## Tuesday, May 17, 2016

### Innovyze President Dr. Paul F. Boulos Appointed to Wharton Initiative for Global Environmental Leadership Corporate Advisory Board

 Innovyze President Dr. Paul F. Boulos Appointed to Wharton Initiative for Global Environmental Leadership Corporate Advisory Board

## Monday, May 16, 2016

### Annotated PID Controller in SWMM5 and InfoSWMM

How does a PID controller work in  InfoSWMM  and SWMMM 5 - this also applies to H2OMap SWMM??
double getPIDSetting(struct TAction* a, double dt)   //  at each time  step find  the PID control  changes for the  current  time step dt
// Input: a = an action object
// dt = current time step (days)
// Output: returns a new link setting
// Purpose: computes a new setting for a link subject to a PID controller.

// Note: a->kp = gain coefficient,
// a->ki = integral time (minutes)
// a->k2 = derivative time (minutes)
// a->e1 = error from previous time step
// a->e2 = error from two time steps ago
{
double e0, setting;
double p, i, d, update;
double tolerance = 0.0001;
// --- convert time step from days to minutes
dt *= 1440.0;
// --- determine relative error in achieving controller set point
// Or how close are we to the set point?

e0 = SetPoint - ControlValue;
if ( fabs(e0) > TINY )
{
if ( SetPoint != 0.0 ) e0 = e0/SetPoint;
// now alter the  value of e0

else e0 = e0/ControlValue;
}
// --- reset previous errors to 0 if controller gets stuck
if (fabs(e0 - a->e1) < tolerance)
{
a->e2 = 0.0;
a->e1 = 0.0;
}
// --- use the recursive form of the PID controller equation to
// determine the new setting for the controlled link
Here is a view of the p, i and d PID internal  parameters https://www.wikiwand.com/en/PID_controller
A block diagram of a PID controller in a feedback loop
p = (e0 - a->e1);
ki, id,  kp are  user  inputs  in InfoSWMM and SWMM5 or from the  EPA SWMM  5 Help  File
if ( a->ki == 0.0 ) i = 0.0;
else i = e0 * dt / a->ki;

d = a->kd * (e0 - 2.0*a->e1 + a->e2) / dt;

update = a->kp * (p + i + d);
if ( fabs(update) < tolerance ) update = 0.0;
// --- update previous errors
a->e2 = a->e1;
a->e1 = e0;
// --- check that new setting lies within feasible limits
// If  the link  is not a pump then the  setting must be between 0 and 1
if ( setting < 0.0 ) setting = 0.0;
if (Link[a->link].type != PUMP && setting > 1.0 ) setting = 1.0;
return setting;}

### Comparison of Three Different ModellingApproaches for the Simulation of Flooding Urban Areas - InnoAqual

Comparison of Three Different ModellingApproaches for the Simulation of Flooding Urban Areas
 Comparison of Three Different Modelling Approaches for the Simulation of Flooding Urban Areas from InnoAqua

## Friday, May 13, 2016

### AAEES 2016 Innovyze Excellence in Computational Hydraulics/Hydrology Award Presented to Colorado School of Mines Doctoral Student

 AAEES 2016 Innovyze Excellence in Computational Hydraulics/Hydrology Award Presented to Colorado School of Mines Doctoral Student

## Tuesday, May 3, 2016

### Oregon’s Clean Water Services Adopts SWMMLive and InfoMaster Technology

 Oregon’s Clean Water Services Adopts SWMMLive and InfoMaster Technology
 Real-Time Sewer Network Modeling and Analytics-Driven Risk-Based Asset Management Software to Improve Business Planning, Infrastructure Sustainability and Resiliency

## Sunday, May 1, 2016

### Why is a Hot Start File important in SWMM 5 and InfoSWMM

A Hot Start File in InfoSWMM  or SWMM 5 is important as it provides initial   depths, initial flows and  initial settings for the hydrology and hydraulics features of the SWMM 5 engine.    You  have three options:
1. Save a hot Start File at the  end of the  simulation,
2. Use a hot Start File  at the beginning of  the simulation,
3. Create a hot start file  from  the a  time during  the  Map Display
If you change any of the network  types or add new links and nodes then  the Hot Start file needes to be recreated.  InfoSWMM use the Tab File in  the Run Manager to name the Hot Start File (Figure 1).   Each and  every Scenario in InfoSWMM  can  use or Save a different scenario with different starting  and ending  times  (Figure 2).  If you USE  a Hot  Start  File then:
1. The  new  simulation  starts at the end  of  the  old  simulation
2. You can  run a Quasi Steady State Simulation and use a very short simulation time of minutes if you use a Hot Start File
3. Figure 3  shows  the effect of Using a Hot Start File
Figure 1. File Tab for Saving or Using a  Hot Start file in InfoSWMM  or  H2OMap SWMM.   There  is  a similar dialog in  SWMM5.
Figure 2.  Each Scenario in  InfoSWMM  and  H2OMap  SWMM can have a   different set of report  and simulation options.

Figure 3.   The Saved Time Series for the  Outfall (Blue) and  Use (Green)  Outfall  Time Series.

### AI Rivers of Wisdom about ICM SWMM

Here's the text "Rivers of Wisdom" formatted with one sentence per line: [Verse 1] ðŸŒŠ Beneath the ancient oak, where shadows p...