| In recent years,all-terrain mobile robots have become increasingly used in the field of outdoor detection,which has drawn extensively international research and attention.At present,most of the research on all-terrain mobile robots is the design of their control systems,whereas rarely studied has been applied to the mechanical structure,especially the suspension mechanism of robots.This paper designs an all-terrain mobile robot with independent suspension damping mechanism,the kinematics and dynamics model are established,and the physical prototype was made.The dynamic characteristics of the vehicle were tested for different road conditions,and the rationality of the design of the suspension damping mechanism was verified.(1)Robot structure design.Aiming at the application scenario of all-terrain mobile robot,a mobile robot with independent suspension damping mechanism is designed,the suspension damping mechanism has good adjustability,the initial preload of the damper can be easily set.Finite element analysis of the mechanical strength of the essential components of the mobile robot is carried out,and the analysis results show that the use of aluminum alloy materials to manufacture body parts is qualified for mechanical strength and meet lightweight design requirements.For different motion scenarios,the dynamics calculation of the robot driven mechanism is carried out,the maximum torque required for the movement is determined,and the selection of the motor and the reducer is completed.(2)Kinematics and dynamics analysis.The kinematics and dynamics model of the all-terrain mobile robot are established,the change of the robot posture during the steering is analyzed.The dynamics of the suspension system is calculated by Lagrangian method,the major influencing factor of the damping performance of the suspension mechanism damper is determined,and the relationship between the spring stiffness and the damping performance of the robot is obtained.(3)Simulation analysis.The robot virtual prototype is established and simulated by Adams(Automatic Dynamic Analysis of Mechanical System).According to the simulation analysis results,the value range of the damper parameters is determined.The simulation model of the robot on the flat road and the pit road is established respectively.The longitudinal amplitude of the wheel,the vehicle and the deformation of the spring are tested.The simulation results show that,compared with the motion on the pit road and the flat road,the overall vibration amplitude does not change much,indicating that the suspension damping mechanism has good vibration damping performance.Simultaneously,the simulation experiment analysis of the robot rotation motion is carried out,and the maximum rotation speed of the robot under the condition of satisfying the motor torque constraint and the robot amplitude threshold is obtained.(4)Experimental test.According to the structure design of the robot,the robot prototype is machined and assembled.The vibration test of the mobile robot studied in this paper and another mobile robot without suspension damping mechanism is tested on the mooring road,cement road,cobblestone road and grass road respectively,the vibration data of the vehicle body is measured by the gyro sensor,which shows that the vibration of the robot body is smaller than that of the mobile robot without the suspension damping mechanism when the mobile robot runs on the above road surfaces,indicating that the suspension mechanism has good vibration damping performance.The change of motor current during the climbing and turning motion of the robot is analyzed,and whether the motor is overloaded is judged by the magnitude of the motor current,the experimental results show that the motor current of the mobile robot is less than the rated current when turning and climbing,which indicates that the designed drive power system of the robot meets the requirements of practical applications. |
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