Merge branch 'oneshot_dirdyn' into 'dev'

Oneshot dirdyn option

See merge request robotran/mbsysc!400

CHANGELOG.md

@@ -12,6 +12,9 @@
  * [Py] User vector outputs are now available in the MbsDirdyn results field.
  * [Py] Using C symbolic library and Python user is possible even with external forces.
  * [Py] Adding missing fields in MbsData.
+ * [dirdyn][new option] A new option option called 'oneshot' is added. 
+		-> It allows to compute the derivative function only once (no time derivation) at time = dt0.
+		-> See the 'flag_oneshot' in dirdyn options. 
  * [dirdyn][Fix] the function user_dirdyn_loop is now called only at the real time steps, even for multisteps integration methods.
  * [dirdyn][Fix] the mbs_data->flag_stop is taken into account in all the integrators now, the simulation stops.
  * [integrators][dirdyn] Add a new integrator called 'AlphaM' for alpha method. It is explicit, fixed step-size but with two stages and a bit smarter than Euler explicit :-) 

ExampleProjects/PendulumSpringC/workR/main_MBsysPy.py

 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
+"""Example of multibody system computed with MBsysPy using Python project files.
+
+Summary
+-------
+This template loads the data file *.mbs and execute:
+   - the coordinate partitioning module
+   - the direct dynamic module (time integration of equations of motion).
+   - the equilibrium module
+   - the modal module
+   - the inverse dynamic module
 """
-    
-       Universite catholique de Louvain
-       CEREM : Centre for research in mechatronics
-       http://www.robotran.be  
-       Contact : info@robotran.be
-    
-    
-       Main script template for complete model:
-       -----------------------------------------------
-        This template loads the data file *.mbs and execute:
-          - the coordinate partitioning module
-          - the direct dynamic module (time integration of
-            equations of motion).
-          - the equilibrium module
-          - the modal module
-          - the inverse dynamic module
-        It may be adapted and completed by the user.
-     
-        (c) Universite catholique de Louvain
-        
-"""
+# Author: Robotran Team
+# (c) Universite catholique de Louvain, 2021
 
-#==============================================================================
+# %%===========================================================================
 # Packages loading
-#==============================================================================
+# =============================================================================
 import sys
-sys.path.append("../../../MBsysC/mbs_interface") # Relative path for this example script
+# Add path to the MBsysC build folder
+sys.path.insert(1, "../../../MBsysC/build/python")
 
 import MBsysPy as Robotran
 
 
-#==============================================================================
+# %%===========================================================================
 # Project loading
-#==============================================================================
-mbs_data = Robotran.MbsData("../dataR/PendulumSpringC.mbs", user_path = "userfctR/userfctR_python", symbolic_path = "symbolicR/symbolicR_python")
+# =============================================================================
+mbs_data = Robotran.MbsData("../dataR/PendulumSpringC.mbs",
+                            user_path="userfctR/userfctR_python",
+                            symbolic_path="symbolicR/symbolicR_python"
+                            )
 print(mbs_data)
 
-#==============================================================================
+# %%===========================================================================
 # Partitionning
-#==============================================================================
+# =============================================================================
 mbs_data.process = 1
 mbs_part = Robotran.MbsPart(mbs_data)
-mbs_part.set_options(rowperm = 1, verbose = 1)
+mbs_part.set_options(rowperm=1, verbose=1)
 mbs_part.run()
 
-#==============================================================================
+# %%===========================================================================
 # Equilibrium
-#==============================================================================
+# =============================================================================
 mbs_data.process = 2
 mbs_equil = Robotran.MbsEquil(mbs_data)
-mbs_equil.set_options(method = 1, senstol = 1e-2, verbose = 1)
+mbs_equil.set_options(method=1, senstol=1e-2, verbose=1)
 mbs_equil.run()
 
-#==============================================================================
+# %%===========================================================================
 # Modal Analysis
-#==============================================================================
+# =============================================================================
 mbs_data.process = 4
 mbs_modal = Robotran.MbsModal(mbs_data)
-mbs_modal.set_options(save_result = 1, save_anim = 1, mode_ampl = 0.2)
+mbs_modal.set_options(save_result=1, save_anim=1, mode_ampl=0.2)
 mbs_modal.run()
 
