Home › RT-Lab Error with Python script to change parameter

RT-Lab Error with Python script to change parameter

We are seeing some weird results when we attempt to manually modify block parameters that are within enabled subsystems from a python script. Have you seen anything like this before?

Question

So I found my problem. The parameter I was attempting to change was a 3x3 matrix in a constant block. Doesn’t RT-Lab support matrices?

Answer

I ran a test python script which modifies the gain parameter within an enabled subsystem. It works fine as long as I closed out the Parameter Control from RT-Lab. This is because the Parameter Control from RT-Lab was taking control of the model parameters and would not allow the python script to modify the gain parameter.

I tested having a 3x3 matrix for a gain block and was able to get the parameter control to work for all of the matrix values. I modified rtdemo1.mdl to have an enabled subsystem with a gain block inside that has the 3x3 matrix.

I then modified the python script to modify each of gains 1 – 9.

Results of python script:

The connection with 'rtdemo1' is completed.

- Here is the list of all parameter values:

rtdemo1/sm_computation/Integrator3/InitialCondition = 0.0

rtdemo1/sm_computation/Integrator3/UpperSaturationLimit = 200.0

rtdemo1/sm_computation/Integrator3/LowerSaturationLimit = 0.0

rtdemo1/sm_computation/Sensor response time/DelayTime = 0.005

rtdemo1/sm_computation/Sensor response time/InitialOutput = 0.0

rtdemo1/sm_computation/Gain Kp/Gain = 20.0

rtdemo1/sm_computation/Integrator1/InitialCondition = 0.0

rtdemo1/sm_computation/Gain Ki/Gain = 5.0

rtdemo1/sm_computation/Gain1/Gain = -1.0

rtdemo1/sm_computation/Gain Kd/Gain = 5.0

rtdemo1/sm_computation/Actuator response time/DelayTime = 0.005

rtdemo1/sm_computation/Actuator response time/InitialOutput = 0.0

rtdemo1/sm_computation/Gain/Gain = 1.0

rtdemo1/sm_computation/Integrator2/InitialCondition = 0.0

rtdemo1/sm_computation/Enabled Subsystem/Gain/Gain(1) = 120.0

rtdemo1/sm_computation/Enabled Subsystem/Gain/Gain(2) = 50.0

rtdemo1/sm_computation/Enabled Subsystem/Gain/Gain(3) = 10.0

rtdemo1/sm_computation/Enabled Subsystem/Gain/Gain(4) = 60.0

rtdemo1/sm_computation/Enabled Subsystem/Gain/Gain(5) = 95.0

rtdemo1/sm_computation/Enabled Subsystem/Gain/Gain(6) = 80.0

rtdemo1/sm_computation/Enabled Subsystem/Gain/Gain(7) = 70.0

rtdemo1/sm_computation/Enabled Subsystem/Gain/Gain(8) = 65.0

rtdemo1/sm_computation/Enabled Subsystem/Gain/Gain(9) = 55.0

rtdemo1/sm_computation/Enabled Subsystem/Integrator2/InitialCondition = 0.0

- The parameter control is acquired.

- The parameter values were set to : (120, 50, 10, 60, 95, 80, 70, 65, 55).

- The parameter values are : (120.0, 50.0, 10.0, 60.0, 95.0, 80.0, 70.0, 65.0, 55.0).

- The parameter control is released.

The connection is closed.

 

  • Matlab plot before python script run:
  • Matlab plot after running parameter control python scripts:
  • enabled subsystem:
  • Gain block 3x3 matrix:

rtdemo1.mdl - PID controller example
rtdemo1_parameter1.py_.txt - python script for parameter change