This study presents a bistable tensegrity robot that can perform repetitive jumps using one motor. This robot is based on a tensegrity structure that uses rigid plate-shaped compressors. To achieve bistability in this structure, we optimized the position of additional springs using a physics simulator that considers geometric constraints attributed to the collision between compression materials. A prototype was constructed based on the simulation model. To achieve jumping repeatability, we used one motor to control three tendons, each used; to control the additional spring strain, trigger the snap-through motion, and reform the structure to its original form. The prototype could jump using snap-through motion and reform back to its original form based on motor rotation. Furthermore, the robot demonstrated its ability to jump over flights of stairs by attaching a stand with a slight angle and using jumping repeatability.

This paper presents a novel method of realizing in-hand manipulation inspired by the peristaltic motion of a large-sized caterpillar. The sharp contrast between the proposed soft-bodied finger and the conventional hard/rigid robotic ones is peristaltic motion with compression and bending deformations. The design is based on the biological fact that large-size caterpillars (e.g., Bombyx mori) utilize bending and compression/extension of the body to produce crawling locomotion. Exploiting the multi-modal deformations, we demonstrated that the prototype hand comprising two proposed fingers could rotate and transport grasped objects. We also observed that the time gap of two-finger motion is required to stabilize in-hand manipulation. The design can provide new insights into designing a gripper inspired by soft-bodied creatures.

Surface robots can have many applications due to multiple degrees of freedom. Accordingly, many open research questions arise due to the limited number of realized cases and insufficient theory foundation. For a surface robot that performs deformations with shear deformation, the inner product calculation in a local coordinate system on the robot generally depends on the shear angle. However, the shear angle cannot be accurately measured, making it difficult to control the robot with coordinate transformation. We present herein a geometric robot with coordinates that are as locally orthogonal as possible. This robot is embodied by adding thickness to a special circle group, called the S-isothermic surface. We propose the utilization of inverse kinematics in S-isothermic-surface robots and demonstrate the results of actual realization.

This paper shows a design and fabrication process that combines soft robotics and origami technology for developing a modular robot. Integration of multiple modular robots provides hyper degrees of freedom and creates a deformable system. The application of soft robotics to a modular robot makes it adaptable to diverse environments. Choosing a feasible method of design and fabrication for the modular robot is necessary to obtain the desirable deformation of the system. Among the various proposed methods, application of origami structures based on mathematical operations can facilitate the design process of elastic robots. Here, we propose a novel circular mesh-type robot that has planar and three-dimensional shape transformation functions. Then, we present the application of conformal mapping origami structure to a soft robot and make a deplorable rubber membrane, which is a key part of a variable-radius circular robot.

In this paper, we propose a motion control algorithm for switching between three motion strategies in unknown environment using a gradually building map. It is well known that the motion control of a coverage problem based on a global map is more efficient than local information based motion control which does not use the map. When the beginning of the coverage task, the building map is insufficient, so the motion control based on the map is not so efficient. When almost end of the coverage task, the built map is expected to be almost perfect one. Our algorithm is designed with the insufficiency of the gradually building map. In the algorithm, the robot selects one of three motion strategies depending on completeness of the map. The strategies include local motion control based on local sensing, wall following control to get environmental information and global motion control based on the built map. The robot selects mainly local motion control at an early stage. As time goes on, a global motion control using the reliable map is more selected automatically. The efficiency of the coverage problem is discussed by comparing the proposed method with a control method only by local information. Some simulations and experiments using the algorithm are shown in the paper.