Add compatibility with only accelerometer and auto calibrate for drift

This commit is contained in:
german 2020-10-03 22:22:01 -05:00
parent 4d0ae1a17a
commit a220d8799e
2 changed files with 106 additions and 12 deletions

View file

@ -16,8 +16,16 @@ void MotionInput::SetAcceleration(const Common::Vec3f& acceleration) {
void MotionInput::SetGyroscope(const Common::Vec3f& gyroscope) {
gyro = gyroscope - gyro_drift;
// Auto adjust drift to minimize drift
if (!IsMoving(0.1f)) {
gyro_drift = (gyro_drift * 0.9999f) + (gyroscope * 0.0001f);
}
if (gyro.Length2() < gyro_threshold) {
gyro = {};
} else {
only_accelerometer = false;
}
}
@ -49,7 +57,7 @@ bool MotionInput::IsCalibrated(f32 sensitivity) const {
return real_error.Length() < sensitivity;
}
void MotionInput::UpdateRotation(u64 elapsed_time) {
void MotionInput::UpdateRotation(const u64 elapsed_time) {
const f32 sample_period = elapsed_time / 1000000.0f;
if (sample_period > 0.1f) {
return;
@ -57,7 +65,7 @@ void MotionInput::UpdateRotation(u64 elapsed_time) {
rotations += gyro * sample_period;
}
void MotionInput::UpdateOrientation(u64 elapsed_time) {
void MotionInput::UpdateOrientation(const u64 elapsed_time) {
if (!IsCalibrated(0.1f)) {
ResetOrientation();
}
@ -68,7 +76,7 @@ void MotionInput::UpdateOrientation(u64 elapsed_time) {
f32 q4 = quat.xyz[2];
const f32 sample_period = elapsed_time / 1000000.0f;
// ignore invalid elapsed time
// Ignore invalid elapsed time
if (sample_period > 0.1f) {
return;
}
@ -80,6 +88,13 @@ void MotionInput::UpdateOrientation(u64 elapsed_time) {
rad_gyro.y = -swap;
rad_gyro.z = -rad_gyro.z;
// Clear gyro values if there is no gyro present
if (only_accelerometer) {
rad_gyro.x = 0;
rad_gyro.y = 0;
rad_gyro.z = 0;
}
// Ignore drift correction if acceleration is not reliable
if (accel.Length() >= 0.75f && accel.Length() <= 1.25f) {
const f32 ax = -normal_accel.x;
@ -92,8 +107,11 @@ void MotionInput::UpdateOrientation(u64 elapsed_time) {
const f32 vz = q1 * q1 - q2 * q2 - q3 * q3 + q4 * q4;
// Error is cross product between estimated direction and measured direction of gravity
const Common::Vec3f new_real_error = {az * vx - ax * vz, ay * vz - az * vy,
ax * vy - ay * vx};
const Common::Vec3f new_real_error = {
az * vx - ax * vz,
ay * vz - az * vy,
ax * vy - ay * vx,
};
derivative_error = new_real_error - real_error;
real_error = new_real_error;
@ -106,9 +124,22 @@ void MotionInput::UpdateOrientation(u64 elapsed_time) {
}
// Apply feedback terms
if (!only_accelerometer) {
rad_gyro += kp * real_error;
rad_gyro += ki * integral_error;
rad_gyro += kd * derivative_error;
} else {
// Give more weight to acelerometer values to compensate for the lack of gyro
rad_gyro += 35.0f * kp * real_error;
rad_gyro += 10.0f * ki * integral_error;
rad_gyro += 10.0f * kd * derivative_error;
// Emulate gyro values for games that need them
gyro.x = -rad_gyro.y;
gyro.y = rad_gyro.x;
gyro.z = -rad_gyro.z;
UpdateRotation(elapsed_time);
}
}
const f32 gx = rad_gyro.y;
