motioncontroller: Store history and add functions for analysis

These are functions for converting acceleration due to gravity to angles in degrees, and some statistical analysis including the mean and variance.
InfiniTimeOrg · May 30, 2023 · 3683f88 · 3683f88
1 parent e0af08d
commit 3683f88
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Showing 5 changed files with 155 additions and 17 deletions.
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
@@ -494,6 +494,8 @@ list(APPEND SOURCE_FILES
 
         buttonhandler/ButtonHandler.cpp
         touchhandler/TouchHandler.cpp
+
+        utility/Math.cpp
         )
 
 list(APPEND RECOVERY_SOURCE_FILES
@@ -559,6 +561,8 @@ list(APPEND RECOVERY_SOURCE_FILES
         components/fs/FS.cpp
         buttonhandler/ButtonHandler.cpp
         touchhandler/TouchHandler.cpp
+
+        utility/Math.cpp
         )
 
 list(APPEND RECOVERYLOADER_SOURCE_FILES
@@ -678,6 +682,7 @@ set(INCLUDE_FILES
         components/motor/MotorController.h
         buttonhandler/ButtonHandler.h
         touchhandler/TouchHandler.h
+        utility/Math.h
         )
 
 include_directories(

diff --git a/src/components/motion/MotionController.cpp b/src/components/motion/MotionController.cpp
@@ -2,25 +2,58 @@
 
 #include <task.h>
 
+#include "utility/Math.h"
+
 using namespace Pinetime::Controllers;
 
+namespace {
+  constexpr inline int32_t Clamp(int32_t val, int32_t min, int32_t max) {
+    return val < min ? min : (val > max ? max : val);
+  }
+
+  // only returns meaningful values if inputs are acceleration due to gravity
+  int16_t DegreesRolled(int16_t y, int16_t z, int16_t prevY, int16_t prevZ) {
+    int16_t prevYAngle = Pinetime::Utility::Asin(Clamp(prevY * 32, -32767, 32767));
+    int16_t yAngle = Pinetime::Utility::Asin(Clamp(y * 32, -32767, 32767));
+
+    if (z < 0 && prevZ < 0) {
+      return prevYAngle - yAngle;
+    }
+    if (prevZ < 0) {
+      if (y < 0) {
+        return prevYAngle + yAngle + 180;
+      }
+      return prevYAngle + yAngle - 180;
+    }
+    if (z < 0) {
+      if (y < 0) {
+        return -prevYAngle - yAngle - 180;
+      }
+      return -prevYAngle - yAngle + 180;
+    }
+    return yAngle - prevYAngle;
+  }
+}
+
 void MotionController::Update(int16_t x, int16_t y, int16_t z, uint32_t nbSteps) {
   if (this->nbSteps != nbSteps && service != nullptr) {
     service->OnNewStepCountValue(nbSteps);
   }
 
-  if (service != nullptr && (this->x != x || this->y != y || this->z != z)) {
+  if (service != nullptr && (this->x != x || yHistory[0] != y || zHistory[0] != z)) {
     service->OnNewMotionValues(x, y, z);
   }
 
   lastTime = time;
   time = xTaskGetTickCount();
 
   this->x = x;
-  lastY = this->y;
-  this->y = y;
-  lastZ = this->z;
-  this->z = z;
+  yHistory++;
+  yHistory[0] = y;
+  zHistory++;
+  zHistory[0] = z;
+
+  stats = GetAccelStats();
 
   int32_t deltaSteps = nbSteps - this->nbSteps;
   if (deltaSteps > 0) {
@@ -29,22 +62,46 @@ void MotionController::Update(int16_t x, int16_t y, int16_t z, uint32_t nbSteps)
   this->nbSteps = nbSteps;
 }
 
+MotionController::AccelStats MotionController::GetAccelStats() const {
+  AccelStats stats;
+
+  for (uint8_t i = 0; i < AccelStats::numHistory; i++) {
+    stats.yMean += yHistory[histSize - i];
+    stats.zMean += zHistory[histSize - i];
+    stats.prevYMean += yHistory[1 + i];
+    stats.prevZMean += zHistory[1 + i];
+  }
+  stats.yMean /= AccelStats::numHistory;
+  stats.zMean /= AccelStats::numHistory;
+  stats.prevYMean /= AccelStats::numHistory;
+  stats.prevZMean /= AccelStats::numHistory;
+
+  for (uint8_t i = 0; i < AccelStats::numHistory; i++) {
+    stats.yVariance += (yHistory[histSize - i] - stats.yMean) * (yHistory[histSize - i] - stats.yMean);
+    stats.zVariance += (zHistory[histSize - i] - stats.zMean) * (zHistory[histSize - i] - stats.zMean);
+  }
+  stats.yVariance /= AccelStats::numHistory;
+  stats.zVariance /= AccelStats::numHistory;
+
+  return stats;
+}
+
 bool MotionController::ShouldRaiseWake(bool isSleeping) {
-  if ((x + 335) <= 670 && z < 0) {
+  if ((x + 335) <= 670 && zHistory[0] < 0) {
     if (!isSleeping) {
-      if (y <= 0) {
+      if (yHistory[0] <= 0) {
         return false;
       }
       lastYForRaiseWake = 0;
       return false;
     }
 
