I have interfaced a simple 2 link exoskeleton with its hip joint coinciding with human hip joint. And to assist human, I am providing a class called AnyKinEqSimpleDriver to exoskeleton hip joint which intends to assist the human model to lift up. But since, the exoskeleton is constrained with human at two nodes, it takes reaction type 'On' by default, and when I switch these reaction type 'Off', I get an error "Muscle recruitment solver: solver aborted due to singular kkt matrix". Please suggest on how to keep the reaction type Off and avoid this error
How is the exoskeleton connected to the human at the two nodes? Are there some reactions that allow a kinetic connection between the human and the exoskeleton at those nodes?
The exoskeleton is connected to human via two nodes on the thigh and two nodes on the trunk. These nodes are defined on the thigh (one medial and one lateral) and trunk (both lying on the same plane and trunk lateral surfaces), A revolute joint is defined between thigh and trunk segment but reaction is kept off.
You would need some reaction force or some recruited actuator to ensure kinetic connection between the human and the exoskeleton (the choice is up to you). Otherwise, the system will remain in imbalance and will not be able to solve for inverse dynamics. Please this page for more information on how to connect an exoskeleton to human.