A series-elastic actuator (SEA) can provide remarkable performance benefits in a robotic system, allowing the execution of highly dynamic manuevers, such as a jump. While SEAs have been used in numerous robotic systems, no comprehensive understanding of an optimal design exists. This paper presents a new analytical basis for maximizing an SEA thrust performance for jumping from rest with an articulated leg. The analytical SEA model is validated with simulation and experimental results from a prototype leg. An SEA decouples the dynamic limitations of a dc motor actuator from the joint, allowing larger lift-off velocities than with a directly driven joint. A detailed analysis of the complex dynamic response of an SEA during the thrust phase leads to a new maximum impulse criterion, where motor speed is approximately half the no-load speed at the moment of peak motor torque. The analytical model and this proposed criterion are used to develop a simple equation for selecting SEA design parameters. Lastly, a novel unidirectional SEA design is presented that allows for accurate positioning of the leg during flight.

1.
Chu
,
D. A.
, 1998,
Jumping into Plyometrics
,
2nd ed.
,
Human Kinetics
,
Champaign, IL.
2.
Wilson
,
A.
,
Watson
,
J.
, and
Lichtwark
,
G.
, 2003, “
A Catapult Action for Rapid Limb Protraction
,”
Nature (London)
0028-0836,
421
, pp.
35
36
.
3.
Roberts
,
T.
, 2002, “
The Integrated Function of Muscle and Tendons During Locomotion
,”
Comparative Biochemistry and Physiology—Part A: Molecular & Integrative Physiology
,
133
(
4
), pp.
1087
1099
.
4.
Roberts
,
T. J.
,
Marsh
,
R. L.
,
Weyand
,
P. G.
, and
Taylor
,
C. R.
, 1997, “
Muscular Force in Running Turkeys: The Economy of Minimizing Work
,”
Science
0036-8075,
275
(
5303
), pp.
1113
1115
.
5.
Hof
,
A.
,
Geelen
,
B.
, and
Van Den Berg
,
J.
, 1983, “
Calf Muscle Moment, Work and Efficiency in Level Walking; Role of Series Elasticity
,”
J. Biomech.
0021-9290,
16
, pp.
523
535
.
6.
Kubo
,
K.
,
Kawakami
,
Y.
, and
Fukunaga
,
T.
, 1999, “
Influence of Elastic Properties of Tendon Structures on Jump Performance in Humans
,”
J. Appl. Physiol.
8750-7587,
87
(
6
), pp.
2090
2096
.
7.
Ettema
,
G. J.
, 1996, “
Mechanical Efficiency and Efficiency of Storage and Release of Series Elastic Energy in Skeletal Muscle During Stretch-Shorten Cycles
,”
J. Exp. Biol.
0022-0949,
199
(
9
), pp.
1983
1997
.
8.
Roberts
,
T. J.
, and
Marsh
,
R. L.
, 2003, “
Probing the Limits to Muscle Powered Accelerations: Lessons From Jumping Bullfrogs
,”
J. Exp. Biol.
0022-0949,
206
(
15
), pp.
2567
2580
.
9.
Bobbert
,
M. F.
, 2001, “
Dependence of Human Squat Jump Performance on the Series Elastic Compliance of the Triceps Surae: A Simulation Study
,”
J. Exp. Biol.
0022-0949,
204
, pp.
533
542
.
10.
Pratt
,
J.
,
Dilworth
,
P.
, and
Pratt
,
G.
, 1997, “
Virtual Model Control of a Bipedal Walking Robot
,” in
IEEE International Conference on Robotics and Automation
,
Albuquerque, NM
, pp.
193
198
.
11.
Pratt
,
J.
, and
Pratt
,
G.
, 1998, “
Intuitive Control of a Planar Bipedal Walking Robot
,” in
IEEE International Conference on Robotics and Automation
,
Leuven, Belgium
, pp.
2014
2021
.
12.
Franzen
,
H.
, 2001, “
Walking the Dinosaur
,” ScientificAmerican.com, available http://www.sciam.comhttp://www.sciam.com.
13.
