Yuji Yamakawa

One-handed knotting of a flexible rope with a high-speed multifingered hand having tactile sensors

This paper proposes a new strategy for making knots with a high-speed multifingered robot hand having tactile sensors. The strategy is divided into three skills: loop production, rope permutation, and rope pulling. Through these three skills, a knot can be made with a single multifingered robot hand. The dynamics of the rope permutation are analyzed in order to improve the success rate, and an effective tactile feedback control method is proposed based on the analysis. Finally, experimental results are shown.

Motion planning for dynamic folding of a cloth with two high-speed robot hands and two high-speed sliders

The purpose of the work described in this paper is to achieve dynamic manipulation of a sheet-like flexible object. As one example, we examine dynamic folding of a cloth with two high-speed multifingered hands mounted on two sliders. First, dynamic folding by a human subject is analyzed in order to extract the necessary motions for realizing this task. Second, a model of a sheet-like flexible object is proposed by extending a linear flexible object model (algebraic equation) that takes advantage of high-speed robot motion. Third, motion planning of the robot system is performed by using the proposed model, and the simulation results are shown. Finally, an experiment was conducted with the robot motion obtained by the simulation.

Skillful manipulation based on high-speed sensory-motor fusion

This video introduces the demonstration of skillful manipulation using a high-speed robot system. The system consists of visual and tactile sensors at a rate of 1 kHz and a high-speed hand-arm manipulator. The high-speed sensory-motor fusion improves not just the speed of existing robot manipulations, but robotic skills by introducing the features peculiar to high-speed motion. Based on such a concept, new variations of skillful manipulation were achieved.

Dynamic compensation by fusing a high-speed actuator and high-speed visual feedback with its application to fast peg-and-hole alignment

This paper presents a dynamic compensation concept to grapple with the dynamic defects of a traditional robot arm, especially while performing high-speed endpoint regulations. The proposed high-speed dynamic compensation concept offers a new point of view for cooperating with a traditional manipulator to realize highly dexterous performance of manipulations. The concept is realized through adoption of a high-speed light-weight actuator as well as endpoint closed loop configured high-speed cameras. The dynamic compensation is analyzed experimentally with 1000 Hz visual feedback and a high-speed finger for a robot arm in the case of one degree of freedom. The advantage of the proposed approach is that the modeling for the robot system’s dynamics is not needed, whereas it is necessary and trivial in order to realize high-speed regulations by traditional approaches. Thus, the control issue becomes easier with the proposed approach. As an application for this concept, fast peg-and-hole alignment with large position and attitude uncertainty is studied. The alignment algorithm is based on a visual compliance strategy. Alignment experiments show that with the proposed concept of dynamic compensation as well as visual compliant motion control, robust and fast convergence was realized for most cases. Graphical Abstract

Knotting manipulation of a flexible rope by a multifingered hand system based on skill synthesis

In this paper, we examine the relationship between a knotting process and the individual skills of which a robot hand is capable. To determine the necessary hand skills required for knotting, we first analyzed the knotting action performed by a human subject. We identified loop production, rope permutation, and rope pulling skills. To take account of handling of the two ends of the rope, we added a rope moving skill. We determined the characteristics of these skills using an intersection-based description. The knotting process was examined based on the analysis of knots and the characteristics of the robot hand skills. Finally, we show experimental results of an overhand knot and a half hitch performed using a high-speed multifingered hand system.

Motion planning for dynamic knotting of a flexible rope with a high-speed robot arm

In this paper, we propose an entirely new strategy for dexterous manipulation of a linear flexible object with a high-speed robot arm. The strategy involves manipulating the object at high speed. By moving the robot at high speed, we can assume that the dynamic behavior of the linear flexible object can be obtained by performing algebraic calculations of the robot motion. Based on this assumption, we derive a model of the linear flexible object and confirm the validity of the proposed model. Finally, we perform simulation of dynamic knotting based on the proposed model. Results of an experiment demonstrating dynamic knotting with a high-speed robot arm are shown.

Simple Model and Deformation Control of a Flexible Rope using Constant, High-Speed Motion of a Robot Arm

In this paper, we propose an entirely new manipulation strategy for dynamic manipulation of a flexible rope with a high-speed robot arm. The manipulation strategy involves manipulating the object at a constant, high speed. Then, we can assume that the dynamic behavior of the flexible rope can be obtained by performing algebraic calculations of the robot motion using the proposed strategy. Based on this assumption, we derive a model of the flexible rope and suggest a motion planning method using the proposed model. Finally, we show experimental results of rope deformation control based on the proposed method.

Fast peg-and-hole alignment using visual compliance

This paper presents a visual compliance strategy to deal with the problem of fast peg-and-hole alignment with large position and attitude uncertainty. With the use of visual compliance and adoption of a light-weight 3-DOF active peg, decoupled alignment for position and attitude is realized. The active peg is capable of high-speed motion and with less dynamic defects than a traditional robot arm. Two high-speed cameras, one configured as eye-in-hand and the other as eye-to-hand are adopted to provide with the task-space feedback. Visual constraints for effecting the visual compliant motion are analyzed. Alignment experiments show that peg-and-hole alignment with the proposed approach could be successfully realized with robust convergence, and on average, the alignment could be realized within 0.7 s in our experimental setting.

Ultra high-speed Robot Based on 1 kHz vision system

This video introduces an ultra high-speed robot as a milestone in the history of intelligent manipulation systems. To develop the ultra high-speed robot under the concept of dynamics matching, we began with the development of a 1 kHz vision system. Next, we developed a sensory-motor fusion system by introducing the 1 kHz vision system. In addition, we have developed a new high-torque mini actuator and a high-speed multi-fingered hand with these incorporated. Integration of these components brings real-time dexterous manipulations unlike commonly-used control based on prediction or learning.

Dexterous manipulation of a rhythmic gymnastics ribbon with constant, high-speed motion of a high-speed manipulator

In this paper, we propose an entirely new manipulation strategy for dynamic manipulation of a ribbon with a high-speed manipulator. The manipulation strategy involves manipulating the object at a constant, high speed. Then, we can assume that the dynamic behavior of the ribbon can be obtained by performing algebraic calculations of the robot motion using the proposed strategy. Based on this assumption, we derive a model of the ribbon and suggest a motion planning method using the proposed model. Finally, we show experimental results of shape control of a ribbon based on the proposed method.