Research On Mobile Robots Based On The Single-Loop Overconstrained Spatial Linkage

Mobile robots are widely used in military,anti-terrorism,post disaster rescue,etc.,which can significantly reduce the casualty rate and effectively improve the work efficiency.It is an important research direction to improve the adaptability of mobile robot to the rough terrain and enable it to obtain the high mobility.Based on the advantages of flexibility,single degree of freedom and high reliability of spatial single-loop overconstrained linkage,the purpose of this dissertation is to explore a novel mobile robot.The robot possesses the obstacle-surmounting ability and the high-speed mobility on rough terrain,and then establish designing method.Develop the prototype for experimental verification,and explore the practical application combined with the specific scene,so as to provide a new configuration and technical way for the design and research of the mobile system in complex environment.The specific contents of the dissertation are as follows:(1)The design method of utilizing the spatial overconstrained linkage as the driving module of mobile robot is summarized and refined.The robot possesses the high flexibility,stiffness and bearing capacity and the ability to traverse through tough terrains.For the mechanical structure,the robot has the characteristics of the simple structure and high stiffness of spatial overconstrained linkage;For the control technology,only one motor needs to be controlled,which can simplify the control system of the robot.Firstly,the characteristics of spatial overconstrained linkage and the trajectory of components are analyzed.Secondly,the mobile mode that can adapt to complex terrain is confirmed in combination with the application requirements.Thirdly,the theoretical contact position of the component is determined.The shaping design of the component is carried out,and the driving module is proposed.Finally,the boundary conditions are established to determine the overall configuration and driving unit layout.(2)A Single-actuator steerable rolling robot based on the Schatz linkage is proposed.According to the kinematic analysis of the Schatz linkage,a spatial overconstrained linkage,the profile of the touchdown component is designed as the Oloid surface.As a result,the robot can move smoothly.It is driven by one actuator,and its steering is controlled by the rotating speed and direction of the actuator.In terms of mechanism composition,the robot is only composed of six components through six rotating pairs,and the mechanical system has been effectively simplified;In terms of control technology,it needs one input variable to control the robot,and the control system is highly simplified.Firstly,the scheme of combining the Oloid surface with the shape design of the touchdown link is analyzed.Secondly,the theoretical model is built to analyze and demonstrate its performance and maneuverability.After the dynamic analysis,the control strategy is figured out,which is that control the direction of the robot by controlling the motor speed and direction.Finally,a prototype is developed and the experiment is carried out to verify the feasibility of the theoretical analysis.Based on the research on the maneuverability of the robot,the unit module technology is studied,which is the theoretical basis for further research on the new concept mobile robot.(3)A portable hexapod crawling robot based on the Schatz linkage is proposed.The module technology based on Schatz mechanism is used to integrate multiple leg modules.According to the requirements of high maneuverability and portability in the field environment,the robot is proposed,which could adapt to the rough terrain.Its leg module is designed by utilizing the characteristics of the spatial overconstrained linkage.The layout of leg modules is optimized to enable the robot possesses the high maneuverability.Firstly,by combining with the module technology based on the Schatz linkage,the scheme of the portable hexapod crawling robot is proposed.Secondly,the gaits are designed,and the kinematics of the robot is analyzed,which is verified in the simulation environment.Thirdly,the prototype is developed for experimental research,its maneuverability is comprehensively investigated,and its application is demonstrated.Then,according to the application scenarios,the field portable emergency rescue robot applied to post disaster rescue is proposed,and its application method is designed.Finally,the prototype is developed and tested,and its practicability and durability are tested by the simulated task.The portable hexapod crawling robot based on the Schatz linkage is not only the application of the module technology,but also the primary research of the module combination technology.(4)A multi-mode tumbling robot based on the Schatz linkage is proposed.The module technology and the unit module combination technology based on the Schatz linkage are used to integrate multiple modules.The robot possesses the flexible mobility,high-speed stability and strong obstacle-surmounting ability.Utilizing the spatial tumbling movement of the Schatz linkage,the robot can work in wheel-like rolling mode,arm-like climbing mode and snake-like crawling mode.The mobile mode is determined by the relative position relationship between the environment and the robot.The switch does not rely on the active switching mechanical component,which simplifies the mechanical structure of the robot and improves the practicability and durability of the whole robot.Firstly,using the module technology based on the Schatz linkage,the spatial rolling movement is combined with the contour design of the touchdown link,and a multimode rolling robot based on the Schatz linkage is proposed.Secondly,after analyzing the layout of the driving module,a simplified theoretical model is established to analyze the kinematics of the robot.Then,verify the analysis in the simulation environment.Finally,the prototype is developed,and the experiment is carried out to test its maneuverability.Its practicability and durability are tested through the mode task.The multi-mode tumbling robot based on the Schatz linkage is an application example of the module technology and module combination technology.At the same time,it possessed flexible mobility,high-speed stability and strong obstacle-surmounting ability.