This paper deals with the trajectory planning of a soccer ball driven by a kicking robot. The trajectory of a ball is function of its initial velocity, launch angle, and some aerodynamic effect. Specially, the initial velocity is created by an instant impulse given to the ball. The external impulse exerted to a ball by a kicking robot is function of robot geometry and dynamic parameters. Initially, we analyze the external impulses for several kicking postures and simulate trajectories for several different kicking conditions. Based on this observation, a trajectory-planning algorithm of a ball, in which the initial velocity and the launch angle of the ball are calculated for a desired trajectory of the ball, is proposed, and then an external impulse required for that motion is calculated and applied to the kicking simulation. The aerodynamic effect such as drag force and lift force is also incorporated into the dynamic simulation of the soccer ball. A kicking robot has been developed for experimental verification of the proposed analytical methodology. It was shown that experimental result is in good agreement with simulation result within 10% error bound.

The human body exploits "redundant degree of freedom" to execute various motions in a suitable fashion. This work deals with development of effective redundancy resolution algorithms for the motion control of humanoid. Differently from the typical kinematically redundant robots that are attached to the fixed ground, the ZMP condition should be taken into account in the human body motion in order to guarantee the system stability. For this, a geometric constraint equation is derived by reshaping the existing ZMP equation. This constraint equation is formed like a second order kinematic equation, which enables one to plan the ZMP trajectory in a feedforward fashion. This constraint equation and the kinematic equation of the humanoid model are solved together. A sequential redundancy resolution algorithm exploiting the remaining kinematic redundancy is also proposed to optimize several secondary criteria such as joint limit index and manipulability. The feasibility of the proposed algorithms is verified by simulating a stable standing up motion and a planar walking motion though planar 5 DOF and 6 DOF humanoid models.

This paper deals with motion generation algorithm considering the external and internal impulses. Initially, we analyze the trend of the impulses with a simple 3-DOF planar robot arm in various contact positions and present a problem that is in discord with the general trend. To cope with this problem, we propose a new motion generation algorithm considering both the external and internal impulse. The gradient projection method is employed to exploit the kinematic redundancy of robot systems. Initially, the effectiveness of the proposed algorithms is verified through simulation of a 3-DOF planar robot arm model, and two application examples considering both the external and internal impulses are investigated. Through simulations for the landing of a 4-DOF planar human-body model and the sawing motion by a dual-arm model, it is shown that the posture is stable and the trend of the impulses calculated by the analytical models is coincident to the human experiences.

This paper deals with modeling and analysis for the landing motion of a human-body model. First, the dynamic model of a floating human body and the impact model are derived and the external impulse exerted on the ground as well as the internal impulse experienced at the joints of the human body model are investigated. Second, a motion planning algorithm exploiting the kinematic redundancy is suggested to ensure stability in terms of ZMP stability condition during a series of landing phases. Four phases of landing motion are investigated. In simulation, the external and internal impulses experienced at the human joints and the ZMP history resulting from the motion planning are analyzed for two different configurations. A desired landing posture is suggested by comparison of the simulation results.

In a humanoid robot system, many human-body motions such as walking, running and jumping require large power. To achieve a high power-to-weight ratio, this paper proposes a new design of the leg mechanism using parallel kinematic chains involving redundant actuators. The kinematics for the leg mechanism is derived and a kinematic index to measure force transmission ratio are introduced. It is demonstrated through simulation that incorporation of redundant actuator into the leg mechanism enhances the power of the mechanism approximately 4 times of the minimum actuation. The leg mechanism is developed and has been integrated into the biomimetic system for the purpose of payload enhancement.

We discuss an inherent problem occurring in the former operational-based compliance control scheme. In order to obviate this problem, an independent joint-based compliance control scheme is proposed. This control method requires that for the adjustment of the operational compliance matrix, a manipulator should have at least the same number of joints as the number of independent components of the desired compliance matrix specified in the operational space. Types of robot structures which are appropriate to independent joint-based compliance scheme are addressed. A five-bar finger with redundant actuators is treated as an illustrative example. Our experimental results show that the proposed compliance modulation method gave satisfactory performance. We also consider an additional stiffness effect due to the antagonistic conflict between the controlled-operational force and the equilibrium joint torque vector. It is also experimentally shown that this additional term notably improved the force tracking performance of the given mechanism.