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7
Real-Time Simulation
pneumatic pipes with constant parameters. The Directional 5-way valve block feeds
the pipe blocks.
5
Look under the mask of the valve block. The spool position dictates the orifice that
receives the gas flow, and therefore, the direction of flow in the pipes that lead to the
motor.
6
Open the Signal Builder block that determines the spool position. Between the
simulation time, t, of 0 and 1 second, the signal puts the spool at position 0. The zero
crossings reflect the chatter that occurs as the system fills.
7
Decrease the chatter, and therefore the number of zero crossings, by increasing the
leakage area of the Directional 5-way valve. Open the Directional 5-way valve block
dialog box and specify 1e-2 for the Leakage area at x=0 (mm^2).
Analyze the Results of the Modified Model
Compare the results to the reference results to ensure the accuracy of your modified
model. Confirm that your modified model has fewer zero crossings.
1
Simulate the model.
2
Print the zero crossing data.
sscprintzcs(simlog)
ssc_pneumatic_rts_stiffness_redux (155 signals, 65 crossings)
+-Directional_5_way_valve (144 signals, 28 crossings)
| +-Area_A_R (12 signals, 2 crossings)
| +-Area_B_S (12 signals, 2 crossings)
| +-Area_P_A (12 signals, 2 crossings)
| +-Area_P_B (12 signals, 2 crossings)
| +-Variable_Area_Orifice_1 (24 signals, 4 crossings)
| +-Variable_Area_Orifice_2 (24 signals, 6 crossings)
| +-Variable_Area_Orifice_3 (24 signals, 6 crossings)
| +-Variable_Area_Orifice_4 (24 signals, 4 crossings)
+-Friction_Load (2 signals, 4 crossings)
+-Pipe_1 (2 signals, 0 crossings)
| +-Constant_Chamber (2 signals, 0 crossings)
+-Pipe_2 (2 signals, 0 crossings)
| +-Constant_Chamber (2 signals, 0 crossings)
+-Pneumatic_Motor (5 signals, 33 crossings)
The overall number of zero crossings has decreased from 101 to 65. The number of
zero crossings in the motor has decreased from 50 to 33.
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