Satoki Tsuichihara, Ph. D.
Department of Mechanical Engineering, Faculty of Science and Technology, Tokyo University of Science
2641 Yamazaki, Noda, Chiba, Japan
Email: satoki-t@rs.tus.ac.jp
"Real-time whole-body motion generation using torso posture regression and center of mass"
Abstract:
For household humanoid robots, reaching as much
workspace as possible with their hands is an important issue
because the locations of target objects may range from the
floor to above the robot’s head (Figure 1). At the same time,
to adapt to the constantly-changing household environment,
inverse kinematics for the whole body must be solved in real
time.
In our contribution, to achieve real-time motion generation
for a humanoid robot, we propose a method of separating the
inverse kinematics calculation into simpler problems. Using
regression to estimate the torso orientation, we independently
solve inverse kinematics for the lower body and both arms.
First, using the target pose of both hands as input, we calculate
the orientation of the torso and determine the target position of
the center of mass considering the reachability of both arms.
At each control step, we calculate the joint angles of the lower
body from the position of the center of mass, feet poses, and
torso orientation. Then, we calculate the joint angles of both
arms.
In experiments, we apply the proposed method to a human-
size humanoid robot for reaching low-height positions while
hunkering down. The proposed inverse kinematics solver is
faster than the numerical solution using the Jacobian matrix.