-- idle_control.lua: a closed loop control throttle control while on ground idle (trad-heli) local PARAM_TABLE_KEY = 73 local PARAM_TABLE_PREFIX = 'IDLE_' assert(param:add_table(PARAM_TABLE_KEY, PARAM_TABLE_PREFIX, 30), 'could not add param table') function bind_add_param(name, idx, default_value) assert(param:add_param(PARAM_TABLE_KEY, idx, name, default_value), string.format('could not add param %s', name)) return Parameter(PARAM_TABLE_PREFIX .. name) end -- parameters for idle control IDLE_GAIN_I = bind_add_param('GAIN_I', 1, 0.05) IDLE_GAIN_P = bind_add_param('GAIN_P', 2, 0.25) IDLE_GAIN_MAX = bind_add_param('GAIN_MAX', 3, 1) IDLE_MAX = bind_add_param('MAX', 4, 17) IDLE_RANGE = bind_add_param('RANGE', 5, 300) IDLE_SETPOINT = bind_add_param('SETPOINT', 6, 600) IDLE_RPM_ENABLE = bind_add_param('RPM_ENABLE', 7, 0) -- internal variables local thr_out = nil local idle_control_active = false local idle_control_active_last = false local last_scaled_output = nil local idle_default = nil local ramp_up_complete = false local idle_adjusted = false local last_idc_time = nil local time_now = nil local pv = nil local thr_ctl = nil local thr_out_last = nil local pot_input = rc:find_channel_for_option(301) local switch_rsc = rc:find_channel_for_option(32) local rsc_output = SRV_Channels:find_channel(31) local SERVO_MAX = Parameter('SERVO' .. (rsc_output+1) .. '_MAX') local SERVO_MIN = Parameter('SERVO' .. (rsc_output+1) .. '_MIN') local SERVO_REV = Parameter('SERVO' .. (rsc_output+1) .. '_REVERSED') local servo_range = SERVO_MAX:get() - SERVO_MIN:get() local H_RSC_IDLE = Parameter('H_RSC_IDLE') local H_RSC_RUNUP_TIME = Parameter('H_RSC_RUNUP_TIME') -- map function function map(x, in_min, in_max, out_min, out_max) return out_min + (x - in_min)*(out_max - out_min)/(in_max - in_min) end -- constrain function local function constrain(v, vmin, vmax) if v < vmin then v = vmin end if v > vmax then v = vmax end return v end -- PI controller function local function PI_controller(kP,kI,iMax,min,max) local self = {} local _kP = kP local _kI = kI local _iMax = iMax local _min = min local _max = max local _last_t = nil local _I = 0 local _total = 0 local _counter = 0 function self.update(target, current) local now = millis() if not _last_t then _last_t = now end local dt = (now - _last_t):tofloat()*0.001 _last_t = now local err = target - current _counter = _counter + 1 local P = _kP:get() * err if ((_total < _max and _total > _min) or (_total >= _max and err < 0) or (_total <= _min and err > 0)) then _I = _I + _kI:get() * err * dt end if _iMax:get() > 0 then _I = constrain(_I, -_iMax:get(), iMax:get()) end local ret = P + _I _total = ret return ret end function self.reset(integrator) _I = integrator end return self end local thr_PI = PI_controller(IDLE_GAIN_P, IDLE_GAIN_I, IDLE_GAIN_MAX, 0, 1) -- main update function function update() local armed = arming:is_armed() -- aux potentiometer for manual adjusting of idle local pot_pos = pot_input:norm_input() local thr_man = map(pot_pos,-1,1,0,1) if armed == false then idle_default = H_RSC_IDLE:get() idle_control_active = false ramp_up_complete = false idle_adjusted = false thr_PI.reset(0) else if switch_rsc:get_aux_switch_pos() == 0 and vehicle:get_likely_flying() == false then if H_RSC_IDLE:get()~= idle_default then H_RSC_IDLE:set(idle_default) gcs:send_text(5, "H_RSC_IDLE set to:".. tostring(H_RSC_IDLE:get())) end if IDLE_RPM_ENABLE:get() == 0 then ramp_up_complete = false idle_adjusted = false thr_out = H_RSC_IDLE:get() + thr_man*(IDLE_MAX:get() - H_RSC_IDLE:get()) else if thr_man == 0 then idle_control_active = false if idle_control_active_last ~= idle_control_active then gcs:send_text(5, "idle control: OFF") end thr_out = H_RSC_IDLE:get() thr_ctl = 0 thr_PI.reset(0) else local rpm_current = RPM:get_rpm((IDLE_RPM_ENABLE:get())-1) ramp_up_complete = false idle_adjusted = false if rpm_current < (IDLE_SETPOINT:get() - IDLE_RANGE:get()) then thr_out = H_RSC_IDLE:get() + thr_man*(IDLE_MAX:get() - H_RSC_IDLE:get()) thr_out_last = thr_out elseif rpm_current > (IDLE_SETPOINT:get() + IDLE_RANGE:get()) then thr_out = H_RSC_IDLE:get() thr_out_last = thr_out else -- throttle output set from the PI controller pv = rpm_current/(IDLE_SETPOINT:get()) thr_ctl = thr_PI.update(1, pv) thr_ctl = constrain(thr_ctl,0,1) thr_out = H_RSC_IDLE:get() + thr_ctl*(IDLE_MAX:get() - H_RSC_IDLE:get()) if thr_out_last == nil then thr_out_last = 0 end thr_out = constrain(thr_out, thr_out_last-0.05, thr_out_last+0.05) thr_out_last = thr_out idle_control_active = true end if idle_control_active_last ~= idle_control_active then gcs:send_text(5, "idle control: ON") end end end last_idc_time = millis() last_scaled_output = thr_out/100 if SERVO_REV:get() == 0 then SRV_Channels:set_output_pwm_chan_timeout(rsc_output, math.floor((last_scaled_output*servo_range)+SERVO_MIN:get()), 150) else SRV_Channels:set_output_pwm_chan_timeout(rsc_output, math.floor(SERVO_MAX:get()-(last_scaled_output*servo_range)), 150) end else -- motor interlock disabled, armed state, flight idle_control_active = false if idle_control_active_last ~= idle_control_active then gcs:send_text(5, "idle control: deactivated") end if ramp_up_complete ~= true then time_now = millis() if ((time_now-last_idc_time):tofloat()*0.001) < H_RSC_RUNUP_TIME:get() then if idle_adjusted ~= true then H_RSC_IDLE:set(last_scaled_output*100) idle_adjusted = true gcs:send_text(5, "H_RSC_IDLE updated for ramp up:".. tostring(H_RSC_IDLE:get())) end else if H_RSC_IDLE:get()~= idle_default then H_RSC_IDLE:set(idle_default) gcs:send_text(5, "H_RSC_IDLE default restored:".. tostring(H_RSC_IDLE:get())) end ramp_up_complete = true end end end -- update notify variable idle_control_active_last = idle_control_active end return update, 100 -- 10Hz rate end gcs:send_text(5, "idle_control_running") return update()