-#==============================================================================
-# Direct Dynamics
-#==============================================================================
+# %%===========================================================================
+# Direct Dynamics, oneshot
+# =============================================================================
+mbs_data.process = 3
+mbs_data.qd[1] = 1.5
+mbs_dirdyn = Robotran.MbsDirdyn(mbs_data)
+mbs_dirdyn.set_options(flag_oneshot=1)
+mbs_dirdyn.run()
+
+# %%===========================================================================
+# Direct Dynamics, time integration
+# =============================================================================
 mbs_data.process = 3
 mbs_data.qd[1] = 1.5
 mbs_dirdyn = Robotran.MbsDirdyn(mbs_data)
-mbs_dirdyn.set_options(dt0 = 1e-3, tf = 10.0, save2file = 1)
-mbs_dirdyn.set_options(integrator = "RK4", resfilename = "RK4")
+mbs_dirdyn.set_options(dt0=1e-3, tf=0.1, save2file=1)
+mbs_dirdyn.set_options(integrator="RK4", resfilename="RK4")
 mbs_dirdyn.run()
 
-#==============================================================================
+# %%===========================================================================
 # Inverse Dynamics
-#==============================================================================
+# =============================================================================
 mbs_data.process = 6
 mbs_data.reset()
 mbs_data.set_qa(4)
@@ -82,8 +86,8 @@ mbs_data.set_qa(1)
 mbs_data.set_qa(3)
 mbs_data.set_qa(2)
 mbs_invdyn = Robotran.MbsInvdyn(mbs_data)
-mbs_invdyn.set_options(trajectoryqname = "../resultsR/RK4_q.res")
-mbs_invdyn.set_options(trajectoryqdname = "../resultsR/RK4_qd.res")
-mbs_invdyn.set_options(trajectoryqddname = "../resultsR/RK4_qdd.res")
-mbs_invdyn.set_options(t0 = 1.0, tf = 2.0, dt = 2.5e-3)
+mbs_invdyn.set_options(trajectoryqname="../resultsR/RK4_q.res")
+mbs_invdyn.set_options(trajectoryqdname="../resultsR/RK4_qd.res")
+mbs_invdyn.set_options(trajectoryqddname="../resultsR/RK4_qdd.res")
+mbs_invdyn.set_options(t0=1.0, tf=2.0, dt=2.5e-3)
 mbs_invdyn.run()

MBsysC/mbs_common/mbs_module/mbs_dirdyn.c

@@ -74,6 +74,8 @@ MbsDirdyn* mbs_new_dirdyn_aux(MbsData* mbs_data, MbsAux* mbs_aux)
 
     opts->compute_all_uxd = 1;
 
+    opts->flag_oneshot = 0;
+
     opts->flag_compute_Qc = COMPUTE_ALL_QC;
     // Initialization for fast computation of Qc
     int i;
@@ -138,6 +140,38 @@ MbsDirdyn* mbs_new_dirdyn_aux(MbsData* mbs_data, MbsAux* mbs_aux)
     return dirdyn;
 }
 
+
+int check_user_dirdyn_options(MbsDirdyn* dd, MbsData* mbs_data)
+{
+    int err = 0;
+    // errors generated
+    if (dd->options->t0 > dd->options->tf)
+    {
+        err = _MBS_ERR_INIT;
+        mbs_msg("\t >Dirdyn> options error: t0 (%f) > tf (%f).\n", dd->options->t0, dd->options->tf);
+        mbs_msg("[%d] in check_user_dirdyn_options !! \n", err);
+        return err;
+    }
+
+    if (dd->options->dt0 <= 0.0)
+    {
+        err = _MBS_ERR_INIT;
+        mbs_msg("\t >Dirdyn> options error: dt0 (%f) is not strictly positive.\n", dd->options->dt0);
+        mbs_msg("[%d] in check_user_dirdyn_options !! \n", err);
+        return err;
+    }
+
+    if (dd->options->t0 == dd->options->tf)
+    {
+        err = _MBS_ERR_INIT;
+        mbs_msg("\t >Dirdyn> options error: t0 (%f) == tf (%f).\n", dd->options->t0, dd->options->tf);
+        mbs_msg("\t >Dirdyn> if you need one evaluation of the derivative function, see the oneshot option in dirdyn. \n");
+        mbs_msg("[%d] in check_user_dirdyn_options !! \n", err);
+        return err;
+    }
+
+    return err;
+}
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 void mbs_delete_dirdyn(MbsDirdyn* dirdyn, MbsData* mbs_data)
@@ -158,10 +192,11 @@ void mbs_delete_dirdyn(MbsDirdyn* dirdyn, MbsData* mbs_data)
 int mbs_run_dirdyn(MbsDirdyn* dd, MbsData* mbs_data)
 {
     int err = 0;
+
     // 1. Initialize the simulation
     // - - - - - - - - - - - - - -
     err = mbs_dirdyn_init(dd, mbs_data);
-    if (err < 0){
+    if (err < 0) {
         // Freeing the buffers, without error catching
         mbs_dirdyn_finish(dd, mbs_data);
         mbs_error_msg("[%d] in mbs_run_dirdyn !! \n", _MBS_ERR_MOD_DIRDYN + err);
@@ -170,14 +205,22 @@ int mbs_run_dirdyn(MbsDirdyn* dd, MbsData* mbs_data)
 
