Humanoids and - dspace.mit.edudspace.mit.edu/bitstream/handle/1721.1/34967/2-12Fall-2004/NR/rdo… · Humanoids and 2.12 Final Lecture Biologically-Inspired Robots Where are we going

2.12 Final LectureHumanoids and Biologically-Inspired Robots

Where are we going in 10 ~ 25 years?2.12 Final Lecture

H. Harry Asadad’Arbeloff Laboratory for Information Systems and Technology

Department of Mechanical Engineering M.I.T.

Humanoids: Can we make our own copy?

Four photos of humanoid robots removed for copyright reasons.

ButteryActuatorsTransmission

Biped locomotion

Anatomy, Physiology, Biomechanics

Kinematics, Dynamics, Control

BehaviorSoftware architectureVisionSpeech recognition

Skills

Biped Locomotion: How does a human walk?

Biomechanics Model Human measurement Kinematics, dynamics, and control

Photo removed for Photo removed for

copyright reasons. copyright reasons.

Fundamentals of biped locomotion

Torso

Gravity

Inertial Force Acceleration

Reaction Force from the Floor

Zero Moment Point (ZMP)

The body may tip over, if the floor reaction varies.

Gravity


Actual Reaction Force

Misalignment Æ Tip Over

Bump, object, or roughness

from the Floor

Zero Moment Point(ZMP)

1. Floor Reaction Control

Zero Moment Point

(ZMP) Accommodate the floor reaction force by

Gravity


distributing the force between the heel and the toe, so that the resultant force may pass

through the ZMP

2. Target ZMP Control

Accelerate the upper torso to increase the inertial force so that the resultant force may pass through the ZMP.

Gravity

Inertial Force Increased Acceleration

New ZMP

Original Zero Moment Point(ZMP)

3. Stride Control

Pre-planned target torso position

As a result of the ZMP control, the target position of the upper torso is shifted towards the direction of acceleration.

ZMP

The stride is accommodated to keep up with the torso speed

Stereo Vision

3-axis accelerometers+ Gyro

6 DOF

Joint angle sensors

Photo removed for copyright reasons: side view of Honda

ASIMO robot. http://world.honda.com/

ASIMO/

Battery Controller RF Link

Compliance Control

6-axis force/torque sensors

Amputee with force feedback. MIT Leg Lab/Media Lab, Hugh Herr

Photo removed for copyright reasons.

Hami Kazerooni’s Robotic ExoskeletonUC Berkeley, Human Engineering and Robotics Lab

Photos removed for copyright reasons.

Source: UC Berkeley Robotics and Human Engineering Laboratory.http://bleex.me.berkeley.edu/bleex.htm

5 body-lengths per second

Stanford Cockroach Robot

Figures removed for copyright reasons.

Mark CutkoskyBiomimetic Design and Fabrication of a Hexapedal Running Robot

Stanford University, Center for Design Research

J. Clark, J. Cham, S. Bailey, E. Froehlich, P. Nahata, R. Full (UC Berkeley, Biology), M. Cutkosky, Proc. 2001 IEEE ICRA

Figures removed for copyright reasons.

Biologically-Inspired Robots

(Courtesy of MIT. Used with permission.)

Robo-Pike at MITPike can accelerate at a rate of 8 ~ 12 G’s.

(http://web.mit.edu/towtank/www/Pike/pike.html)

Snake Robots by Shigeo Hirose

(Courtesy of Prof. Shigeo Hirose. Used with permission.)

Biologically-Inspired Robots

Photo courtesy of Los Alamos National Laboratory. (Courtesy of MIT. Used with permission.)

Dinosaur Robot, Troody Spyder 1.0 by Mark Tilden

Still long way to go.

What are missing?Brain and Muscle

Photo removed for copyright reasons: promotional image for film I Robot.

Actuator Research and Development:Very slow progress

Progress

Computer

Sensor

Actuator

Year

Sensors, everywhere …..

Actuators, everywhere …

Sensor

Actuator

1995 2005

MITTom Swager, Solder Nanotech Lab & Chemistry

Ian Hunter, Bioinstrumentation Lab, Mechanical Engineering

Diagrams removed for copyright reasons.

Initial results on a new conducting polymer actuator show strains of 6% against an applied load of 1 MPa at a strain rate of 1% per second. The material is Poly EDOT and it is actuated electrochemically in the ionic liquid BMIMBF4. The results will be presented in two weeks at the SPIE 11th Annual International Symposium on Smart Structures and Materials.