Robinson
,
D. W.
,
Pratt
,
J. E.
,
Paluska
,
D. J.
, and
Pratt
,
G. A.
, 1999, “
Series Elastic Actuator Development for a Biomimetic Walking Robot
,” in
IEEE∕ASME International Conference on Advanced Intelligent Mechatronics
.
14.
Pratt
,
G. A.
, and
Williamson
,
M. M.
, 1986, “
Series Elastic Actuators
,” in
IEEE∕RSJ International Conference on Intelligent Robots and Systems
, Vol.
1
, pp.
399
406
.
15.
Raibert
,
M.
, 1986,
Legged Robots That Balance
,
MIT
,
Cambridge, MA
.
16.
Buchler
,
M.
, and
Koditschek
,
D. E.
, 1988, “
Analysis of a Simplified Hopping Robot
,” in
IEEE International Conference on Robotics and Automation
, pp.
817
819
.
17.
Scarfogliero
,
U.
,
Stefanini
,
C.
, and
Dario
,
P.
, 2006, “
A Bioinspired Concept for High Efficiency Locomotion in Micro Robots: The Jumping Robot Grillo
,” in
IEEE International Conference on Robotics and Automation
,
Orlando, FL
, pp.
4037
4042
.
18.
Mennitto
,
G.
, and
Buehler
,
M.
, 1996, “
Carl: A Compliant Articulated Robot Leg for Dynamic Locomotion
,”
Rob. Auton. Syst.
0921-8890,
18
, pp.
337
344
.
19.
Niiyama
,
R.
,
Nagakubo
,
A.
, and
Kuniyoshi
,
Y.
, 2007, “
Mowgli: A Bipedal Jumping and Landing Robot With an Artificial Musculoskeletal System
,” in
IEEE International Conference on Robotics and Automation
,
Rome, Italy
, pp.
2546
2551
.
20.
Paluska
,
D.
, and
Herr
,
H.
, 2006, “
The Effect of Series Elasticity on Actuator Power and Work Output: Implications for Robotic and Prosthetic Joint Design
,”
Rob. Auton. Syst.
0921-8890,
54
, pp.
277
287
.
21.
Salisbury
,
K.
, 1980, “
Active Stiffness Control of a Manipulator in Cartesian Coordinates
,” in
IEEE International Conference on Design and Control
,
Albuquerque, NM
, pp.
95
100
.
22.
Spong
,
M. W.
, 1987, “
Modeling and Control of Elastic Joint Robots
,”
ASME J. Dyn. Syst., Meas., Control
0022-0434,
109
, pp.
310
319
.
23.
Ghorbani
,
R.
, and
Wu
,
Q.
, 2006, “
Closed Loop Control of an Intentionally Adjustable Compliant Actuator
,”
American Control Conference
,
Minneapolis, MN
, pp.
3235
3240
.
24.
Yamaguchi
,
A.
, and
Takanishi
,
J.
, 1997, “
Design of Biped Walking Robots Having Antagonistic Driven Joints Using Nonlinear Spring Mechanism
,” in
IEEE∕RSJ International Conference on Intelligent Robots and Systems
,
Grenoble, France
, pp.
251
259
.
25.
Yamaguchi
,
J.
,
Nishino
,
D.
, and
Takanishi
,
A.
, 1998, “
Realization of Dynamic Biped Walking Varying Joint Stiffness Using Antagonistic Driven Joints
,” in
IEEE International Conference on Robotics and Automation
,
Leuven, Belgium
, pp.
2022
2029
.
26.
Migliore
,
S. A.
,
Brown
,
E. A.
, and
DeWeerth
,
S. P.
, 2007, “
Novel Nonlinear Elastic Actuators for Passively Controlling Robotic Joint Compliance
,”
ASME J. Mech. Des.
1050-0472,
129
, pp.
406
412
.
27.
Curran
,
S.
, 2007, “
Analysis and Optimization of a Jump for a Prototype Leg With Series-Elastic Actuation
,” MS thesis, The Ohio State University, Columbus.
28.
Knox
,
B. T.
, 2007, “
Evaluation of a Prototype Series-Compliant Hopping Leg for Biped Robot Applications
,” Undergraduate Honors thesis, The Ohio State University, Columbus.
You do not currently have access to this content.