     // 2. Run the simulation
     // - - - - - - - - - - -
-    err = mbs_dirdyn_loop(dd, mbs_data);
-    if (err < 0){
+    if (dd->options->flag_oneshot)
+    {
+        err = mbs_fct_dirdyn(dd->tsim, dd->y, dd->yd, mbs_data, dd);
+    }
+    else
+    {
+        err = mbs_dirdyn_loop(dd, mbs_data);
+    }
+    if (err < 0) {
         // Freeing the buffers, without error catching
         mbs_dirdyn_finish(dd, mbs_data);
         mbs_error_msg("[%d] in mbs_run_dirdyn !! \n", _MBS_ERR_MOD_DIRDYN + err);
         return _MBS_ERR_MOD_DIRDYN + err;
     }
 
+
     // 3. Finish the simulation
     // - - - - - - - - - - - -
     err = mbs_dirdyn_finish(dd, mbs_data);
@@ -262,6 +305,10 @@ int mbs_dirdyn_init(MbsDirdyn* dd, MbsData* mbs_data)
     if (dd->options->verbose)
     {
         mbs_msg("\n>>DIRDYN>> Starting direct dynamics module.\n");
+        if (dd->options->flag_oneshot)
+        {
+            mbs_msg("\n>>DIRDYN>> One shot evaluation of the direct dynamics is activated.\n");
+        }
     }
 
     // Checking mbs_data coherence
@@ -377,6 +424,14 @@ int mbs_dirdyn_init(MbsDirdyn* dd, MbsData* mbs_data)
     }
     user_dirdyn_init(mbs_data, dd);
 
+    // Checking time options
+    err = check_user_dirdyn_options(dd, mbs_data);
+    if (err < 0) {
+        mbs_msg("\t >Dirdyn> Incoherence detected during module initialization! \n");
+        mbs_msg("[%d] in mbs_dirdyn_init !! \n", err);
+        return err;
+    }
+
     /* TODO : Move in initialize_integrator when 2nd order integrator will be implemented */
     // Simulation state initialization
     for (i = 1; i <= mbs_data->nqu; i++)
@@ -417,9 +472,14 @@ int mbs_dirdyn_init(MbsDirdyn* dd, MbsData* mbs_data)
         bufElemNb = (int*)malloc(bufSize * sizeof(int));
 
         // set the filename if not specified
-        if (dd->options->resfilename == NULL) {
+        if (dd->options->resfilename == NULL && !dd->options->flag_oneshot) {
             resfilename = "dirdyn";
         }
+        else if (dd->options->resfilename == NULL && dd->options->flag_oneshot)
+        {
+            resfilename = "oneshot";
+            mbs_msg("\n>>DIRDYN>> Output filename is called 'oneshot' by default.\n");
+        }
         else {
             resfilename = dd->options->resfilename;
         }
@@ -728,7 +788,7 @@ int mbs_dirdyn_loop(MbsDirdyn* dd, MbsData* mbs_data)
                 mbs_msg("\t >Dirdyn> Error: in dirdyn loop during save realtime update  ! \n");
             }
             mbs_msg(">>DIRDYN>> [%d] during direct dynamics loop.\n", err);
-            return (err<0)?err:err2;
+            return (err < 0) ? err : err2;
         }
         // Update times
         cur_t0 = cur_tf;
@@ -740,6 +800,7 @@ int mbs_dirdyn_loop(MbsDirdyn* dd, MbsData* mbs_data)
             return 0;
         }
     }
+
     return 0;
 }
 
@@ -1014,3 +1075,4 @@ int save_realtime_update(MbsDirdyn* dd, MbsData* mbs_data)
 
     return 0;
 }
+

MBsysC/mbs_common/mbs_module/mbs_dirdyn.h

@@ -174,4 +174,14 @@ int mbs_fct_dirdyn(double t, double y[], double dydt[], MbsData *s, MbsDirdyn *d
  */
 int save_realtime_update(MbsDirdyn* dd, MbsData* mbs_data);
 
