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Planetary Robotics Vision Scout

Final Report Summary - PROVISCOUT (Planetary robotics vision scout)

Project context and objectives:

The search for traces of life, past or present, is at the centre of Europe's ongoing planetary exploration programme. In the near future, robots with life science sensors will explore the surface of Mars and drill below its surface to look for signs of life.

The EC FP7-Space project PROVISCOUT aimed at demonstrating the feasibility of vision-based autonomous sample identification and selection as well as terrain hazard analysis for a long range scouting/exploration mission on a terrestrial planet along with the robotic elements required. It has brought together major groups currently working on planetary robotic vision, leading experts in planetary surface operations and experienced planetary scientists, consisting of research institutions all over Europe, National Aeronautics and Space Administration (NASA) Jet Propulsion Laboratory (JPL) in the United States of America (USA) and the industrial stakeholders involved in mission design, vision, navigation and data exploitation for robotic space missions, convening to a final end-to-end demonstration.

Further information could be obtained at: http://www.proviscout.eu.

The project beneficiaries were the following:

1. Joanneum Research (JR), Austria
2. SciSys UK Ltd. (SSL), United Kingdom (UK)
3. German Aerospace Centre (DLR), Germany
4. Aberystwyth University (AU), UK
5. Czech Technical University (CTU), Czech Republic
6. GMV, Spain
7. University of Leicester (ULEIC), UK
8. Swiss Centre for Electronics and Microtechnology (CSEM), Switzerland
8. TraSys (TRS), Belgium
9. University College London (UCL), UK
10. University of Strathclyde (UoS), UK
11. Kings College London (KCL), UK.

Robotic planetary space missions are unmanned missions performing in situ exploration of the surface and (if applicable) atmosphere for any planetary objects outside the Earth. Most such missions involve a means of mobility provided by either a surface vehicle (rover) or by aerial vehicles (balloons, aerobots etc.). Mobile systems are among the most critical of all space missions in requiring a rapid and robust on-site processing and preparation of imaging data to allow efficient operations for a maximum use of their limited lifetime. In future, the number and variety of such platforms will require more autonomy than is feasible today, particularly in the autonomous on-site selection of and access to scientific and mission-strategic targets. PROVISCOUT provides the building blocks on board of such future autonomous exploration systems in terms of robotics vision and decisions based thereupon. Populate a robotic vision on-board processing chain (PRoViSC) with representative components available at the proposing institutions, with minor adaptation and integration effort.

Its main objectives are summarised below:

1. address and merge a representative set of sensors (including a novel zoom 3D TOF camera) to fulfil important scientific objectives and prove the general applicability to the approach in different mission scenarios
2. include the search for scientifically interesting targets as an essential component for mission success into the navigation chain by autonomous tasking (goal based planning and re-planning)
3. compile a PROVISCOUT demonstrator on a mobile platform that combines sensors, processing and locomotion on-board ready for an integrated outdoor demonstration
4. integrate a monitoring function (PRoViM) to understand the behaviour of the system
5. demonstrate the feasibility of long-term vision-based scouting making use of a representative outdoor test bed and the PROVISCOUT demonstrator platform.

Project results:

Summary of foreground

Within PROVISCOUT a novel, autonomous planetary exploration system was set-up and demonstrated within an external field test at the end of the project:

