Applied Mechanics and Materials Vol. 461

Abstract: Insect has a highly sensitive and accurate discrimination capacity for sensing odorants in the environment, though its olfactory system is much simpler than mammalians. Insect olfactory receptor (OR) proteins play key roles in odor detection and discrimination. Unlike the complex olfactory signaling in mammalian, the insect ORs can be directly gated by odorants, and can function without the co-expression of downstream signaling molecules. Therefore, insect ORs hold great promise as detectors in a biosensor for detection of volatile chemicals. Several important OR genes in Drosophila, which respond to explosive vapor or related precursors such as PTEN and 2-ehtyl-hexanol, have been reported. The present work screened and selected OR genes which are sensitive to explosive vapor and related precursors by calcium imaging and electrophysiological techniques. Furthermore, a biomimetic odorant sensor which co-expresses these OR genes and a companion receptor Or83b in living cells is being constructed, in order to classify unknown volatile chemicals and detect specific types of illicit substances. This study provides an alternative way for the construction of odorant sensors, comparing to the traditional electronic noses which are not as sensitive and accurate as natural noses, and would promote the development and application of biomimetic odorant sensors in a range of applications such as security and environmental monitoring.

Abstract: In order to accomplish the task of wind power tower inspection, a heavy-loaded climbing robot inspired by geckos is presented in this paper. The robot not only imitates body’s functions of geckos but also shows a design method. Wind power tower is a conical wall surface and its smallest radius is less than 2m. There will be a great gap when a robot climbing on such wall with small radius. The extraordinary climbing ability of geckos is considered as a remarkable design of nature that is attributed to its soft body, its multi-degree-of-freedom legs, and its strong-adsorbed toes. Focus on the feature of working on such wall surface, gecko’s body, toes and legs are simplified as free joints, magnetic units and redundant tracks respectively, based on the functions of gecko’s limbs and body. The adaptability of the robot is tested by the experiments in laboratory. With the gecko-inspired structure, the robot can climb on the wall surface with minimum 2m in diameter in any direction.

Abstract: To represent various human facial expressions is an essential requirement for emotional bio-robots. The human expressions can convey certain emotions for communications of human beings with some muscles positions and their movements. To design and develop emotional robots, it is necessary to build a generic 3D human face model. While the geometrical features of human faces are freeform surfaces with complex properties, it is the fundamental requirement for the model to have the ability of representing both primitive and freeform surfaces. This requirement makes the Non-rational Uniform B-Spline (NURBS) are suitable for 3D human face modelling. In this paper, a new parameterised feature based generic 3D human face model is proposed and implemented. Based on observation of human face anatomy, the authors define thirty-four NURBS curve features and twenty-one NURBS surface features to represent the human facial components, such as eyebrows, eyes, nose and mouth etc. These curve models and surface models can be used to simulate different facial expressions by manipulating the control points of those NURBS features. Unlike the existing individual based face modelling methods, this parameterised 3D face model also gives users the ability to use the model imitate any face appearances. In addition the potential applications of the new proposed 3D face model are also discussed. Besides emotional bio-robots, it is believed that the proposed model can also be applied in other fields such as aesthetic plastic surgery simulation, film and computer game characters creation, and criminal investigation and prevention.

Abstract: We developed a rat-robot system based on optogenetic techniques for the precise freezing behavior. Rat-robots were built up by optogenetic modulation at the dlPAG of rat brains. We conducted track navigation for the rat-robots and found they were able to exhibit precise freezing at given positions with high spatiotemporal accuracy. Different types of optical stimulation were compared and their influence on the rat-robots was investigated. Furthermore we recorded the neural electrical activity in real time during the optical stimulation. The system could be used to explore the mechanism of freezing behaviors and to build up a more integrated rat-robot navigation system based on optical modulations.