+
+/*! \brief check that the dirdyn options performed by the user are correct
+ *
+ * \param[in] dd direct dynamics module
+ * \param[in] mbs_data Robotran main structure
+ *
+ * \return Error status, <0 in case of failure.
+ */
+int check_user_dirdyn_options(MbsDirdyn* dd, MbsData* mbs_data);
+
 #endif

MBsysC/mbs_common/mbs_numerics/integrator.c

@@ -31,7 +31,7 @@ int mbs_estim_jac_acc(double x, double htry, double y[], double dydx[], int comp
                        int(*derivs)(double, double[], double[], MbsData *, MbsDirdyn *), MbsData *s, MbsDirdyn *dd)
 {
     // setting the flag to ON
-    dd->options->flag_ongoing_jac_computation = 1;
+    dd->flag_ongoing_jac_computation = 1;
 
     int i, j, err;
     double perturb;
@@ -100,7 +100,7 @@ int mbs_estim_jac_acc(double x, double htry, double y[], double dydx[], int comp
     }
 
     // setting the flag to OFF
-    dd->options->flag_ongoing_jac_computation = 0;
+    dd->flag_ongoing_jac_computation = 0;
     return 0;
 }
 
@@ -154,80 +154,90 @@ void set_integrator(MbsDirdyn *mbs_dd) {
 
     int id = opts->integrator;
 