Material Based Artificial Muscle Actuators

ShapeShape ElectroactiveElectroactive CarbonCarbon MemoryMemory PolymerPolymer NanotubeNanotubeAlloy ActuatorsAlloy Actuators ActuatorsActuators ActuatorActuator

HN

NH HN

NH HN

Temperature

Strain Photos removed for copyright reasons.

Courtesy of NASA JPL.

Actuation Mechanism: Uses Shrinkage or Expansion of material to create displacement

There are several kinds of Material based artificial muscle actuators, fromshape memory alloys to eap, and most recently carbon nanotube actuators. These actautors share a conceptually common actuation mechanism, which is shrinkageor expansion of material to create a strain.

Actuator Characteristics

Energy Density Stress x Strain

Cross-sectional Area: A

Force: F Strain ε

These graphs show the comparison of material characteris of these actautors,against natural muscles, energy densiy, specific power.

Actuators Compared with Material Characteristics of Muscle

And this table shows you more of the material characteristics of these actuators. And these characteristics dictatesthe implementation of these actuators into real systems. The point I would like to make here, is that lots ofresearchers are interested in the material characteristics of these actuators and tries to exploit these charactericswhen designing a system. But how about the architectural characteristics of muscles? Is there anything interesting or useful in the architectural characteristics of muscles?

Robotics: Systems

Fill the technology gap We cannot wait!

Materials Technology

Shape Memory AlloyShape Memory AlloyThe largest stress and energy density among all the actuator materials

> 200 MPa> 4x107 J/m3 Hysteresis

Strain

cooling

Temperature

Joule heating and forced air cooling

Shape Memory AlloyShape Memory Alloy

The hysteresis curve shifts depending on the stress applied

Hysteresis cooling

Strain


Stress

Temperature

Shape Memory AlloyShape Memory Alloy

The hysteresis curve shifts depending on the stress applied

Strain

Hysteresis

Stress


cooling

Temperature

The Traditional Approach is “BULK” FEEDBACK.

Control Actuator Material

Since the process is highly distributed and nonlinear, bulk feedback does not work well.

The Traditional Approach to these systems is BULK FEEDBACK.

Control Actuator Material

Since the process is highly distributed and nonlinear, bulk feedback does not work well.

New Approach:

A c t u a t o r M a t e r i a l

Segmented Binary Control

Local Control

Segment-by-segment simple local controls (binary, finite state controls)

Muscles have Segmented Architecture

Whole Muscles Long strap muscle

Muscle fibers Unit of independent Innervation

Myofibrils Muscle thread

Functional unit ofSarcomeres contraction

Myosin, actin Components of sarcomeres

Figures by MIT OCW.

One interesting point is that muscles have segmented architecture. This is a picture from basic human anatomy book, and as you can see, muscles are segmented in several hierachy. It starts with myosin, and actin, which are components, and sarcomeres are put in series to form myofibrils, which is a muscle thread.

Regardless the size of animal, the building block is the same!

Figure by MIT OCW.

Segmented Binary Control

• Divide the whole into a multitude of smaller segments controlled separately.

• Overall strain is the sum of the individual strains for each segment

Temperature

Strain

Segmented

ONOFF

Binary State Controls

• Each segment may take either hot state or cold state

• Wash out all material hysteresis and nonlinearities

StressNormalized Displacement

0

0.5

1.0

C D

A

B

Increase

TM Temperature TA

Phase transition diagram of SMA and selection of threshold temperature TA and TM

The hypothesis.Based on expected stress states in the design, hot and cold temperatures can be chosen.

Implementation of Segmented Binary ControlSMA Use of Thermoelectric devices (Peltier Effect) for

selective, local heating and coolingselective, local heating and cooling

Tension

SMA Wire Thermoelectric Devices sandwiching the SMA wire

Use of Thermoelectric devices (Peltier Effect) for selective, local heating and coolingselective, local heating and cooling

Heating

−

+ Cooling

−

+

Schematic diagram removed for copyright reasons.Source: http://www.tellurex.com.

