This dissertation presents algorithms for the simulation and control of articulated rigid bodies and related applications. The first algorithm is a novel approach for dynamically simulating articulated rigid bodies undergoing frequent and unpredictable contact and collision. In order to leverage existing algorithms for nonconvex bodies, multiple collisions, large contact groups, stacking, etc.,...

This paper presents a physically based method to deal with haptic feedback of manipulated deformable virtual objects in contact with rigid or deformable environment. The haptic rendering algorithm is based on the Signorini’s formulation of the contact as proposed in theoretical mechanics. Since haptic interaction requires high refresh rates, a multi-threaded methodology, sharing configuration v...

We recently developed a time-stepping method for simulating rigid multi-body systems with intermittent contact that is implicit in the geometric information [1]. In this paper, we extend this formulation to quasi-rigid or locally compliant objects, i.e., objects with a rigid core surrounded by a compliant layer, similar to Song et al. [2]. The difference in our compliance model from existing qu...

This paper deals with the handling of deformable linear objects (DLOs), such as hoses, wires or leaf springs. It investigates the a priori knowledge about the 6-dimensional force/torque signal for a changing contact situation between a DLO and a rigid polyhedral obstacle. The result is a complete list, containing for each contact change the most significant combination of force/torque signal co...

This paper deals with the robust manipulation of deformable linear objects such as hoses or wires. We propose manipulation based on the qualitative contact state between the deformable workpiece and a rigid environment. First, we give an enumeration of possible contact states and discuss the main characteristics of each state. Second, we investigate the transitions which are possible between th...

The relative sliding motion of two elastic bodies in contact induces wear process and contact shape evolution. The transient process tends to a steady state occuring at fixed contact stress and strain distribution. This state corresponds to the minimum of the wear dissipation power. The optimality conditions of the functional provide the contact stress distribution and the wear rate compatible ...

CASE REPORT A 27-year-old woman with congenital glaucoma with high myopia, low visual acuity and nystagmus in both eyes, was referred for contact lens fitting. We fitted her with aspherical rigid gas permeable (RGP) contact lenses with high transmissibility, which she wore on a daily basis. Her visual acuity improved with the wearing of these lenses, which remained comfortable whilst being worn...

In this paper, we plan robotic multi-contact nongaited motion by solving an overall optimization problem. Our algorithm takes as input the contact stances, the model of the robot and its environment, and generates the joints trajectories that achieve multi-contact motion under explicit constraints such as joint position, velocity and torque limits, equilibrium and eventually other task objectiv...

A solution based on a Hertzian approximation to the contact pressure distribution is obtained for the transient thermoelastic contact of a sphere sliding on a rigid non-conducting plane. With this simplification an integral equation formulation is obtained. In a nondimensional form the only independent parameter is the starting condition and numerical results are presented for various values. A...

In this report an iterative method from the theory of maximal monotone operators is transfered into the context of linear complementarity problems and numerical tests are performed on contact problems from the field of rigid multibody dynamics.