Design And Study Of The Mechanical System For Mine Detection And Rescue Robot

Coal mine detection and rescue robots can assist or replace rescuers to enterdisaster area after coal mine accident to handle rescue disposition, bring down disasterlosses and reduce the risk of rescue. Base on the analysising of coal mine rescuerobot s application strategys and functions, considering the topography condition andgas atmosphere in the tunnel after coal mine accidents, referencing the currentresearch status at home and abroad of coal mine rescue robots, hazardous environmentworking robots, the design and study of the mechanical system of mine detection andrescue robot are carried out in this paper.This paper employ the method of mechanism innovation and infering,mechanical analysing, theoretical modeling and deriving, virtual prototyping andsimulation, physical prototype testing to study the functional system and componentsof robot s mechanical system which include mobile mechanism, cab supportingmechanism and manipulating robot arm, the research unfold in the following way：Firstly, coal mine rescue robot s application strategys and functions are derivedby introducing Chen-JiaShan coal mine gas explosion accident and it s rescue process,topography condition and gas atmosphere in the tunnel after coal mine accidents isanalysed to obtain terrain s geometric feature and feature s essential parameters, thisinformation also used to build mobile robot s ADAMS virtual obstacle-crossingability testyard. According to those terrain features, figure out rescue robot sperformance index table which can be used as design target for different actual coalmine environment.Secondly, base on the coal mine rescue robot s working environment, a new typeof6-wheel guide-bar-linkage suspension is proposed according to the rough terrainthat mobile robots drive over, by considering the factors of obstacles crossing over,terrain adaptability and robot cab stability. Its structure and working scheme arethoroughly discussed, and a mechanical model, formed by wheels, terrain andsuspension in the condition of the robot running over the terrain, is built. Thesuspension s terrain-adaptability is evaluated from the view of DOF computation. Aparametric model of the suspension in Pro/E is built, the cab s stability simulations areconducted in Pro/Mechanism environment when single wheel lifting and doublewheel lifting respectively, and Euler angles of cab are measured while the heights offront, middle or rear wheels independently or collaboratively changing. These tests are followed by simulations in ADAMS to examine the adaptability and loaddistribution ability of the suspension in heave and comprehensive terrain. By syntheticthose analysis and simulation work, induction and summarize the evaluation andanalysis method of mobile mechanism.Tertialy, the planar kinematics model of6-wheel guide-bar-linkage linkagesuspension has been built up base on the basic hypotheses for planar kinematicmodeling of mobile mechanism. The change rate expression of contact-point s arccoordinate has been derived by analysis the kinematics solve method of an arbitraryrigid body pure rolling on the fixed curve. Combine the expression with the exampleof wheel pure-rolling on the terrain, iteration algorithm of integral definition was usedto obtain the coordinate of the contact point which wheel press when wheel purerolling on the terrain. This coordinate then been used to derive the wheel centerpoint s coordinate through the method of normal-offset from terrain curve, make thewheel center trajectory ascertain and to appear as a constraint equation in mechanismsolve model.After complete above work, the guide-bar-linkage-linkage suspension is dividedinto two parts to solve, formulate each part s mechanical constraints equation, andsolve the nonlinear equations in MATLAB software with the method of integraldefinition iteration algorithm. After complete the calculation, transfer this result intothe parameter what we want, and compare those result to the ADAMS simulationoutcome to verify the correctness of the theoretical kinematics model and accuracy ofthe calculation process. After complete the derivation of general kinematics model,another suspension s terrain adaptability evaluation method which measured by radiusdecided by three wheel center was also analyzed for a further research.Afterwards, by considering the design requirements of support-mechanism usedto connect cab with each side suspension which used in passive-rocker suspension,introduces a new type of angle-average balance spatial linkage. Input-outputrelationship was discussed in the way of calculating model s DOF, and a specificposition-pose relational expression between cab and rocker was given. Then pitchangle equation between cab and rocker is built up in the method of rotational transfer,the equation indicates this mechanism can do well in average each rocker s swingangle to cab s pitch angle in rocker s swing-angle range. Tests are followed bysimulations in Pro/Mechanism to validate the rightness of theoretical model, and themodel was used to evaluate linear-average character effects by partial parameters of the mechanism, the spherical joint s rotate angle range was also given base on thekinematics model. At last, the assembly of this mechanism to6-wheel guide-barlinkage suspension was displayed.Finally, a new type of2-level manipulate robot arm which the near-level can holdup a heavy object and the far-level can accurately perform the operation is proposedaccording to rescue robot s operation requirements. Extract the main parameters of therobot s operating arm, and calculate the drive torque of lift-level arm in the process ofthe arm lift up an object of80kg. Introducing the scheme and the structure of therobot s mobile platform, a physical prototype is manufactured and performances ofthe prototype are tested in respect of grade climbing and obstacle crossing over. Theresults indicate that the distribution of load on the wheel is even, the adaptability toterrain is strong, and it can cross over a vertical obstacle as high as350mm. Then, theexplosion-proof design requirements and design methods/measures are beingdiscussed base on the composition and the possible ignition source of the mechanicalsystem of coal mine detection and rescue robot. At last, Synthetic all those researchresults to make a brief ideal of the overall program for coal mine detection and rescuerobot.