1. all requirements from science and operational point of view were collected and documented. This includes the definition of the target scenario planned for the field test during the final project phase
2. the system design was developed. All interfaces between the components, e.g. rover, vision system, hardware (HW) trade-offs, navigation system, decision module, execution control and monitoring system, were defined and the main functions as well as distributed and shared data were identified and documented in a design document
3. candidate field test sites in Morocco, Tenerife, Wales and Iceland were investigated, assessed and discussed. Based on evaluating a set of selection criteria, Minas de San José on Tenerife was chosen as test site for the external field trials
4. a set of reference targets (in terms of heterogeneous criteria like texture, colour etc.) was defined and published in a web catalogue of targets
5. the provided target data were used for implementation, enhancement and verification of pattern recognition, learning, object detection and classification algorithms to detect meaningful targets (like sediment layers, rocks etc.)
6. based on the localisation of potential science targets within a wide-angle camera (WAC) image, pointing commands (PTU, pan and tilt unit, angles) were produced to capture close-up images of those targets with a narrow-angle camera, or other imaging device, e.g. automatic pointing and image capture (APIC)
7. an approach to distinguish between fluorescence of microorganisms and of host minerals was established
9. a new 3D TOF camera was designed by CSEM being able to zoom and integrate RGB high-resolution images.
9. the following sensors were mechanically and electrically integrated into the hardware (HW) system: rover and PTU, multispectral PanCam, high resolution camera (HRC), HyperCam and 3D-TOF.
10. SW interfaces of the following HW components were realised using CORBA: rover and PTU, multispectral PanCam, HRC and 3D-TOF (never having been tested). No CORBA interface was implemented for the HyperCam.
11. CORBA was also used for the integration of the following SW components into the SW framework running on-board of the rover (PRoViSC): vision processing, navigation, science assessment, decision module (MMOPS), executive and rover control.
12. an off-board SW component (PRoViM) for monitoring and visualising all rover operations, decisions etc. has been implemented.
13. a simulator, modelling the elements of a robotised system and the morphology and the texture of its environment, has been implemented in 3D (3DROV).
14. a (mono-chromatic) aerobot camera was set-up and mounted on a balloon. Image capturing tests were performed. Using the final system, aerial images captured from an aerobot tethered to a rover were used for DEM generation of the test site during the external test.
15. all integrated on-board HW / SW components were tested in a series of laboratory tests.
16. an integrated rover and instrument deployment was performed in a representative environment to test science goals and performance and utility for sample targeting, i.e. in the Arctic Mars Analogue Svalbard Expedition (AMASE) 2011.
17. the implemented 3D vision, science assessment and 3D reconstruction algorithms were verified by means of applying them to planetary date system (PDS) archived Mars Exploration Rover (MER) imaging data.
18. an internal test including all integrated on- and off-board HW and SW components was performed.
19. a 10-day external integrated test was planned, organised and performed in Minas de San José, a representative (Mars-like) landscape located in the caldera of Tenerife. During the first trial days, minor interface adaptations were implemented, all integrated components were tested on site, the site was mapped using aerobot images, including short-term generation of a digital elevation model (DEM) in the global coordinate frame.
20. at the end of the trial, the PROVISCOUT demonstrator platform autonomously ran an integrated outdoor demonstration containing vision based navigation, monitoring of actions and visualising 3D scene, demonstrating science autonomy capabilities and combining science autonomy with navigation in a decision system.
21. a high impact could be reached by a set of dissemination activities such as a press day during the external field trial, the website including live streams during the field trial, scientific publications, presentations at conferences, a web target catalogue and student projects.

Within PROVISCOUT a variety of results and foreground could be achieved in the following areas of research and development:

1. missions, targets and system design,
2. science selection and science assessment,
3. vehicles and sensors,
4. on-board and off-board SW,
5. system simulation and testing and
6. planning, organising and performing an integrated external field test.

More details about the named components are given below.

Missions, targets and system design

Missions and targets

Right in the beginning of the project, mission cases were collected for all relevant planetary surface missions and requirements were derived, taking into account the context of PROVISCOUT. The major result was the deliverable D2.4.1 'Mission requirements' document. It took into account the following objectives:

1. provide mission cases that represent possibilities
2. derive a number of requirements
3. identify realistic scenarios in analogue environments
4. define scientific objectives with success criteria
5. define different scenarios dependant on resources.

The science assessments were reviewed and prioritised in terms of science and implementations, leading to a set of PROVISCOUT operational scenarios.

The main objectives were settled as:

1. applicable to a Martian analogue environment
2. navigation and localisation over 200 m
3. identification of scientifically interesting targets
4. plan adaption depending on current situation.

The concept objectives were identified as follows:

1. making decisions more quickly, allowing a greater exploration activity
2. enable autonomous long range navigation and operations
3. enabling the detection and detailed capture of dynamic science events which would otherwise be missed
4. enabling a local science assessment of an area without compromising traverse schedules.

Further breakdown of the scenarios generated dependencies and chains, visualised in a scouting timeline and a unified modelling language (UML) representation of a typical sequence of actions.

Finally, 33 scientific requirements were mapped to 56 functional requirements, broken down to the following components:

1. PRoVIM vision and rendering
2. PRoVIM mission planning, analysis and control
3. PRoVIM web
4. PRoVISC science target selection
5. PRoVISC vehicle navigation
6. PRoVISC executive
7. PRoVISC planning
8. PRoVISC vision processing
9. HW: rover and aerobot.

System design

From the gathered knowledge the system design was derived and summarised in the systems design document in terms of camera specifications and platform interface definitions. The guidance, navigation and control (GNC) requirements and constraints were analysed and components were designed and modelled. A 3D TOF processing prototype was generated and the design for a mapping cycle was elaborated. C++ interface discussions of vision and navigation core functions took place and pattern recognition use cases including examples were formulated. Overall architectural design raised a set of issues that were jointly discussed and resolved in major part.

After architectural design, system design and test analysis, the preparation and release of base system design documents, including interface control documents (ICDs) were distributed to relevant partners for their review, with aim of inclusion of inputs to be received into the final design. Based on this, architectural design, system design, code and test analysis incorporating ICD inputs were received from consortium partners (including the relationships to the web interface, the GNC requirements and constraints, component design and modelling and the specification of RGB/TOF sensor). Emphasis was also laid to the interface between vision processing and relevant visualisation in PRoViM.

The interface for the request and return of information about the execution of tasks and their current status was formulated in discussions (decision module). The structure of example use-cases in order to identify the ways in which the decision module would interact with the choices offered to it was analysed and documented.

