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9.3.1 Solving for Two Parameters

To demonstrate the use of coupled systems to satisfy higher-order conditions, the four-bar model developed in Section 9.1 is used again. In the following example, the lengths of the drive bar and the driven bar are adjusted to satisfy two geometric conditions that are specified in two different mechanism configurations. One of the conditions is a first-order expression, specifying a component of the velocity of a point.
In the following example, bar2 and bar3 are adjusted so that the X coordinate of point 3 on the center bar is 0.4 at T = 0.3, and the Y velocity of point 3 on the center bar is 6.0 at T = 0.1. Initial guesses are specified for each configuration, and the initial guess for configuration 1, which contains the velocity condition, includes velocity terms.

Here are two initial guesses for the two configurations.

This builds the CoupleSystem object.

This solves the CoupleSystem object.

The nested list of rules returned by SolveCouple has one complete solution for each of the two mechanism configurations. Note that SolveCouple automatically determined that a velocity solution was needed for the first configuration by the presence of first-order terms in the geometric condition.

This shows that the desired goal has been achieved.