On the properties of 3D equilibrium grasping forces

We focus on the 3D four-fingered grasps and analyze the properties of the equilibrium grasping forces among the grasping fingers. We introduced the concept of force concentration line to analyze the force distribution among the grasping fingers. The “invariant grasping configuration base” is also introduced in formulating a new representation scheme for the grasping forces. The characteristics of the invariant grasping configuration base and the relationship between it and the grasping forces are discussed. The grasping forces can be determined using this new representation scheme and the properties of the force concentration lines. It turns out that, by analyzing the properties of this new representation scheme, we can calculate all the feasible grasping configurations which will give all the solutions to the equilibrium grasping forces. This gives the general solution to the grasping force distribution problem