Interaction force modeling and analysis of the human–machine kinematic chain based on the human–machine deviation

A mechanical model for a human–machine interaction force based on the man–machine kinematic chain is established. This is combined with screw theory and a virtual rigid body model for the human–machine interaction force is proposed. This model interprets the basic principle model of the human–machine contact force. The deviation of the human–machine kinematic chain is calculated using the virtual model. In order to carry out the calibration simulation for the model, a 6-sps parallel mechanism is taken as an example to illustrate the construction principle of the human–machine interaction virtual rigid body model. This is calibrated by introducing finite element software. Finally, using the knee exoskeleton as an example, a numerical simulation is introduced. This illustrates the relationship between the driving force of the exoskeleton, the human–machine deviation as well as the virtual stiffness. The modeling method of this paper provides theoretical reference for controller design of human–machine interaction forces in the future.