What is the practical application of animate constraints in Catia?

Like many other people, I have played with animate constraints tool present in sketcher workbench, and have had my share of fun in the past. However, today I am going to talk about the way in which this tool can actually be used, so that you become more oriented about its significance and understand one more way in which it can save you some time. One of the most commonly used suspension system in an inexpensive car is MacPherson strut with a control arm and a stabilizer bar and perhaps other one is with a sturt and two control arms, or some other derivative of this. 

Animate constraints - Sketch of a suspension geometry that a car may employ

While designing, you may be faced with questions like what length of the control arms you should employ, or where will the rolling centres lie if you take a certain length of control arm, or what should be the angle of the king pin knuckle etc. All these questions can be answered with the help of sketcher workbench of Catia. All you have to do is to apply constraints keeping in mind the geometry of parts themselves, and how they may behave or maintain a relationship with the other parts. For example, the lengths of control arms in a suspension system would not change, these would be mounted on one end to the car's chassis and on the other to the knuckle. Likewise, the tyre width and height can be built into the sketch, so that it can rotate about a certain point (known as roll centre), this may be the point where axis of the upper and lower control arms intersect. The king pin axis and it's angle can also be built into the sketch itself. So, after you have applied all the constraints appropriately, you should be able to animate the mechanism and investigate a parameter of your choice. For example, in the case that I have considered, I chose to apply animate constraint to the angle between upper control arm and horizontal axis and I investigated the angle that tyre's horizontal surface would make with the ground. You can see the video below so as to see how the whole sketch would come to animate.

The example that I have considered is one of the many cases to which animate constraints tool can be put to use. Other examples may be whitworth quick-return mechanism used in shaper machine, wheels of a locomotive, four bar chain etc. There are more advanced softwares that are specifically used for mechanism analysis these days. Nonetheless, you should be able to do most of the preliminary investigation using Catia Sketcher. For more advanced analysis you may use DMU kinematics, where you may be able to check the mechanism in 3D space, for things like if the parts would clash or the kind of volume a certain mechanism will come to occupy or range of motion in 3D etc.