A 25 year-old Construction worker underwent neck laceration following penetrating neck trauma in a falling incident. The 3rd tracheal ring was injured which was initially repaired and the patient was discharged in good general condition. (Figure 1 shows the patient’s neck view after discharge from hospital).Two months later the patient was again admitted due to provocative coughing and a metal ...

In many virtual reality applications it is necessary to simulate the interaction among solid objects. One of the basic requirements is to ensure a non-penetration of rigid bodies. We show algorithms for detecting a collision of moving bodies along with the exact time of collision determination. Next we present a method for computation the postcollision velocities and positions of colliding obje...

During the last few years motion analysis has developed into a major field of interest in image analysis and understanding . Considerable progress has been made as evidenced by the number of publications . However , most of these have been confined to the study of rigid body mot ion . Very few have addressed the issue of non-rigid body motion which poses many interesting and difficult problems ...

These course notes will explain in details the physics behind rigid-body motion. Previously, we treated bodies as dimensionless “particles”. At time t, they existed in pointwise position x(t) with velocity v(t). Net force F(t) induced acceleration a(t), where F(t) = ma(t), with m as the mass of the particle. For readability, note that we mark vector quantities with bold notation: v ∈ R3 = (v1, ...

Practical problems like regulating robot grippers critically rely on accurately predicted friction forces. Qualified methods are derived and discussed subsequently. Special attention is paid to the question of solution existence. A time-stepping scheme which supports Coulomb friction and inelastic impacts is implemented and the numerical results are analyzed. The approach proofs to be stable, a...

We present a theory of qualitative rigid body mechanics and describe a program that uses this theory to compute qualitative dynamic simulations. The program works directly from a qualitative representation of geometry (qc-space). It employs a new qualitative representation for forces that reduces ambiguity in force sums and hence reduces branching.

We propose a new three-dimensional dynamic theory of transforming materials intended to make realistic simulations of the dynamic behavior of these materials accessible. The theory is appropriate for materials whose free energy function rises steeply from its energy wells. Essentially, the theory is the multiwell analog of ordinary rigid body mechanics with three additional features: the full s...

We present a general method to intuitively create a wide range of locomotion controllers for 3D legged characters. The key of our approach is the assumption that efficient locomotion can exploit the natural vibration modes of the body, where these modes are related to morphological parameters such as the shape, size, mass, and joint stiffness. The vibration modes are computed for a mechanical m...

The dynamic characteristics of deflectable nose missiles with rotary single-channel control were investigated in this paper. Firstly, the effective angle of attack, effective angle of sideslip and quasi-body coordinates were introduced based on the spin characteristics of the missile’s body. Secondly, considering the interaction between the missile’s nose and body, the rigid kinetic model of mi...