From 153114aec8571a9105541b1fef473d36c4099519 Mon Sep 17 00:00:00 2001 From: Anton Babushkin Date: Sat, 28 Dec 2013 00:16:10 +0400 Subject: mc_pos_control: calculate velocity error derivative without setpoint acceleration to get more clean output --- src/modules/mc_pos_control/mc_pos_control_main.cpp | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) (limited to 'src/modules/mc_pos_control/mc_pos_control_main.cpp') diff --git a/src/modules/mc_pos_control/mc_pos_control_main.cpp b/src/modules/mc_pos_control/mc_pos_control_main.cpp index f7d50f45d..948459c43 100644 --- a/src/modules/mc_pos_control/mc_pos_control_main.cpp +++ b/src/modules/mc_pos_control/mc_pos_control_main.cpp @@ -177,7 +177,7 @@ private: math::Vector<3> _vel; math::Vector<3> _pos_sp; math::Vector<3> _vel_sp; - math::Vector<3> _vel_err_prev; /**< velocity on previous step */ + math::Vector<3> _vel_prev; /**< velocity on previous step */ /** * Update our local parameter cache. @@ -261,7 +261,7 @@ MulticopterPositionControl::MulticopterPositionControl() : _vel.zero(); _pos_sp.zero(); _vel_sp.zero(); - _vel_err_prev.zero(); + _vel_prev.zero(); _params_handles.takeoff_alt = param_find("NAV_TAKEOFF_ALT"); _params_handles.takeoff_gap = param_find("NAV_TAKEOFF_GAP"); @@ -693,11 +693,15 @@ MulticopterPositionControl::task_main() reset_int_xy = true; } - /* calculate desired thrust vector in NED frame */ + /* velocity error */ math::Vector<3> vel_err = _vel_sp - _vel; - math::Vector<3> thrust_sp = vel_err.emult(_params.vel_p) + (vel_err - _vel_err_prev).emult(_params.vel_d) / dt + thrust_int; - _vel_err_prev = vel_err; + /* derivative of velocity error, not includes setpoint acceleration */ + math::Vector<3> vel_err_d = (sp_move_rate - _vel).emult(_params.pos_p) - (_vel - _vel_prev) / dt; + _vel_prev = _vel; + + /* thrust vector in NED frame */ + math::Vector<3> thrust_sp = vel_err.emult(_params.vel_p) + vel_err_d.emult(_params.vel_d) + thrust_int; if (!_control_mode.flag_control_velocity_enabled) { thrust_sp(0) = 0.0f; -- cgit v1.2.3