tool bar) to setup the Matlab workspace.
Caution: Most of the settings in setup.m should not be changed.
This script has been configured
for the 6 DOF Hexapod system that was shipped and therefore most the parameters should
not be changed.
4.3
CREATING AN EARTHQUAKE: MAKE_QUAKE_XYZ.M
The make_quake_xyz.m script builds a trajectory that can be used in the Hexapod_Earthquake.mdl Simulink dia-
gram and ran on the shake table. The resulting trajectory created is the setpoint or command position that is to be
tracked by the stage in order to achieve the same accelerations as the recorded earthquake.
As listed in Table 4.2, the Northridge, Kobe, El-Centro, and Cape Mendocino raw earthquake acceleration files are
already supplied. Additional earthquake data files can be downloaded from the Internet from locations such as the
PEER Ground Motion website, as explained in Section 3.3.
Follow these steps to run the make_quake_xyz.mfile:
1. Load
Matlab
r
.
2. In the
Current Directory
window, go to the 6 DOF Hexapod files on your PC (copied from the 6 DOF Hexapod
CD).
3. Open the
make_quake_xyz.m
script.
4. Set the
input_filename_x
and
input_filename_y
variables in the script to the name of the earthquake file that
is to be replayed on the shake table. As shown below, set the variable to NGA_no_1806_SYL090.AT2 and
NGA_no_1806_SYL360.AT2 for the Northridge earthquake. The
x_max
parameter determines the maximum
position of the scaled setpoint trajectory.
%% INPUT
% name of data source file:
% Northridge
input_filename_x = 'NGA_no_1086_SYL090.AT2';
input_filename_y = 'NGA_no_1086_SYL360.AT2';
input_filename_z = 'NGA_no_1086_SYL-UP.AT2';
% Kobe
% input_filename_x = 'NGA_no_1105_HIK000.AT2';
% input_filename_y = 'NGA_no_1105_HIK090.AT2';
% input_filename_z = 'NGA_no_1105_HIK-UP.AT2';
% Cape Mendocino
% input_filename_x = 'NGA_no_825_CPM000.AT2';
% input_filename_y = 'NGA_no_825_CPM090.AT2';
% input_filename_z = 'NGA_no_825_CPM-UP.AT2';
% El Centro
% input_filename_x = 'NGA_no_180_H-E05140.AT2';
% input_filename_y = 'NGA_no_180_H-E05230.AT2';
% input_filename_z = 'NGA_no_180_H-E05-UP.AT2';
%
% Maximum scaled position (cm). NOTE: Do not exceed stroke limit. It is
% recommend you keep this value below 2.5 cm for most trajectories.
x_max = 2.5;
%
Caution:
Do not set x_max greater to value greater then the maximum stroke of the table! In general,
keep the variable under 2.5 cm for most trajectories.
HEXAPOD Laboratory Guide
30