Dis

plac

emen

t (m

m)

Segmented Binary Control:SMA works like a stepping motorstepping motor

9

8

7

6

5

4

3

2

1

0 0 1 2 3 4 5

Number of Elements "On"

Load = 0 Load = 1 N Load = 2N Load = 3N Load = 4.5N

X =η n N

η ≈ 6.1 mm

Con

trol

Con

trol

Con

trol

Con

trol

Con

trol

Con

trol

Con

trol

Con

trol

Drawback: Too many controls

16 units

Con

trol

Con

trol

Solution: Grouping

ControlControl Control

1 2 units 4 units 8 units

Minimum segmentation of single axis

1248

D t S r

S e

3 3

2 2

1 1

0 0 2222 aaaa +++

isplacemenenso

MA Wir

Can we make more saving?Particularly for multi axis actuators

S1 S2 S3 SN

A1

S1 S2 S3 SN

A2

M × N segments

S1 S2 S3 SN

AM

Too many segments Couple the segmentsfor multi-axis case

Disadvantage of segmented binary control

Two-dimensional segmentation of multi-axis SMA actuator system on a Peltier pellet bed

CoupledFixture SMA wire bundle

Axis 1

Axis M

segments

Independent Dependent segmentssegments

Array Actuators

Muscles are Coupled

Deep anterior musclesof the arm

Several muscles for single motion Several Muscles with Different Functions Work together to create single DOF (Fine motion and Gross Motion)

Muscle for Gross Motions

Muscles for Fine Motions

Single muscle for several motions Some muscles are connected to multiple bones

Flexor digitorum profundus: connected to four fingers

Flexor digitorum superficialis

Figure by MIT OCW. This is a diagram of deep anterior muscle of the arm. Please note that several muscles are used for activating single DOF, meaning several muscles are attahed to the same bone, and sometimes single muscle is connected to multiple bones. For example this gross motion

Muscles for Fine Motions

Gross Motions

profundus

Muscles for

F lexor digitorum

Figure by MIT OCW.

Coupled SegmentsIndependent Segments

Embodiment of the muscle-tendon-bone coupled architecture

Architectural Characteristics

Conventional Architecture

Current Muscle-Like actuators use this architecture

1. Actuators as a whole 2. One actuator per each degree of freedom

Muscle-like Architecture

1. Segmented architecture2. Coupled architecture

Multiple actuators for each degree of freedom and some actuators drive several d.o.f.

So in summary so far, the architectural characteristics of actuators using conventional approach is that each actuator is treated as a whole, and there is only actuator per each degree of freedom. Where as muscle-like approach would be to have a segmented architecture, and coupled architecure. And systems developed with artificial muscle actuators don’t necessarily have a muscle-like architecture.

Implementation using Thermoelectric Devices

Top View of Actuator Array built with SMA sandwiched between Thermoelectric Modules

Postures of the human hand

PINCH1 PINCH4

POINT

For daily manipulative tasks we use only a limited number of hand postures.

OPEN SURVEY ENVELOPE1 ENVELOPE2

BALL GRIP1 BALL GRIP2 FIST GRIP1 FIST GRIP2

PINCH2 PINCH3

WRITE

Photos removed for copyright reasons.

Optimal Design: Minimum Segmentation

Two-dimensional segmentation of multi-axis SMA actuator system for Robotic Hand

Segmentation Designed to Minimize the Number of Segments Based on Trajectory of Each Actuator Total of 21 Segments → reduction from 50 segments

