a 'collision' with the vessel to be intercepted, while never intersecting a conflict area ... Automatic intercept function and GUI for control of CSHIELD navigation.
DESIGN AND EVALUATION OF OPERATOR SUPPORT FUNCTIONS FOR THE CSHIELD PLATFORM E. Theunissen Netherlands Defence Academy Royal Netherlands Naval College
Background • Combined System for Harbor, Infrastructure and Littoral Domains (CSHIELD) project (2011-2013) • Dutch Society Innovation Agenda ‘Safety’ • Realize a concept and validation model of a small, potentially unmanned vessel for: • • • • •
Patrol Control Information gathering Anti-piracy Securing of ships and maritime infrastructure, both at sea and in coastal and harbor areas
• The design of the platform is based on a modular vessel • Consortium: Thales, NLDA, NLR, TP-Marine, De Vries Lentsch
Navigation, guidance and control • In the CSHIELD concept, only the manned version with the crew module will have a direct control capability. The lowest level of control an operator can exercise over the unmanned version is through directional and velocity commands • For an unmanned operation, the vessel is required to have an autonomous navigation capability, i.e. being capable to derive and execute the required course and speed from the navigation plan and the estimated state • An operator will supervise the process and intervene when necessary • Associated design questions and challenges for the operator interface are very similar and sometimes nearly identical to those encountered in the domain of self-separation and Detect, Sense and Avoid (DSA) systems for Unmanned Aerial Systems (UAS) • An important difference with UAS is that in case of loss of the control link, the CSHIELD platform can stop / remain at a fixed location and revert to the conventional methods to signal other ships that it is not capable of maneuvering
Benefitting from Solutions in Related Domains • For the CSHIELD platform, the operator needs to be supported in intercepting a particular vessel while avoiding collisions with other vessels • Hence, the goal is to find the track/speed combinations which lead to a ‘collision’ with the vessel to be intercepted, while never intersecting a conflict area • Already in the Seventies, nautical displays which show predicted areas of danger were designed and implemented • In terms of support for the separation and collision avoidance tasks, NLDA already had experience with design, integration and evaluation of conflict probe displays for UAV operator support which were based on the developments in the nautical domain
Design and Implementation • Benefit from the existing NLDA UAS research infrastructure: – Use the already existing software for the UAS CDTI as the starting point – Change and/or extend where appropriate/ necessary – Re-use the architecture of the simulation environment
• Based on the properties and constraints of the nautical environment and the requirements that were derived from the anticipated CONOPS, specific functions and symbology were adapted and/or added: – Sectional charts were replaced with nautical maps used in ECDIS – Time horizons for conflict prediction and separation criteria were changed – Automatic intercept function and GUI for control of CSHIELD navigation functions were designed and integrated
Operator Interface • Plan-view navigation display to present an ownship-referenced electronic map (track-up or Northup) • Graphically integrated presentation of: – – – –
Navigation plan Surrounding traffic Hazards and constraints Result of trial-settings of the intercept function
• Control display to interact with the CSHIELD navigation system using a touch-screen interface
Operator Interface
• Operator can set course and speed, command vessel to autonomous path following or autonomous intercept • Predictive support functions continuously show the impact of course changes in terms of future separation (CPA) with other vessels • A trial speed function allows the operator to evaluate the impact of a speed change on the future separation • Intercept guidance computes an intercept track towards a selected target for a given speed
Example: intercept vessel 01 • Magenta line: track towards intercept point (x) with current speed • Cyan line: track towards intercept point with trial speed • Yellow blob: area where separation will be lost with vessel 02 • Cyan dashed contour: area where separation will be lost with vessel 02 for trial speed
Simulation architecture 1. Simulation of the CSHIELD vessel including the relevant subsystems a) Autonomous guidance loop
2. Prototype control station 3. Simulation of other vessels
Evaluation • Condition with the support functions vs. no support • Four different scenarios
– Goal: intercept a target in the presence of other vessels – Do not violate separation with other vessels
• Conflict geometries and target maneuvering varied in each scenario • 7 subjects participated • Measures used for comparison: – – – –
Distance travelled Mission duration Separation violations Amount of button inputs on touch-screen
Results - Efficiency Average mission duration Scen.
Condition
Differ
1
No support 00:11:17
Support 00:10:50
4%
2
00:10:47
00:10:37
2%
3
00:04:12
00:03:54
7%
4
00:06:01
00:04:32
25 %
Average distance travelled Condition
Scen.
Differ
No support
Support
1
13560
12924
5%
2
13092
13090
0%
3
4341
4223
3%
4
6039
4682
22 %
Results - Safety Scenario 1 2 3 4
Condition
No support
Support
422 153
28 4
Rem. margin
96% 43% 79%
>99%
• In case separation was lost when using the support tools, it was by a marginal amount • The amount of separation lost was far more severe in the condition without support tools
Results – Operator Effort
• Average amount of course changes in degrees (blue=no support, red=support)
Results – Operator Effort
• Average amount of button inputs (blue=no support, red=support)
Results – Guidance Strategy
• Without support tools, the operator spends a considerable effort to (iteratively) setup a course and speed to remain conflict free with the other traffic
Results – Guidance Strategy
• With support tools: operator quickly sets-up required course and speed and only occasionally makes a change
Next Steps in CSHIELD project • Demo of communication system/network between platform and shore-based station (November 21) • Integration of the radar/EO sensor suite onto a conventional (manned) vessel is scheduled for the beginning of 2013 • During phase 1, the vessel will not be remotely controlled, nor will it already possess an autonomous navigation capability • Demonstration of the capability to remotely control the different sensors and distribute the resulting data to a shore-based mission management station will mark the end of phase 1 • Ownship and track data transmitted by the test vessel during the demonstration in phase 1 will be used to drive the prototype system discussed in this paper • The actual integration of the autonomous navigation capability will take place during phase 2 of the project
Summary & Conclusions • In the current phase of the CSHIELD project, a concept demonstrator for remote management of navigation and guidance, with integrated operator support functions has been realized • Extensive use was made of findings and lessons learned from past research into autonomous navigation and conflict detection, both for manned and unmanned systems, and both in the nautical and aeronautical domain – Predictive support functions have been designed that continuously show the impact of course changes in terms of separation with other vessels – A support function has been designed that allows the operator to evaluate the impact of a speed change on the future separation – Intercept guidance has been integrated that computes and displays an intercept track towards a selected target for a given speed (advisory) and can be used in an autonomous intercept mode
Summary & Conclusions • To explore the potential of these support functions, a simulation-based evaluation has been performed • Results shows that with the support tools the following improvements are achieved: – A consistent reduction in average mission completion time and average distance travelled – A consistent and significant reduction in operator effort – In those cases where separation was lost, the amount was far less severe
• The use of the predictive support functions will increase mission efficiency and safety of the CSHIELD platform, while reducing the required operator effort
Thank you for your attention Questions?
