In this paper, an action space description“StateNet”is introduced. It includes an automatic error recovery function. Robots should be able to go on moving without human support even if they fall into an unexpected situation. However, it is very difficult for developers to write all error handlers, especially in the case the robot has various actions and acts in various situations. So the description must includes relations between actions and situations. The action space is described as a state transition graph which is defined in a state space constructed by sensory information. Using a state and path generation, a distance calculation and a path finding, the automatic error recovery function is realized. Finally, StateNet is implemented on a remote-brained humanoid robot and its effect is confirmed.
In teleoperation of manipulators, the positions and velocities of the slave actuators should resemble those of the master controls to help the operator project his presence into the slave space. Direct viewing by TV has been in-corporated into teleoperator design based on this philosophy, and then becomes a most common sensor subsystem of teleoperator. Force reflection to the operator is also recognized as a useful sensory correspondence for enhancing the operator's identification with the task at hand. Several exoskeletal devices have been proposed as the master arms for the force reflection. However, the mechanisms become complicated because the arms should have the same number of active joints as the slave manipulators; moreover, those provide not only the required sensory feedbacks on the operator but also uncomfortable constraints. So as to overcome this difficulty, we propose a new man-machine interface in which functional electrical stimulation is used to present the reaction forces to the operator. Three small electrodes and two small position/orientation sensors are attached on the skin of the upper limb of the operator. Force reflection from the slave manipulator to the operator is achieved by functional electrical stimulation through the surface electrodes. There is no mechanical element in our master subsystem because the upper limb of the operator works as the master arm by itself. It is shown in this paper that the proposed structure of master subsystem allows the operator to be released from the unnecessary constraints of exoskeletal devices. The effectiveness of the proposed teleoperator is illustrated by several experiments with a seven axis slave manipulator.
In this paper, we propose a planar parts mating method using structured compliance. First, a simple example of parts mating illustrates importance of structure of compliance between parts. Then, parts mating using the structured compliance is proposed. Structure of compliance is determined by a coordinate system describing compliant motion of a part. The structure of compliance, position of compliance center for planar parts mating, is designed based on motion constraints between parts. How the structure of compliance is designed is illustrated using examples.
Master-slave system takes advantage of human cognitive and sensorimotor skills. However, in conventional system, the operator's visual and haptic frames of reference are widely separated. This lack of registration of sensory infor-mation causes a mental burden and contributes to a long learning curve in acquiring skills. Therefore, an intuitive teleoperation based on a natural and instinctive manner is strongly desired. In this study, keeping medical applications in mind, the master console with a compact spherical stereoscopic display, namedMicro Dome, is developed and the accurate visual/haptic registration is realized based on the framework of a mixed reality. The operator looks like a fortuneteller viewing a crystal ball and can use his full set of daily experiences. The validity of proposed system is demonstrated by experiments of teleoperation.
This paper describes a slip sensor using Acoustic Resonant Tensor Cell (ARTC) . This slip sensor is made smaller than previous researches. We conducted a finite element method simulation to ensure the hypothesis of slip detection. Then we propose how to feedback the slip information to grasping force. Furthermore its performance of slip detection is shown through experiments for evalueation.
There are some researches which perform complex manipulation tasks with low degree-of-freedom manipulator by sliding, rolling, releasing, etc. They are called dynamic manipulation. In this paper, tossing manipulation is introduced as one of dynamic manipulation. A 1 degree-of-freedom manipulator swings its arm to roll/slide an object on it, and then tosses it to locate to goal position. This paper shows an analysis and a simulation of kinematic model of tossing manipulation. Performance indices are implemented to solve inverse problem, and they enable to manipulate an object variously. Finally some experiments and their consideration are discussed.
This paper is concerned with quantitative evaluation of disturbance torques caused by irregular terrain when a mobile manipulator travels on the terrain. Mobile manipulators can improve their work efficiencies by performing moving operations. However, disturbances generated from terrain disturb correct moving operations because irregularities exist even on a man-made floor. When the mobile manipulator travels on irregular terrain, disturbance torques are induced by inertial forces, centrifugal and Coriolis forces and gravitational forces, respectively. Although the influences can not be ignored for correct operations, such problems have not been discussed. Then, we have proposed the model of a dynamic mobile manipulator traveling on irregular terrain in the vertical plane. In this paper, we clarified relationships between disturbance torques caused from irregular terrain, the amplitudes of terrain, traveling speeds and terrain shapes. First, the calculation method of disturbance torques are defined based on the proposed model. Second, simulations in which the mobile manipulator travels on the simple cosine shape are performed. Third, changes in disturbance torques in case that the mobile manipulator travels on the two different shapes of terrain are discussed. Finally, dominant disturbance torques caused from terrain are clarified quantitatively.
In this paper, we introduce 6DOF (degree-of-freedom) finger-mounted haptic device which we have developed. When we operate virtual objects with our fingers, it is necessary to use 6DOF finger-mounted haptic device. But such a device is often so large with many actuators equipped, that most of these reserches to operate virtual objects with haptic device have been done using those with only 3DOF. It is clear, however, that we need to use 6DOF haptic device for more detailed operation. Thus, we developed a small-sized, finger-mounted haptic device, with the mechanism of bevel gear, and then confirmed its operational effectivness by operating a virtual object with two fingers. To calculate force and moment at the state of contact in virtual world, we have used“friction contact model”.