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A non-wheeled snake robot can propel itself by pushing against obstacles. This is called obstacle-aided locomotion. To expand the exploration range of a snake robot using this method, it is preferable to utilize obstacles that are both on the ground and by the side or above. To achieve these goals, we propose an obstacle-aided locomotion using piecewise helixes. This target shape comprises grounding and obstacle-contacting parts. The length and shape of the grounding part can be changed from a straight line to a circular arc. The height of the obstacle-contacting part can be changed or its direction can be reversed. The robot can adapt to various obstacles by appropriately changing its body shape. In addition, we propose a snake robot locomotion in a flat ground using the same shape as that used for obstacle-aided locomotion. This involves a combination of shift control and rolling motion. The robot can move in a straight line in the forward or lateral direction or can turn in a circular arc using the proposed method. Finally, experiments that confirm the effectiveness of the proposed method are presented.

Snake robots have shown limited ability to perform manipulation tasks in comparison to their locomotion capabilities. In this article, we propose a mobile manipulation approach that increases the manipulation ability of snake robots by using their full-body motion. We consider a snake robot that moves along the outer surface of a pipe using the helical rolling gait. To perform a manipulation task, we extend the front links of the robot to form a manipulator-part, where the remaining links form a helical base that wraps around the pipe. In the proposed approach, the motion of the manipulator-part is combined with a rolling motion performed by the base-part. This results in enhanced rotational ability of the end-effector, without the need to install an additional rotary motor. The stability of the robot structure is also improved via the resulting tightening force between the helical base-part and the pipe. The kinematics of the proposed robot arrangement is represented considering a dynamically changing contact point between the links of the helical base and the pipe. To realize the proposed method, we introduce a two-level controller that enables the manipulator-part and the helical base to work simultaneously during manipulation. The experimental results showed the validity of the proposed method to track various trajectories and carry out manipulation tasks using a typical snake robot without extra actuators.

A snake robot performs diverse motions. To realize a wide range functions in a complex environment, it is necessary to transition between various motions suited to each environment. In this article, we propose a method of transitioning the motion of a snake robot across different environments to expand the application environment of the robot. We first find that the motion at the connection point between two motions must coincide with the tangential movement during motion transition across different environments. We then design a gait called the circular pedal wave. This circular pedal wave allows a hoop-passing motion in which the whole body moves as if it is passing through a virtual hoop fixed in space in sequence from its head through combination with a proposed shift part. The hoop-passing motion allows motion transition across different environments. We propose three application examples of this hoop-passing motion, namely passing through a hole in a wall, entering an underfloor, and attaching to a ladder. We report on experiments conducted to verify the effectiveness of the proposed method and to realize the described motions.

Robots are needed in rescue activities and the inspection of infrastructure. We developed the rescue robot FUHGA2 so that it has various functions. FUHGA2 has high mobility, with main crawlers cove...

Development of geothermal power plants and local geothermal energy initiatives have lagged due to the social problems such as conflicts with stakeholders such as Onsen (Hot Spa) owners, despite the abundant geothermal resources. Study area was Tsuchiyu Onsen in Fukushima prefecture, Tohoku (Northeast) District, Japan, where the Great East Japan Earthquake and Fukushima Nuclear Accident occurred in 2011, and the reconstruction and local initiatives of geothermal energy were still unclear. Agent-based modeling (ABM) is an effective methodology for modeling and analysis of opinion formation. Parameter estimation method was proposed to extract appropriate parameters from various factors through a Bayesian Network. The characteristics of stakeholders and communities that affected opinion formation in the survey area were successfully extracted. Here we show the sufficient methodology to quantify the characteristics of each person using survey data, and to extract the parameters of the agent by data-driven inverse analysis. By using this methodology, we could reproduce opinion diversity, which is a property of opinion formation in real communities. This result suggests that the model replicates the actual formation of opinion in Tsuchiyu, where the economy was boosted by the construction of a binary cycle power plant.

