Research Of Leg Robot Based On Partial Compliance

In recent years,legged robot has become a hot research topic because it can adapt to complex and varied terrain environment.At present,most legged robots are purely rigid mechanisms.They can only use spring,torsion springs,lubricants and other auxiliary parts to achieve vibration reduction,impact resistance,friction and wear reduction.The flexible mechanism realizes the transfer and transformation of movement,force and energy through its own deformation.The flexible mechanism can solve the disadvantages of the above pure rigid legged robot from the structural design.In order to improve the performance of legged robots in vibration reduction,impact resistance and wear reduction,a contact assisted variable stiffness bending strengthening device and compliant mechanical feet are designed.On the basis of this,a rigid flexible coupling legged robot is designed according to the motion principle and scale proportion of human legs.The main tasks of the thesis are as follows:(1)In order to enhance the carrying capacity and impact resistance of the new cross reed flexure hinge in the rotation direction,a contact aided variable stiffness bending strengthening device is designed,and the device is analyzed theoretically.The accuracy of the theoretical analysis is verified by the finite element simulation and experimental test of the device.(2)Based on the variable stiffness principle of the contact assisted variable stiffness bending strengthening device,a compliant mechanical foot applied to the leg of a legged robot is designed,and the compliant characteristics of compliant mechanical feet are tested by six bar and seven legged legs.The vibration test of six mechanisms and six pairs of compliant mechanism feet is carried out by using the ADAMS simulation software,which proves that the compliant mechanical foot has vibration reduction and impact resistance.The performance of the six bar and seven pairs of compliant mechanisms is processed,and the experimental platform is built to verify the adaptability of compliant machine feet to the environment.(3)According to the motion principle and scale proportion of human leg,and combining the characteristics of the contact auxiliary variable stiffness bending strengthening device and compliant mechanical foot,a rigid flexible coupling humanoid walking leg was designed.The dynamics analysis of the humanoid walking leg was carried out,and the dynamic model of the mechanical leg was established based on the Lagrange process.The ADAMS simulation software was used to simulate the walking leg of the humanoid walking machine.The dynamics simulation is carried out to confirm the accuracy of the dynamic model within a certain range.The prototype of the humanoid walking leg is made,and the experimental platform is built to carry out the experiment,which confirms the accuracy of the dynamic model.(4)Based on the humanoid walking legs,a rigid-flexible coupling humanoid walking legs robot is designed.The whole structure and walking gait of the humanoid walking legs robot are designed,and the appropriate driving mode and driving mode are selected for it;the motion simulation and vibration test of the legged robot are carried out by using ADAMS simulation software.The simulation results show that the humanoid walking legs robot is a rigid-flexible coupling robot.It can not only achieve stable walking,but also have a certain carrying capacity and good amplitude-frequency characteristics.The main innovations of this paper are as follows: the design of the contact assisted variable stiffness bending strengthening device can enhance the bearing capacity and impact resistance of flexure hinges in the rotation direction.The design process provides a new method for the flexible coupling design of compliant bending devices.The compliant mechanical design of this paper improves the legged robot from the structural design.The humanoid walking legged robot designed in this paper has good dynamic performance and realizes the coupling of rigid mechanism and flexible mechanism.