Science target selection and assessment

A representative set of test images for pattern recognition development was prepared (three sets of test images, with three versions of each image: original, annotated, labelled). The data included data sets of original and annotated images from Svalbard and Iceland. Furthermore, test images from different terrestrial analogue environments that are representative for science targets on Mars (including labelled versions and masks) were prepared for simulation and testing purposes. An interactive web-based catalogue of test images (deliverable D3.1.1) has been designed and implemented, making synergetic use of existing FP7 funded research infrastructure (i.e. the 'Interiors and surfaces' node, operated by DLR in the context of Europlanet's international dismantling information system (IDIS).

An aerobot campaign was performed in Aberystwyth in order to assess the viability of the aerobot images and potential for aerial science extraction.

A list of candidate sites for the external field test has been compiled. These sites were visited in June 2011 and the results presented at JPL MSL meeting in December 2011. Based on this information, Minas de San José on Tenerife has been chosen as test site for the external field trials.

The fluorescence response of different microbial and prebiotic molecular targets as well as the degradation of such a fluorescent signal by the ultraviolet (UV) and ionising radiation environment of the Martian surface, have been characterised. A handheld fluorescence imaging instrument, a WALI, was developed. The specific objectives achieved are:

1. full characterisation of the fluorescence response from different microbial and prebiotic target fluorophores by generating excitation emission matrices (EEMs)
2. determination of the degradation of cyanobacterial fluorescent biosignatures by ionising radiation on Mars
3. determination of the degradation of prebiotic polycyclic aromatic hydrocarbons (PAH) fluorescent signal by solar UV on the surface of Mars
4. design, construction and testing of a handheld fluorescence imaging device, WALI.

The AU APIC SW was developed and tested. The primary purpose of the AU APIC rover SW is to locate potential science targets of interest in a wide-angle camera (WAC) image and then produce pointing commands (pan and tilt unit, PTU, angles) to capture close-up images of those targets with a narrow-angle camera, or other imaging device. Given an initial image or camera pointing direction APIC can, if required, run autonomously. The main aim of APIC is to help maximise the science data return from a rover exploration platform.

The analysis and development of potential object definition and classification techniques, incorporated into an image capture and processing application was performed; resulting in code and successful tests with sample data. A science assessment and detection component, which was ultimately tested in the presence of the reviewers on the test site in Tenerife, was developed. The science assessment and response agent (SARA) assesses images based on a set of fundamental operations and compares these against given scientific priorities for a particular Sol. Final tests in Tenerife showed how the system extracted the required region of interest (ROI) in-situ which in turn triggered a science response.

Another pattern recognition agent that makes use of scale-invariant feature transform (SIFT) based classification was developed as backup solution at JR. PROVISCOUT scientists were instructed for using the training component. Further tests with Mars exploration rover (MER) imagery showed that the learning / classification approach is mature enough to distinguish between rocks and sediment layers. An option to include masks into the assessment was implemented and a clustering prototype was integrated.

Vehicles and sensors

Tethered aerobot

The AU aerobot is a tethered system, physically attached to an electric winch mounted on the Idris rover chassis. Once deployed, the rover is driven along a pre-selected route while the aerobot takes multiple overlapping images from above. The aerobot survey is a preliminary activity to allow area DEM generation prior to the main autonomous rover traverse. During the aerobot survey, the rover is manually driven and acts as a mobile anchor point for the aerobot. Once the aerobot survey is complete, the aerobot is hauled in and detached from the rover, in preparation for rover autonomous operation.

Rover

Different to the initial plan, AU and the PROVISCOUT consortium decided to use a larger, more robust, rover for final field testing, based on platform mobility tests and mass and momentum considerations. In March 2011 a decision was taken towards the Idris Rover.

A heavy-duty pan and tilt unit was designed and built to house the PROVISCOUT cameras. These sensors included the TOF/RGB camera (CSEM), the two hyper-spectral cameras (UCL) and the AUPE stereo multi-spectral cameras (AU). Integration and testing of these cameras with the new heavy-duty pan and tilt unit took place during a variety of laboratory and integration tests.

Sensors

The TOF/RGB camera

The PROVISCOUT camera developed by the CSEM is equipped with a RGB camera and a TOF camera sharing the same lens to measure co-registered colour images and range maps. The RGB/TOF camera is equipped with a zoom lens and a zoomable high-power laser illumination to improve the depth information at higher zoom levels of the camera. In the first project period the camera has been developed and assembled. In the second project period, the TOF/RGB camera has been further developed in three steps:

1. optimisation of the status quo after period one,
2. calibration and
3. testing.

During the internal integration campaign the camera switched off at an integration time exceeding 27 months. Time and budget were not sufficient to detect and fix the cause of this problem. Thus, the TOF/RGB camera did not join the external field test in Tenerife.