Development of geothermal power plants and local geothermal energy initiatives have lagged due to the social problems such as conflicts with stakeholders such as Onsen (Hot Spa) owners, despite the abundant geothermal resources. Study area was Tsuchiyu Onsen in Fukushima prefecture, Tohoku (Northeast) District, Japan, where the Great East Japan Earthquake and Fukushima Nuclear Accident occurred in 2011, and the reconstruction and local initiatives of geothermal energy were still unclear. Agent-based modeling is an effective methodology for modeling and analysis of opinion formation. Parameter estimation method was proposed to extract appropriate parameters from various factors through a Bayesian Network. The characteristics of stakeholders and communities that affected opinion formation in the survey area were successfully extracted. Here we show the sufficient methodology to quantify the characteristics of each person using survey data, and to extract the parameters of the agent by data-driven inverse analysis. By using this methodology, we could reproduce opinion diversity, which is a property of opinion formation in real communities. This result suggests that the model replicates the actual formation of opinion in Tsuchiyu, where the economy was boosted by the construction of a binary cycle power plant.

A unified method for designing the motion of a snake robot negotiating complicated pipe structures is presented. Such robots moving inside pipes must deal with various “obstacles,” such as junctions, bends, diameter changes, shears, and blockages. To surmount these obstacles, we propose a method that enables the robot to adapt to multiple pipe structures in a unified way. This method also applies to motion that is necessary to pass between the inside and the outside of a pipe. We designed the target form of the snake robot using two helices connected by an arbitrary shape. This method can be applied to various obstacles by designing a part of the target form specifically for given obstacles. The robot negotiates obstacles under shift control by employing a rolling motion. Considering the slip between the robot and the pipe, the model expands the method to cover cases where two helices have different properties. We demonstrated the effectiveness of the proposed method in various experiments.

A method for designing the motion of a snake robot negotiating complicated pipe structures having a constant diameter is presented. For such robots moving inside pipes, there are various "obstacles" such as junctions, bends, shears, and blockages. To surmount these obstacles, we propose a method that enables the robot to adapt to multiple pipe structures of a constant diameter. We designed the target form of the snake robot of two helices connected with an arbitrary shape. This method is applicable to various obstacles by designing a part of the target form conforming to the obstacle. The robot negotiates obstacles under shift control by employing a rolling motion. We demonstrated the effectiveness of the proposed method in various experiments.

This paper presents a method for designing the gait of a snake robot that moves in a complicated environment. We propose a method for expressing the target form of a snake robot by connecting curve segments whose curvature and torsion are already known. Because the characteristics of each combined shape are clear, we can design the target form intuitively and approximate a snake robot configuration to this form with low computational cost. In addition, we propose two novel gaits for the snake robot as a design example of the proposed method. The first gait is aimed at moving over a flange on a pipe, while the other is the crawler gait aimed at moving over rough terrain. We demonstrated the effectiveness of the two gaits on a pipe and rough terrain in experiments.

Purpose When designing a performance involving people and mobile robots, the required functions and shape of the robot must be considered. However, it can be difficult to account for all of the requirements. The purpose of this paper is to discuss a mobile robot in the shape of a ball that is used in theatrical performances. Design/methodology/approach The paper proposes a mobile robot that can give the audience the optical illusion of the unique movements of a sphere by mounting a spherical light-emitting diode (LED) display on a high-agility wheeled robot. Findings It was found that movements that are difficult to implement with existing mechanisms can nonetheless be visualized through the use of light. Originality/value The paper proposes the concept of using pseudo-physical movements in performances with robots. The authors built a robot that visually reproduces the movements of a rolling sphere and is capable of faster movements and easier position estimations in comparison with previous spherical robots.

This paper presents a method that allows a snake robot to climb a ladder. We propose a ladder climbing method for a snake robot that has a smooth surface shape. We design a novel gait for the snake using a gait design method that configures the target form of the snake robot by connecting simple shapes. The climbing motion is executed via shift control and the corresponding motion required to catch the next step on the ladder. In addition, we developed a snake robot that has a smooth exterior body surface through construction of pectinate-shaped parts of the links. We demonstrated the effectiveness of both the proposed gait and the design of the snake robot experimentally.

When designing a performance involving people and mobile robots, we must consider the required functions and shape of the robot. However, it can be difficult to account for all of the requirements. In this paper, we discuss a mobile robot in the shape of a ball that is used in theatrical performances. Such a spherical robot should be agile and be able to roll like a ball. However, it is difficult to create a robot with all of these characteristics. Instead, we propose a mobile robot that can give the audience the optical illusion of the unique movements of a sphere by mounting a spherical LED display on a high-agility wheeled robot. The results of an experiment using a prototype indicate that this sort of robot can broaden the range of possible performances by giving the optical illusion of being a rolling sphere.