From 2210c461623b97eea1ec700cae4cc27ab5042376 Mon Sep 17 00:00:00 2001
From: Lars Berning <151194+laberning@users.noreply.github.com>
Date: Mon, 31 Jan 2022 19:55:27 +0100
Subject: [PATCH] improves metrics of first stroke by setting reasonable
 initial values

---
 app/engine/RowingEngine.js      | 17 ++++++++++++-----
 app/engine/RowingEngine.test.js |  4 ++--
 app/engine/WorkoutRecorder.js   |  1 -
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/app/engine/RowingEngine.js b/app/engine/RowingEngine.js
index 3db1723..ef8ea5a 100644
--- a/app/engine/RowingEngine.js
+++ b/app/engine/RowingEngine.js
@@ -34,8 +34,8 @@ function createRowingEngine (rowerSettings) {
   let drivePhaseAngularDisplacement
   let driveLinearDistance
   let recoveryPhaseStartTime
-  let recoveryPhaseStartAngularDisplacement
   let recoveryPhaseAngularDisplacement
+  let recoveryPhaseStartAngularDisplacement
   let recoveryPhaseLength
   let recoveryStartAngularVelocity
   let recoveryEndAngularVelocity
@@ -293,6 +293,9 @@ function createRowingEngine (rowerSettings) {
   }
 
   function reset () {
+    // to init displacements with plausible defaults we assume, that one rowing cycle transforms to nine meters of distance...
+    const defaultDisplacementForRowingCycle = 8.0 / Math.pow(((rowerSettings.dragFactor / 1000000) / rowerSettings.magicConstant), 1.0 / 3.0)
+
     movingDragAverage.reset()
     cyclePhase = 'Recovery'
     totalTime = 0.0
@@ -301,11 +304,15 @@ function createRowingEngine (rowerSettings) {
     drivePhaseStartTime = 0.0
     drivePhaseStartAngularDisplacement = 0.0
     drivePhaseLength = 2.0 * rowerSettings.minimumDriveTime
-    drivePhaseAngularDisplacement = rowerSettings.numOfImpulsesPerRevolution
+    // split defaultDisplacementForRowingCycle to aprox 1/3 for the drive phase
+    drivePhaseAngularDisplacement = (1.0 / 3.0) * defaultDisplacementForRowingCycle
     driveLinearDistance = 0.0
-    recoveryPhaseStartTime = -2 * rowerSettings.minimumRecoveryTime // Make sure that the first CurrentDt will trigger a detected stroke by faking a recovery phase that is long enough
-    recoveryPhaseStartAngularDisplacement = -1.0 * rowerSettings.numOfImpulsesPerRevolution
-    recoveryPhaseAngularDisplacement = rowerSettings.numOfImpulsesPerRevolution
+    // Make sure that the first CurrentDt will trigger a detected stroke by faking a recovery phase that is long enough
+    recoveryPhaseStartTime = -2 * rowerSettings.minimumRecoveryTime
+    // and split defaultDisplacementForRowingCycle to aprox 2/3 for the recovery phase
+    recoveryPhaseAngularDisplacement = (2.0 / 3.0) * defaultDisplacementForRowingCycle
+    // set this to the number of impulses required to generate the angular displacement as assumed above
+    recoveryPhaseStartAngularDisplacement = Math.round(-1.0 * (2.0 / 3.0) * defaultDisplacementForRowingCycle / angularDisplacementPerImpulse)
     recoveryPhaseLength = 2.0 * rowerSettings.minimumRecoveryTime
     recoveryStartAngularVelocity = angularDisplacementPerImpulse / rowerSettings.minimumTimeBetweenImpulses
     recoveryEndAngularVelocity = angularDisplacementPerImpulse / rowerSettings.maximumTimeBetweenImpulses
diff --git a/app/engine/RowingEngine.test.js b/app/engine/RowingEngine.test.js
index 0685bbf..5c4d224 100644
--- a/app/engine/RowingEngine.test.js
+++ b/app/engine/RowingEngine.test.js
@@ -61,7 +61,7 @@ test('sample data for WRX700 should produce plausible results with rower profile
   await replayRowingSession(rowingEngine.handleRotationImpulse, { filename: 'recordings/WRX700_2magnets.csv' })
   assert.is(workoutEvaluator.getNumOfStrokes(), 16, 'number of strokes does not meet expectation')
   assertPowerRange(workoutEvaluator, 50, 220)
-  assertDistanceRange(workoutEvaluator, 159, 163)
+  assertDistanceRange(workoutEvaluator, 165, 168)
   assertStrokeDistanceSumMatchesTotal(workoutEvaluator)
 })
 
@@ -72,7 +72,7 @@ test('sample data for DKNR320 should produce plausible results with rower profil
   await replayRowingSession(rowingEngine.handleRotationImpulse, { filename: 'recordings/DKNR320.csv' })
   assert.is(workoutEvaluator.getNumOfStrokes(), 10, 'number of strokes does not meet expectation')
   assertPowerRange(workoutEvaluator, 75, 200)
-  assertDistanceRange(workoutEvaluator, 65, 68)
+  assertDistanceRange(workoutEvaluator, 71, 73)
   assertStrokeDistanceSumMatchesTotal(workoutEvaluator)
 })
 
diff --git a/app/engine/WorkoutRecorder.js b/app/engine/WorkoutRecorder.js
index d7ea77f..0cbd312 100644
--- a/app/engine/WorkoutRecorder.js
+++ b/app/engine/WorkoutRecorder.js
@@ -186,7 +186,6 @@ function createWorkoutRecorder () {
     const minimumRecordingTimeInSeconds = 10
     const rotationImpulseTimeTotal = rotationImpulses.reduce((acc, impulse) => acc + impulse, 0)
     const strokeTimeTotal = strokes.reduce((acc, stroke) => acc + stroke.strokeTime, 0)
-    console.log(`strokeTimeTotal: ${strokeTimeTotal} rotationImpulseTimeTotal: ${rotationImpulseTimeTotal} `)
     if (rotationImpulseTimeTotal < minimumRecordingTimeInSeconds || strokeTimeTotal < minimumRecordingTimeInSeconds) {
       log.debug(`recording time is less than ${minimumRecordingTimeInSeconds}s, skipping creation of recording files...`)
       return