International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) V...
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Simulation of eight wheeled rocker bogie suspension system using

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Simulation of eight wheeled rocker bogie suspension system using

  1. 1. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 2, March - April (2013) © IAEME436SIMULATION OF EIGHT WHEELED ROCKER BOGIE SUSPENSIONSYSTEM USING MATLABAlok Kumar Pandey*; Dr R. P. Sharma *** ME (Student) Dept. of Mechanical Engineering, Birla Institute of Technology,Mesra, Ranchi, 835215 India.** Dept. of Mechanical Engineering, Birla Institute of Technology, Mesra, Ranchi,835215 India.ABSTRACTRovers are important vehicles of today’s solar system exploration. Most of the roverdesigns have been developed for Mars and Moon surface in order to understand thegeological history of the soil and rocks. Several mechanisms have been suggested in recentyears for suspensions of rovers on rough terrain. Our design of eight wheeled rocker-bogiesuspension system has advantage of linear bogie motion which protects the whole systemfrom getting rollover during high speed operations. This improvement increases the reliabilityof structure on rough terrain and also enables its higher speed exploration with same obstacleheight capacity as diameter of wheel.In this paper we simulate rover to find slip and its deviation from desired path andexpress the complete process of importing SolidWorks file into MATLAB. We use eightwheeled rocker bogie suspension mechanism for our simulation. For this purpose we madecomponent in SolidWorks. In SolidWorks each and every parts are analyzed and simulatedusing SimulationXpress. A Simulink diagram is generated by importing SolidWorksassembly file into MATLAB followed by simulation.Keyword- MATLAB, SolidWorks, Rocker Bogie,1. INTRODUCTION & LITERATURES SURVEYIn recent years almost all exploration mission uses rocker bogie mechanisms due to itsgreat obstacle climb capacity. Rover’s faces slip problem on uneven terrain. This slip reducesrovers speed and leads to power loss. In loose soil rover deviates from its intended path andINTERNATIONAL JOURNAL OF MECHANICAL ENGINEERINGAND TECHNOLOGY (IJMET)ISSN 0976 – 6340 (Print)ISSN 0976 – 6359 (Online)Volume 4, Issue 2, March - April (2013), pp. 436-443© IAEME: www.iaeme.com/ijmet.aspJournal Impact Factor (2013): 5.7731 (Calculated by GISI)www.jifactor.comIJMET© I A E M E
  2. 2. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 2, March - April (2013) © IAEME437can stick with soil, which also increases power loss. Power loss reduces mission time bydischarging batteries. Since we cannot control the availability of solar energy, as this is onlypower source on the other planet, we have to control power loss. We can extend mission timeby controlling slip and reducing rover sinking into loose soil which gives more time to ourrover for exploration.A. Winterholler, et -al [1] (2005) “Design Of A High-Mobility Low-Weight LunarRover” have reported a set of experiments using a new highly mobile rover prototype thatwas tested under lunar-like operational conditions in the lava fields of the Mojave desert nearAmboy, CA.Thomas Thueer, Pierre Lemon [2] (2006) “Carb –Exploration Rover with AdvancedObstacle Negotiation Capabilities” have introduced locomotion concept CRAB, andcompared it with other rovers regarding obstacle negotiation capabilities.Jan Danek, et –al [3] (2007) “Simulation and Animation of Mechanical Systems” hasdiscussed a process for simulating and animating mechanical components in the context of alarger system and also described how a dynamic model created from the CAD assembly canbe integrated into the larger model of the overall flight vehicle.Robert Bauer, et -al [4] (2008) “Dynamic Simulation Tool Development for PlanetaryRovers” have developed a dynamic computer simulator for step-obstacle negotiation bycomparing simulation results with a quasi-static analysis of a rocker bogie suspension.Hrishi Shah, Sourish Chakravarty [5] (2009) “HW6-Wheeled Mobile Manipulator” (2009)wrote a MATLAB programme for non-linear feedback linearization to reduce the equationsof motion to a second order dynamic equation for the error of position of the wheeled robot.LI