Vision-based docking system for an aromatic-hydrocarbon-inspired reconfigurable robot

Aromatic hydrocarbons generally refer to compounds containing benzene rings.Many types of isomers can be formed by replacing hydrogen atoms on the benzene ring.In this paper,an aromatic-hydrocarbon-inspired modular robot(AHIMR)is proposed.The robot can be reassembled into different configurations suitable for various task requirements.A vision-based docking system is designed for the AHIMR.The system primarily consists of two stages:a remote guidance stage and a precise docking stage.During the remote guidance stage,an object module is identified using an illumination adaptive target recognition algorithm,and then the active module moves to the docking area through communication with ZigBee.In the precise docking stage,the active module calculates the relative pose with the object module using a perspective-n-point method and dynamically adjusts its posture to dock.In this process,a Kalman filter is used to reduce target occlusion and jitter interference.In addition,the docking system feasibility is verified via several simulation experiments.The module docking accuracy is controlled within 0.01 m,which meets the reconfiguration task requirements of the AHIMR.In the AHIMR submodule docking experiment,the active module accurately moves to the expected position with a docking success rate of 95%.

Illumination Adaptive Identification Algorithm of a Reconfigurable Modular Robot

Reconfigurable modular robots feature high mobility due to their unconstrained connection manners.Inspired by the snake multi-joint crawling principle,a chain-type reconfigurable modular robot(CRMR)is designed,which could reassemble into various configurations through the compound joint motion.Moreover,an illumination adaptive modular robot identification(IAMRI)algorithm is proposed for CRMR.At first,an adaptive threshold is applied to detect oriented FAST features in the robot image.Then,the effective detection of features in non-uniform illumination areas is achieved through an optimized quadtree decomposition method.After matching features,an improved random sample consensus algorithm is employed to eliminate the mismatched features.Finally,the reconfigurable robot module is identified effectively through the perspective transformation.Compared with ORB,MA,Y-ORB,and S-ORB algorithms,the IAMRI algorithm has an improvement of over 11.6%in feature uniformity,and 13.7%in the comprehensive indicator,respectively.The IAMRI algorithm limits the relative error within 2.5 pixels,efficiently completing the CRMR identification under complex environmental changes.

A reconfigurable tracked mobile robot based on four-linkage mechanism

A novel reconfigurable tracked robot based on four-link mechanism was proposed and released for the complicated terrain environment. This robot was modularly designed and developed, which is composed of one suspension and one pair of symmetrical deployed reconfigurable track modules. This robot can implement multiple locomotion configurations by changing the track configuration, and the geometric theory analysis shows that the track length keeps constant during the process of track reconfiguration. Furthermore, a parameterized geometric model of the robot was established to analyze the kinematic performance of the robot while overcoming various obstacles. To investigate the feasibility and correctness of design theory and robot scheme, an example robot was designed to climb 45° slopes and 200 mm steps, and a group of design parameters of the robot were determined. Finally, A prototype of this robot was developed, and the test results show that the robot own powerful mobility and obstacle overcoming performance, for example, running across obstacle like mantis, extending to stride over entrenchment, standing up to elevate height, and going ahead after overturn.

Configuration representation and reconfiguration optimization for the reconfigurable robots with independent manipulation

Single module of the reconfigurable robots with independent manipulation can perform the actions of locomotion and manipulation. In conformity with the request for achieving autonomous operation in the unstructurized environment instead of fixed operation in the structurized environment, these robots are applied in the complicated and dangerous environment. The existing researches on the configuration theory focus on the reconfigurable robots with limited locomotion and the ones with independent locomotion, not being applicable to the reconfigurable robots with independent manipulation. The vector configuration is put forward, the research content of which contains the topology and locomotion direction of configuration, the posture and orientation and connection relation between modules. Module state vector and configuration state matrix are proposed for representation methodology for the swarm configuration of these reconfigurable robots, which supports transformation operation to represent and trigger behavior motion of the module and reconfiguration between configurations. Optimization algorithm of assembly reconfiguration applying workload as the optimization target is presented, as well as optimization algorithm of transformation reconfiguration applying the integration of posture_orientation_workload and connection_workload. The result of optimization is the relation of state transformation between the initial configuration and the object one as the basic of reconfigurallon plan and control.

