Dexterous Whole-boby Manipulation of Humanoid robot

在本财年，我们的目标是实现用人形机器人动态举起重物的动作。提升运动的关键问题是如何减轻采用低功率执行器的仿人手臂上的载荷。众所周知，使用单一的手臂姿势可以避免手臂的致动器饱和。我们首先发展了选择运动的初始和最终静态稳定状态的方法。这两种状态都是通过对低功率肢体采取单一姿势，而对高功率肢体采取高可操纵性姿态来获得的。因此，我们解决了如何将对象从初始状态移动到最终状态，通过不稳定区域，在不稳定区域中，由于执行器饱和，机器人不能静态地保持对象。为了生成动态提升运动，我们提出了一种基于优化方法的运动规划器，该方法更好地利用了执行器的特性。在优化过程中，以执行器的输出极限为约束条件，以零矩点(ZMP)为基础，使执行器的能量消耗最小。通过将物体向上加速和物体滑入物体下方两种不同的类人运动相结合，我们证明了该方法能够在举起物体的同时将一种奇异的手臂姿势转换为另一种姿势。通过使用Kawada工业公司开发的仿人机器人HRP-2进行仿真和实验，验证了所提出的减轻手臂负载的方法的有效性。我们证实，重量超过机器人重量的40%的重物可以在5秒内举过机器人的头部。部分成果在全国会议和国际会议上公布。

In this fiscal year, our goal is to realize a motion of lifting a heavy object dynamically with the humanoid robot. Key issue of lifting motion is how to reduce the load on humanoid arms in which lowed power actuators are implemented. The use of singular postures of arms is well-known to avoid actuator saturation of the arms. We firstly develop the method of selecting initial and final statically stable states of the motion. Both states are obtained by taking singular posture for low powered limbs, and high-manipulability posture for high powered ones. We thus address how to move the object from initial sate to final one passing through the unstable area in which the robot cannot hold the object statically due to saturation of the actuators. To generate the dynamic lifting motion, we propose a motion planner based on an optimization method with making better use of actuator's characteristics. In the optimization, the energy consumption of the actuators is minimized under constraints of the output limit of actuators, and stability based on the zero moment point(ZMP). By combining two different kinds of humanoid's motions such as accelerating an object upward and sliding the body into under the object, we show that the method enables to transit one singular posture of arms to another while lifting the object. We verify the effectiveness of the proposed method for reducing the load on the arms through simulation and experiments using the humanoid robot HRP-2 developed by Kawada Industries Inc. We confirm that a heavy object whose weight is more than forty percents of that of the robot can be lifted above the head of the robot within five seconds. A part of the results are presented in the National conference, and the International conference.