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IEEE JOURNAL OF ROBOTICS AND AUTOMATION, VOL. RA-3, NO. 2

APRIL

66

Book

Reviews

In t roduc t ion to Robotics : Mechanics

and

Control-John J. Craig

Reading, MA: Addison-Wesley, 1985,

400

pp.) Reviewed by

Frank

L

Merat Department

of

Electrical Engineering and

Applied Physics Case Institute

of

Technology Case Western

Reserve University Cleveland OH 441 6 USA.

I have found Craigs book to be an excellently written robotics

textbook. I have actually used it in an introductory graduate course n

robotics where was previously using Richard auls

Robot

Manipulators.

Overall,

I

have found the text to b e outstanding. The

material is developed in a logical manner.

Chapter

2

reviews basic three-dimensional frames and frame

orientations such as RPY orEu ler angles) and he ransforms

between frames. Although this is simple material to the mechanical

engineer, this section was simply written and electrical engineering

students had no trouble with the material.

Chapters and

4

cov er forw ard nd inverse kinematics. Craig uses

the Denavit-Hartenberg convention and his examples for assigning

frames are well illustrated. The book does not address robot w ork

envelopes and concentrates on m echanics rather than robot specifica-

tions. Craig seems to be averse to prismatic joints-almost all of his

homew ork and example problems use rotary joints-which allowed

for the instructors use of prismatic joints in many ho mework and

exam problems.

As

with most robot textbooks, this one uses several

commercial robots as examples-the PUM A

56

and the Yasukawa

Motoman L-3 instead of the usual Stanford robot).

Chapter

5

introduces the Jacobian and static fo rces and velocities.

Craig introduces velocity propagation from one rotating frame to

another) which he later uses for dynamics. Again, all examples are

for rotary oints with equivalent ormulas given for prismatic

joints,

My favorite chapter of the book is Chapter 6 on robot dynamics.

Craig uses the iterative Newton-Euler approach which is intuitively

easy for students particularlylectricalngineers) to quickly

understand. T his is not the case with the L agrange-Euler approach

which many textbo oks use. Cra ig doe s not, however, acknowledg e

the existence of o ther approaches o robot dynamics, and you will not

even find the classic closed-form Lagrange-Euler analysis of the two-

link planar manipulator.

Chapter

7

develops trajectorygeneration in joint and Cartesian

space. Chapters

8

and

9

discuss robot control. The reader expecting a

classical discussion of PID controllers will be disappointed here.

There is no discussion of simple control nor of dc motors or any

hard echnology. Crai g instead uses the deaofacontrol law

which computes forces and which can be used to partition complex

control problems into simple ervocontrolproblems.This is an

excellent approach, particularly for forc e control, if the student has a

goodcontrolbackground.Overall, hecontrolchapters are well

written with an excellent discussion of practical limits on co

algorithms; however, there are o clear obot control examples

section, which limits its utility a s a textbook.

Chapter 10 on robot programming languages is a simple intr

tion to programm ing languages with three six-line program e

ples. The chapter s very cursory and almost seems to have

added

as

an afterthought.

Overall, th e book is an excellent introduction to robotics. Th

very little concentration on technology and, nstead, Craig co

trates on robotics. The book is well written, with the exam

logically placed. For a new textbook, it is almost error-free-I f

only one typographical error in the book. The homework prob

covered he text material well, and as an nstructor, I apprec

Craigs relative ranking of he difficulty of theproblems w

allowed me o composehomew ork assignments rapidly. Unf

nately, there is no homew ork solution manual to facilitate furthe

instructors job. A very nice touch is the inclusion of program

exercises at he end of eachchapter.Theseprograms tart

implementations of simpleransformsndnd with com

simulation of

a

three-link planar manipulator. Theprogramm

exercises ar e well organized and illustrate m anyf the limitation

advantages of robot simulation; how ever, there s no way an ord

class can be expected to perform all

24

programming exercises

many of the ex ercises rely upon the solution to prev ious exerc

Having some form of solution available forhe rogramming

exercises would be a definite plus to instructors.

Craig only discusses the Newton-Euler approach to robo

namics. Having taught both Newton-Euler and Lagrange-E

approaches,

I

found that Craigs Newton-Euler was very easy fo

students to grasp with well-done examples.

One of my major criticisms of the books is the section on c o

As

it says on he flyleaf, he book, ...is directly of use to

engineers d eveloping ro botic ystem s..

.

and this approach sho

his treatment

of

control systems. T here is no review o r discussi

simple IDontrol methods; instead,Craig uses controla

partitioning. This is fine for a reference book, but a poor choice

robotics textbook.

Robot programm ing languages may as well not have been cov

The chapter gives three six-line-or-less programm ing example

briefly mentions several commercial programm ing languages.

In summary, th e book s an excellent textbook or referenc

robot kinematics and dynamics. Craigs chapters on kinematic

dynamics ar e the best w ritten and easiest to follow that I have

read.The ontrolection is well written but

is

probably

comprehensiveenough for a irstcourse

in

robotics. Finall

mention whatsoever is made of robot sensors-especially com

vision-which is now an integral part of many robotics course

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