Yunwang, et -al [6] (2010) “Mobile platform of rocker-type coal mine rescuerobot” have discussed the flameproof design of the rocker assembly, as well as provide theoperational principles and mechanical structure of the bevel gear differential.Harjinder Singh, et -al [7] (2011) “Design and Experimentation of a Six Wheel LunarRover for Motion on Uneven Terrain” have described the design, development andexperimentation of a six-wheel mobile robot (rover) for motion on uneven lunar like terrain.The suspension mechanism of the rover was designed using a rocker-bogie mechanism.DongmokKim, et -al [8] (2012) “Optimal design of hand & carrying rocker & bogiemechanism for stair climbing” have proposed a stair climbing hand-carrying cart based on therocker-bogie mechanism. They conduct experiments to find an optimal design of thekinematic variables of the rocker-bogie mechanism for stable stair climbing.2. SYSTEM SIMULATIONFor simulation purpose of our robot we assemble each and every part in proper place,give direction of each component, and apply mate instructions of SolidWorks. Then we try toimport our model in MATLAB but there is no direct option in SolidWorks. So to create aSimMechanics model from assembly we download and install SolidWorks-to-SimMechanicsTranslator. One can download it directly from SimMechanics Link download website athttp://www.mathworks.com/products/simmechanics/download_smlink.html. On this websitethere are many versions but only the same version of installed MATLAB is working. Afterdownloading the zip file we need to write command in MATLAB to install this file withoutextracting it. In the MATLAB command window write: path(path,<installation_file_folder>) then again write install_addon(<zip_file_name>.zip). Now incommand window of MATLAB write smlink_linksw this will complete integration process
  3. 3. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 2, March - April (2013) © IAEME438with SolidWorks. This time open SolidWorks, go to tool, open Add-Ins and check theSimMechanics Link in both Active Add-ins and start up boxes.Figure 2.1: Shows von-mises stess on the RockerFigure 2.2: Shows the displacement of RockerAfter installation of this free software, it was possible to generate a textual descriptionof the assembly that lists the mass properties for each body and the characteristics of eachjoint defined in the SolidWorks assembly. This description was saved to a SimMechanicsXML file. After saving the SolidWorks assembly as a SimMechanics XML file, we caneasily convert it into SimMechanics model. It should be noted that only CAD assembaly filescan be converted into Simulink model.
  4. 4. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 2, March - April (2013) © IAEME439Figure 2.3: Shows the von-misses stress on wheelFigure 2.4: The von-misses stress on wheelFor importing this model into MATLAB set/browse working directory as currentfolder, double click to open xml file or write mech_import (filename.xml) in the MATLABcommand window. MATLAB®automatically creates a SimMechanics model from .xml file(as Figure no. 2.5 shown). The resulting SimMechanics model can be rearranged and addbackground colours for easier understanding. It was noted that all CAD assemblies are notexported into SimMechanics models.
  5. 5. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 2, March - April (2013) © IAEME440Figure 2.5: Simulink model of our rover generated by MATLABThis is due to SolidWorks mates. SolidWorks-to-SimMechanics Translator attempts to find aSimMechanics joint corresponding to each mate in SolidWorks assembly. As there is no one-to-one correspondence between SolidWorks mates and SimMechanics joints, the conversionis not always possible, or it does not translate as intended. In this case we need to updatemanually SimMechanics diagram and change Simulink blocks with correspondenceSolidWorks mates and after final simulation through MATLAB we get figure no.2.6Figure 2.6: simulation of rover in MATLAB
