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.