pid: rename variables with full names
Use full names and camelcase for the variables in the pid loop to
improve readability and consistency.
Change-Id: I86be69d94d3008faa497eace050d1f3b9b6a9ff4
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/pid/ec/pid.cpp b/pid/ec/pid.cpp
index 6c70bbe..af70da7 100644
--- a/pid/ec/pid.cpp
+++ b/pid/ec/pid.cpp
@@ -44,9 +44,9 @@
{
double error;
- double p_term;
- double i_term = 0.0f;
- double ff_term = 0.0f;
+ double proportionalTerm;
+ double integralTerm = 0.0f;
+ double feedFwdTerm = 0.0f;
double output;
@@ -54,21 +54,22 @@
// Pid
error = setpoint - input;
- p_term = pidinfoptr->proportionalCoeff * error;
+ proportionalTerm = pidinfoptr->proportionalCoeff * error;
// pId
if (0.0f != pidinfoptr->integralCoeff)
{
- i_term = pidinfoptr->integral;
- i_term += error * pidinfoptr->integralCoeff * pidinfoptr->ts;
- i_term = clamp(i_term, pidinfoptr->integralLimit.min,
- pidinfoptr->integralLimit.max);
+ integralTerm = pidinfoptr->integral;
+ integralTerm += error * pidinfoptr->integralCoeff * pidinfoptr->ts;
+ integralTerm = clamp(integralTerm, pidinfoptr->integralLimit.min,
+ pidinfoptr->integralLimit.max);
}
// FF
- ff_term = (setpoint + pidinfoptr->feedFwdOffset) * pidinfoptr->feedFwdGain;
+ feedFwdTerm =
+ (setpoint + pidinfoptr->feedFwdOffset) * pidinfoptr->feedFwdGain;
- output = p_term + i_term + ff_term;
+ output = proportionalTerm + integralTerm + feedFwdTerm;
output = clamp(output, pidinfoptr->outLim.min, pidinfoptr->outLim.max);
// slew rate
@@ -80,21 +81,21 @@
if (pidinfoptr->slewNeg != 0.0f)
{
// Don't decrease too fast
- double min_out =
+ double minOut =
pidinfoptr->lastOutput + pidinfoptr->slewNeg * pidinfoptr->ts;
- if (output < min_out)
+ if (output < minOut)
{
- output = min_out;
+ output = minOut;
}
}
if (pidinfoptr->slewPos != 0.0f)
{
// Don't increase too fast
- double max_out =
+ double maxOut =
pidinfoptr->lastOutput + pidinfoptr->slewPos * pidinfoptr->ts;
- if (output > max_out)
+ if (output > maxOut)
{
- output = max_out;
+ output = maxOut;
}
}
@@ -102,15 +103,15 @@
{
// Back calculate integral term for the cases where we limited the
// output
- i_term = output - p_term;
+ integralTerm = output - proportionalTerm;
}
}
// Clamp again because having limited the output may result in a
// larger integral term
- i_term = clamp(i_term, pidinfoptr->integralLimit.min,
- pidinfoptr->integralLimit.max);
- pidinfoptr->integral = i_term;
+ integralTerm = clamp(integralTerm, pidinfoptr->integralLimit.min,
+ pidinfoptr->integralLimit.max);
+ pidinfoptr->integral = integralTerm;
pidinfoptr->initialized = true;
pidinfoptr->lastOutput = output;