Update quaternion calculation

equinor · Aug 10, 2023 · b0512e8 · b0512e8
1 parent f7806ca
commit b0512e8
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Showing 2 changed files with 66 additions and 6 deletions.
diff --git a/backend/api.test/Database/Models.cs b/backend/api.test/Database/Models.cs
@@ -8,10 +8,10 @@ namespace Api.Test.Services
     public class TestPose
     {
         [Fact]
-        public void TestRotation()
+        public void TestRotationNorth()
         {
             var mockAngleAxisParameters = new EchoVector(0, 0, 1);
-            float mockAngle = MathF.PI / 2;
+            float mockAngle = 0;
 
             var expected = new Orientation()
             {
@@ -22,7 +22,51 @@ public void TestRotation()
             };
 
             Assert.Equal(
-                expected.X,
+                expected.Z,
+                new Pose(mockAngleAxisParameters, mockAngle).Orientation.Z,
+                3.0
+            );
+        }
+
+        [Fact]
+        public void TestRotationSouth()
+        {
+            var mockAngleAxisParameters = new EchoVector(0, 0, 1);
+            float mockAngle = MathF.PI;
+
+            var expected = new Orientation()
+            {
+                X = 0,
+                Y = 0,
+                Z = -0.7071F,
+                W = 0.7071F
+            };
+
+            var pose = new Pose(mockAngleAxisParameters, mockAngle);
+
+            Assert.Equal(
+                expected.Z,
+                pose.Orientation.Z,
+                3.0
+            );
+        }
+
+        [Fact]
+        public void TestNegativaRotation()
+        {
+            var mockAngleAxisParameters = new EchoVector(0, 0, 1);
+            float mockAngle = -180F * MathF.PI / 180F;
+
+            var expected = new Orientation()
+            {
+                X = 0,
+                Y = 0,
+                Z = 1F,
+                W = 0
+            };
+
+            Assert.Equal(
+                expected.Z,
                 new Pose(mockAngleAxisParameters, mockAngle).Orientation.Z,
                 3.0
             );
@@ -64,6 +108,12 @@ private static AxisAngle ConvertOrientation(Orientation orientation)
             if (orientation.Z >= 0)
                 angle = 2 * MathF.Acos(qw);
 
+            angle = (450 * MathF.PI / 180) - angle;
+
+            angle %= 2F * MathF.PI;
+
+            if (angle < 0) angle += 2F * MathF.PI;
+
             return new AxisAngle(new EchoVector(0, 0, 1), angle);
         }
 

diff --git a/backend/api/Database/Models/Pose.cs b/backend/api/Database/Models/Pose.cs
@@ -93,15 +93,25 @@ public class Pose
 
         // Since this is a ground robot the only quaternion vector
         // that makes sense is up (0, 0, 1)
-        public Orientation AxisAngleToQuaternion(float angle)
+        // Echo representes North at 0deg and increases this value clockwise
+        // Our representation has East at 0deg with rotations anti-clockwise
+        public Orientation AxisAngleToQuaternion(float echoAngle)
         {
+            float angle;
+            echoAngle %= 2F * MathF.PI;
+
+            if (echoAngle < 0) echoAngle += 2F * MathF.PI;
+
+            angle = (450 * MathF.PI / 180) - echoAngle;
+
             var quaternion = new Orientation()
             {
                 X = 0,
                 Y = 0,
                 Z = MathF.Sin(angle / 2),
                 W = MathF.Cos(angle / 2)
             };
+
             return quaternion;
         }
 
@@ -125,10 +135,10 @@ float w
             Orientation = new Orientation(x_ori, y_ori, z_ori, w);
         }
 
-        public Pose(EchoVector enuPosition, float angle)
+        public Pose(EchoVector enuPosition, float echoAngle)
         {
             Position = new Position(enuPosition.East, enuPosition.North, enuPosition.Up);
-            Orientation = AxisAngleToQuaternion(angle);
+            Orientation = AxisAngleToQuaternion(echoAngle);
         }
 
         public Pose(Position position, Orientation orientation)