Toggle Kinematic Mode - Example Application
A typical example would be the lower control arm of a suspension subsystem. We could constrain this part to the vehicle body in two ways:
■Kinematic constraint - Allows the control arm to rotate about a fixed axis (similar in concept to a door swinging on its hinge; its only
Degrees of Freedom is rotation about a direction which is constrained by the physical location of the hinges).
■Compliant constraint - Allows the control arm to move in all directions based on a force-displacement relationship in all six degrees of freedom.
If we used the kinematic and the compliant constraints at the same time, we would see no force components in either the x, y, or z directions and only a torque in one of the rotational directions (typically the z-axis is used to define the rotational axis; for example, the z-axis would point from one door hinge to the other door hinge). The reason there is no force component is because the kinematic constraint (revolute joint) removes the ability of the bushing to be deformed. In most cases, using the two constraints at the same time is pointless. Typically we are either interested in the motion of the mechanism (
Kinematic Analysis) or the compliance of the system (compliant analysis).