1. Biped Robots

2. Definitions Static Walking Static Walking The centre of gravity of the robot is always within the area bounded by the feet that are touching the ground The centre of gravity of the robot is always within the area bounded by the feet that are touching the ground Dynamic Walking Dynamic Walking At significant periods during the gait the centre of gravity of the robot is outside of the area bounded by the feet that are touching the ground At significant periods during the gait the centre of gravity of the robot is outside of the area bounded by the feet that are touching the ground

3. History Dynamic Walking Toys Dynamic Walking Toys Static Walking Wind up Toys Static Walking Wind up Toys Static Walking Robots Static Walking Robots Dynamic Walking Robots Dynamic Walking Robots

4. Research Labs MIT AI Lab MIT AI Lab Waseda University Waseda University HanYang University HanYang University Honda Labs Honda Labs Sony Labs Sony Labs

5. The Walking Problem Design a gait sequence in joint space Design a gait sequence in joint space Provide sensors and actuators at joints Provide sensors and actuators at joints Implement a PID controller at each joint Implement a PID controller at each joint Command the PID controllers to follow gait sequence Command the PID controllers to follow gait sequence

6. Challenges Designing gaits that don’t violate the maximum torque available Designing gaits that don’t violate the maximum torque available PID controller will not be able to generate the large torque until the error between the gait and actual joint angle becomes too large. PID controller will not be able to generate the large torque until the error between the gait and actual joint angle becomes too large. Gait design is a time consuming process that is difficult to implement online in real time Gait design is a time consuming process that is difficult to implement online in real time

7. Raibert’s One Legged Robot One Legged One Legged Hopping/Running Hopping/Running Simple Dynamic Model Simple Dynamic Model

8. Leg Lab’s Spring Flamingo Planar biped robot Planar biped robot Linear actuators Linear actuators Inverted knees Inverted knees Toe Lift off Toe Lift off

9. Leg Lab’s M2 3D biped 3D biped Linear actuators Linear actuators

10. Waseda’s Early 3D biped Early 3D biped

11. KAIST’s DC motors DC motors Servomotors Servomotors Onboard camera Onboard camera

12. Singapore Polytechnics Roboerectus Servomotors Servomotors Gait defines servomotor setpoints Gait defines servomotor setpoints

13. Honda’s Asimo & P3 Commercial humanoid Commercial humanoid Well defined tasks Well defined tasks General Intelligence required General Intelligence required

14. Sony’s BP Entertainment Robot Entertainment Robot Commodity Structure Commodity Structure Stereo vision Stereo vision

15. Designing Gaits Controlling Balance Controlling Balance when standing, “not required” when walking when standing, “not required” when walking Controlling Speed Controlling Speed change step size (swing leg must keep up) change step size (swing leg must keep up) Controlling Height Controlling Height used to control speed and energy efficiency used to control speed and energy efficiency Generate intermediate joint angles based on these constraints Generate intermediate joint angles based on these constraints

16. Biped Robot Simulators Kinematic Simulators Kinematic Simulators for gait design for gait design Dynamic Simulators Dynamic Simulators for control system testing for control system testing Yobotics Simulation Construction Set Yobotics Simulation Construction Set dynamic simulation of linked mechanisms dynamic simulation of linked mechanisms