This solves the linkage for one position. A new set of values can be put into the A
and C matrices for each position of interest at which a force analysis is needed. Read
the disk file EII-03.mat into program MATRIX to exercise this example. The disk file
EII-03.4br can also be read into program FOURBAR which will run the linkage through
a series of positions starting with the stated parameters as initial conditions. The linkage
will slow to a stop and then run in reverse due to the negative acceleration. The matrix
of equation (g) can be seen within FOURBAR using Dynamics/Solve/Show Matrix.
It is worth noting some general observations about this method at this point. The
solution is done using cartesian coordinates of all forces and position vectors. Before
being placed in the matrices, these vector components must be defined in the global coordinate
system (GCS) or in nonrotating, local coordinate systems, parallel to the global
coordinate system, with their origins at the links' CGs (LNCS). Some of the linkage parameters
are normally expressed in such coordinate systems, but some are not, and so
must be converted. The kinematic data should all be computed in the global system or
in parallel, nonrotating, local systems placed at the CGs of individual links. Anyexternal
forces on the links must also be defined in the global system.