Axis 3

Axis 2

Axis 4

Axis 7

Axis 6

Axis 1

Axis 9

Axis 8

Axis 10

Axis 5

Each posture can be represented by 21 bits of 0’s and 1’s

1.OPEN

Axis 3

Axis 2

Axis 4

Axis 7

Axis 6

Axis 1

Axis 9

Axis 8

Axis 10

Axis 5


2.SURVEY

Axis 3

Axis 2

Axis 4

Axis 7

Axis 6

Axis 1

Axis 9

Axis 8

Axis 10

Axis 5


3.ENVELOPE1

Axis 3

Axis 2

Axis 4

Axis 7

Axis 6

Axis 1

Axis 9

Axis 8

Axis 10

Axis 5


4.ENVELOPE2

Axis 3

Axis 2

Axis 4

Axis 7

Axis 6

Axis 1

Axis 9

Axis 8

Axis 10

Axis 5


5.BALL GRIP1

Axis 3

Axis 2

Axis 4

Axis 7

Axis 6

Axis 1

Axis 9

Axis 8

Axis 10

Axis 5


6.BALL GRIP2

Axis 3

Axis 2

Axis 4

Axis 7

Axis 6

Axis 1

Axis 9

Axis 8

Axis 10

Axis 5


7.FIST GRIP1

Axis 3

Axis 2

Axis 4

Axis 7

Axis 6

Axis 1

Axis 9

Axis 8

Axis 10

Axis 5


8.FIST GRIP2

Axis 3

Axis 2

Axis 4

Axis 7

Axis 6

Axis 1

Axis 9

Axis 8

Axis 10

Axis 5


9.PINCH1

Axis 3

Axis 2

Axis 4

Axis 7

Axis 6

Axis 1

Axis 9

Axis 8

Axis 10

Axis 5


10.PINCH2

Axis 3

Axis 2

Axis 4

Axis 7

Axis 6

Axis 1

Axis 9

Axis 8

Axis 10

Axis 5


11.PINCH3

Axis 3

Axis 2

Axis 4

Axis 7

Axis 6

Axis 1

Axis 9

Axis 8

Axis 10

Axis 5


12.PINCH4

Axis 3

Axis 2

Axis 4

Axis 7

Axis 6

Axis 1

Axis 9

Axis 8

Axis 10

Axis 5


13.POINT

Axis 3

Axis 2

Axis 4

Axis 7

Axis 6

Axis 1

Axis 9

Axis 8

Axis 10

Axis 5


14.WRITE

Axis 3

Axis 2

Axis 4

Axis 7

Axis 6

Axis 1

Axis 9

Axis 8

Axis 10

Axis 5


10 Axes of actuator array controlled by 12 ON-OFF controllers

Peltier Effect Thermoelectric Devices Programmable Array

Jumper Cable Terminals

Five-Fingered HandWith 10 DOF Actuators

Power Grip 10 Axis SMA Wires

Temperature Sensors

Coupled Motions

Coupled Motions

Cellular Actuators

• Think small! Control of small building blocks

• Think big! A vast number of DOF streamlined

• Think simple! Finite state machines: Software

• Think as a system! A system exhibits something special

Cognition: Another grand challenge

Photo of MIT's Cog robot removed for copyright reasons.See http://www.ai.mit.edu/projects/humanoid-robotics-group/cog/cog.html.

http://www.ai.mit.edu/projects/humanoid-robotics-group/cog/cog.html

Home Robotics in Japan

Photos removed for copyright reasons.See http://www.menzelphoto.com/gallery/big/robo2.htm.

http://www.menzelphoto.com/gallery/big/robo2.htm

Home Robotics

NEC Personal Assistant Robot R100



Your mom said, “…”

Pet robot, “Tama”, can comfort and heal the elderly and the disabled

UbiquitousHome

Robotics

H. Asada, MIT Exoskeleton Rehabilitation Suit

FingernailSensors for Human-Machine Interface Ring Sensor

Repositioning Active Bed Sheet

Wearable HealthMonitoring

Health Chair

Monitor pilot light in furnace Monitor fire

alarms

Monitor heating and

cooling

Monitor windows &

doors

Pet Monitoring

Home Appliance Maintenance

Home Security

Robot Market

• Home robotics – Vacuum cleaner robots – Entertainment – Hobby/education

• Elderly care • Security

Santa’s Home Delivery Robot2.12 Introduction to Robotics

Final Project

Final Project Demonstration• 2:30 Meet in the 2.12 Lab

Final check/preparation • 2:50 Move your machine to the pit in

front of the graduate machine shop • 3:00 Welcome and introduction, Chorus• 3:10 Task 1 and Task 2 Demo

Have the robot run from the North Station to the Village • 3:25 Task 3 and Task 4 Demo within the Village• 3:40 Task 5 and Task 6 (if presentable) • 3:50 Award presentation

» Best Group Award: 2.12 Robot Hall-of-Fame » Rudolph Prize (MVP)

• 4:00 Refreshments

2.12 Lab Pappalardo Lab Entrance

North Pole StationElevator

Robot Pits

Doll House Village

Polar Express Way d’Arbeloff Lab Entrance

2.12 Lab Doll House Village

No. 9 Magnet First Doll House

Chimney (Second Doll House)

Third Doll House Polar Express Way

Documents

Humanoids and - dspace.mit.edudspace.mit.edu/bitstream/handle/1721.1/34967/2-12Fall-2004/NR/rdo… · Humanoids and 2.12 Final Lecture Biologically-Inspired Robots Where are we going