Design of the hybrid gripper with the jaw-tip grip and suction
End effectors are disposed in the end of the manipulator. And the end effectors do physical contact with target materials for doing assigned and required tasks. On the analysis of requirements for assigned tasks, there is one gripper should handle the solid material and soft material together. In the pick and place task, it is better to do suctions than grips. For this need, in this paper, we describe the proposed gripper that can do grip the solid material and absorb the soft material. Further the proposed gripper has linear motion guide (LM guide) and electric motor for linear displacements. This leads to various suction strategies.
Study of Torsion Spring’s Parameters with Angular Type Grippers
Angular type grippers are proper to grip the small size material than linear type grippers (clamping). It is due to the grip force of angular type grippers separates to the normal and the opposite directional force to gravity forces, when the contact between the gripper tip and the gripped material occurs. Whereas, the linear type gripper with prismatic joint has only normal forces. Therefore, even less gripping force of angular type grippers than linear type can generate slip-less pick-and-place motions. But this angular type gripper has some restrictions. For generating the opposite direction force to gravity forces, it is necessary that the length between each angular joint position is larger than the length of gripped materials. This should be considered on the design step of angular type grippers. Otherwise, the gripping force separates to the normal and the same directional force to gravity forces. The other restriction is that the tip of gripper must have passive joint or active joint for the plane-to-plane contact between faces of gripped material and gripper tip, for getting the high frictional coefficient. In this paper, we describe the case of adaptation of passive joint. This leads simpler implementation than the active joint. Especially, we focus on the torsional spring deposed at between jaw link and tip as the passive joint, with effects of design parameters of this torsional spring such as the torsional stiffness and preload with multi-body dynamics simulation.
Signal Processing and Performance of a Six-Axis Force-Torque Sensor Using Strain Gauges
The importance of sensing the force and torque with arbitrary direction and magnitude is becoming more crucial for robotic applications and manufacturing automations. Recently, several designs of a multi-axis force-torque sensor have been tried to sense this force and torque. This paper deals mainly with the signal processing of a six-axis force-torque sensor using cross-shaped elastic structures with circular holes. In this paper, we show principle of sensing force and torque, the signal processing methodology, and efficient methods of seeking strain gage positions in the sensor structure. The validity of the proposed method is shown via experiments.