Creating Kinematic Models in CAD/CAM Systems

Kinematics model is the last subset of information required to complete the model of a mechanism. The first kinematics related decision is place and type of joints. The assembly model includes information for the places where the parts are in contact relationships. Joints are proposed to be placed at these connections automatically. Part geometry and inertia properties are accessed from the assembly model. At the construction of the kinematics, joints are defined between connecting geometries of parts. A choice of practice-oriented and user-configurable joint 1 types is available in industrial modeling systems. They are associative with the geometry of connecting parts. Once joints, constraints, and functions have been defined the mechanism can be analyzed automatically using a solver that understands and displays both kinematic and dynamic behaviors. Consistency of motions with the functional specifications, degrees-of-freedom calculations to evaluate the integrity of the design, solids based interference and clearance checking, the swept volume of a moving part, which is defined by a part moving through its entire range of motion, and joint validity checking are the main automatic analyses. User-defined kinematic laws allow time-based simulation. Mechanism motions are sketched or defined using mathematical formulas.