@ -143,6 +174,67 @@ std::array<Common::Vec3f, 3> MotionInput::GetOrientation() const {
Common::Vec3f(-matrix4x4[8], -matrix4x4[9], matrix4x4[10])};
}
void MotionInput::SetOrientationFromAccelerometer() {
int iterations = 0;
const f32 sample_period = 0.015f;
const auto normal_accel = accel.Normalized();
const f32 ax = -normal_accel.x;
const f32 ay = normal_accel.y;
const f32 az = -normal_accel.z;
while (!IsCalibrated(0.01f) && ++iterations < 100) {
// Short name local variable for readability
f32 q1 = quat.w;
f32 q2 = quat.xyz[0];
f32 q3 = quat.xyz[1];
f32 q4 = quat.xyz[2];
Common::Vec3f rad_gyro = {};
const f32 ax = -normal_accel.x;
const f32 ay = normal_accel.y;
const f32 az = -normal_accel.z;
// Estimated direction of gravity
const f32 vx = 2.0f * (q2 * q4 - q1 * q3);
const f32 vy = 2.0f * (q1 * q2 + q3 * q4);
const f32 vz = q1 * q1 - q2 * q2 - q3 * q3 + q4 * q4;
// Error is cross product between estimated direction and measured direction of gravity
const Common::Vec3f new_real_error = {
az * vx - ax * vz,
ay * vz - az * vy,
ax * vy - ay * vx,
};
derivative_error = new_real_error - real_error;
real_error = new_real_error;
rad_gyro += 10.0f * kp * real_error;
rad_gyro += 5.0f * ki * integral_error;
rad_gyro += 10.0f * kd * derivative_error;
const f32 gx = rad_gyro.y;
const f32 gy = rad_gyro.x;
const f32 gz = rad_gyro.z;
// Integrate rate of change of quaternion
const f32 pa = q2;
const f32 pb = q3;
const f32 pc = q4;
q1 = q1 + (-q2 * gx - q3 * gy - q4 * gz) * (0.5f * sample_period);
q2 = pa + (q1 * gx + pb * gz - pc * gy) * (0.5f * sample_period);
q3 = pb + (q1 * gy - pa * gz + pc * gx) * (0.5f * sample_period);
q4 = pc + (q1 * gz + pa * gy - pb * gx) * (0.5f * sample_period);
quat.w = q1;
quat.xyz[0] = q2;
quat.xyz[1] = q3;
quat.xyz[2] = q4;
quat = quat.Normalized();
}
}
Common::Vec3f MotionInput::GetAcceleration() const {
return accel;
}
@ -160,17 +252,17 @@ Common::Vec3f MotionInput::GetRotations() const {
}
void MotionInput::ResetOrientation() {
if (!reset_enabled) {
if (!reset_enabled || only_accelerometer) {
return;
}
if (!IsMoving(0.5f) && accel.z <= -0.9f) {
++reset_counter;
if (reset_counter > 900) {
// TODO: calculate quaternion from gravity vector
quat.w = 0;
quat.xyz[0] = 0;
quat.xyz[1] = 0;
quat.xyz[2] = -1;
SetOrientationFromAccelerometer();
integral_error = {};
reset_counter = 0;
}

View file

@ -29,8 +29,8 @@ public:
void EnableReset(bool reset);
void ResetRotations();
void UpdateRotation(u64 elapsed_time);
void UpdateOrientation(u64 elapsed_time);
void UpdateRotation(const u64 elapsed_time);
void UpdateOrientation(const u64 elapsed_time);
std::array<Common::Vec3f, 3> GetOrientation() const;
Common::Vec3f GetAcceleration() const;
@ -43,6 +43,7 @@ public:
private:
void ResetOrientation();
void SetOrientationFromAccelerometer();
// PID constants
const f32 kp;
@ -63,6 +64,7 @@ private:
f32 gyro_threshold = 0.0f;
u32 reset_counter = 0;
bool reset_enabled = true;
bool only_accelerometer = true;
};
} // namespace InputCommon