Development of integrated hand-foot function can speed up the practical application of four-legged walking robots.A new type of robot which has the structure of four-legged walking robot based on hand-foot-integration is introduced.The image system is installed in the body of the robot

which is used to direct the robot to complete grabbing object.Kinematics relations for grasping states of robot are described.Kinematics error model of four-legged walking robots for grabbing object is built.Relations between image system errors and working arm kinematics errors of robot is discussed based on inverse kinematics analysis.Detailed calculation formulas are given

and the analysis process is illustrated by an example.The model can be used to robot motion control and error compensation for grabbing object.