25 accepted papers
We developed a simple peg-in-hole strategy that uses flexible joints and peg rotations. Even when the circle peg in the peg-in-hole assembly contains position and orientation errors, it can be inserted in a passive and robust manner. Additionally, using force-torque sensors to estimate the contact p…
This letter presents a novel multi-gripper robotic hand system driven by a single motor. To achieve the operation of multiple grippers through a single motor, this study develops a new transmission mechanism that switches the torque path to each gripper using magnetic coupling and gravity. The motor
We developed a simple peg-in-hole strategy that uses flexible joints and peg rotations. Even when the circle peg in the peg-in-hole assembly contains position and orientation errors, it can be inserted in a passive and robust manner. Additionally, using force-torque sensors to estimate the contact p
This study proposes a novel robotic gripper with variable grasping configurations for grasping various objects. The fingers of the developed gripper incorporate multiple different surfaces. The gripper possesses the function of altering the finger surfaces facing a target object by rotating the fing
This letter proposes a novel robotic gripper that can expand workable spaces in a target environment to pick up objects from confined spaces. The proposed gripper is most effective for retrieving objects from deformable environments, such as taking an object out of a drawstring bag, or for extractin
This paper presents a stiffness-changeable soft finger using chain mail jamming. This finger can achieve adaptive grasping and in-hand manipulation by reshaping and exerting changeable gripping force. The jamming phenomenon happens when particles in a chamber get interlocked where confining pressure…
This study proposes a soft robotic device with a slim and flexible body that switches between air blowing and suction with a single airflow control. Suction is achieved by jet flow entraining surrounding air, and blowing is achieved by blocking and reversing jet flow. The thin and flexible flap gate
This letter proposes a novel robotic hand that can achieve self-adaptive grasping and a large payload (over 20 kg) with a single actuator. Accordingly, two novel mechanisms, an actuation system with self-motion switching and a self-adaptive finger with a self-locking mechanism, are installed in a 1-
This study proposes a novel robotic gripper driven by a single motor. The main task is to pick up objects in confined spaces. For this purpose, the developed gripper has three operating modes: grasping, finger-bending, and pull-in modes. Using these three modes, the developed gripper can rotate and
This study presents a method for estimating the three-dimensional (3D) shapes of transparent objects from an RGB-D image using a statistical shape model. Statistical shape models compress the dimensions of multiple shapes to represent shape variations using fewer parameters. It is difficult to measu…
This study proposed a novel robotic gripper that can achieve grasping and infinite wrist twisting motions using a single actuator. The gripper is equipped with a differential gear mechanism that allows switching between the grasping and twisting motions according to the magnitude of the tip force ap
This letter proposes a robust grasping strategy for unknown objects by performing non-contact grasp-stability evaluation based on proximity sensing. First, we developed a proximity sensor for a multi-fingered hand. Its features are sensor mounting on a spherical fingertip and coating with transparen
Recently, soft robotics research has focused on mechanisms to control the stiffness of robot structures. There are several types of variable stiffness mechanisms that can change the stiffness of such structures by altering friction force. Among these, the negative-pressurization method applies negat
This letter proposes a novel single-fingered reconfigurable robotic gripper for grasping objects in narrow working spaces. The finger of the developed gripper realizes two configurations, namely, the insertion and grasping modes, using only a single motor. In the insertion mode, the finger assumes a
This letter proposes a novel pneumatic soft robotic hand that incorporates a mechanism that can switch the airflow path using a single airflow control. The developed hand can control the finger motion and operate the surface friction variable mechanism. In the friction variable mechanism, a lubrican
This letter presents a novel small gripper capable of grasping various types of small-sized items from flat surfaces for the assembly of small devices. Using a single actuator, the proposed gripper realizes two grasping modes: parallel-grip and turn-over modes. The gripper's mode can be switched via
This letter presents a novel versatile parallel gripper equipped with a sheet-embedded belt that enables passive pull-in operations. The belt is wrapped around each fingertip of the gripper, and it passively moves with the opening and closing motions of the gripper. The fingertip is made of plastic,
Quickness, preciseness and robustness are required in manipulation tasks of robotic hands for automation of manufacturing sites. Previous researches have found that sensing from fingertips equipped with proximity sensors is available for the requirements, because it complements blind areas of vision…
In this letter, we present a novel gripper, whose design was inspired by chuck clamping devices, for transferring heavy objects and assembling parts precisely in industrial applications. The developed gripper is lightweight (0.9 kg), can manipulate heavy payloads (over 23 kgf), and can automatically
This letter investigates the effect of the surface texture of soft deformable fingertips on the maximum resistible force under dry and wet conditions, and proposes a new hybrid structure that provides a stable grasp under both conditions. One definition of stable grasp is the capability of balancing
This paper presents methodologies for dexterous manipulation by an underactuated robotic soft gripper with a low DOF. While the softness and passive joints provide a stable grasp, the manipulations become challenging owing to the complexities of modeling and state estimation. To investigate the draw…
A novel robotic gripper with soft surfaces and underactuated joints was proposed. The soft surface was fabricated from a deformable rubber bag filled with incompressible fluid and a microgripper inside the fluid. A ratchet was installed at the underactuated joint so that the joint's rotation caused
In this study, we focused on sheet manipulation with robotic hands. This manipulation involves grasping the sides of the sheet and utilizing the convex area resulting from bending the sheet. This sheet manipulation requires the development of a model of a bent sheet grasped with fingertips. We inves
In this study, we experimentally investigated the effect of robot fingertip stiffness on the maximum resistible force. The maximum resistible force is defined as the maximum tangential force at which the fingertip can maintain contact when applying and increasing tangential/shearing force. We includ…
In this study, we experimentally investigated the process leading to fracture in tofu grasping by deformable fingertips filled with a fluid. In our previous papers [1, 2], we developed deformable fingertips using a rubber bag filled with a viscoelastic fluid, and presented a strategy for delicate to…