Adams Car Package > Adams Car > Appendix > DIFSUB

DIFSUB

 
DIFF 901
DIFF 903

DIFF 901

DIFF 901 (dif901) used in Adams Car for adjustable force elements. This differential equation drives the adjusters to achieve the desired alignment or ride height.

Input:

DIFF/id, FUNCTION = USER(routing_code, type_astring, desired_value, i_measmar, j_measmar, array, 0.0 , susp_par_array)
Routine= abgFDM::dif901
where:
 
Description
routing_code
=
Used only when routine= is not specified to dispatch to the proper routine
type_astring
=
Specify 'CAM', 'CAS', 'TOE' or ‘RID’
desired_value
=
Specify desired value
i_measmar
=
ID of I marker
j_measmar
=
ID of J marker
array
=
ID of array that specify pattern of ones (on) and zeros (off) to control the sequence of adjustment for multiple adjustable forces. See Adjustable Forces.
susp_par_array
=
ID of suspension_parameters_ARRAY, required when type astring = 'CAS'

Output

Return the difference between desired value and current value.

Notes on Input and Output

See SFORCE 901

DIFF 903

DIFF 903 (dif903) used in Adams Car for controlling an actuator force/displacement/variable during a static or quasi-static analysis to drive the difference between a command signal and a feedback signal to zero.

Input:

DIFF/id, FUNCTION = USER(routing_code, type_actuator, dof_actuator, id_actuator, id_command_signal, id_feedback_signal, force_limits_min, force_limits_max,disp_limits_min,disp_limits_max,gain_error, gain_force_limits,gain_disp_limits)
Routine= acarSDM::dif903
where:
 
Description
routing_code
=
Used only when routine= is not specified to dispatch to the proper routine
type_actuator
=
Specify 0 for motion, 1 for force or 2 for variable
dof_actuator
=
Specify 0 for translational or 1 for rotational degrees of freedom
id_actuator
=
ID of force or motion actuator
Id_command_signal
=
ID of command signal variable statement
id_feedback_signal
=
ID of feedback signal variable statement
force_limits_min
=
Minimum force limits
force_limits_max
=
Maximum force limits
disp_limits_min
=
Minimum displacement limits
disp_limits_max
=
Maximum displacement limits
gain_error
=
(Optional) Gain on error signal
gain_force_limits
=
(Optional) Gain on force limiting
gain_disp_limits
=
(Optional) Gain on displacement limiting

Output

The controller output is the DIF value which is used in either an action only SFORCE, MOTION or VARIABLE as
SFORCE/id_sfo, ACTIONONLY, I=....., J=...... {ROT,TRA}, FUNCTION = DIF(id_dif)
MOTION/id_mot, JOINT=id_joi, {ROT,TRA}, FUNCTION = DIF(id_dif)
VARIABLE/id_var, FUNCTION = DIF(id_dif)

Notes on Input and Output

See Example of using actuator limits.