Facts About the New Four-Legged Robot

Kinematics of the New Four-Legged Robot

The new robot has 15 rotational joints (3 per leg and 3 for the neck).

Although the robot previously used in the Four-Legged League of RoboCup has the same number of joints only walking at low stance on the elbows has been used recently by almost all teams. Several reasons have led to this effect:

• At high stance the old robot more easily looses its balance when pushed aside.
• Although in principle the old robot could walk faster in high stance than in low stance because of the longer level of the legs to propel the robot's body forward, it could not be applied in practice because the point like contact of the feet with the ground slips at medium to high walking speed.
• If the ball lies in front of the feet of the old robot then if it looks down to see the ball it cannot see the environment. Simultaneous perception of the ball in front of the robot and the environment is much better in low stance of the old robot.

The design and kinematics of the new robot overcomes these deficiencies:

• At high stance the new robot is much more stable with respect to a push from aside because of its wider stance.
• Fast walking at high stance is enabled by properly designed feet.
• Also at high stance the robot can put its head down to see the ball in front of it and simultaneously glance at the environment by a specially designed neck.

Moreover the new robot can look back underneath its torso to see the world behind it upside down. It can also kick the ball underneath its torso to the back.

High stance with high head pose looking forward:

High stance with low head pose looking forward:

Head pose for looking underneath the robot to its back to see the world behind upside down or to kick the ball underneath the torso to its back: