AP_Scripting: improved stall turn with wind

compensate for wind drift and shift position
This commit is contained in:
Andrew Tridgell 2022-11-26 18:42:38 +11:00
parent a9e7f473bd
commit 1a68da49f1
1 changed files with 88 additions and 25 deletions

View File

@ -57,7 +57,7 @@ GRAVITY_MSS = 9.80665
--[[
list of attributes that can be added to a path element
--]]
local path_attribs = { "roll_ref", "set_orient", "rate_override", "thr_boost", "pos_corr", "message", "shift_y" }
local path_attribs = { "roll_ref", "set_orient", "rate_override", "thr_boost", "pos_corr", "message", "shift_xy" }
--[[
Aerobatic tricks on a switch support - allows for tricks to be initiated outside AUTO mode
@ -186,6 +186,19 @@ function calc_lowpass_alpha(dt, time_constant)
return dt/(dt+rc)
end
--[[ get the c.y element of the DCM body to earth matrix, which gives
the projection of the vehicle y axis in the down direction
--]]
function get_ahrs_dcm_c_y()
local ahrs_quat = ahrs:get_quaternion()
local q1 = ahrs_quat:q1()
local q2 = ahrs_quat:q2()
local q3 = ahrs_quat:q3()
local q4 = ahrs_quat:q4()
local q3q4 = q3 * q4
local q1q2 = q1 * q2
return 2*(q3q4 + q1q2)
end
-- a PI controller implemented as a Lua object
local function PI_controller(kP,kI,iMax,min,max)
@ -1298,28 +1311,36 @@ function rudder_over(_direction, _min_speed)
local reached_speed = false
local kick_started = false
local pitch2_done = false
local descent_done = false
local target_q = nil
local initial_q = nil
local last_t = nil
local initial_z = nil
--[[
the update() method is called during the rudder over, it
should return true when the maneuver is completed
--]]
function self.update(path, t, target_speed)
if pitch2_done then
if descent_done then
-- we're all done
return true
end
local ahrs_quat = ahrs:get_quaternion()
local ahrs_pos = ahrs:get_relative_position_NED_origin()
local ahrs_gyro = ahrs:get_gyro()
local now = millis():tofloat() * 0.001
local pitch_threshold = 60.0
if target_q == nil then
-- should go full vertical
target_q = ahrs_quat
-- initialising
initial_z = ahrs_pos:z()
target_q = quat_copy(ahrs_quat)
initial_q = quat_copy(target_q)
last_t = now
end
local dt = now - last_t
last_t = now
@ -1332,7 +1353,7 @@ function rudder_over(_direction, _min_speed)
-- use user set throttle for achieving the stall
local throttle = AEROM_STALL_THR:get()
local pitch_deg = math.deg(ahrs:get_pitch())
if not kick_started and math.abs(math.deg(rate_rads:z())) > ACRO_YAW_RATE:get()/3 then
if reached_speed and not kick_started and math.abs(math.deg(ahrs_gyro:z())) > ACRO_YAW_RATE:get()/3 then
kick_started = true
end
if kick_started then
@ -1342,11 +1363,11 @@ function rudder_over(_direction, _min_speed)
vehicle:set_target_throttle_rate_rpy(throttle, rate_dps:x(), rate_dps:y(), rate_dps:z())
local current_speed = ahrs:get_velocity_NED():length()
log_pose('POSM', ahrs:get_relative_position_NED_origin(), ahrs:get_quaternion())
log_pose('POST', ahrs:get_relative_position_NED_origin(), target_q)
log_pose('POSM', ahrs_pos, ahrs:get_quaternion())
log_pose('POST', ahrs_pos, target_q)
if not reached_speed and current_speed <= min_speed then
local current_speed_up = -ahrs:get_velocity_NED():z()
if not reached_speed and current_speed_up <= min_speed then
reached_speed = true
end
@ -1355,37 +1376,75 @@ function rudder_over(_direction, _min_speed)
end
-- integrate desired attitude through yaw
local ahrs_gyro = ahrs:get_gyro()
local q_rate_rads = makeVector3f(0,0,ahrs_gyro:z())
if pitch2_done then
-- stop adding yaw
q_rate_rads:z(0)
end
local rotation = Quaternion()
rotation:from_angular_velocity(q_rate_rads, dt)
target_q = target_q * rotation
target_q:normalize()
--[[
override rudder to maximum, basing PWM on the MIN/MAX of the channel
according to the desired direction
--]]
