Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Actuator Components

• Actuators – Hydraulics – Pneumatics – Electric Motors

• Gearing

• Bearings • Seals

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Fundamental Elements of Robotics

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SensingPlanning

and Reasoning

Actuation

Environment

Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Prime Mover Taxonomy

• Electrical – Direct Current – Alternating Current

• Non-Electrical – Hydraulics – Pneumatics – Chemical – Thermal – Stored Energy

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Hydraulics and Pneumatics

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Pneumatic Actuator Cutaway

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Hydraulic System Schematic

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Hydraulic Spool Valve Schematic

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Brushed DC Motor Schematic

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

DC Brushed Motor Schematic

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Brushed DC Motor Commutator

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Brushless DC Motor

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Brushless Outrunner Motor

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

DC Brushless Motor Schematic

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Basic DC Motor Drive Characteristics

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Effects of Temperature on DC Motors

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Effects of Temperature on DC Motors

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Speed as a Function of Torque

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Standard DC Motor Characteristics

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Motor Power

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P = ⌧!

P = ⌧ (!NL + E⌧) = ⌧!NL + E⌧2

! = E⌧ + !NL (E < 0)

dP

d⌧= !NL + 2E⌧ = 0

⌧max power

= �!NL

2E

Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

DC Motor Power and Efficiency

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Typical DC Motor Specification

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Standard Motor Specifications

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Axial Flux Motor

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Stepper Motor Exploded Image

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Stepper Motor Schematic

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Gearhead Motor Cutaway

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Gear Forms

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Gearing Calculations

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Gear ratio ⌘ N

⌧output

= N⌘gear

⌧input

!output

=!input

N

Ioutput

= N2Iinput

⌧ = I!̇ =) I =⌧

!̇

Ioutput

=⌧output

!̇output

Ioutput

=N⌘

gear

⌧input

!̇input

N

Ioutput

= N2⌘gear

Iinput

!̇output

=!̇input

NFor ideal gearing,

Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Spur Gears

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Spur Gear Parameters

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Helical Gears

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Planetary Gears

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Bevel Gears

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Bevel Gear Kinematics

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Automotive Differential Schematic

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Automotive Differential (more realistic)

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Worm Gear

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Chain Drives

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Chain Drive with Idler

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

V-Belt Drive

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Toothed Belt Drive

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Rack and Pinion Gears

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Screw Drive Schematic

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Linear Actuator Cutaway

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Cup-Style Harmonic Drive

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Operating Principle of Harmonic Drives

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Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Pancake Harmonic Drive

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