  6. 6. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 2, March - April (2013) © IAEME4413. RESULTS AND DISCUSSIONWe simulate our rover on a fixed elliptical path. Ellipse major axis is 3.5 m and minoraxis is 2.5 m. Centre of ellipse is lies in x plane at x =2 and y =0. Angle subtended betweenmajor axis and horizontal is 450. We are generating total 540 points in our simulation andrunning it for 10 seconds. We are tried to figure out slip behaviour for our wheel design. Forthis purpose we simulate with different linear velocity and angular velocity. In eachsimulation rover follow same path and generate 540 points, which is analyzed to find bestdriving speed and exact slip of the wheel.3.1 Simulation at V= 1 m/s and ω = 1.17 rad/ s2Figure 3.1(a): Trace point variations Figure 3.1(b): percentage of slip vs. time3.2 Simulation at V= 0.5 m/s and ω = 1.75 rad/ s2Figure 3.2(a): Trace point variations Figure 3.2(b): percentage of slip vs. time
  7. 7. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 2, March - April (2013) © IAEME4423.3 Simulation at V= 0.25 m/s and ω = 1.75 rad/ s2Figure 3.3(a): Trace point variations Figure 3.3(b): percentage of slip vs. timeThe above figures-3.1a, 3.2a and 3.3a show that as velocity increases with constant ω,means less slip cases, the bubbles are shifting towards outer periphery of ellipse. It means therover is more tend to follow desired path in the case of less slip.The above figures also shows that as velocity of rover increases all curve shifted towardsright.The above figure-3.1b, 3.2b and 3.3b shows that the slip vs. time curve becomesteeper as velocity increases. The curve is shifting towards origin which shows that at highvelocity initial slip is high and as time passes slip value goes down.4. CONCLUSIONSFollowing are vital conclusions drawn from paper:• Slip diminishes as time passes.• Initially slip is very high.• We cannot eliminate slip completely it can reduce to some extent only.• Path traced by rover is depends on velocity, as velocity changes path missingincreases.• The load simulation of different components shows the stress and deflectionbehaviour of components.• The simulation in SimulationXpress shows that our design is enough strong and it cansustain in adverse condition of loading.• Simulations of rover in MATLAB confirm movability of linkage and their relativemotion with each other.• Simulation of rover on elliptical path gives us visual representation of rover motion.
  8. 8. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 2, March - April (2013) © IAEME443REFERENCES1. A. Winterholler, et -al (2005) “Design Of A High-Mobility Low-Weight Lunar Rover”Proceedings of iSAIRAS 2005. Munich Germany. September 2005.2. Thomas Thueer, pierre Lemon (2006) “Carb –Exploration Rover with Advanced ObstacleNegotiation Capabilities” In proceeding of the 9thESA workshop on Advanced SpaceTechnologies for Robotics and Automation ‘ASTRA 2006’ ESTEC, Noordwijk, TheNetherlands, November 28-30, 20063. Jan Danek, et -al (2007) “Simulation and Animation of Mechanical Systems” AmericanInstitute of Aeronautics and Astronautics 2007.4. Robert Bauer, et -al (2008) “Dynamic Simulation Tool Development for Planetary Rovers”International Journal of Advanced Robotic Systems, Vol. 5, No. 3 (2008)5. Hrishi Shah, SourishChakravarty (2009) “HW6-Wheeled Mobile Manipulator” (2009)University At Buffalo, http://www.mathworks.in/matlabcentral/fileexchange/23962-dynamic-control-of-a-wheeled-mobile-robot/content/HW6_MAIN_1.m6. LI Yunwang, et -al, (2010) “Mobile platform of rocker-type coal mine rescue robot”ScienceDirect, Mining Science and Technology 20 (2010) 0466–04717. Harjinder Singh, et -al (2011) “Design and Experimentation of a Six Wheel Lunar Roverfor Motion on Uneven Terrain” International Journal for Engineering and Technology, Issue1, Volume 2, December 2011.8. DongmokKim, et -al (2012), “Optimal design of hand & carrying rocker & bogiemechanism for stair climbing” Journal of Mechanical Science and Technology 27 (1) (2012)125~132.9. Gopichand Allaka, Prasad Raju Kalidindi, Koteswara Rao S, Manibabu Daadi and AbhayPatnala, “Design of Solid Shafts using MATLAB”, International Journal of MechanicalEngineering & Technology (IJMET), Volume 3, Issue 3, 2012, pp. 645 - 653, ISSN Print:0976 – 6340, ISSN Online: 0976 – 6359.10. Flt Lt Dinesh Kumar Gupta, “Linear Programming in MATLAB”, International Journalof Industrial Engineering Research and Development (IJIERD), Volume 4, Issue 1, 2013,pp. 19 - 24, ISSN Online: 0976 - 6979, ISSN Print: 0976 – 6987.

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