Multi-spectral panoramic camera and aerobot camera

The new AUPE-2 camera HW comprised 5 MegaPixel, 14 bit, GigE cameras and improved optics for each of the WACs and a 1.3 MegaPixel, 14 bit GigE camera with an RGB filter wheel for the high resolution camera (HRC). All of the cameras now have very high quality lenses. We serviced the WAC filters to replace any faulty filters and the AUPE-1 suitcase-based PC-server was replaced with a FitPC to minimise (volume, mass and power) the associated image capture (server) computer. The new cameras meant that we could bin etc. and extract 1024 x 1024 images when emulating the ExoMars PanCam, for example. The upgraded detectors, optics and 14 bit A/Ds meant that we had significantly better science cameras when compared to the old 1024 x 768, 8-bit cameras. We also lost the FireWire interface and reduced the overall mass and complexity of AUPE-2 for field trial deployment. The AUPE-2 system was used extensively during the Tenerife field trails and proved to be an invaluable data source for the PRoViSC SW modules.

The AU aerobot's primary sensor is a five MegaPixel monochrome camera. Images are captured by the camera and stored on-board the aerobot for later retrieval. The aerobot also has an inertial measurement unit (IMU) to measure its orientation in roll, pitch and yaw and a global positioning system (GPS) to measure absolute position and altitude. Note that neither of these systems are high-accuracy and provide only an estimate of attitude to constrain image registration and DEM reconstruction. Operation of the AU aerobot is coordinated by an embedded Linux computer. The camera used in the current version of the AU aerobot is a Prosilica GC2450. This camera has a Sony ICX625 monochrome charge-coupled device (CCD) sensor with a resolution of 2448 x 2050 (five MegaPixels) and a gigabit (1 000 Mbps) ethernet interface. It is capable of imaging up to 15 frames per second at full sensor resolution with 8 or 12 bit pixel data. The camera allows operation modes such as single or triggered frame capture and supports configurable auto-exposure and auto-gain algorithms. Image sub-framing and pixel binning are also possible.

WALI

It was proposed that the on-board rover system consist of the camera plus hyperspectral imager based on use of liquid crystal tuneable filter (LCTF) technology (i.e. HC-1) for obtaining hyperspectral images of rock face targets. WALI-A (tripod mounted) would then be employed for UV laser induced fluorescent observations using the sigma camera and a specially designed baffle, to house and isolate the UV light emitting diode (LED) emission during the day. White LEDs were included in the baffle to allow context images to be captured. This also meant that WALI-A could be employed for fieldwork with or without the rover.

The WALI A system retains the original fovean sigma digital single-lens reflex (DSLR) imaging system. The camera is securely attached to a metal frame, also bearing a light-tight black-out tube. The DLSR is zoomed in to its fullest extent and thus the lens forms a light-tight seal with the circular opening in the black-out tube. Arranged around the lens on the closed end of the tube are both white LEDs and 365nm UV LEDs. These are powered by a removable battery pack mounted on the frame and the white-light and UV sources are switch-operated independently. In the interests of safety, a warning indicator LED, sited on the outside of the black-out tube to be visible whilst operating the camera, shows when the UV LEDs are on.

HyperCam

The MSSL hyperspectral camera (HyperCam1 or HC1) is a small camera mounted on the PTU. HC1 consists of two BlueFox complementary metal-oxide semiconductor (CMOS) cameras and attached LCTF to acquire narrow band multispectral images. Since HC1 uses available light it is entirely passive. HC1 took part in both the PRoVisG and PROVISCOUT Tenerife field trials (in September 2011 and 2012 respectively). However, the design was modified for the 2012 trial with the EMCCD camera replaced by two BlueFox CMOS cameras (with auto exposure capability) allowing both LCTF's to be used simultaneously.

The HyperCam was operated wirelessly by remote desktop sharing to allow the operator to interact through the LabView based control SW. The named components, except WALI, were mechanically and electrically integrated into the HW system.

On-board and off-board SW

On-board SW

The SW framework running on-board of the rover (PRoViSC) enables the operational vision-based navigation and control of the rover for an end-to-end demonstration.

The SW interfaces of the following HW components were defined in the system design process and realised using CORBA: rover and PTU, multispectral PanCam, HRC and 3D TOF (never having been tested). No CORBA interface was implemented for the HyperCam. CORBA was also used for the integration of the following SW components into PRoViSC: executive, decision module (MMOPS), science assessment, navigation, vision processing and rover control.

Executive

The executive had two main purposes in PROVISCOUT:

1. act as an interface between the PROVIM and Rover. This includes providing status/monitoring information such as rover position and timeline status to PROVIM and receiving plans and science templates from Overseer and forwarding these to MMOPS for possible insertion into the plan
2. maintain a model of the onboard plan as prescribed by MMOPS and execute this at appropriate times.