Crossing ditch for reconfigurable planetary robots

A new reconfigumble planetary robots system （RPRS） is introduced. The locomotion mechanism alld crossing ditch ability by negotiation among ckild-robots are analyzed. Three configurations are introduced and their characteristics for crossing ditch compared. In order to cross the ditch whose width is broader than the length of the triangle wheel＇ s edge, a novel method based on the locomotion mechanism of the child-robot is proposed. This makes the two leading robots hold the first robot together with their velocities in opposite directions. Statics for the reconfigurable robot group are analyzed. The result shows that the motors can supply sufficient force moment to cross channel. Simulation .experiments are carried out with VC and OPENGL.

2nd ASME/IFToMM International Conference on Reconfigurable Mechanisms and Robots(ReMAR2012)

With the development of science and technology and with space exploration, hazardous environment work, and production requirements of small batch and quick change-over, the traditional concept of mechanisms and robots development is facing a challenge in the 21 st century for adaptability and reconfigurability.

ANALYSIS OF TIPOVER STABILITY FOR NOVEL SHAPE SHIFTING MODULAR ROBOT

A novel three-module robot has been introduced. It can change its configuration to adapt to the uneven terrain and to improve its tipover stability. This three-module tracked robot has three kinds of symmetry configuration. They are line type, triangle type, and row type. After the factors and the countermeasures of mobile robot＇s tipover problem are analyzed, stability pyramid and tipover stabil-ity index are proposed to globally determinate the mobile robot＇s static stability and dynamic stability. The shape shifting robot is tested by this technique under the combined disturbance of pitch, roll and yaw in simulation. The simulation result shows that this technique is effective for the analysis of mobile robot＇s tipover stability, especially for the reconfigurable or shape shifting modular robot. Experiments on three symmetry configurations are made under unstructured environments. The environment experiment shows the same result as that of the simulation that the triangle type configuration has the best stability. Both simulation and experiment provide a valid reference for the reconfigurable robot＇s potential application.

Center-configuration selection technique for the reconfigurable modular robot

The reconfigurable modular robot has an enormous amount of configurations to adapt to various environments and tasks. It greatly increases the complexity of configuration research in that the possible configuration number of the reconfigurable modular robot grows exponentially with the increase of module number. Being the initial configuration or the basic configuration of the reconfigurable robot, the center-configuration plays a crucial role in system＇s actual applications. In this paper, a novel center-configuration selection technique has been proposed for re- configurable modular robots. Based on the similarities between configurations＇ transformation and graph theory, configuration network has been applied in the modeling and analyzing of these configurations. Configuration adjacency matrix, reconfirmation cost matrix, and center-configuration coefficient have been defined for the configuration network correspondingly. Being similar to the center-location problem, the center configuration has been selected according to the largest center-configuraUon coefficient. As an example of the reconfigurable robotic system, AMOEBA-I, a three-module reconfigurable robot with nine configurations which was developed in Shenyang Institute of Automation （SIA）, Chinese Academy of Sciences （CAS）, has been introduced briefly. According to the numerical simulation result, the center-configuration coefficients for these nine configurations have been calculated and compared to validate this technique. Lastly, a center-configuration selection example is provided with consideration of the adjacent configurations. The center-configuration selection technique proposed in this paper is also available to other reconfigurable modular robots.

Configuration analysis of a chain-type reconfigurable modular robot inspired by normal alkane

Normal alkane is an unbranched alkane whose structural formula is H–CH2–CH2–…–CH2–…–CH2–H,which can be regarded as a reconfigurable chain-type structure composed of–CH2–modules.Inspired by normal alkane,a normal-alkane-like reconfigurable modular robot (NAR) is proposed.The module consists of two differential gear trains mounted orthogonally.Each differential gear train contains two input degrees of freedom and two output degrees of freedom.Due to the genderless interface design,multiple modules can be assembled into chain-type configuration.With the genderless interfaces and flexible degrees of freedom,NAR can be reconfigured into different dimensions of spatial configuration.The bond matrix is used to describe the configuration,which represents the bond attitude of the adjacent connected modules.In addition,full interconnected geometric feature (FIGF) algorithm is proposed for non-isomorphic configuration enumeration and judgment.The configurations with three modules are simulated and the results verify the feasibility of the algorithm.Finally,a prototype with three modules is fabricated and the configuration motion sequence is demonstrated.