Describes dual mode control of walk and manipulation of a prototype hexapod with integrated limb mechanism, named MELMANTIS-1. MELMANTIS-1 uses six-bar linkages with four degrees-of-freedom as an integrated limb mechanism with dual use for a leg and for an arm. Omni-directional drive control is introduced to the hexapod walk with alternative tripod gait. The transformation from hexapod walking style into the combination of dual arms and quadruped platform is introduced. A remote control to handle an object by dual arms is experimented with in a simple application of a trash pitcher.

Describes the development of a leg-wheel hybrid mobile robot and its step-passing algorithm. The authors have been developing a mobile robot named "Walk'n Roll". It has a leg-wheel hybrid locomotion mechanism. The robot has four legs, and a wheel is attached at the end of each leg. Legged locomotion has high adaptability for rough terrain, and wheeled locomotion possesses speed and efficiency. One of the obstacles that a wheeled vehicle can not pass is a step. A control algorithm for the leg-wheel hybrid mobile robot to pass a step is considered. The developed algorithm is implemented on Walk'n Roll, and is evaluated experimentally.

The research aim is to apply locomotive robots to rescue tasks, such as searching for sufferers and removing obstacles to save sufferers. The paper discusses the exploitation of arm and leg integrated robots and basic experiments of infrared probing sensor, in the application of rescue tasks. First, the limb mechanism is introduced and discussed in the aspect of locomotion capability and stability in rough terrain of disaster area. Then, the probing sensor is evaluated in the aspect of its detection range and capability. Assuming the sensor is mounted on the tip of robot arm for probing, the probing algorithm is proposed to find quickly and locate precisely a sufferer. The basic experiments have been carried out using a parallel arm to confirm the applicability and the usefulness of the proposed rescue system.

Describes the mechanism and control of a leg-wheel hybrid mobile robot. Legged locomotion has high adaptability for rough terrain, and wheeled locomotion possesses speed and efficiency. A locomotion mechanism that combines legs and wheels is proposed, and a prototype mobile robot that adopts the mechanism is introduced. The robot has four legs, and a wheel is attached at the end of each leg. The front leg has three joints and a passive wheel. The rear leg has one joint and an active wheel. In order to make the best of the mechanism, three locomotion modes, wheel mode, hybrid mode, and step mode, are developed. In the wheel mode, four wheels are used on flat terrain. On rough terrain, the hybrid mode is selected, and two legs and two active wheels are used for locomotion. To climb or descend a large step, the step mode is used.

This paper describes a walking control scheme for a quadruped robot. In conventional walking control scheme, the leg motion is generated from the robot moving trajectory beforehand and it is difficult to control in real time. The proposed control scheme employs a real time command from a human operator instead of the moving trajectory. The operator gives a current planar moving velocity command to the robot. Body propulsive action is basically continued according with the command unless a problem arises. When a foot reaches the border of the work space of the leg, the body propulsive actions is interrupted and a supporting foot pattern is changed. That is, a foot's arrival at the border is considered as an event to trigger a recovery action for the body propulsion. The recovery actions are decided to converge to the intermittent crawl gait when straight walking command is continued. The proposed control scheme is evaluated using actual walking robot.

This paper describes a control method of a manipulator mounted on a quadruped walking robot. One of the advantages of legged robots is the capability to change the body position and posture without changing the foot points. When a manipulator is mounted on a legged robot, it obtains extra motion from the body. By coordinating leg motion and manipulator motion, the end-effector has more sophisticated motion. When six degrees of freedom velocity command of the end-effector is supplied the proposed control method gives each joint velocity of the manipulator and the legs. This control method is experimentally evaluated using actual robot.

This paper describes the mechanical design and basic control of a prototype hexapod with "integrated limb mechanism", named MELMANTIS. MELMANTIS uses a six-bar linkage with four degrees of freedom as an example of integrated limb mechanism with both advantages for leg and for arm. The kinematic analysis is done for mechanical design. Basic control program of MELMANTIS is developed to experiment simple walking motion and transformation from a leg into an arm.

The concept of "limb mechanism" is proposed, consisting of several common link mechanisms which can be used for either arm or leg, selectively. Integrated kinematics is introduced for r legs and one arm mechanism. Based on the derived kinematics evaluation criteria are introduced in order to design the mechanism itself as well as a motion controller. Simulation results show how the proposed methods work effectively to analyze motion of the integrated mechanism.

This paper provides a new concept for the integration of locomotion and manipulation, "the integrated limb mechanism". The concept covers the technical fields both of the control integration and of the mechanism integration necessary for the practical working robot. Here, a six-bar linkage mechanism with four degrees-of-freedom is introduced as an example of the integrated limb mechanism with both advantages for leg sand for arms. Computer simulation with a dynamic model is performed to verify the transformability from leg posture into arm posture of this mechanism. The kinematic analysis is done for this mechanism, and it is suggested that the kinematic analysis is useful for the geometric and mechanical design. The possibility of dual arms or triple arm work is analyzed.

An excavation robot is required to build a large scale underground dome. The excavation robot is developed which is composed of a parallel manipulator and four legged locomotion machine. Although the parallel manipulator has a nice feature of producing large force required for the excavation, cooperative control should be considered to achieve effective excavation. This paper discusses integrated kinematics for r legs and parallel arm mechanism for analysis of the mechanism and its control. Based on the derived kinematics, evaluation criteria are introduced in order to design the mechanism itself as well as the motion controller. Numerical examples show how the proposed methods work effectively to analyze motion of the integrated mechanism.

This paper introduces a new concept for the integration of locomotion and manipulation. "the integrated limb mechanism" covers the technical fields of both the control integration and the mechanism integration necessary for the practical working robot. Here, a six-bar linkage mechanism with four degrees-of-freedom is introduced as an example of integrated limb mechanism. Kinematic analysis for the geometric and mechanical design suggests that the mechanism satisfies a contradictory conditions, not only for leg with slow heavy motion in downward posture, but also for arm with fast light motion in upward posture. The work space that two or three arms can reach is analyzed and evaluated by volume numerically for dual arm work and triple arm work. According to these analysis, a prototype hexapod with integrated limb mechanism, "MELMANTIS", was made.