Tasks that can be executed by the executive include:

1. navigation/traverse
2. acquire RGB using 3D TOF's RGB camera
3. science Assessment (RGB), assessment of science from RGB image data
4. acquire high resolution image
5. acquire WAC image
6. acquire 3D TOF
7. replan.

Decision Module (MMOPS)

MMOPS relies upon to update and ensure the consistency of the mission timeline. In addition to receiving an initial plan, it receives requests to add navigation tasks and science opportunities to the timeline. Before doing so it ensures that there are enough resources (time, power, memory) for continued operation using static and dynamic information. Timeline validation and repairing (as required) also occurs periodically to ensure correct operation of the rover. Depending on the type of sub plan currently executing, task failures/overruns are treated differently. For example, if a science opportunity sub plan fails, this is simply removed and execution continues as normal. If a navigation task fails it is possible to recover if there is a task overrun and there is no restriction on time. Any changes made to the plan are passed on to the executive for execution.

Science assessment

In order to fulfil science autonomy requirements, a number of science assessment components are available to analyse images taken using cameras on-board the rover. Although these have implemented a different set of algorithms, these all need to identify features such as structural layering, compositional layering, cross bedding and slumped structures. As part of the science assessment tasks, the science assessment component uses a DEM to determine the location of a target in 3D space and determine the most appropriate coarse waypoint from which to perform the next level of science.

Navigation

The Navigation component is in charge of instructing the Platform to move the rover from one location to another. This typically involves taking WAC images, constructing a DEM and combining this with mechanical odometry and inertial measurement unit (IMU) readings to determine current location and produce a series of internal waypoints required to traverse to the destination.

Vision processing

Vision processing provides a set of utilities to perform various functions involving imagery, including:

1. image acquisition (e.g. 3D TOF, RGB, WAC, WALI)
2. construction of a panoramic image from the WAC
3. reconstruction of stereo imagery from WAC and ACAM
4. generation of hazard and slope maps from DEM
5. calculation of visual odometry for use in the navigation component
6. maintenance of a global map.

Rover control

In its simplest form, the rover platform component provides an abstraction to the low level functionality specific to the platform. This includes access to:

1. a pan/tilt unit mounted on the mast
2. a WAC system, comprised of two cameras with RGB filters. Twelve geology filters are also provided and spread between cameras (i.e. six geo filters per camera). Nominally full 360 x 180 panoramic produced on all available wavelengths taken at each coarse waypoint, although possible to specify more limited angles and only in RGB
3. a 3D TOF camera with RGB capabilities - nominally full 360 x 180 panoramic taken at each navigation step, although possible to specify more limited angles, zoom and RGB/3D TOF only
4. the locomotion subsystem
5. (potentially) a hyper spectral imager (not realised within PROVISCOUT).

Off-board SW (monitoring and control)

An off-board SW framework (PRoViM) for monitoring and visualising all rover operations / decisions etc. during a running mission was implemented and tested. This SW framework consists of three parts: overseer, vision and rendering (3DROV) and web interface.

Overseer

The overseer was directly communicating with the on-board Executive. It was responsible for the planning of the rover tasks and the visualisation of task timeline's and the rover's progress.

Vision and rendering

The simulator, modelling the elements of a robotised system and the morphology and the texture of its environment, was implemented in 3D. The 3D robotic visualisation (3DROV) and rendering function mainly includes:

1. the 3D scene rendering module that renders in a photo-realistic virtual scene the real or the simulated rover and its surrounding environment. It visualises also additional items such as 'targets', activities glyphs and image overlays and allows the animation of all modelled mechanisms.
2. the rover S/S movement control that supports the specification of 'targets' to be reached be the rover mechanisms (i.e. locomotion or mast) and allows the rehearsal of motions of mechanisms.
3. the data monitoring that allows animating the robotic system in the synthetic scene, displaying on-line in 3D and analysing downloaded or simulated data.

Web-based backend

A web based system for monitoring and visualisation of experimental missions providing a unified www presentation of the status of a mission was developed. The system was designed to support remote missions connected over only a slow, e.g. satellite, network. Activity in the mission control centre (path planning, simulation and monitoring) and in the field (web cam) were transmitted over a satellite link to a CTU server and transformed into a live video feed at 'http://cmp.felk.cvut.cz/projects/proviscout/vfeed/'.

System simulation and testing

In order to integrate, test and verify developed HW and SW components as well as to implement improvements, a variety of laboratory tests, integration campaigns and simulations have been performed to ensure the system running during the final field demonstration.

Laboratory tests

HW and SW testing has occurred on many occasions during the project. Much of this work has involved the testing of individual HW and SW components in isolation (referred to as 'unit' testing), in readiness for the Internal Integration Test which brought the components together for integration tests. The driving force has been to ensure that the goals of the PROVISCOUT project would be delivered and a successful final Tenerife field trial in September 2012 would be achieved.