local rudd_pwm = nil
if direction * (RUDD_REVERSED:get()*2-1) < 0 then
local desired_direction = direction
if desired_direction == 0 then
local c_y = get_ahrs_dcm_c_y()
if c_y > 0 then
desired_direction = 1
else
desired_direction = -1
end
end
if desired_direction * (RUDD_REVERSED:get()*2-1) < 0 then
rudd_pwm = RUDD_MAX:get()
else
rudd_pwm = RUDD_MIN:get()
end
SRV_Channels:set_output_pwm_chan_timeout(rudder_chan, rudd_pwm, math.floor(4*1000/LOOP_RATE))
if not pitch2_done then
SRV_Channels:set_output_pwm_chan_timeout(rudder_chan, rudd_pwm, math.floor(4*1000/LOOP_RATE))
end
if not kick_started then
return false
end
-- see if we are nose down
if pitch_deg > AEROM_STALL_PIT:get() then
-- not done
if kick_started and pitch_deg < AEROM_STALL_PIT:get() and not pitch2_done then
-- lock onto a descent path
pitch2_done = true
target_q = initial_q * qorient(0, 0, 180)
--[[ correct the attitude to the opposite correction that we
had at the start of the slowdown, so we fight the wind on
the way down
--]]
local error_q = initial_q:inverse() * qorient(0, 90, math.deg(initial_q:get_euler_yaw()))
local error_pitch = error_q:get_euler_pitch()
local error_yaw = error_q:get_euler_yaw()
target_q = target_q * qorient(0, math.deg(-2*error_pitch), math.deg(2*error_yaw))
target_q:normalize()
return false
end
if not pitch2_done or ahrs_pos:z() < initial_z then
-- haven't finished the descent
return false
end
-- all done, update state
pitch_done2 = true
descent_done = true
path_var.tangent = path_var.tangent:scale(-1)
path_var.path_t = path.get_next_segment_start(t)
path_var.accumulated_orientation_rel_ef = path_var.accumulated_orientation_rel_ef * qorient(0,0,180)
path_var.last_time = now
path_var.last_ang_rate_dps = ahrs_gyro:scale(math.deg(1))
path_var.pos = rotate_path(path, path_var.path_t, path_var.initial_ori, path_var.initial_ef_pos)
-- ensure that the path will move fwd on the next step
path_var.pos:z(path_var.pos:z()-10)
-- cancel rudder override
SRV_Channels:set_output_pwm_chan_timeout(rudder_chan, rudd_pwm, 0)
@ -1407,7 +1466,7 @@ function stall_turn(radius, height, direction, min_speed)
{ path_vertical_arc(radius, 90), roll_angle(0) },
{ path_straight(h), roll_angle(0) },
{ path_reverse(h/4), roll_angle(0), rate_override=rudder_over(direction,min_speed), set_orient=qorient(0,-90,0) },
{ path_straight(h), roll_angle(0), pos_corr=0.5, shift_y=true },
{ path_straight(h), roll_angle(0), pos_corr=0.5, shift_xy=true },
{ path_vertical_arc(-radius, 90), roll_angle(0), set_orient=qorient(0,0,180) },
})
end
@ -1745,7 +1804,7 @@ function do_path()
path_var.pos = path_var.initial_ef_pos:copy()
path_var.roll = 0.0
path_var.last_shift_y = nil
path_var.last_shift_xy = nil
path_var.path_shift = Vector3f()
-- get initial tangent
@ -1795,20 +1854,24 @@ function do_path()
end
--[[
see if this path element has a shift_y attribute
see if this path element has a shift_xy attribute
--]]
local shift_y = attrib.shift_y
if shift_y and not path_var.last_shift_y then
local shift_xy = attrib.shift_xy
if shift_xy and not path_var.last_shift_xy then
--[[
we have entered a new sub-element with a shift_y
we have entered a new sub-element with a shift_xy
--]]
local curpos_mf = quat_body_to_earth(path_var.initial_ori, current_measured_pos_ef)
local pathpos_mf = quat_body_to_earth(path_var.initial_ori, p1)
path_var.path_shift = makeVector3f(0, curpos_mf:y() - pathpos_mf:y(), 0)
p1 = p1 + path_var.path_shift
p0 = p0 + path_var.path_shift
local shift = curpos_mf - pathpos_mf
shift:z(0)
path_var.path_shift = path_var.path_shift + shift
local shift_ef = quat_earth_to_body(path_var.initial_ori, shift)
p1 = p1 + shift_ef
p0:y(p1:y())
p0:x(p1:x())
end
path_var.last_shift_y = shift_y
path_var.last_shift_xy = shift_xy
--[[
get tangents to the path