD) Integrated automation s (IAS/VMS) We can test any safety or operational critical computer! 2012 Marine Cybernetics www.marinecyb.com
23 Academic results 2007 Tekna prize "Faglig stipend yngre forsker" for PhD work at NTNU 2007 ExxonMobil prize For applied research at NTNU 17 main publications: 3 journal articles 14 conference articles 20 co-authored publications: 8 journal articles 12 conference articles
24 Industrial results PhD Increased industry focus on propulsion in waves Attention on the possibilities given by automatic control Results open and ready for use Marine Cybernetics Central contributions to developing a whole new regime for testing and verification of control software on ships and rigs New methods for analyzing dynamic station-keeping capability of floating vessels
25 Work methodology and key success factors Theory Modeling and simulation Experiments Cooperation, openness and inclusion