Continuously during the project, the internal test plan was updated. Given the necessity to bring key PROVISCOUT partners together for the number of integration campaigns that have been undertaken, it has often proved to be a complex timetabling and logistics activity to ensure that the right partners were available at the right times, with the right equipment being available. With so many SW modules and the rover and sensor HW being constantly improved, ensuring that versions of all HW and SW could be 'frozen' at key dates for integrated test purposes took a good deal of effort to organise.

As well as unit tests, some elements of integration tests were conducted at SciSys and the AU planetary analogue terrain laboratory (PATLab) and the AU robotics workshop.

MER processing

In order to verify the implemented 3D vision, science assessment and 3D reconstruction algorithms developed and improved in the context of PROVISCOUT and related projects (i.e. PRoVisG) as well as to show the benefits of the autonomous science selection approach and its applicability in planetary environment, these algorithms were applied to PDS-archived MER imaging data serving as real comprehensive data from a planetary surface.

The 3D vision product generation, science assessment algorithms and the 3D reconstruction cycle developed by CTU were successfully tested.

Arctic Mars Analogue Svalbard Expedition (AMASE) contribution

As preparation for the PROVISCOUT deployment on AMASE 2011, DLR organised a preparatory workshop, hosted by AU in July 2011. During this workshop, the PROVISCOUT sensor suite was tested and prepared for field deployment in Svalbard. The workshop included detailed shake-downs of the instruments and SW in the lab and at Clarach Bay, as well as calibration of PanCam.

From 8 to 21 August 2011, a part of the PROVISCOUT team participated in the AMASE 2011 in the Svalbard archipelago, Norway, together with around 30 European Space Agency (ESA) and NASA scientists and engineers involved in Mars exploration. During AMASE, a part of the PROVISCOUT sensor suite, including PanCam (Aberystwyth AUPE-1 emulator) and a WALI emulator were deployed in several Mars-analogue field sites in Svalbard as part of an integrated, Mars rover-representative instrument suite (including field models of ExoMars and MSL instruments) to test science goals and performance and utility for astrobiology sample targeting.

Integration tests internal

The integrated test internal has built upon the unit and laboratory integration tests. It brought the components together for integration tests. The driving force was to ensure that that the goals of the PROVISCOUT project would be delivered and a successful final Tenerife field trial in September 2012 would be achieved.

Two integration campaigns were performed, one at a site in Wales, UK (Ysbyty Ystwyth) and one as a remote partner connection campaign with the rover at Aberystwyth. Finally an aerobot and communication infrastructure test was undertaken just prior to packing and transportation of all of the field trial equipment to Tenerife.

Summary of integration campaign four at Ysbyty Ystwyth, Wales

The major SW/HW integration campaign took place from 23 March to 6 June 2012. The number of days at the chosen site approximated to the field trial duration that would be experienced in Tenerife. The site was a quarry at Ysbyty Ystwyth near Aberystwyth, Wales (approximately 40 minutes drive). A good deal of effort went into the selection of the Ysbyty Ystwyth quarry site. We needed a location that was not too far away, but one that forced us to collect all of the equipment together and transport it away from Aberystwyth, thus ensuring that we could not be reliant upon local infrastructure. Most importantly, the site had to be sufficiently remote to allow the 3D TOF to be powered and tested in an environment that would be safe to all humans in the area. Finally, the site had to sufficiently large and varied (slopes etc.) to exercise the vision processing visual odometry (VO) and navigation SW modules.

The campaign required the use of the AU robotics group transportation van, which doubled as a 'mission' control room. Preliminary check-out work was first conducted at the AU robotics workshop before packing and travelling to Ysbyty Ystwyth. Despite some periods of mixed weather, integration campaign four provided the most realistic tests so far undertaken within the PROVISCOUT period, in preparation for the final field trial in Tenerife.

Based upon the lessons learnt from Integration campaign three, it was realised that further rationalisation of the camera mounting head was required. Too many control and power cables were being routed via a very restricted opening and there was significant weight being place upon the heavy-duty PTU. Prior to travelling to the Ysbyty Ystwyth site for the first tests, several hours were spent redesigning the camera mounting configuration to improve the reliability of all of the connections and to speed up the mounting and un-mounting of the camera head which was required to allow the Idris rover to be able to be moved in and out of the transportation van.

Summary of integration campaign five at AU workshop, remote tests

Based upon the results from the Ysbyty Ystwyth integration campaign, it was decided that some of the SW modules required additional tests in preparation for the final Tenerife field trial. The fifth Integration campaign, which occurred from 13 to 25 July 2012, involved an internet connection being established with the Idris rover PC based at the AU robotics workshop. Text communication between remote team members at their home institutions was established using a web chat room (http://www.chatzy.com) and AU team members started, monitored and stopped (when requested) the various PROVISCOUT SW models whilst ensuring that Idris moved in a safe manner.

