diff options
Diffstat (limited to 'testsuite/vests/vhdl-ams/ashenden/compliant/analog-modeling/pendulum_wa.vhd')
| -rw-r--r-- | testsuite/vests/vhdl-ams/ashenden/compliant/analog-modeling/pendulum_wa.vhd | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/testsuite/vests/vhdl-ams/ashenden/compliant/analog-modeling/pendulum_wa.vhd b/testsuite/vests/vhdl-ams/ashenden/compliant/analog-modeling/pendulum_wa.vhd new file mode 100644 index 000000000..bf3381127 --- /dev/null +++ b/testsuite/vests/vhdl-ams/ashenden/compliant/analog-modeling/pendulum_wa.vhd @@ -0,0 +1,90 @@ + +-- Copyright (C) 2002 Morgan Kaufmann Publishers, Inc + +-- This file is part of VESTs (Vhdl tESTs). + +-- VESTs is free software; you can redistribute it and/or modify it +-- under the terms of the GNU General Public License as published by the +-- Free Software Foundation; either version 2 of the License, or (at +-- your option) any later version. + +-- VESTs is distributed in the hope that it will be useful, but WITHOUT +-- ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or +-- FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +-- for more details. + +-- You should have received a copy of the GNU General Public License +-- along with VESTs; if not, write to the Free Software Foundation, +-- Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + +-- Pendulum example. Look at velocity quantity, phi_dot, to see effects of +-- discontinuity. Run simulation for about 20 sec. + +library IEEE_proposed; +use IEEE_proposed.mechanical_systems.all; + +library ieee; use ieee.math_real.all; + +entity pendulum_wa is +end entity pendulum_wa; + +-- ====================================================================================== +-- constrained architecture +-- ====================================================================================== +architecture constrained of pendulum_wa is + constant mass : real := 10.0; + constant arm_length : real := 5.0; + constant pin_angle : real := 0.25*math_pi; + constant pin_distance : real := 2.5; + constant damping : real := 1.0; + constant gravity : real := 9.81; + constant short_length : real := arm_length-pin_distance; + quantity phi : real := -0.5*math_pi; + signal current_length : real := arm_length; + quantity acceleration, velocity : real; + quantity phi_dot : real; + signal pin_thresh : boolean; + signal phi_dot_at_pin_thresh : real := 0.0; + signal transition : boolean := false; + +begin + if domain = quiescent_domain use + phi == -0.5*math_pi; + phi'dot == 0.0; + elsif transition and pin_thresh use + phi == pin_angle; + phi'dot == phi_dot_at_pin_thresh*arm_length/short_length; + elsif transition and not pin_thresh use + phi == pin_angle; + phi'dot == phi_dot_at_pin_thresh*short_length/arm_length; + else + mass*acceleration == -mass*gravity*sin(phi)-damping*velocity; + velocity == current_length*phi'dot; + end use; + + acceleration == velocity'dot; + phi_dot == phi'dot; + + pin_thresh <= phi'above(pin_angle); + + process + begin + wait on pin_thresh; + phi_dot_at_pin_thresh <= phi_dot; + if pin_thresh = true then + current_length <= short_length; + transition <= true; + else + current_length <= arm_length; + transition <= true; + end if; + wait for 1 us; + transition <= false; + end process; + break on pin_thresh; + break on transition; + +end architecture constrained; + + + |