1. Realization of Dynamic Walking of Biped Humanoid Robot
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology
Jung-Yup Kim

2. Jung-Yup Kim Biped Walking Basic Structure for Biped Walking
Observation Human Walking Motions
Simple Dynamic Model
Walking Pattern
Planning
(slow process)
Biped Walking
Posture
Stabilization
(fast process)
Online Controller Design Based On Sensory Feedback
Vibration Controller
ZMP Compensator
Landing Position Controller
Landing Timing Controller .
System ID Based on Experiments
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology
Jung-Yup Kim

3. Jung-Yup Kim - basically cyclic function
Walking pattern design parameters
Description
Value
Apelvis
Lateral swing amplitude of pelvis
32 (mm)
Hfoot
Maximum elevation of foot
40 (mm)
Tstride
Walking period
(stride time)
1.9 (seconds)
Tstep
Step time
0.95 (seconds)
Tdelay
Delay time
0.2 (second)
Double support ratio
0.05 (5 %)
Tssp
Single support time
Tdsp
Double support time
Cosine function is used to generate smooth curve
- basically cyclic function
- easy to prevent velocity discontinuity
- easy to differentiate the function
Jung-Yup Kim
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology

4. Jung-Yup Kim • Online Control Structure + -
Walking
Parameters
Setting
: Step length, step period, DSP ratio …
Walking Pattern
Control (WPC)
Walking Type
Selection
: Go forward/backward, Turning around, Go aside
Torso
Roll & Pitch
Controller
Walking
Pattern
Generation
Real-Time Balance Control (RTBC)
Pelvis
Swing Amp.
Controller
Upright
Pose
Controller
Inverse
Kinematics
Landing
Position
Controller
Cartesian Space + -
Joint
Space
Tilt Over
Controller
Soft
Landing
Controller
PD controller
Vibration
controller
ZMP
Compensator
Landing
Timing
Controller
HUBO
Predictive Motion
Control(PMC)
Landing
Detection
Jung-Yup Kim
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology

5. Walking Pattern Control
Modifies the walking pattern at every walking cycle.
Learning strategy :
Jung-Yup Kim
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology

6. Activation Time Table of Online Controllers
Grey box : controller is active.
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology
Jung-Yup Kim

7. (1) Vibration Control Jung-Yup Kim
Objective : Suppress the vibrations due to the joint compliance.
(a) Vibration control of torso
Jung-Yup Kim
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology

8. (1) Vibration Control Jung-Yup Kim
Objective : Suppress the vibrations due to the joint compliance.
(b) Vibration control of swing foot
Jung-Yup Kim
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology

9. Jung-Yup Kim Modeling u + - HUBO Lab, Humanoid Robot Research Center,
Mathematical Model
Equation of motion
Transfer function
Modeling
where,
: Desired ankle joint angle
: Actual ankle joint angle
: measured torque at F/T sensor
Torque of ankle joint
Ref. input of ankle joint u +
Feedback Control -
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology
Observer
Damping ratio can be assigned freely by changing kd
Observer equation
Jung-Yup Kim

10. Jung-Yup Kim HUBO Lab, Humanoid Robot Research Center,
Root-Locus
: Closed loop pole
Experimental Results
Jung-Yup Kim
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology

11. Jung-Yup Kim - HUBO Lab, Humanoid Robot Research Center,
Mathematical Model
Equation of motion
Hip Pitching Joint
Hip Roll Joint
Swinging
leg
Swinging
leg
Transfer function
Supporting
leg
Supporting
leg
Coronal Plane View
Sagittal Plane View
: Desired hip joint angle
: Actual hip joint angle
Feedback Control
Lead compensator
Plant -
Double
Integrator
Accelerometer
Jung-Yup Kim
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology

12. Jung-Yup Kim HUBO Lab, Humanoid Robot Research Center,
Root-Locus
Damping ratio can be increased !!
: Closed loop pole
Experimental Results
Jung-Yup Kim
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology

13. (2)ZMP Compensator Jung-Yup Kim
Objective : Maintain dynamic balance all the time.
Pelvis Center
Transverse Plane Z Z Z Y Y Y
ZMP X X X
Mode 1
(Double Support Phase)
Mode 2
(Double Support Phase)
Mode 3
(Single Support Phase)
Horizontal pelvis motion on the transverse plane is used
for the ZMP compensation
Jung-Yup Kim
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology

14. Jung-Yup Kim 1) For Mode 3 (Single Support Phase) :
System identification using frequency response test
Bode Plot
Jung-Yup Kim
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology

15. Jung-Yup Kim 2) For Mode 1 and 2 (Double Support Phase) :
System identification using a simple inverted pendulum model
Laplace Transform
We can derive unknown K, l through simple experiments !!!
Jung-Yup Kim
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology

16. Jung-Yup Kim Pole placement and step response simulation
Feedback Control + -
Jung-Yup Kim
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology

17. Jung-Yup Kim Experimental results (Mode 3) Video
Steady-state error is nearly zero !
Video
Jung-Yup Kim
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology

18. (3) Landing Position Control
Objective : Find out best landing position at every step.
Just before landing
Just after landing
Impulse-Momentum Principle on the Coronal Plane :
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology
Jung-Yup Kim

19. Jung-Yup Kim Principle HUBO Lab, Humanoid Robot Research Center,
The moment of inertia is constant
Angular impulse
(1)
Desired angular
momentum
after landing
(constant)
Measured angular
momentum
before landing
(variable)
Control Input
(2)
By the way,
Moment of ankle joint
at ground contact
(constant)
Finally,
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology
Jung-Yup Kim

20. Jung-Yup Kim Experimental results Video
Without control
With control
Without control
With control
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology
Jung-Yup Kim

21. (4) Landing Timing Control
Objective : Find out best landing time at every step.
Stable region
Prescribed
left foot
height
Prescribed
right foot
height A B A B
Angular velocity of body
Angular Velocity[deg/s] or
Displacement[mm] E
Time [sec]
ZCP(Zero Crossing Point)
(inside tilt over case) E
ZCP(Zero crossing point)
(normal case)
(Coronal Plane View)
Compensated
right foot
altitude
Angular velocity,
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology
Jung-Yup Kim

22. (5) Stable Landing Control
Objective : Absorb the landing impact at every step.
Sagittal plane view
Impedance Control :
Virtual Spring & Damper 1
Virtual Spring & Damper 2 T F
HUBO Lab, Humanoid Robot Research Center,
Department of Mechanical Engineering,
Korea Advanced Institute of Science and Technology
Jung-Yup Kim