An asymmetric robotic catapult based on the closed elastica for jumping robot
ABSTRACT In this paper, we propose a new asymmetric robotic catapult based on the closed elastica. The conventional robotic catapults based on the closed elastica which the authors developed are the robotic elements for generating impulsive motions by utilizing a snap-through buckling. In a typical closed elastica, the two ends of an elastic strip are fixed to a passive rotational joint and an active rotational joint, respectively. Here we found that by adding only a range limitation to the passive rotational joint, compared to the conventional type, the deforming shape of the elastic strip becomes more complicated and 40% more elastic energy can be stored. Using this modification, we can develop a compact jumping robot which is able to leap over 700[mm] away and 200[mm] high.
- SourceAvailable from: Daniel Weihs[show abstract] [hide abstract]
ABSTRACT: The spinner dolphin (Stenella longirostris) performs spectacular leaps from the water while rotating around its longitudinal axis up to seven times. Although twisting of the body while airborne has been proposed as the mechanism to effect the spin, the morphology of the dolphin precludes this mechanism for the spinning maneuver. A mathematical model was developed that demonstrates that angular momentum to induce the spin was generated underwater, prior to the leap. Subsurface corkscrewing motion represents a balance between drive torques generated by the flukes and by hydrodynamic forces at the pectoral fins, and resistive torques, induced by the drag forces acting on the rotating control surfaces. As the dolphin leaps clear of the water, this balance is no longer maintained as the density of the air is essentially negligible, and a net drive torque remains, which permits the dolphin's rotation speed to increase by as much as a factor of three for a typical specimen. The model indicates that the high rotation rates and orientation of the dolphin's body during re-entry into the water could produce enough force to hydrodynamically dislodge unwanted remoras.Journal of Experimental Biology 03/2006; 209(Pt 4):590-8. · 3.24 Impact Factor
Conference Proceeding: Circular/Spherical Robots for Crawling and Jumping[show abstract] [hide abstract]
ABSTRACT: We describe circular/spherical robots for crawling and jumping. Locomotion over rough terrain has been achieved mainly by rigid body systems including crawlers and leg mechanisms. This paper presents an alternative method of moving over rough terrain, one that employs deformation. First, we describe the principle of crawling and jumping as performed through deformation of a robot body. Second, in a physical simulation, we investigate the feasibility of the approach. Next, we show experimentally that prototypes of a circular robot and a spherical robot can crawl and jump.Robotics and Automation, 2005. ICRA 2005. Proceedings of the 2005 IEEE International Conference on; 05/2005
Conference Proceeding: The 100G Capturing Robot - Too Fast to See.[show abstract] [hide abstract]
ABSTRACT: This paper discusses the 100G Capturing Robot that can produce the maximum acceleration of 100G in design specification. To achieve such a high acceleration, we utilize spring energy with a light arm/gripper. The Arm/Gripper Coupling Mechanism (AGCM) is newly introduced so that we can efficiently transmit a single energy resource for finally closing the gripper. Experimental results show that the developed robot can capture a dropping ball with the maximum acceleration of 91G and the capturing time of roughly 25ms. We also discuss various technical issues to be considered when designing such a high speed capturing robot.Robotics Research, The Eleventh International Symposium, ISRR, October 19-22, 2003, Siena, Italy; 01/2003