-    switch (id) {
-
-    case RK4:
-        mbs_dd->initialize_integrator = initialize_rk4;
-        mbs_dd->loop_integrator = loop_rk4;
-        mbs_dd->finish_integrator = finish_rk4;
-        mbs_msg("        >> Integrator : \t RK4 \n");
-        break;
-
-    case Dopri5:
-        mbs_dd->initialize_integrator = initialize_dopri5;
-        mbs_dd->loop_integrator = loop_dopri5;
-        mbs_dd->finish_integrator = finish_dopri5;
-        mbs_msg("        >> Integrator : \t Dopri5 \n");
-        break;
-
-    case Rosenbrock:
-        mbs_dd->initialize_integrator = initialize_rosenbrock;
-        mbs_dd->loop_integrator = loop_rosenbrock;
-        mbs_dd->finish_integrator = finish_rosenbrock;
-        mbs_msg("        >> Integrator : \t Rosenbrock \n");
-        break;
-
-    case EulerEx:
-        mbs_dd->initialize_integrator = initialize_eulerEx;
-        mbs_dd->loop_integrator = loop_eulerEx;
-        mbs_dd->finish_integrator = finish_eulerEx;
-        mbs_msg("        >> Integrator : \t Euler Explicit \n");
-        break;
-
-    case Eulaire:
-        mbs_dd->initialize_integrator = initialize_eulerEx;
-        mbs_dd->loop_integrator = loop_eulerEx;
-        mbs_dd->finish_integrator = finish_eulerEx;
-        mbs_msg("        >> Integrator : \t Eulaire \n");
-        break;
-    case AlphaM:
-        mbs_dd->initialize_integrator = initialize_eulerEx;
-        mbs_dd->loop_integrator = loop_eulerEx;
-        mbs_dd->finish_integrator = finish_eulerEx;
-        mbs_msg("        >> Integrator : \t Alpha Method \n");
-        break;
-    case EulerIm:
-        mbs_dd->initialize_integrator = initialize_euler_implicit;
-        mbs_dd->loop_integrator = loop_euler_implicit;
-        mbs_dd->finish_integrator = finish_euler_implicit;
-        mbs_msg("        >> Integrator : \t Euler Implicit \n");
-        break;
-    case Bader:
-        mbs_dd->initialize_integrator = initialize_bader;
-        mbs_dd->loop_integrator = loop_bader;
-        mbs_dd->finish_integrator = finish_bader;
-        mbs_msg("        >> Integrator : \t Semi-implicit Bader-Deuflhard extrapolation method \n");
-        break;
-    case WMethods:
-        mbs_dd->initialize_integrator = initialize_w_methods;
-        mbs_dd->loop_integrator = loop_w_methods;
-        mbs_dd->finish_integrator = finish_w_methods;
-        mbs_msg("        >> Integrator : \t W Methods \n");
-        break;
-
-    case Custom:
-        mbs_dd->initialize_integrator = initialize_custom;
-        mbs_dd->loop_integrator = loop_custom;
-        mbs_dd->finish_integrator = finish_custom;
-        mbs_msg("        >> Integrator : \t Custom \n");
-        break;
-
-    default:
+    if (!opts->flag_oneshot)
+    {
+        switch (id) {
+
+        case RK4:
+            mbs_dd->initialize_integrator = initialize_rk4;
+            mbs_dd->loop_integrator = loop_rk4;
+            mbs_dd->finish_integrator = finish_rk4;
+            mbs_msg("        >> Integrator : \t RK4 \n");
+            break;
+
+        case Dopri5:
+            mbs_dd->initialize_integrator = initialize_dopri5;
+            mbs_dd->loop_integrator = loop_dopri5;
+            mbs_dd->finish_integrator = finish_dopri5;
+            mbs_msg("        >> Integrator : \t Dopri5 \n");
+            break;
+
+        case Rosenbrock:
+            mbs_dd->initialize_integrator = initialize_rosenbrock;
+            mbs_dd->loop_integrator = loop_rosenbrock;
+            mbs_dd->finish_integrator = finish_rosenbrock;
+            mbs_msg("        >> Integrator : \t Rosenbrock \n");
+            break;
+
+        case EulerEx:
+            mbs_dd->initialize_integrator = initialize_eulerEx;
+            mbs_dd->loop_integrator = loop_eulerEx;
+            mbs_dd->finish_integrator = finish_eulerEx;
+            mbs_msg("        >> Integrator : \t Euler Explicit \n");
+            break;
+
+        case Eulaire:
+            mbs_dd->initialize_integrator = initialize_eulerEx;
+            mbs_dd->loop_integrator = loop_eulerEx;
+            mbs_dd->finish_integrator = finish_eulerEx;
+            mbs_msg("        >> Integrator : \t Eulaire \n");
+            break;
+        case AlphaM:
+            mbs_dd->initialize_integrator = initialize_eulerEx;
+            mbs_dd->loop_integrator = loop_eulerEx;
+            mbs_dd->finish_integrator = finish_eulerEx;
+            mbs_msg("        >> Integrator : \t Alpha Method \n");
+            break;
+        case EulerIm:
+            mbs_dd->initialize_integrator = initialize_euler_implicit;
+            mbs_dd->loop_integrator = loop_euler_implicit;
+            mbs_dd->finish_integrator = finish_euler_implicit;
+            mbs_msg("        >> Integrator : \t Euler Implicit \n");
+            break;
+        case Bader:
+            mbs_dd->initialize_integrator = initialize_bader;
+            mbs_dd->loop_integrator = loop_bader;
+            mbs_dd->finish_integrator = finish_bader;
+            mbs_msg("        >> Integrator : \t Semi-implicit Bader-Deuflhard extrapolation method \n");
+            break;
+        case WMethods:
+            mbs_dd->initialize_integrator = initialize_w_methods;
+            mbs_dd->loop_integrator = loop_w_methods;
+            mbs_dd->finish_integrator = finish_w_methods;
+            mbs_msg("        >> Integrator : \t W Methods \n");
+            break;
+
+        case Custom:
+            mbs_dd->initialize_integrator = initialize_custom;
+            mbs_dd->loop_integrator = loop_custom;
+            mbs_dd->finish_integrator = finish_custom;
+            mbs_msg("        >> Integrator : \t Custom \n");
+            break;
+
+        default:
+            mbs_dd->initialize_integrator = initialize_rk4;
+            mbs_dd->loop_integrator = loop_rk4;
+            mbs_dd->finish_integrator = finish_rk4;
+            mbs_warning_msg("        >> Integrator not found, possibly not yet supported !\n");
+            mbs_warning_msg("        >> Continuing with RK4 (Default) \n");
+        }
+    }
+    else
+    {
+        mbs_msg("        >> Integrator : \t rk4 is set but useless because oneshot option is activated \n");
         mbs_dd->initialize_integrator = initialize_rk4;
         mbs_dd->loop_integrator = loop_rk4;
         mbs_dd->finish_integrator = finish_rk4;
-        mbs_warning_msg("        >> Integrator not found, possibly not yet supported !\n");
-        mbs_warning_msg("        >> Continuing with RK4 (Default) \n");
     }
 
