Øyvind Hegrenæs

• Ph.D.
• Business Development Manager at Kongsberg Maritime AS

In this paper, an explicit model predictive controller for the attitude of a satellite is designed. Explicit solutions to constrained linear MPC problems can be computed by solving multi-parametric quadratic programs (mpQP), where the parameters are the components of the state vector. The solution to the mpQP is a piecewise affine (PWA) function, w...

This paper reports the development and experimental evaluation of a state-of-the-art model-aided inertial navigation system (MA-INS) for underwater vehicles. Together with real-time sea current estimation, the output from an experimentally validated kinetic vehicle model is integrated in the navigation system to provide velocity aiding for the INS....

Navigation of underwater vehicles has been and remains a substantial challenge to all underwater platforms.With the emergence of new applications and the growing acceptance of autonomous underwater vehicles (AUVs) in both military and civilian institutions, comes the need for enhanced accuracy and robustness, sustainability, and de-risking. This pa...

This paper reports what to our best knowledge is the first commercially delivered under-ice survey carried out by an autonomous underwater vehicle (AUV). The campaign was completed as a collaboration between Kongsberg Maritime (KM) and Ballard Marine Construction in January 2017. The surveys took place beneath a frozen lake in North America using a...

This paper reports the development and comparison of several mathematical models for describing the response of the HUGIN 4500 AUV as a function of measured actuator inputs. As a crucial step in fitting the derived models to experimental field data, a combination of dedicated experiments and least-squares estimation is applied in order to obtain an...

Knowledge gaps about how the ocean melts Antarctica’s ice shelves, borne from a lack of observations, lead to large uncertainties in sea level predictions. Using high-resolution maps of the underside of Dotson Ice Shelf, West Antarctica, we reveal the imprint that ice shelf basal melting leaves on the ice. Convection and intermittent warm water int...

Nortek has developed a new Doppler velocity log (DVL) based on a novel bottom detection principle. This allows for the ability to estimate individual beam and ping Doppler measurement noise in real time. Another capability that has been embedded in the new DVL is an accurate timing reference of the velocity estimate. Using the Kongsberg Maritime (K...

This paper addresses the navigation of an autonomous underwater vehicle (AUV) when approaching a docking station. The following array of underwater navigation sensors is considered available: ultra short baseline (USBL), Doppler velocity log (DVL) with bottom track, compass, and gyro. Based on this sensor array, we propose a modular and cascaded Ka...

The majority of cruising Autonomous Underwater Vehicles (AUVs) rely on similar technologies for navigation and positioning solutions. This paper examines the traditional approach and some enhancements designed to improve autonomous operations that are available today. Finally it will explore some new techniques under current development. Examples o...

Underwater vehicles are used in a wide range of tasks in various sectors. Cost-effective and accurate seabed surveying and mapping using autonomous underwater vehicles (AUVs) have been carried out for years in the offshore oil and gas sector. Much of the experience gained is now being benefited upon in new and challenging applications. One of the e...

Navigation of underwater vehicles has been and remains a substantial challenge to all platforms. The need for improved accuracy and robustness, sustainability, and de-risking develops with the emergence of new applications, and with the growing acceptance of autonomous underwater vehicles (AUVs) in both military and civilian institutions. One of th...

Navigation post-processing or smoothing is the process of optimizing all navigation estimates based on the entire measurement set. For underwater vehicles this gives much smoother and more accurate estimates than what is obtained in real-time. The enhanced quality of the smoothed estimates is shown in this paper by examples from autonomous underwat...

Increasing the autonomy of AUVs will open many new markets for such vehicles ? but it should also provide substantial benefits to current users: Better power sources facilitate longer endurance and/or more power-hungry sensors. Increased navigation autonomy relaxes the requirement for USBL positioning from a surface vessel, the frequency of GPS sur...

AUVs have proved robustness and high performance in applications including naval mine counter measures, marine research and deep water offshore oil and gas surveys. A next step is to introduce AUVs to under ice geophysical surveys. A main challenge for regular under ice operations is to handle the risk of a loss of a vehicle, or long operational in...

This paper reports the development and experimental evaluation of a complete model-aided inertial navigation system (INS) for underwater vehicles. The navigation system is novel in that accurate knowledge of the vehicle dynamics is utilized for aiding the INS, and the performance is evaluated using real data collected by an autonomous underwater ve...

A key component of an autonomous underwater vehicle (AUV) is the navigation system. It is important for navigating the vehicle but it is also vital for being able to utilize the data collected during a mission. This paper presents the main challenges faced when designing reliable underwater navigation systems, and outlines a framework for detecting...

This paper reports the development and preliminary experimental evaluation of a model-aided inertial navigation system (INS) for underwater vehicles. The implemented navigation system exploits accurate knowledge of the vehicle dynamics through an experimentally validated mathematical model, relating the water-relative velocity of the vehicle to the...

This paper presents a method for identifying dynamic models of autonomous underwater vehicles (AUV) from logged data and a physically motivated model structure. Such models are instrumental for model-based control system design, but also for integrated navigation systems. We motive our work from the perspective of developing second generation integ...

This paper reports the development and experimental evaluation of a simple and intuitive framework for obtaining steady-state maneuvering characteristics of a wide class of underwater vehicles. The possible use of steady-state characteristics includes navigation, fault-detection and vehicle design evaluation. The presented algorithms allow unknown...

We report the development of Navproc, a new set of software tools for post-processing oceanographic submersible navigation data that exploits previously reported improvements in navigation sensing and estimation (e.g. Eos Trans. AGU, 84(46), Fall Meet. Suppl., Abstract OS32A- 0225, 2003). The development of these tools is motivated by the need to h...

Explicit solutions to constrained linear MPC problems can be computed by solving multi-parametric quadratic programs (mpQP), where the parameters are the components of the state vector. The solution to the mpQP is a piecewise affine (PWA) function, which can be evaluated at each sample to obtain the optimal control law. The online computation effor...