Experimental Study On Walking Of Hexapod Robot With Leg Injury

Due to human exploration of nature,the environment that human beings need robots to go to is becoming more and more challenging.Foot robots capable of operating in special environments such as earthquake-stricken areas and war fronts are gradually replacing wheeled and tracked robots sent to complex unstructured environments.Compared with biped and quadruped robots,hexapod robots have more redundant degrees of freedom in legs and discrete foot drop points.Moreover,hexapod robots are more adaptable to unstructured environments and have become an excellent solution to mobility problems in complex unstructured environments.However,due to the interference and impact of the external environment,the hexapod robot may suffer from mechanical,electrical,control and other aspects of damage or failure,causing mission termination.In view of the above problems,this thesis will give full play to the characteristics of redundant degrees of freedom of hexapod robot,through theoretical analysis and experimental analysis.This study puts forward the walking strategy of hexapod robot with leg injury,the research contents are as follows:(1)This thesis studies on the mechanical structure of the hexapod robot and optimizes the body and leg structure of the hexapod robot.Motors and harmonic reducers are placed at the coxa and fuselage to reduce joint torque.At the same time,synchronous belts are used to transmit power to the thigh and calf joints to reduce the moment of inertia of the thigh and calf.These measures can improve the flexibility of the hexapod robot and reduce the impact load on the drive system.(2)Kinematic and dynamic modeling of the hexapod robot are carried out,and at the same time,mathematical constraints of motion parameters such as the foot end motion space of the hexapod robot are obtained through analyzing the kinematic model.The static moment and dynamic moment of the hexapod robot's joints are obtained by analyzing the dynamic model,the motors and reducers are selected according to the torque relationship.The static stability margin of the hexapod robot is analyzed and used to judge the gait stability of the hexapod robot.(3)In the study,the hexapod robot is built with electrical system and control system,and uses bus communication to collect information from force and angle sensors.In order to simplify the circuit and improve the electrical reliability,the electrical equipment is selected reasonably.A three-layer control system consisting of task planning layer,motion control layer and drive execution layer is built to optimize the control process and improve the real-time and extended performance of the control system.(4)The walking gait of the hexapod robot with leg injury is planned.By analyzing the static stability margin during the walking process of the hexapod robot with leg injury,the movement stage that hexapod robot is prone to dumping is found.By changing the gait parameters of the hexapod robot with leg injury,the scheme of improving the walking stability is obtained.(5)The walking experiments of the hexapod robot under the condition of leg injury are conducted to verify the theoretical scheme.Through analyzing the experimental results,the walking strategy under actual conditions is obtained.