Summary of final test campaign, pre van and equipment travel to Tenerife

Prior to departure for Tenerife, we wanted to test the new, larger (7 ' diameter) tethered aerobot envelope that had recently been delivered. Having calculated the nett lift that our original (6 ' diameter) envelope would generate at the altitude we would be operating at in Tenerife, we realised that a larger envelope would be required. We also wanted to undertake a final test of the communications infrastructure that would be used in Tenerife and to assign internet protocol (IP) addresses etc. The aerobot envelop and communication infrastructure both performed as required and all of the field trials equipment was loaded into the AU robotics research group Luton van and the journey to Tenerife commenced.

Integrated test external

Site selection considerations for the Tenerife field trials had been taken already early in the project. Among others, two main candidates were considered, namely Montana Rajada (being challenging in terms of permission as well as traversability and access by car) and the Minas de San Jose Area (with minor scientific challenge). After a trade-off it was decided to go to Minas de San Jose.

After thorough preparation the external integrated field test took place from 10 to 19 September 2012 in the El-Teide National Park / Minas de San José on Tenerife. All HW and SW components developed during PROVISCOUT and related projects should finally be integrated to the rover platform to test their performance under realistic Mars-like conditions.

During a variety of internal tests and campaigns afore, the single system components have been tested and improved. A full integration of all components wasn't reached by the beginning of the external test. Furthermore, not all sensors could come into operation during the trials.

External field trial planning and logistics

The decision for the test site location was made on the base of a field visit in June 2011 and the experience gathered during the PRoVisG field trial on Tenerife in September 2011. The field test planning and organisation was managed by task leader JR. All planning information were summarised in the internal deliverable D7.2.1. This document was continually updated until the beginning of the trials and provided to all field test participants via the CMS.

Test setup and realisation

During the field test all available HW and SW components were integrated to the rover and to the SW modules PRoViM and PRoVisc. The performance of the system was continually evaluated. To verify the navigated path and the generated 3D data of the work area, an overview digital terrain model with geo-referenced coordinates was generated. To make this possible, JR placed more than 80 GPS measured white landmarks in the terrain, creating a photogrammetric network along the rover's planned route. Overlapping aerial images of the terrain and markers were then used to create a 3D reconstruction by CTU. The aerial images were captured by the AU aerobot. In a final demonstration at the end of the trials, the rover was required to navigate autonomously between three given waypoints: a start point, an intermediate stop and an end point. Each section of the route was at least 30 m in length. At a maximum speed of 20 cm per second, Idris followed its planned route, scanning the terrain metre by metre and constantly updating its 3D map and navigation path. Due to a lack of geologically interesting Mars-like rocks along the traverse, ULEIC prepared some artificial targets and placed them near the second waypoint, to be detected by the science assessment component of PRoVisc. These targets were detected as potential regions of interest, which led to Idris' on-board system reacting and trying to get closer to the targets to capture high resolution image data. The whole mission was controlled remotely from the control centre situated in the van. The real time 3D visualisation system 3DROV by TRS enabled operators to monitor Idris and its behaviour at the test site. During the field trial, a live web stream on the PROVISCOUT website was used to broadcast the 3D visualisation, a display of information from the overseer component and a video feed of the rover itself as viewed from an on-site webcam.

Field trial supervision, documentation and data storage

For everyday data storage and exchange, AU provided a hard drive with a pre-defined directory structure in the wireless PROVISCOUT network at the Parador. Next day schedules containing time and responsibility information were provided by JR after having discussed results and problems in everyday's team meetings. Overall documentation of the trials (who did what when including pictorials) was done by JR and published as LogBook on the PROVISCOUT website. Detailed documentation was individually done by the participating parties. For future missions it might be useful to define a protocol template to be used by all team members. This information would allow quantifiably analysing single on-site actions and being valuable input for the planning of future field trials.

All data produced and processed on-board Idris as well as on board of the aerobot and taken by participants' single-lens reflex (SLR) cameras was made available to PROVISCOUT members on the PROVISCOUT internal file transfer protocol (ftp) page. This will be maintained at least for two years after PROVISCOUT termination.

Scientific performance of the field trial

A full assessment of the scientific performance of the robotics field trial was conducted both on site and post facto once all the test results have been collated. The main justifications for selecting the Minas de San Jose site were as follows:

1. general suitability of the terrain for rover-based traversing (i.e. geomorphology, surface type and lack of visible intrusions from the rover's perspective)
2. authorised access (compared to other more scientifically interesting sites)
3. logistical access.

However, one drawback of the site was the absence of suitable natural geological features displaying layering. This attribute was chosen because it is one of the most fundamental features and diagnostic indicators in field geology. To compensate for the lack of natural layering, ULEIC prepared artificial targets that were designed to be inserted into the terrain and merge with the natural geology. No budget was assigned to the effort of creating the targets so they could not be made much greater than A2 size.

