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Stair-climbing function of Micro Mobile Robot（ MMR） conflict with their portability. The Beijing Institute of Technology has developed a four-wheeled MMR which can climb stairs by flipping chassis. This robot weights 2. 5kg,so it is portable and can be deployed by throwing in short distance. In allusion to that robot,three concerns as well as assessments in dropping process have been put forward. The hyperelastic model of rubber and elastic-plastic model considering strain rate of metals were established,and a finite element model（ FEM） was established with ABAQUS furthermore. The FEM was tested on three typical working conditions of dropping horizontally,vertically and side-vertically by 1m height. Problems of the original structure were discussed and optimization measures were put forward,concerning tire,shell and motor shaft and so on.Simulation experiments have been done to confirm the validity of those measures. The results show that the dropping resistance is improved,and the optimized structure can sustain drops of 3 m.

Piezoelectric actuators are widely utilized to convert electrical energy into mechanical strain with considerable potential in micro mobile robot applications. However, the use of Pb-based Lanthanumdoped Zirconate Titanates (PZTs) leads to two difficulties in drive circuit design, namely, high voltage step-up ratio and high energy conversion efficiency. When some devices driven by piezoelectric actuators are used in emerging technologies, such as micro mobile robot, to perform special tasks, low mass, high energy density, and high conversion efficiency are strategically important. When these demands are considered, conventional drive circuits exhibit the disadvantages of being too bulky and inefficient for low mass applications. To overcome the aforementioned drawbacks, and to address the need for a piezoelectric bimorph actuator, this work proposed a high step-up ratio flyback converter cascaded with a bidirectional half-bridge stage controlled, via a pulse width modulation strategy, and a novel control method. Simulations and experiments were conducted to verify the ability of the proposed converter to drive a 100 V-input piezoelectric bimorph actuator using a prototype 108 mg (excluding printed circuit board mass), 169 (13 × 13) mm2, and 500 mW converter. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes about a prototype system for active interaction experiment to a cricket by utilizing an operated micro mobile robot. It is also able to measure/collect behavior data of the cricket on-line. The behavior selection of the cricket (Gryllus bimaculatus) is influenced by the experience or the context in living environment. In our current research, we are trying to investigate neuronal mechanisms underlying adaptive behavior switching of the cricket based on individual interactions. However in conventional biological experiments, the conditions are not maneuverable intentionally. Therefore, we are developing an integrated system for conducting active interaction experiments and gathering behavior data related to the effect of interactions. The prototype consists of a micro mobile robot as a physical interaction agent, a camera and a microphone and a computer. The computer is for commanding the robot by the operator’s input. It also works for recording the data of a video sequence, on-line motion tracking and the audio during the experiment. Interaction experiments with the cricket utilizing the prototype system were done. From the results, we could confirm it works well especially for maneuvering experimental conditions and on-line experimental data gathering. [Copyright &y& Elsevier]

In this study, a micro converter for driving a piezoelectric actuator is designed and implemented. The converter can produce 100 V, 80 Hz AC voltage from 3.7 V DC voltage. With regard to the requirements of micro mobile robots, the main contributions of this study are the design and implementation of a circuit topology supplying power for micro mobile robots at low power and the miniaturization of this topology to make it suitable for driving a centimeter-level robot. The 91 mg mass (excluding printed circuit board mass), 14 × 12 × 4 mm size, and 84.6% efficiency of the converter indicate that this circuit could be applied in micro mobile robots driven by piezoelectric actuators. [ABSTRACT FROM AUTHOR]