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Design And Analysis On The Terrain-Adaptive Omni-Directional Unmanned Fire-Fighting Vehicle Locomotion System

Posted on:2017-04-25Degree:MasterType:Thesis
Country:ChinaCandidate:G J MengFull Text:PDF
GTID:2296330485485276Subject:Mechanical engineering
Abstract/Summary:PDF Full Text Request
With the increase of large-scale petrochemical enterprises and hazardous goods warehouses, disaster risks such as oil gas explosion, gas leak and other hazardous disasters are also increasing. These disasters tend to have very large damaging effects. In order to rescue people trapped in these disasters and to prevent the secondary disasters, it is required to take the rescue actions timely. But these disasters are often accompanied by poisonous, radiant, flammable, explosive and other dangerous situations, which make it hard for firefighters to go into the accident scene to execute surveillance and rescue tasks. If the firefighters are in the face of such dangerous environments without adequate on-site reconnaissance and analysis, they may make wrong decisions and take blind actions. Thus they not only cannot achieve effective fire rescue, but may sacrifice because of the danger environments paying a heavy price. Even with fully understand of the environment, if the firefighters themselves go into the dangerous environment personally, it is also likely to cause casualties because of radiation, toxic or sudden secondary disasters. In response to these problems, many countries are engaged actively in the development of unmanned fire-fighting vehicles in order to help firefighters to execute surveillance or rescue tasks in dangerous zones. Due to the complex terrain on fire disaster scene, it has certain requirements for the unmanned fire-fighting vehicle locomotion system. In order to improve the mobile efficiency in narrow areas and complex road conditions suitability, this paper carries out the research on the terrain-adaptive omni-directional unmanned fire-fighting vehicle locomotion system. The main work of this paper is as follows:First of all, the design of terrain-adaptive omni-directional unmanned fire-fighting vehicle locomotion system.Based on the analysis of the advantages and disadvantages of the main current mobile mechanism and steering mechanism using in unmanned fire-fighting vehicle, this paper proposes the overall structural design of a novel unmanned fire-fighting vehicle taking the mobile efficiency and steering flexibility into account. The mobile mechanism can switch between the passive terrain-adaptive mode and active obstacle-climbing mode, while the steering mechanism can realize omni-directional movements. The specific mechanism design of the locomotion system is completed including the terrain-adaptive mechanism, active-climbing mechanism, omni-directional steering mechanism. At the same time, the matching environment perception module and drive control module is designed on the basis of mechanism design.Secondly, the modeling and analysis of the terrain-adaptive omni-directional unmanned fire-fighting vehicle locomotion system.The vehicle dynamics model is established to make kinetic analysis to verify whether the mobile system meet the driving requirements. Through the establishment of typical passive adaptive obstacles, the static equilibrium equations are obtained when the mobile system passing over typical obstacles. The static equilibrium equations can be used to analyze its adaptive ability to rough terrain. By establishing the active uplifting torque equation and lifting height model, the equations are obtained including the required active lifting torque, the relationship between lifting height and each rod and the relationship between the former rocker and the vehicle body pitch angle. Through the kinematic model of normal steering mode and omni-directional steering mode, we get the relationship between the angle and driving speed of each wheel in different steering modes.Finally, simulations and experiments are conducted to show the validity of the proposed terrain-adaptive omni-directional unmanned fire-fighting vehicle locomotion system.The paper has built up the testing prototype of the proposed locomotion system and conducted the obstacle detection, terrain-adaptive, obstacles crossing and obstacle avoidance simulations and experiments. Through the terrain adaptive simulation and the actual undulating road experiment, its adaptability to rough terrain was tested. For its active mode, the active lifting torque simulation and obstacle-surmounting experiments were carried out. Then, the obstacle avoidance simulation and experiments were implemented to validate the feasibility of its two wheels steering, zero radius steering and lateral steering mode. The simulation and experimental results show that the proposed locomotion system can adapt to rough terrain passively, climb up obstacles actively, and realize omni-directional movements such as zero radius turning and lateral movement.
Keywords/Search Tags:Terrain-adaptive, Omni-directional Steering, Unmanned Fire-fighting Vehicle, Locomotion System, Mechanism Design
PDF Full Text Request
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