Design And Experimental Analysis Of Foot-ground Interaction Mechanism Test Bench For Legged Robot

With the rapid development of machinery,electronics and other industries,robot technology is more mature and widely used.Legged robot has the advantages of small soil mechanical compaction,light damage to crops during operation,easy evacuation from the scene and so on.It is becoming one of the development directions in the field of agricultural information collection at home and abroad.At present,the research mechanism of the interaction mechanism between the leg and the rheological soil of the foot robot is weak,and its leg design methods and design basises are very scarce.Therefore,it is of great significance to carry out the dynamic simulation and experimental study on the interaction between leg structure and rheological soil.It is of great significance to promote the technological progress and industrial application of farmland robot.The purpose of this project is to design the single leg soil bin test system for legged robot,and to construct a set of virtual simulation test platform for single leg foot-ground interaction.Through the finite element simulation of the running of the leg on the soil surface and the actual walking test in the soil bin test bench,the energy consumption and motion characteristics of the system are analyzed to reveal the interaction mechanism between the robot propulsion mechanism and the rheological soil.And provide scientific basises for legs design and optimization of farmland robot.First of all,based on the overall mechanical design scheme of the test bench,the detailed design,verification,processing and assembly of the mechanical parts of the test bench are carried out to build the physical platform of the test bench.Secondly,the hardware design and software design of the measurement and control system of the leg soil bin test bench are completed.The hardware of the test bench is selected to complete the production of the electric control cabinet.Through the joint programming of C#and PLC,the automatic control and data acquisition of the soil bin test bench are realized.Then,ABAQUS finite element software is used to establish the constitutive model of rheological soil.Based on ABAQUS/Explicit algorithm,the virtual simulation test platform for mechanical leg walking in farmland soil was constructed.And the rationality of the finite element model is verified in the test of the mechanical leg.Finally,the optimal gait trajectory and foot end structure are found by the orthogonal test of the finite element simulation test platform.The reliability of the conclusion is verified based on the actual experiment of the soil bin test bench.The experimental results show that the influence of each parameter on the energy consumption of the system is:foot shape>step size>cycle>step height.And the influence of the foot shape was the most significant.When the mechanical leg uses the parameters of step size of 150mm,step height of 55mm,cycle of 2.4s and cylindrical foot structure in unit distance,the system requires the least energy consumption.Throughout the cycle of movement,the process of mechanical legs into the soil is the most energy-consuming.The experimental results reveal the motion mechanism of the legged robot in the farmland to a certain extent,which lays the foundation for the design and optimization of the farmland robot.