Research On Buffer And Vibration Reduction Mechanism Of The Goat Hoof Box And Design Of Bionic Buffer Foot For Foot Type Robot

When the foot type robot are motivated by the shock and vibration on an unstructured ground,its movement joints and other important body parts would be affected in control functions.Improve the foot of the foot type robot damping and shock resistance has become the key to accurate control and stable movement.This article is based on the facts that biological has an adaptive buffer damping ability under changeable environment,and choose a goat hoof box as bionic prototype,which studies the characteristics of structure vibration isolation buffer mechanism.Using buffer and vibration reduction mechanism of vibration reduction unit to design the foot type robot's buffer foot,which provide theory and technology support to the development and application of buffer damping technology.With the method of biology,we did anatomy of goat hoof box and observed its structural features at the macro level and micro level respectively.Combined with the hoof box outside load stress value,we analyzed the hoof box buffer and vibration reduction mechanism.The macroscopic observation shows that the hoof box bottom was made by raised hard nails and sag soft toe pillow,and the root is composed of raised hard toe pillow.The microscopic observation shows that the hoof box is composed of two layers of organization,and the inner surface is a layer of the organization of the inclined hole.Through the measurement of the area that hoof box contacted with the ground and the calculation about goat quality,the surface load pressure on hard and soft ground respectively is1.34 MPa and 0.24 MPa.According to the law of momentum,relative to other layer,the inclined hole layer has a large shape variable under the same reaction,thus extend the impact contact time and reduce the impact force and improve the buffer performance.According to single degree of freedom vibration theory,relative to other layers,the stiffness of inclined holes layer is small,thus reduces the inherent frequency and enlarged the vibration area and improve the vibration reduction effect.According to the structure characteristics of goat hoof box,bionic vibration reduction unit model is established,then based on the model to achieve the design and manufacture of vibration reduction unit.After selecting the bionic parameters of goat hoof box,we finished the size design of the model and 3d modeling.In order to complete the physical manufacture of vibration reduction unit,according to the biological material properties of the hoof box,we select the silicone RTV-2 as the equivalent materials of vibration reduction unit and choose casting processing method.According to the requirements of the casting molding processing,we finished casting mold design and manufacturing with 3d printing production.According to the requirements of the silicone RTV-2 material pouring process,we completed the physical manufacture of vibration reduction unit,providing test samples for the vibration test and compression experiments.In order to study the vibration reduction mechanism of goat hoof box,we completed the vibration test and compression experiment with vibration reduction unit.Through contrasting vibration test results and compression experiment results between ordinary vibration reduction unit and bionic vibration reduction unit respectively,it is concluded that the vibration reduction mechanism of goat hoof box.The ratio of the maximum amplitude between the vibration transfer before and after as the index,we design a vibration test scheme between 5 to 100 Hertz frequency.According to scheme requirements,we did the clamp of vibration reduction unit design,modeling and manufacturing to finish assembly of vibration test platform and construction of the vibration test system.The vibration test experiment results show that the natural frequencies of bionic vibration reduction unit is less than the ordinary vibration reduction unit;The greater the load stress is,the smaller its inherent frequency is.The amplitude of vibration source has no impact on the natural frequency;the greater the amplitude of vibration source is,the greater peak transmission rate is.The compression experiment results show that the compression stiffness of bionic vibration reduction unit is less than the ordinary vibration reduction unit;the smaller the inclination of the bionic vibration reduction unit is,the smaller the compression stiffness is.According to the structure characteristics of goat hoof box in the macro and micro level,we completed the design of the vibration reduction buffer foot.The design and modeling of cushion is basis on the internal microstructure configurations of goat hoof box.The design and modeling of planta is basis on goat hoof box bottom structure configuration.According to the design of cushion and planta,we completed the overall design and assembly of vibration reduction buffer foot to lay the foundation on impact simulation analysis and vibration simulation analysis.In order to analyze the bionic vibration reduction buffer foot buffer and dynamics performance,we completed the touchdown impact simulation analysis and vibration characteristic simulation analysis by comparing the results of transient dynamic analysis,modal analysis and steady-state kinetics analysis.The transient dynamics analysis shows that after an impact process,compared with the ordinary vibration reduction buffer foot,the bionic vibration reduction buffer foot's residual kinetic energy is small,and with the decrease of the Angle,the residual kinetic energy becomes smaller,The friction energy dissipation of the bionic vibration reduction buffer foot is greater than the ordinary vibration reduction buffer foot,and with the loss of the slope,the friction energy consumption more.The impact of the bionic vibration reduction buffer foot suffer is less than the ordinary vibration reduction buffer foot,the smaller the slope Angle,the lower the impact,the longer the duration,The above results indicate that the oblique hole features improve the buffer effect.Known from the modal analysis,the first three order natural frequency of the bionic vibration reduction buffer foot is less than the ordinary vibration reduction buffer foot,and with the decrease of the slope,the inherent frequency values gradually reduced.The steady-state kinetics analysis shows that compared with the ordinary vibration reduction buffer foot,the bionic vibration reduction buffer foot's displacement response is big,and with the decrease of the slope Angle,the displacement response and the dynamic flexibility is increase;the bigger the dynamic flexibility,the better for vibration isolation and control.