Other integrated tests external of HRC and WALI

Aside from the Tenerife field test, at MSSL/UCL, an integrated stereo and hyperspectral imaging system was developed and tested in two pre-selected sites located in Brecon Beacon, Wales, where NERC airborne datasets and WALI images had been acquired in previous relevant scientific studies. These showed that these nearby sites contained a number of extremophile environments including endolithic cyanobacteria in spring deposit terraces, bright pink alkaliphillic biomass growing on rock surfaces and possible ferric oxide staining on the surface of carbonate deposits. The integrated imaging instruments built at MSSL provided visible and near infrared hyperspectral images of the astrobiological interesting content and stereo images provided the 3D information on the surrounding context. The stereo capability allowed 3D reconstruction of detected geological and biological features and further research possibilities of structurally different bio-signature types or any extensive classification as well as recognition of fossilised biomat structures.

The alkaline nature of these sites contrasts well with acidic, volcanic sites (e.g. Tenerife/Spain) and mineralogical deposits provide a challenge for hyperspectral imaging which are priority targets for any astrobiological focused mission to Mars. In addition, the sites also have a combination of endolithic cyanobacteria in the spring terraces, which is of particular interest to astrobiology since endolithic environments on Mars have been theorised to constitute potential refuges for extraterrestrial microbial communities and bright pink alkaliphillic biomats growing on the surface.

Summary of field trials findings

Following the field trials from PRoVisG and PROVISCOUT, a lot of experience in planning and organisation was acquired. The major findings consisting of known issues, having been confirmed in Tenerife, as well as completely new experiences are summarised in the following (compiled in cooperation with the PRoVisG team).

1. Team and responsibilities:

1. for the field test it was inevitable to have different people with different roles, such as in a real mission
2. for each of the entities, one official was assigned who was mentioned in the participants list handed out to all participants and to the local authorities
3. to guarantee a good organisation on-site, a local support team was introduced (active connect team). Their tasks included providing interpretation services, organising authorisation to access to the El Teide National Park, liaising with local institutions and organisations (local government, police, local officials), organising the press day event in conjunction with Astrium Ltd's public relations (PR) department, organising local logistics and equipment hire, providing the trials team with food and water during the day, restoring the park to its natural condition after completion of the field trials and having the test sites checked and approved by the park authorities.

Objectives, priorities, schedules and backup procedures:

1. it was necessary to have a list of objectives with priorities, estimated schedules and backup procedures
2. each experiment came with a sequence chart that allows minute-by-minute monitoring of the experiment in order to find delays early enough
3. in general it was necessary to stick to the schedule to avoid a loss of time
4. a backup plan was required for potential system failures and unexpected environment conditions
5. for some experiments the realisation deviated from planning due to immediate availability of resources
6. some decisions had to be made on-site, reacting on circumstances and in better knowledge about expected durations, such as common file system structure to store the captured data, communication procedures via hand-held radios, paths for the rover and distribution / timeline of individual experiments' components (panoramas / VO / science targets etc.), daily schedule
7. shakedown days were necessary to ensure that rover and test infrastructure have been set up and were functioning correctly.

Site selection:

1. the test site(s) should be chosen carefully, concerning environmental restrictions, altitude and temperature / climate, diseases / health risks etc.
2. it was useful to brief all field trial participants in advance to guarantee smooth functioning on-site and efficient conduct of the trials.

Site infrastructure:

The conduct of field trials demanded infrastructure and support systems to ensure that all goals were met within the window of opportunity provided by the site authorities. Essential operational capabilities were necessary to ensure the efficient execution of tests and operations and to maintain high levels of communications between parties and equipment. The following items were regarded as essential as infrastructure:

1. box van to transport the rover and support equipment and to act as an in-the-field local control centre
2. Communications, including (for broadcast) V-SAT satellite broadband links to allow upload of image data to the internet ftp site, to the field trials website, to provide email, Skype, virtual private network (VPN) and data access for the whole team, personal mobile radios for members of the team working in the field, at the local control centre and at the Parador, wifi link up between the rover and the local control centre to allow remote control operations - repeater stations extended the range to around 1 km line of sight, mobile phones where they were able to obtain sufficient signal
3. tools and equipment to operate, service, maintain and modify the Rover and to support the fitting of instruments and equipment in the field and back at the Parador
4. monitoring webcams mounted in the field (or on the rover) to enable local control centre staff to drive the rover remotely and to enable them to see, hear and be aware of what was happening in, on and around the rover during trials operations
5. batteries capable of providing sufficient power for one full day of operations
6. solar panels and a petrol driven electric generator as backup to power the local control centre equipment and to allow charging of batteries in the field where required
7. shade for personnel and equipment - gazebo with side panels - to avoid the effects of direct sunlight
8. furniture for the local control centre (tables, chairs)
9. computing and communications equipment for the local control centre to support control of and communications with the rover
10. food and drink facilities for the team both in the field and at the local control centre to maintain energy levels and maintain hydration
11. fence to protect the site from visitors and the visitors from injury by the rover.
prvc-rep-jr-final-report-2012-11-30-pag.pdf