Abstract: This paper proposes a novel method for a swarm of robots searching in an unknown environment. The approach focuses on the process of feeding and individual coordination characteristics that are inspired by the foraging behavior in nature. First, the searching area is divided into several sub-regions using a target utility function, from which each robot can identify an area that should be initially searched. Then, a predatory strategy is used for searching in the sub-regions; this hybrid approach integrates a random search technique with a dynamic particle swarm optimization (DPSO) search algorithm. If a robot cannot find any target information in the sub-region, it uses a global random search algorithm; if the robot finds any target information in the sub-region, the DPSO search algorithm is used for a local search. The particle swarm optimization search algorithm is dynamic as all the parameters in the algorithm are refreshed synchronously through a communication mechanism as the searching progresses until the robots find the target position. Then, the robots fall back to a random searching mode and continue to search for other places that were not searched previously. In this searching strategy, the robots alternate between two searching algorithms until the whole sub-area is covered. During the searching process, the robots use a local communication mechanism to share map information and the DPSO parameters to reduce the communication burden and overcome hardware limitations.

Abstract: Abstract.Quadruped not only possess excellent kinetic speed and stability but also can adapt to various complex terrains, with the result that hydraulically actuated quadruped bionic robots with high load and outstanding adaptability have become the research hotspot. Hydraulic system, which is regarded as the dynamic part of a hydraulic quadruped robot, has a direct effect on the kinetic capability of robots. Based on dog’s structure bionics, hydraulically actuated quadruped robot was designed. In accordance with distribution modes of hydraulic cylinders which drive robot’s kinetic joints, a hydraulic oil-line system of the robot was designed in this paper. Combining the maximum design kinetic velocity, trotting movement pattern within foot’s work space was planned. Velocity curve of each joint’s hydraulic cylinder was obtained through simulation analysis of dynamic analysis software. According to the structure of asymmetrical hydraulic cylinder, minimum flux which the oil hydraulic pump theoretically requires at the robot’s maximum kinetic speed was calculated. With practical experience, the oilsource parameter which could meet the demands of hydraulic quadruped robot were determined.

Abstract: Bionics has greatly improved the development of quadruped robot, in the paper we propose three bionic methods for the quadruped robot. These methods have been used for control method design, gait design and control architecture design. The quadruped robot control method has been divided into two parts, because the four-legged animals change their trot speed by adjustment of step length in swing phase and maintain their balance in support phase; control architecture is derived from the four-legged animals nerve system; gait of quadruped robot is based on event driven, and its trot gait is the same as German shepherd. Simulations and experiments are performed, which prove bionics design to be realizable for the quadruped robot.

Abstract: The paper proposed a series of image processing algorithm to recognize the evidences in an image accurately for humanoid soccer robot, such as color image segmentation based on HSV model, edge detection based on four linear operator, field straight line extraction by Hough transform based on 8-neighbhour connected domain clusters and identification of line intersection shape based on Hopfield network. Based on evidences from image processing, Piecewise Monte Carlo localization is presented to solve kidnap problem so that localization of humanoid robot can be not only adapt to rule changes for competition, but also be more efficient and robust. The effectiveness of the piecewise MCL is verified by RoboCup Adult Size humanoid soccer robot, Erectus. The experimental results showed that the humanoid robot was able to solve the kidnap problem adaptively with two strategies: resetting or revising, in which resetting was more efficient than revising gradually.

Abstract: In this paper, a new 6-DOF bionic swimming robot with two screw propellers and one balance paddle is designed. This robot can swim up-and-down and roll without any effect on forward motion. The spiral swimming method is modeled and analyzed firstly. In order to optimize the bionic robots structures, the motion resistance and propulsive force are simulated and calculated. Also, experiments are performed to verify the action principle and the optimal analysis results of the robot. Key words:Bionic, Micro swimming robot, vascular unclogging, paddle

Abstract: During the design of biped robot HEUBR_1, a new structure of tandem and parallel connection is used in lower-limbs, adding toe-joints to feet. In order to make sure the rationality of humanoid structure design and feasibility of the humanoid gait planning, we built the simulating model of biped robot HEUBR_1 by using software ADAMS. The simulating model of biped robot HEUBR_1 walked stably with toe-joints in fictitious surrounding, which used the motion data exported by humanoid gait planning. During humanoid gait simulation, the biped robot kinematic and dynamical characteristics were achieved. Simulation indicates that the structure of tandem and parallel connection is rational and the method of humanoid gait planning is feasible. Humanoid walking with toe-joints has the characteristic: balanced motion, lower energy and small impact on feet. Simulated data of steady walking will be used as reference for biped robot HEUBR_1 walking experiments.