 }

MBsysC/mbs_common/mbs_struct/mbs_dirdyn_struct.h

@@ -49,7 +49,8 @@ typedef struct MbsDirdynOptions
      * default = 1
      */
     int save2file;
-    /** The keyword used for determining the name of result files */
+    /** The keyword used for determining the name of result files 
+         Default: 'dirdyn', or 'oneshot' in case the flag_oneshot is activated*/
     char* resfilename;
     /** Path in which result file are saved.
      *  Default: the resultsR folder of the project
@@ -87,6 +88,10 @@ typedef struct MbsDirdynOptions
 
     int accelred; //!< 1 to use accelred, 0 otherwise, default = 0
 
+    int flag_oneshot; //!< 1 to compute the derivative function only once (no time integration !), default = 0
+                      //!< The time is the value found in the option t0
+                      //!< The default resfilename is changed to 'oneshot'.
+
     int flag_compute_Qc; //!< choose to compute (or not) the Qc for driven variables. For dirdyn only. ==1 by default
                          //!< this allows to go faster
 
@@ -126,9 +131,7 @@ typedef struct MbsDirdynOptions
     // Options related to integrator that need Jacobian computation
     /*TO BE COMPLETED*/
     int n_freeze; //!< number of time step when the jacobian is freezed (computed once at the start of the n_freeze time steps), default = 0;
-    int flag_ongoing_jac_computation; //!< flag is ON when the implicit integrator is computing the jacobian. 
-    //!< it allows the user the make a distinction in his user functions (typically a FSM state that should now change during jacobian computation).
-
+    
     // Various options
     int show_failed_closure; //!< 1 to generate animation of the failed Newton-Raphson procedure, default = 0.
 
@@ -171,6 +174,9 @@ struct MbsDirdyn
     int savePeriodCounter;
 
     // Part related to numerical integrator
+    int flag_ongoing_jac_computation; //!< flag is ON (=1) when the implicit integrator is currently computing the jacobian, default is 0.
+    //!< it allows the user the make a distinction in his user functions (typically a FSM state that should now change during jacobian computation).
+
     /** pointer to store integrator structure **/
     void *integrator_struct; // set by initialize_integrator
     /** pointer to integrator initialize function **/
@@ -180,6 +186,7 @@ struct MbsDirdyn
     /** pointer to integrator closing function **/
     finish_integrator_ptr finish_integrator;
 
+    
 };
 
 

MBsysC/mbs_interface/MBsysPy/_mbsysc_loader/mbs_dirdyn_c.py

 # -*- coding: utf-8 -*-
-"""
--------------------------------
-(c) Universite catholique de Louvain, 2019
-
-Creation : 2019 by O. Lantsoght
-Last update : 2019
-
-version MBsysC v1.11.2
-
--------------------------------
-Portable Python interface to MBsysC using Ctypes.
-
-While generating the libraries:
-  - SENSORKIN MUST BE UNDEFINED
-  - REALTIME  MUST BE UNDEFINED
-
-  - PRJ_FCT_PTR MUST BE DEFINED
-
-Declaration of MBsysC structure related to mbs_dirdyn_struct.h file in MBsysC.
-
-"""
+"""Declaration of MBsysC structure related to mbs_dirdyn_struct.h file in MBsysC."""
+# Author : Robotran Team
+# (c) Universite catholique de Louvain, 2021
 
 import ctypes
 
@@ -31,15 +13,15 @@ from .forward_decl import MbsBuffer_c
 from .forward_decl import MbsGrowingBuffer_c
 
 
-#==============================================================================
+# =============================================================================
 # Global parameter of the current module
-#==============================================================================
+# =============================================================================
 __DEBUG__ = False
 
 
-#==============================================================================
+# =============================================================================
 # MbsDirdynOptions_c
-#==============================================================================
+# =============================================================================
 MbsDirdynOptions_c._fields_ = [
         ("t0", ctypes.c_double),
         ("tf", ctypes.c_double),
@@ -56,13 +38,17 @@ MbsDirdynOptions_c._fields_ = [
         ("buffersize", ctypes.c_int),
         ("realtime", ctypes.c_int),
         ("accelred", ctypes.c_int),
+        ("flag_oneshot", ctypes.c_int),
         ("flag_compute_Qc", ctypes.c_int),
-        ("compute_all_uxd", ctypes.c_int), 
+        ("compute_all_uxd", ctypes.c_int),
         ("compute_Qc", ctypes.POINTER(ctypes.c_int)),
         ("integrator", ctypes.c_int),
         ("verbose", ctypes.c_int),
         ("flag_stop_stiff", ctypes.c_int),
         ("flag_precise_dynamics", ctypes.c_int),
+        ("flag_baumgarte_stabilization", ctypes.c_int),
+        ("baumgarte_alpha", ctypes.c_double),
+        ("baumgarte_beta", ctypes.c_double),