use velocity component in bin direction instead of norm

This commit is contained in:
baumanta 2019-05-17 09:00:19 +02:00 committed by Mathieu Bresciani
parent 33cd032c35
commit 09e1d4888c
3 changed files with 15 additions and 11 deletions

View File

@ -65,7 +65,8 @@ bool CollisionPrevention::initializeSubscriptions(SubscriptionArray &subscriptio
return true;
}
void CollisionPrevention::calculateConstrainedSetpoint(Vector2f &setpoint, const float max_acc, const float curr_vel)
void CollisionPrevention::calculateConstrainedSetpoint(Vector2f &setpoint, const float max_acc,
const Vector2f &curr_vel)
{
const obstacle_distance_s &obstacle_distance = _sub_obstacle_distance->get();
@ -90,17 +91,20 @@ void CollisionPrevention::calculateConstrainedSetpoint(Vector2f &setpoint, const
float distance = obstacle_distance.distances[i] / 100.0f; //convert to meters
float angle = math::radians((float)i * obstacle_distance.increment);
//max admissible velocity in current bin direction: v = sqrt(2 * a * d), where d is the distance to standstill
//a is the constant acceleration and v the current velocity. We use a = a_max/2 and j = j_max/2 to stay well within the limits
float acceleration_distance = 2.f * curr_vel * max_acc / _param_mpc_jerk_max.get();
float distance_to_standstill = math::max(0.f, distance - _param_mpc_col_prev_d.get() - acceleration_distance);
float vel_max_sqrd = max_acc * distance_to_standstill;
//split current setpoint into parallel and orthogonal components with respect to the current bin direction
Vector2f bin_direction = {cos(angle), sin(angle)};
Vector2f orth_direction = {-bin_direction(1), bin_direction(0)};
float sp_parallel = setpoint_sqrd.dot(bin_direction);
float sp_orth = setpoint_sqrd.dot(orth_direction);
float curr_vel_parallel = math::max(0.f, curr_vel.dot(bin_direction));
//max admissible velocity in current bin direction: v = sqrt(2 * a * d), where d is the distance to standstill
//a is the constant acceleration and v the current velocity. We use a = a_max/2 and j = j_max/2 to stay well within the limits
float acceleration_distance = 2.f * curr_vel_parallel * max_acc / _param_mpc_jerk_max.get();
float distance_to_standstill = math::max(0.f, distance - _param_mpc_col_prev_d.get() - acceleration_distance);
float vel_max_sqrd = max_acc * distance_to_standstill;
//limit the setpoint to respect vel_max by subtracting from the parallel component
if (sp_parallel > vel_max_sqrd) {
@ -144,7 +148,7 @@ void CollisionPrevention::calculateConstrainedSetpoint(Vector2f &setpoint, const
}
void CollisionPrevention::modifySetpoint(Vector2f &original_setpoint, const float max_speed,
const float max_acc, const float curr_vel)
const float max_acc, const Vector2f &curr_vel)
{
//calculate movement constraints based on range data
Vector2f new_setpoint = original_setpoint;

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@ -69,7 +69,7 @@ public:
bool is_active() { return _param_mpc_col_prev_d.get() > 0; }
void modifySetpoint(matrix::Vector2f &original_setpoint, const float max_speed, const float max_acc,
const float curr_vel);
const matrix::Vector2f &curr_vel);
private:
@ -91,6 +91,6 @@ private:
void update();
void calculateConstrainedSetpoint(matrix::Vector2f &setpoint, const float max_acc, const float curr_vel);
void calculateConstrainedSetpoint(matrix::Vector2f &setpoint, const float max_acc, const matrix::Vector2f &curr_vel);
};

View File

@ -134,7 +134,7 @@ void FlightTaskManualPosition::_scaleSticks()
// collision prevention
if (_collision_prevention.is_active()) {
_collision_prevention.modifySetpoint(vel_sp_xy, _velocity_scale, _param_mpc_acc_hor_max.get(), _velocity.norm());
_collision_prevention.modifySetpoint(vel_sp_xy, _velocity_scale, _param_mpc_acc_hor_max.get(), Vector2f(_velocity));
}
_velocity_setpoint(0) = vel_sp_xy(0);