From 1d1bdb7bba4623defa38917641ffb70d6d433874 Mon Sep 17 00:00:00 2001 From: Kento Yabuuchi Date: Fri, 7 Jun 2024 10:36:13 +0900 Subject: [PATCH] add some comments Signed-off-by: Kento Yabuuchi --- .../include/pose2twist/pose2twist_core.hpp | 4 +- .../pose2twist/src/pose2twist_core.cpp | 7 +- .../pose2twist/test/test_angular_velocity.cpp | 104 +++++++++++++++--- 3 files changed, 97 insertions(+), 18 deletions(-) diff --git a/localization/pose2twist/include/pose2twist/pose2twist_core.hpp b/localization/pose2twist/include/pose2twist/pose2twist_core.hpp index 10f7d79ef7996..d1ff6ee5ff8b6 100644 --- a/localization/pose2twist/include/pose2twist/pose2twist_core.hpp +++ b/localization/pose2twist/include/pose2twist/pose2twist_core.hpp @@ -27,8 +27,10 @@ #include #endif -geometry_msgs::msg::Vector3 rotation_vector_from_quaternion( +// Compute the relative rotation of q2 from q1 as a rotation vector +geometry_msgs::msg::Vector3 compute_relative_rotation_vector( const tf2::Quaternion & q1, const tf2::Quaternion & q2); + class Pose2Twist : public rclcpp::Node { public: diff --git a/localization/pose2twist/src/pose2twist_core.cpp b/localization/pose2twist/src/pose2twist_core.cpp index 0a1eaa3f2c1db..1ffad737a8ad1 100644 --- a/localization/pose2twist/src/pose2twist_core.cpp +++ b/localization/pose2twist/src/pose2twist_core.cpp @@ -41,9 +41,12 @@ tf2::Quaternion get_quaternion(const geometry_msgs::msg::PoseStamped::SharedPtr return tf2::Quaternion{orientation.x, orientation.y, orientation.z, orientation.w}; } -geometry_msgs::msg::Vector3 rotation_vector_from_quaternion( +geometry_msgs::msg::Vector3 compute_relative_rotation_vector( const tf2::Quaternion & q1, const tf2::Quaternion & q2) { + // If we define q2 as the rotation obntained by applying dq after applying q1, + // then q2 = q1 * dq . + // Therefore, dq = q1.inverse() * q2 . const tf2::Quaternion diff_quaternion = q1.inverse() * q2; const tf2::Vector3 axis = diff_quaternion.getAxis() * diff_quaternion.getAngle(); return geometry_msgs::msg::Vector3{}.set__x(axis.x()).set__y(axis.y()).set__z(axis.z()); @@ -67,7 +70,7 @@ geometry_msgs::msg::TwistStamped calc_twist( geometry_msgs::msg::Vector3 diff_xyz; const geometry_msgs::msg::Vector3 diff_rpy = - rotation_vector_from_quaternion(pose_a_quaternion, pose_b_quaternion); + compute_relative_rotation_vector(pose_a_quaternion, pose_b_quaternion); diff_xyz.x = pose_b->pose.position.x - pose_a->pose.position.x; diff_xyz.y = pose_b->pose.position.y - pose_a->pose.position.y; diff --git a/localization/pose2twist/test/test_angular_velocity.cpp b/localization/pose2twist/test/test_angular_velocity.cpp index 099cb7b22b6c3..baff54170910f 100644 --- a/localization/pose2twist/test/test_angular_velocity.cpp +++ b/localization/pose2twist/test/test_angular_velocity.cpp @@ -16,26 +16,100 @@ #include -TEST(AngularVelocityFromQuaternion, CheckNumericalValidity) +// 1e-3 radian = 0.057 degrees +constexpr double ACCEPTABLE_ERROR = 1e-3; + +TEST(AngularVelocityFromQuaternion, CheckMultiplicationOrder) { - tf2::Quaternion initial_q; - initial_q.setRPY(0.2, 0.3, 0.4); + // If we define q2 as the rotation obntained by applying dq after applying q1, then q2 = q1 * dq . + // + // IT IS NOT q2 = dq * q1 . + // + // This test checks that the multiplication order is correct. + + const tf2::Vector3 target_vector(1, 2, 3); + // initial state + // Now, car is facing to the +x direction + // z + // ^ y + // | ^ + // | / + // | / + // car -> x + // + // + // + + tf2::Quaternion q1; + q1.setRPY(0., 0., M_PI / 2.); // yaw = 90 degrees + const tf2::Vector3 initially_rotated_vector = tf2::quatRotate(q1, target_vector); + // after applying q1 + // Now, car is facing to the +y direction + // z + // ^ + // | y + // | ^ + // | / + // <--car x + // + // + // + EXPECT_NEAR(initially_rotated_vector.x(), -2., ACCEPTABLE_ERROR); + EXPECT_NEAR(initially_rotated_vector.y(), 1., ACCEPTABLE_ERROR); + EXPECT_NEAR(initially_rotated_vector.z(), 3., ACCEPTABLE_ERROR); + + tf2::Quaternion dq; + dq.setRPY(0., M_PI / 2., 0.); // pitch = 90 degrees + const tf2::Vector3 finally_rotated_vector = tf2::quatRotate(q1 * dq, target_vector); + // after applying dq + // Now, car is facing to the -z direction + // z y + // ^ + // / + // / + // / + // <--car x + // | + // v + // + EXPECT_NEAR(finally_rotated_vector.x(), -2., ACCEPTABLE_ERROR); + EXPECT_NEAR(finally_rotated_vector.y(), 3., ACCEPTABLE_ERROR); + EXPECT_NEAR(finally_rotated_vector.z(), -1., ACCEPTABLE_ERROR); - const tf2::Vector3 expected_axis = tf2::Vector3(0.1, 0.2, 0.3).normalized(); - const double expected_angle = 0.1; // 0.1 radian = 5.7 degrees + // Failure case + { + const tf2::Vector3 false_rotated_vector = tf2::quatRotate(dq * q1, target_vector); + + EXPECT_FALSE(std::abs(false_rotated_vector.x() - (-2)) < ACCEPTABLE_ERROR); + EXPECT_FALSE(std::abs(false_rotated_vector.y() - (3)) < ACCEPTABLE_ERROR); + EXPECT_FALSE(std::abs(false_rotated_vector.z() - (-1)) < ACCEPTABLE_ERROR); + } +} + +TEST(AngularVelocityFromQuaternion, CheckNumericalValidity) +{ + auto test = [](const tf2::Vector3 & expected_axis, const double expected_angle) -> void { + tf2::Quaternion expected_q; + expected_q.setRotation(expected_axis, expected_angle); - tf2::Quaternion expected_q; - expected_q.setRotation(expected_axis, expected_angle); + // Create a random initial quaternion + tf2::Quaternion initial_q; + initial_q.setRPY(0.2, 0.3, 0.4); - const tf2::Quaternion final_q = initial_q * expected_q; + // Calculate the final quaternion by rotating the initial quaternion by the expected + // quaternion + const tf2::Quaternion final_q = initial_q * expected_q; - const geometry_msgs::msg::Vector3 rotation_vector = - rotation_vector_from_quaternion(initial_q, final_q); + // Calculate the relative rotation between the initial and final quaternion + const geometry_msgs::msg::Vector3 rotation_vector = + compute_relative_rotation_vector(initial_q, final_q); - // 1e-3 radian = 0.057 degrees - constexpr double ACCEPTABLE_ERROR = 1e-3; + EXPECT_NEAR(rotation_vector.x, expected_axis.x() * expected_angle, ACCEPTABLE_ERROR); + EXPECT_NEAR(rotation_vector.y, expected_axis.y() * expected_angle, ACCEPTABLE_ERROR); + EXPECT_NEAR(rotation_vector.z, expected_axis.z() * expected_angle, ACCEPTABLE_ERROR); + }; - EXPECT_NEAR(rotation_vector.x, expected_axis.x() * expected_angle, ACCEPTABLE_ERROR); - EXPECT_NEAR(rotation_vector.y, expected_axis.y() * expected_angle, ACCEPTABLE_ERROR); - EXPECT_NEAR(rotation_vector.z, expected_axis.z() * expected_angle, ACCEPTABLE_ERROR); + test(tf2::Vector3(1.0, 0.0, 0.0).normalized(), 0.1); // 0.1 radian = 5.7 degrees + test(tf2::Vector3(1.0, 1.0, 0.0).normalized(), -0.2); // 0.2 radian = 11.4 degrees + test(tf2::Vector3(1.0, 2.0, 3.0).normalized(), 0.3); // 0.3 radian = 17.2 degrees }