-    if (y >= 0) {
+    if (yHistory[0] >= 0) {
       lastYForRaiseWake = 0;
       return false;
     }
-    if (y + 230 < lastYForRaiseWake) {
-      lastYForRaiseWake = y;
+    if (yHistory[0] + 230 < lastYForRaiseWake) {
+      lastYForRaiseWake = yHistory[0];
       return true;
     }
   }
@@ -53,7 +110,8 @@ bool MotionController::ShouldRaiseWake(bool isSleeping) {
 
 bool MotionController::ShouldShakeWake(uint16_t thresh) {
   /* Currently Polling at 10hz, If this ever goes faster scalar and EMA might need adjusting */
-  int32_t speed = std::abs(z + (y / 2) + (x / 4) - lastY / 2 - lastZ) / (time - lastTime) * 100;
+  int32_t speed =
+    std::abs(zHistory[0] + (yHistory[0] / 2) + (x / 4) - yHistory[histSize - 1] / 2 - zHistory[histSize - 1]) / (time - lastTime) * 100;
   //(.2 * speed) + ((1 - .2) * accumulatedSpeed);
   // implemented without floats as .25Alpha
   accumulatedSpeed = (speed / 5) + ((accumulatedSpeed / 5) * 4);

diff --git a/src/components/motion/MotionController.h b/src/components/motion/MotionController.h
@@ -6,6 +6,7 @@
 
 #include "drivers/Bma421.h"
 #include "components/ble/MotionService.h"
+#include "utility/CircularBuffer.h"
 
 namespace Pinetime {
   namespace Controllers {
@@ -24,11 +25,11 @@ namespace Pinetime {
       }
 
       int16_t Y() const {
-        return y;
+        return yHistory[0];
       }
 
       int16_t Z() const {
-        return z;
+        return zHistory[0];
       }
 
       uint32_t NbSteps() const {
@@ -67,12 +68,27 @@ namespace Pinetime {
       TickType_t lastTime = 0;
       TickType_t time = 0;
 
+      struct AccelStats {
+        static constexpr uint8_t numHistory = 2;
+
+        int16_t yMean = 0;
+        int16_t zMean = 0;
+        int16_t prevYMean = 0;
+        int16_t prevZMean = 0;
+
+        uint32_t yVariance = 0;
+        uint32_t zVariance = 0;
+      };
+
+      AccelStats GetAccelStats() const;
+
+      AccelStats stats = {};
+
       int16_t x = 0;
       int16_t lastYForRaiseWake = 0;
-      int16_t lastY = 0;
-      int16_t y = 0;
-      int16_t lastZ = 0;
-      int16_t z = 0;
+      static constexpr uint8_t histSize = 8;
+      Utility::CircularBuffer<int16_t, histSize> yHistory = {};
+      Utility::CircularBuffer<int16_t, histSize> zHistory = {};
       int32_t accumulatedSpeed = 0;
 
       DeviceTypes deviceType = DeviceTypes::Unknown;

diff --git a/src/utility/Math.cpp b/src/utility/Math.cpp
@@ -0,0 +1,49 @@
+#include "utility/Math.h"
+
+#include <lvgl/src/lv_misc/lv_math.h>
+
+using namespace Pinetime::Utility;
+
+#ifndef PINETIME_IS_RECOVERY
+
+int16_t Pinetime::Utility::Asin(int16_t arg) {
+  int16_t a = arg < 0 ? -arg : arg;
+
+  int16_t angle = 45;
+  int16_t low = 0;
+  int16_t high = 90;
+  while (low <= high) {
+    int16_t sinAngle = _lv_trigo_sin(angle);
+    int16_t sinAngleSub = _lv_trigo_sin(angle - 1);
+    int16_t sinAngleAdd = _lv_trigo_sin(angle + 1);
+
+    if (a >= sinAngleSub && a <= sinAngleAdd) {
+      if (a <= (sinAngleSub + sinAngle) / 2) {
+        angle--;
+      } else if (a > (sinAngle + sinAngleAdd) / 2) {
+        angle++;
+      }
+      break;
+    }
+
+    if (a < sinAngle) {
+      high = angle - 1;
+    }
+
+    else {
+      low = angle + 1;
+    }
+
+    angle = (low + high) / 2;
+  }
+
+  return arg < 0 ? -angle : angle;
+}
+
+#else
+
+int16_t Pinetime::Utility::Asin(int16_t /*arg*/) {
+  return 0;
+}
+
+#endif
diff --git a/src/utility/Math.h b/src/utility/Math.h
@@ -0,0 +1,10 @@
+#pragma once
+
+#include <cstdint>
+
+namespace Pinetime {
+  namespace Utility {
+    // returns the arcsin of `arg`. asin(-32767) = -90, asin(32767) = 90
+    int16_t Asin(int16_t arg);
+  }
+}