Control the Braking and Steering Tables relative to Impact

When you input time history input tables for steering and braking in msmac you have to determine the approximate time of impact and make the table change accordingly (in consideration that normally during a collision the steering and/or braking change as a result of the collision forces).

A new option in msmac has been added to automatically detect the impact and ramp up the steering and/opr braking tables over the user defined time period.

The VARINC variable (Table header card, field 6) for table inputs (input cards 8,9,10,11) now includes 3 options:

•    (default) If=0.0, table is assumed a fixed increment table

•    (optional) If =1.0, flag to indicate Variable time increment inputs. Field 4 is then used to indicate the number of table inputs.

•    (optional) If=2.0, flag to indicate Variable time increment inputs AND the 1st two entries in the table are for pre-impact and post-impact. The 1st value is applied until impact is detected and then the value is changed to the 2nd value over the time difference between the two entries.

The following is the table data for the Torque data for vehicle#1:

 

In this example, we have set the difference between the first two items in the table to 0.1 seconds, and set the VARINC = 2.0, so the program detects contact and transitions from the 1st to the second input variables in 0.10 seconds. You can view the results once you have run msmac by selecting View menu->Input Echo:

The indication for Vehicle 1 is as follows:

   VEHICLE NO. 1

           % Tractive or Braking                 % Tractive or Braking      

    SEC      RF      LF      RR      LR        SEC      RF      LF      RR      LR

   99.000  0.0000  0.0000  0.0000  0.0000       99.100 -0.3000  0.0000 -0.2000 -0.2000

     Torque Tables, Veh#1, Table 8 Detect Contact Option Set:

        The 99.00 SEC in the table will be replaced with the Detected Contact Time.

        The Control inputs for the Table will be changed over   0.10 Seconds

 

And at the bottom of the dataset an indication of the detection of impact:

  Veh1 Torque Table08 DetectContact Option Message, At T=   0.166 Contact detected                                                                     

So the simulation will ramp the torque tables from 0.166 to 0.266 seconds.

 

Acceleration/velocity display vectors in msmac Animation program