State-Feedback Control of the SpaceHawk Earth-Based Lunar Hopper

State-Feedback Control of the SpaceHawk Earth-Based Lunar HopperAndrew Abraham, May 2013Background

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OBSTACLELocation ALocation BResearching the dynamics and controls associated with a hopping spacecraft trajectory

Background

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Surveyor 6Mars Exploration Rover1967- Surveyor 6 has been the only spacecraft to hop- Travelled 8 ft.Conventional landers are designed to be rovers constrained to the ground- Disadvantageous for exploring

Specifications

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4 ducted fans; each with 10lbs of thrust @ full throttle

Fans Produce ZERO torque @ 75%

Gimbaled in 1 direction

Frame made from aluminumEasy to construct

Total weight: 32lbs

26 From end to end

Arduino Mega for control computer

MEMS IMU

4 LiPoly Batteries: 2.25lbs each

ICE 80amp Electronic Speed Controller

Project funded by NASA

Specifications

56 DOF Analog IMUArduino Mega1 of 4 LiPo Batteries

Testing

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Testing

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Axis and Forces

8Definitions

9Equations of Motion

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Feedback Linearization(Position)

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Exact Linearization Control LawPlug Into Equations of MotionNow, linear control laws can be used with r as the virtual input

12Exact Feedback Linearization(Angles)

Exact Linearization Control LawPlug Into Equations of Motion

Now, linear control laws can be used with r as the virtual input

13Approximate Feedback Linearization(Angles)

Exact Linearization Control Law(highly nonlinear)

Near = 0

Approximate Linearization Control Law (linear)&Critically-DampedPD Controller

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Control Strategy

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Control Implementation

16Over-Actuated System Without Following Two Additional Constraints

TimePWM Simulation

17AB3m10mDefinitions18

Red = Reference Signal, Blue = Exact, Green = Approximate

18Acknowledgements

19Authors: Anthony Dzaba, Andrew Abraham, Evan Mucasey, Terry Hart, and Eugenio Schuster

Funding Agencies: NASA PA Space Grant

Thank You!

20Definitions

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