Adjusted odometry and tuned drives.

Author: dhebbeker

robot-control-src/Drives.cpp

@@ -33,16 +33,18 @@ bool Drive<MOTORCONTROL, motorControlpin, DIRECTIONPIN, directionPin, ODOPIN, od
  * cycle of the right motor control.
  * 
  * The calibration fraction is defined as follows: It has been observed, that when the 
- * duty cycle of the left is 350/1023, then the right should be 325/1023 in order for the
+ * duty cycle of the left is x/1023, then the right should be y/1023 in order for the
  * drives to be equally fast. The linear functions is such that the difference is 0 with 
  * a duty cycle of 100%.
  */
 static Amplitude calcRightSpeed(const Amplitude leftSpeed)
 {
-  constexpr double calibrationFraction = 25.0 / (maxAmplitude - 350.0);
-  constexpr float a = 1.0 + calibrationFraction;
-  constexpr float b = maxAmplitude * calibrationFraction;
-  return a*leftSpeed - b;
+	constexpr Amplitude leftAmplitude = 350; // x
+	constexpr Amplitude rightMatchingAmplitude = 290; // y
+	constexpr double calibrationFraction = (leftAmplitude
+			- rightMatchingAmplitude)
+			/ static_cast<double>(maxAmplitude - leftAmplitude);
+	return leftSpeed - calibrationFraction * (maxAmplitude - leftSpeed);
 }
 
 void rotateCounter(const Counter steps, const Amplitude amplitude, bool const clockwise)

robot-control-src/Drives.hpp

@@ -26,17 +26,23 @@ class Drive
 	{
 		target = counter = 0;
 		pinMode(odoPin, INPUT);
-		attachInterrupt(digitalPinToInterrupt(odoPin), evaluateInterval, FALLING);
+		attachInterrupt(digitalPinToInterrupt(odoPin), evaluateInterval, RISING);
 
 		analogWrite(motorControlpin, 0);
 		pinMode(directionPin, OUTPUT);
 	}
 
 	IRAM_ATTR static void evaluateInterval()
 	{
-		if (++counter >= target)
+		const Milliseconds now = millis();
+		static Milliseconds riseTime = now;
+		if(now - riseTime > board::odoMinIntervalDuration)
 		{
-			stop();
+			if (++counter >= target)
+			{
+				stop();
+			}
+			riseTime = now;
 		}
 	}
 

robot-control-src/board.hpp

@@ -26,8 +26,23 @@ extern MCP23017Pin rightBackwards;
 extern MCP23017Pin leftBumper;
 extern MCP23017Pin rightBumper;
 
+/**
+ * Maximum robot velocity.
+ *
+ * According to [this wiki](https://rn-wissen.de/wiki/index.php/CCRP5#Technische_Daten).
+ */
 constexpr auto maxVelocity = 220; //!< [mm/s]
+/**
+ * distance of one outer wheel turn U = d*pi
+ * diameter of outer wheel d = 50 mm
+ * fraction of one odometry interval to outer wheel f = 6/25
+ * distance of one odometry interval = f*U
+ */
 constexpr float odoIntervalLength = 12*pi; //!< [mm]
+//! Minimum time with buffer factor [ms]
+constexpr Milliseconds odoMinIntervalDuration = (odoIntervalLength * 1000.0) / (maxVelocity*2.0);
+static_assert(odoMinIntervalDuration > 38, "threshold must be greater than longest pulse of photoelectric sensor (measured at slowest speed)");
+static_assert(odoMinIntervalDuration < 142, "threshold must be smaller than shortest odometry interval between pulses (measured at highest speed)");
 };
 
 #endif // BOARD_HPP