Concept Study for the FASTER

Micro Scout Rover

R. Sonsalla

DFKI RIC

May, 16th 2013

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Outline

• Project Outline

• Idea and Objectives

• Mission Scenario

• Mission Architecture

• Design Considerations

• Scout Rover Prototype

• Outlook

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Project Outline

FASTER Forward Acquisition of Soil and Terrain data for

Exploration Rover

Funded by the 7th Framework Programme of

the European Commission (GA 284419)

Project Partner

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Main Work Packages

• Development of scout rover platform

• Development of light-weight soil sensors for the scout rover

Load testing feet

Ground penetrating radar

Hybrid dynamic plate and cone penetrometer

• Development of primary rover’s soil sensors

Wheeled Bevameter

PathBeater

• Development of cooperative autonomy for the rover team

• Development of autonomous traversal algorithms

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FASTER Idea and Objectives

FASTER Idea

Analyzing past and future exploration

missions and/or mission scenarios like MER

or MSR, a need arises to provide faster and

safer traversal of exploration rovers.

FASTER Objectives

Concept development, implementation and

demonstration of a system for in-situ

evaluation of soil properties

• to improve the mission safety and

• the effective traverse speeds using

• autonomous collaboration between the

primary rover and a small scout rover.

[1]

[1]

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Mission Scenario

• FASTER baseline scenario related to ESA/NASA

MSR-Mission and SFR-Architecture

Mission duration: 180 sols / 110 sols

traversing

Distance to traverse: 20 km

Time of traversal: 4 h/sol

Min. average rover speed: 1.25 cm/s

• FASTER traversal scenario

Based on waypoints

Path planning by primary rover

Use of SSS (scout & primary rover) to

assess trafficability

Low confidence in trafficability leads to path

replanning

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FASTER Architecture

• Primary Rover (BRIDGET)

With SSS-payload

• Scout Rover

With SSS-payload

As remote ‘sensor unit’

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Scout Rover System Context

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Scout Rover Concept Study

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System Decomposition

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Key Design Driver

• Scout rover mass: < 20 kg

(incl. payload)

• High all terrain mobility providing:

Traversability of slopes up to 25°

Static stability angles of 40 degrees

in all directions

Min. average speed of 1.25 cm/s

• Design challenges

Rover steering (wheel design)

Wheel sinkage on soft soil vs.

High mobility on rough terrain vs.

Digging over of soft soil

[1]

[2]

[2]

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Locomotion Concept

• Front: Hybrid legged-wheels

• Rear: Helical wheels

• Steering: Side-to-side

• Chassis: Body roll joint (1 DoF) Asguard v2

CESAR

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Initial Side-to-Side Steering Test

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Scout Rover Prototype

Prototype for first test

sequence, including:

Locomotion tests

Maneuver tests

Subsystem tests

Traversal tests

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System Overview

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Technical Overview

• Boundary Box: 400 x 830 x 500 mm

• Mass (incl. 20% margin): 14.8 kg / 18.4 kg

• Wheel torque: 28 Nm

• Average power: 100 W

• Peak power: 500 W

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Technical Overview

• Data Handling:

Distributed processing of operational data and payload data

• Communication:

Primary rover serves as relay station

Based on wireless access-point @ 2.4 GHz and 54 Mbps

• Navigation:

Optical navigation System based on stereo camera and laser range finder

Body pose measurement based on motor position and torque measurement, IMU and body joint angular encoder

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Outlook

• Locomotion performance tests

• Navigation tests

• Implementation of autonomous

rover-to-rover collaboration

• Soil sensor integration

• Dual rover team soil examination

and traversal tests

FASTER Demonstration Workshop

November 2013

in Warsaw, Poland

https://www.faster-fp7-space.eu/

Thank you!

https://www.faster-fp7-space.eu/

Contact

Thomas Vögele (Project Manager),

Roland Sonsalla (Systems Engineer) German Research Center for Artificial Intelligence

email: thomas.voegele@dfki.de

roland.sonsalla@dfki.de

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References

[1] L. Richter et.al., “Freeing the Spirit Rover on Mars –

Progress Report” on 11th European Regional Conference of

the International Society of Terrain-Vehicle Systems

(ISTVS), October 2009, Bremen, 2009

[2] M. Golombeck et.al., „Rocks at the MSL Landing

Sites“, 4th MSL Landing Site Workshop, September 2010,

Monrovia, CA, 2010

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Baseline Operational Scenarios

• Normal Operation

Use of elevation map in combination with waypoints and scout position

Travel along predefined path (about 4 m ahead of primary rover)

Perform soil and terrain sensing and hazard avoidance

• Scouting Operation

Use scout rover as remote stereo camera for scouting

Expand elevation map on primary based on stereo images of scout

• Survival Operation

Follow previous path back using the last received elevation map

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Structure & Mechanism

• Mass (incl. 20% margin) 14.8 kg (excl. Payload)

18.4 kg (incl. Payload)

• Boundary Box (h x l x w) 400 x 830 x 500 mm

• Chasis: 1DoF in roll direction

• Locomotion and Steering Front: hybrid legged-wheels

Rear: helical wheels

Side-to-side steering

• Actuators: 4 x Robodrive with HarmonicDrive (28 Nm max.)

• Climbing Front: min. 224 mm

Rear: min. 100 mm

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OBDH and COM

• On Board Data Handling

Distributed processing of scout rover

operational data (OBC) and payload data

(PDH)

OBC: Embedded single board computer

PDH: Sensor related micro controller

• Communication

Primary rover serves as relay station for

scout rover communication

COM module:

Wireless access-point (802.11g wifi-module)

UHF emergency control

Asus WL-330gE

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EPS and TSC

• Electrical power supply

Assumed average power: 100 W

Estimated peak power: 588 W

Power supply:

LiPo accu: 44.4 V @ 2.1 Ah

External power supply

• Thermal Control System

Passive control for motor

modules

Active control for OBDH

Temperature sensors for

HMS

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Navigation

• Two different sensor packages are

planned for the scout rover navigation

system

1.Optical Navigation System

Stereo camera (2 x Guppy by AVT)

Scanninc laser range finder

2.Body Pose Measurement

AHRS (IMU) attached to main body

Body joint angular encoder

Motor position and torque

measurement

Guppy by AVT

AHRS by Xsens

UTM-30XL by Hokuyo

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Payload Integration Study

• Scout Rover SSS-payload:

Load Testing Feet and Belly Camera

Ground Penetrating Radar

Dynamic Plate and Cone Penetrometer