Hirotaka Komura

Development of snake-like robot ACM-R8 with large and mono-tread wheel

One of the important advantages of an active wheeled snake-like robots is that it can access narrow spaces which are inaccessible to other types of robot (such as crawlers, walking robots), since snake-like robots have an elongated, narrow body. Additionally, in areas with rubble, snake-like robots can traverse rough terrain and large obstacles since its body can conform to the terrain’s contours. ‘ACM-R8’ is a new snake-like robot which can climb stairs and reach doorknobs in addition to the features explained above. To fulfill these functions, the design of this robot incorporates several key features: joints with parallel link mechanism, mono-tread wheels with internal structure, force sensors and ‘swing-grousers’ which were developed to improve step climbability. In this paper, the design and control methods are described. Experiments confirmed high mobility on stairs and steps, with the robot succeeding in overcoming a step height of 600 mm, despite the height of the robot being just 300 mm. Graphical Abstract

Study of swing-grouser wheel: A wheel for climbing high steps, even in low friction environment

Generally, wheel mechanisms are inferior to a tracked or walking mechanism in terms of step climbability or traversability in rough terrain; however, they are superior in terms of energy efficiency, structural simplicity, and carrying capacity. This paper proposes a new wheel mechanism, the swing-grouser wheel, which can climb high steps (especially in low friction environments) and has high energy efficiency. In addition, the swing-grouser wheel can climb regardless of the body inclination. Its merits are compared to the results of prior studies. Furthermore, the performance of the swing-grouser wheel was confirmed using a real device experiment and a 2D physics simulation, and improved using a full search of the parameters of the swing-grouser wheel. As a result, one improved parameter resulted in climbing at over 68% of the wheel diameter in a low friction environment; additionally, the energy efficiency was better than that of the previous model.

Spiral Mecanum Wheel achieving omnidirectional locomotion in step-climbing

The vehicle using omnidirectional wheels has ability to move in all directions without changing the body direction unlike a normal four wheel drive vehicle. However most of omnidirectional vehicle are designed for using only on flat ground. In this paper, we propose a new type of omnidirectional wheel, “Spiral Mecanum Wheel”, which enables vehicle climb the step. This new wheel consists of spiral beams and many small rollers, and these small rollers are arranged along the spiral beams. When the vehicle with this spiral Mecanum Wheels moves in normal direction, the edge of the spiral moves to cover the step from above. We have performed the experiments using Spiral Mecanum Wheel and showing the wheel works very well. As a result, in the experiment using single Spiral Mecanum Wheel, this Spiral Mecanum Wheel climbed the step about 83% of the wheel diameter in normal direction motion. The vehicle with Spiral Mecnaum Wheel climbed the step about 37% of the wheel diameter in tangential direction motion and 59% in normal direction.

Eccentric Crank Rover: A novel crank wheel mechanism with eccentric wheels

The crank wheel mechanism, consisting of a wheel mechanism and parallel links connected to each wheel, achieved high mobility and efficiency because it has both wheels and legs in a simple structure. However, each prior model of crank wheel mechanism has had shortcomings such as mass oscillation or fragile structure. In this paper, we propose a novel crank wheel mechanism, the “Eccentric Crank Rover”(ECR), which is an enhanced crank wheel mechanism with eccentric wheels. The eccentric wheels increase the under-body clearance, and change the body trajectory from straight to trochoid curve, which has the same shape as the crank legs but opposite phase trajectory. Thus, the body itself acts as a “second” crank leg. We experimentally confirmed higher step climbability, larger clearance, and lower cost of transport than other models such as normal wheel model, eccentric wheel model, and crank wheel model without eccentric wheel.

Turning method that minimizes turning radius for snake-like robot with active joints and active wheels

Snake-like robot which has active joints and thruster mechanisms has been proven to have its high mobility on narrow and rough terrain because of its slim and long trunk. However, larger space than its slim trunk is necessary for snakelike robot to turn. Thus, in order to improve the mobility of snake-like robot, turning method which makes turning radius smaller is needed. In this paper, a new turning method for snake-like robot which has both pitch and yaw joints, and thruster mechanism in each module is proposed. In this method, both pitch and yaw joints are bent to their limits, and take advantage of steep bent area which are not used normally. This new method was applied to an active snake-like robot ACM-R8, and experimented in physics simulations and hardware experiments. As a result of these experiments, it was confirmed that the new method made the turning radius smaller.

Crank Tether Thruster : A Thruster Mechanism for Teleoparated Robots

Article / Book Information 論題(和文) ケーブル牽引を補助するCrank Tether Thruster の開発 Title(English) Crank Tether Thruster : A Thruster Mechanism for Teleoparated Robots 著者(和文) 古村博隆, 広瀬茂男, 山田浩也, 遠藤玄, 鈴森康一 Authors(English) Hirotaka Komura, Shigeo Hirose, Hiroya Yamada, Gen Endo, Koichi Suzumori 出典(和文) ロボティクス・メカトロニクス講演会2016講演概要集, Vol. , No. , 2A2-08a2 Citation(English) Proceedings of the 2016 JSME Conference on Robotics and Mechatronics, Vol. , No. , 2A2-08a2 発行日 / Pub. date 2016, 6

Gliding, swimming and walking: Development of multi-functional underwater robot Glide Walker.

In order to investigate under the sea, various types of underwater robots have been developed. However, most robots can only perform one type of moving such as screw, water gliding or walking, even though there are some creatures which use various types of locomotion in the wild life. Thus, we propose a new type of underwater robot, the “Glide Walker”, which can change its way of locomotion between gliding, walking and swimming depending on the situation. It can be performed by using its two wings with 3 DOFs each and its tail with 1 DOF. This article presents the basic concept, the moving strategy and the mechanical design of the robot in details. Moreover, it also presents the developed prototype, as well as the conducted experiments in which the robot was able to perform the three ways of locomotion successfully. Additionally, it also shows the high manipulation capability and the loop maneuver performance of the robot when in the swimming mode.