Accurate underwater navigation is a fundamental challenge in ocean science, exploration, and inspection. Deep Trekker ROVs have been at the forefront of this innovation, integrating advanced navigation technologies to provide precise positioning even in the most demanding subsea environments. Read more >>
Dead Reckoning, a time-tested navigation technique, plays a crucial role in enhancing these capabilities.
This feature explores the step-by-step setup of Dead Reckoning with Deep Trekker ROVs, highlighting the key technologies involved and how they contribute to greater accuracy, efficiency, and operational confidence in underwater missions.
Understanding Dead Reckoning in Underwater Operations
Dead Reckoning enhances positional awareness and data integrity, providing maritime professionals with a reliable method to track their ROVs without external reference points. This improves operational safety, optimizes travel routes, and reduces overall energy consumption — aligning with environmental and cost-saving objectives.
Unlike systems that rely on Ultra-Short Baseline (USBL) positioning, Dead Reckoning is performed using only onboard sensors. This allows for reliable navigation in environments where external acoustic tracking methods face challenges, such as areas with surface reflections, net interference, or shadowing effects.
How Dead Reckoning Works with Deep Trekker ROVs
- Initial Position Acquisition: The process begins with an initial position, typically obtained via GPS or other surface-based navigation systems before the ROV submerges. The vehicle’s velocity, heading, and other relevant parameters are also recorded.
- Position Estimation: Once submerged, the ROV continuously calculates its position by integrating velocity and heading data over time. This tracking method estimates movement in the north, east, and depth directions.
- Error Accumulation: Over time, environmental factors such as water currents, turbulence, and magnetic interference can cause deviations from the estimated path, leading to accumulated positioning errors.
- Error Correction: Deep Trekker ROVs incorporate sensor fusion technology to mitigate error accumulation. By integrating data from multiple sources, these systems maintain accuracy over extended missions.
Key Technologies for Dead Reckoning in Deep Trekker ROVs
- Inertial Measurement Unit (IMU): Measures specific force and angular rate, refining heading and orientation data.
- Doppler Velocity Log (DVL): Determines velocity relative to the seabed, counteracting drift effects caused by underwater currents.
- Sonar and Acoustic Systems: Utilized for terrain mapping and localization, these systems compare environmental acoustic signatures with pre-existing data to refine position estimates.
- Deep Trekker ROV GPS: While GPS is ineffective underwater, surface-bby Deep Trekkerased updates allow recalibration when the ROV surfaces, integrating seamlessly with Dead Reckoning for improved accuracy.
Equipment Requirements for Dead Reckoning with Deep Trekker ROVs
To enable successful Dead Reckoning navigation, the following components are required:
- Topside:
- BRIDGE Controller (version 8 or above)
- Underwater ROV:
- PIVOT (3.0 or above)
- REVOLUTION (6.9 or above)
- Sensors:
Map Modes and Initializing Underwater ROV Position
ROV: 5.8m, 2.0m
To start tracking underwater ROV position, first select a map mode through the hand controller. This will affect the map’s appearance along with what values are used to track position.
Local map: Uses a grid overlay with no map tiles. Tracks position through distance in meters from a starting point (0.0). This map can be useful when operating in indoor environments especially when the dimensions of the asset being inspected is known.
Global map: Uses real world map data and tracks position through latitude and longitude. This mode allows you to use different map styles such as street maps or satellite view.
ROV: 43.4056949, -80.4676221
On first boot, the hand controller will prompt a selection between which map mode to operate in. Otherwise, the Local map mode can be toggled in the Maps settings page.
Initializing Underwater ROV Position: The last step before being able to track ROV position is giving the vehicle an initial position to track from. This can always be set manually through the controller, however it will also be set automatically depending on the map mode or if a USBL is in use (see diagram below).
If using the local map: On startup, ROV position will be set automatically to 0.0 meters. Afterwards manual initialization is required.
If using the global map: Manual initialization is required, however if a USBL is in use its pings will correct the ROV position automatically. A latitude and longitude can be entered as well through the keypad.
In either scenario, the ROV position can be manually initialized simply by pressing FN + Camera Home when the mini or full-screen map is open:
Position Uncertainty: When Dead Reckoning, the ROV’s position uncertainty will continue to grow as time passes. This is represented by the uncertainty bubble seen on the navigation map.
10-20m uncertainty
Typically you will get 30 minutes of operation before reaching an uncertainty of 10 meters.
If the position uncertainty grows too high, it’s recommended to re-initialize your ROV’s position when possible using any of the methods stated above.
20m+ uncertainty
ROV Trail: Along with the other updates in Controller version 8, the ROV’s previous positions will be displayed on the map through a ghost trail. This will be drawn as long as there is an ROV position being provided (regardless of Data Logging).
The trail can also be cleared at any point by pressing FN + Pitch Lock or by pressing “Clear ROV trail” in the Maps settings page.
Transforming Maritime Navigation with Advanced Robotics
Deep Trekker’s innovative approach to integrating Dead Reckoning into compact ROVs represents a significant advancement for the maritime industry. These capabilities enable precise positioning of ROVs during underwater inspections, ensuring comprehensive and reliable data collection.
With accurate navigation, vessel inspections become more efficient, optimizing cleaning schedules, reducing operational downtime, and enhancing fuel efficiency. Additionally, regular corrosion monitoring through precise tracking ensures early defect detection, minimizing costly repairs.
Deep Trekker’s Mission Planner further refines these capabilities by allowing operators to track dive paths, collect targeted data, and automate inspections using predefined waypoints. The integration of IMU, DVL, and USBL sensors ensures real-time positional awareness, allowing for seamless autonomous navigation.
The Future of Underwater ROV Navigation
As technology advances, Deep Trekker’s solutions continue to push the boundaries of underwater exploration. The ability to rapidly deploy cost-effective, highly maneuverable ROVs with robust navigation capabilities is transforming vessel inspections, offshore energy operations, and marine research.
With powerful LED lighting, live 4K video feeds, 360-degree field-of-view cameras, imaging sonar, and versatile sampling tools, Deep Trekker ROVs provide an unparalleled level of adaptability.
For industry professionals seeking precise and reliable underwater navigation solutions, Deep Trekker offers expert guidance and customized configurations to meet specific operational needs. Reach out today to explore how Deep Trekker ROVs can enhance your underwater missions.
Read the original article, or visit the Deep Trekker website for more information.
