Fix orientation errors and improve drift correction

This commit is contained in:
german 2020-08-26 16:49:24 -05:00
parent e6fc3b5662
commit 1be18dc110
2 changed files with 31 additions and 14 deletions

View file

@ -37,18 +37,25 @@ void MotionInput::ResetRotations() {
} }
bool MotionInput::IsMoving(f32 sensitivity) const { bool MotionInput::IsMoving(f32 sensitivity) const {
return gyro.Length2() >= sensitivity || accel.Length() <= 0.9f || accel.Length() >= 1.1f; return gyro.Length() >= sensitivity || accel.Length() <= 0.9f || accel.Length() >= 1.1f;
} }
bool MotionInput::IsCalibrated(f32 sensitivity) const { bool MotionInput::IsCalibrated(f32 sensitivity) const {
return real_error.Length() > sensitivity; return real_error.Length() < sensitivity;
} }
void MotionInput::UpdateRotation(u64 elapsed_time) { void MotionInput::UpdateRotation(u64 elapsed_time) {
rotations += gyro * elapsed_time; const f32 sample_period = elapsed_time / 1000000.0f;
if (sample_period > 0.1f) {
return;
}
rotations += gyro * sample_period;
} }
void MotionInput::UpdateOrientation(u64 elapsed_time) { void MotionInput::UpdateOrientation(u64 elapsed_time) {
if (!IsCalibrated(0.1f)) {
ResetOrientation();
}
// Short name local variable for readability // Short name local variable for readability
f32 q1 = quat.w; f32 q1 = quat.w;
f32 q2 = quat.xyz[0]; f32 q2 = quat.xyz[0];
@ -56,12 +63,20 @@ void MotionInput::UpdateOrientation(u64 elapsed_time) {
f32 q4 = quat.xyz[2]; f32 q4 = quat.xyz[2];
const f32 sample_period = elapsed_time / 1000000.0f; const f32 sample_period = elapsed_time / 1000000.0f;
// ignore invalid elapsed time
if (sample_period > 0.1f) {
return;
}
const auto normal_accel = accel.Normalized(); const auto normal_accel = accel.Normalized();
auto rad_gyro = gyro * 3.1415926535f; auto rad_gyro = gyro * 3.1415926535f * 2;
const f32 swap = rad_gyro.x;
rad_gyro.x = rad_gyro.y;
rad_gyro.y = -swap;
rad_gyro.z = -rad_gyro.z; rad_gyro.z = -rad_gyro.z;
// Ignore drift correction if acceleration is not present // Ignore drift correction if acceleration is not reliable
if (normal_accel.Length() == 1.0f) { if (accel.Length() >= 0.75f && accel.Length() <= 1.25f) {
const f32 ax = -normal_accel.x; const f32 ax = -normal_accel.x;
const f32 ay = normal_accel.y; const f32 ay = normal_accel.y;
const f32 az = -normal_accel.z; const f32 az = -normal_accel.z;
@ -72,14 +87,14 @@ void MotionInput::UpdateOrientation(u64 elapsed_time) {
const f32 vz = q1 * q1 - q2 * q2 - q3 * q3 + q4 * q4; const f32 vz = q1 * q1 - q2 * q2 - q3 * q3 + q4 * q4;
// Error is cross product between estimated direction and measured direction of gravity // Error is cross product between estimated direction and measured direction of gravity
const Common::Vec3f new_real_error = {ay * vz - az * vy, az * vx - ax * vz, const Common::Vec3f new_real_error = {az * vx - ax * vz, ay * vz - az * vy,
ax * vy - ay * vx}; ax * vy - ay * vx};
derivative_error = new_real_error - real_error; derivative_error = new_real_error - real_error;
real_error = new_real_error; real_error = new_real_error;
// Prevent integral windup // Prevent integral windup
if (ki != 0.0f) { if (ki != 0.0f && !IsCalibrated(0.05f)) {
integral_error += real_error; integral_error += real_error;
} else { } else {
integral_error = {}; integral_error = {};
@ -112,13 +127,15 @@ void MotionInput::UpdateOrientation(u64 elapsed_time) {
} }
std::array<Common::Vec3f, 3> MotionInput::GetOrientation() const { std::array<Common::Vec3f, 3> MotionInput::GetOrientation() const {
const Common::Quaternion<float> quad{.xyz = {-quat.xyz[1], -quat.xyz[0], -quat.w}, const Common::Quaternion<float> quad{
.w = -quat.xyz[2]}; .xyz = {-quat.xyz[1], -quat.xyz[0], -quat.w},
.w = -quat.xyz[2],
};
const std::array<float, 16> matrix4x4 = quad.ToMatrix(); const std::array<float, 16> matrix4x4 = quad.ToMatrix();
return {Common::Vec3f(matrix4x4[0], matrix4x4[1], matrix4x4[2]), return {Common::Vec3f(matrix4x4[0], matrix4x4[1], -matrix4x4[2]),
Common::Vec3f(matrix4x4[4], matrix4x4[5], matrix4x4[6]), Common::Vec3f(matrix4x4[4], matrix4x4[5], -matrix4x4[6]),
Common::Vec3f(matrix4x4[8], matrix4x4[9], matrix4x4[10])}; Common::Vec3f(-matrix4x4[8], -matrix4x4[9], matrix4x4[10])};
} }
Common::Vec3f MotionInput::GetAcceleration() const { Common::Vec3f MotionInput::GetAcceleration() const {

View file

@ -61,7 +61,7 @@ private:
Common::Vec3f gyro_drift; Common::Vec3f gyro_drift;
f32 gyro_threshold = 0.0f; f32 gyro_threshold = 0.0f;
f32 reset_counter = 0.0f; u32 reset_counter = 0;
bool reset_enabled = true; bool reset_enabled = true;
}; };