diff options
| -rw-r--r-- | advtrains/api_doc.txt | 3 | ||||
| -rw-r--r-- | advtrains/init.lua | 3 | ||||
| -rw-r--r-- | advtrains/lzb.lua | 192 | ||||
| -rw-r--r-- | advtrains/trainlogic.lua | 24 | ||||
| -rw-r--r-- | advtrains/wagons.lua | 4 | ||||
| -rw-r--r-- | advtrains_interlocking/approach.lua | 113 | ||||
| -rw-r--r-- | advtrains_interlocking/init.lua | 2 | ||||
| -rw-r--r-- | advtrains_interlocking/lzb.lua | 292 | ||||
| -rw-r--r-- | advtrains_interlocking/signal_api.lua | 4 | ||||
| -rw-r--r-- | advtrains_interlocking/tsr_rail.lua | 2 | ||||
| -rw-r--r-- | advtrains_line_automation/stoprail.lua | 2 |
11 files changed, 339 insertions, 302 deletions
diff --git a/advtrains/api_doc.txt b/advtrains/api_doc.txt index 0a2cb44..34f1beb 100644 --- a/advtrains/api_doc.txt +++ b/advtrains/api_doc.txt @@ -180,8 +180,9 @@ minetest.register_node(nodename, { ^- called when a train leaves the rail -- The following function is only in effect when interlocking is enabled: - on_train_approach = function(pos, train_id, train, index) + on_train_approach = function(pos, train_id, train, index, lzbdata) ^- called when a train is approaching this position, called exactly once for every path recalculation (which can happen at any time) ^- This is called so that if the train would start braking now, it would come to halt about(wide approx) 5 nodes before the rail. + ^- lzbdata should be ignored and nothing should be assigned to it } }) diff --git a/advtrains/init.lua b/advtrains/init.lua index 14a5a02..4e5ae90 100644 --- a/advtrains/init.lua +++ b/advtrains/init.lua @@ -25,6 +25,7 @@ local no_action=false local function reload_saves() atwarn("Restoring saved state in 1 second...") no_action=true + advtrains.lock_path_inval = false --read last save state and continue, as if server was restarted for aoi, le in pairs(minetest.luaentities) do if le.is_wagon then @@ -192,6 +193,8 @@ dofile(advtrains.modpath.."/craft_items.lua") dofile(advtrains.modpath.."/log.lua") dofile(advtrains.modpath.."/passive.lua") +dofile(advtrains.modpath.."/lzb.lua") + --load/save diff --git a/advtrains/lzb.lua b/advtrains/lzb.lua new file mode 100644 index 0000000..efbce66 --- /dev/null +++ b/advtrains/lzb.lua @@ -0,0 +1,192 @@ +-- lzb.lua +-- Enforced and/or automatic train override control, providing the on_train_approach callback + +--[[ +Documentation of train.lzb table +train.lzb = { + trav = Current index that the traverser has advanced so far + oncoming = table containing oncoming signals, in order of appearance on the path + { + pos = position of the point + idx = where this is on the path + spd = speed allowed to pass + fun = function(pos, id, train, index, speed, lzbdata) + -- Function that determines what to do on the train in the moment it drives over that point. + } +} +each step, for every item in "oncoming", we need to determine the location to start braking (+ some safety margin) +and, if we passed this point for at least one of the items, initiate brake. +When speed has dropped below, say 3, decrease the margin to zero, so that trains actually stop at the signal IP. +The spd variable and travsht need to be updated on every aspect change. it's probably best to reset everything when any aspect changes +]] + + +local params = { + BRAKE_SPACE = 10, + AWARE_ZONE = 50, + + ADD_STAND = 2.5, + ADD_SLOW = 1.5, + ADD_FAST = 7, + ZONE_ROLL = 2, + ZONE_HOLD = 5, -- added on top of ZONE_ROLL + ZONE_VSLOW = 3, -- When speed is <2, still allow accelerating + + DST_FACTOR = 1.5, + + SHUNT_SPEED_MAX = advtrains.SHUNT_SPEED_MAX, +} + +function advtrains.set_lzb_param(par, val) + if params[par] and tonumber(val) then + params[par] = tonumber(val) + else + error("Inexistant param or not a number") + end +end + + +local function look_ahead(id, train) + + local acc = advtrains.get_acceleration(train, 1) + local vel = train.velocity + local brakedst = ( -(vel*vel) / (2*acc) ) * params.DST_FACTOR + + local brake_i = advtrains.path_get_index_by_offset(train, train.index, brakedst + params.BRAKE_SPACE) + --local aware_i = advtrains.path_get_index_by_offset(train, brake_i, AWARE_ZONE) + + local lzb = train.lzb + local trav = lzb.trav + + --train.debug = lspd + + while trav <= brake_i do + trav = trav + 1 + local pos = advtrains.path_get(train, trav) + -- check offtrack + if trav > train.path_trk_f then + table.insert(lzb.oncoming, { + pos = pos, + idx = trav-1, + spd = 0, + }) + else + -- run callbacks + -- Note: those callbacks are defined in trainlogic.lua for consistency with the other node callbacks + advtrains.tnc_call_approach_callback(pos, id, train, trav, lzb.data) + + end + end + + lzb.trav = trav + +end + +--[[ +Distance needed to accelerate from v0 to v1 with constant acceleration a: + + v1 - v0 a / v1 - v0 \ 2 +s = v0 * ------- + - * | ------- | + a 2 \ a / +]] + +local function apply_control(id, train) + local lzb = train.lzb + + local i = 1 + while i<=#lzb.oncoming do + if lzb.oncoming[i].idx < train.index then + local ent = lzb.oncoming[i] + if ent.fun then + ent.fun(ent.pos, id, train, ent.idx, ent.spd, lzb.data) + end + + table.remove(lzb.oncoming, i) + else + i = i + 1 + end + end + + for i, it in ipairs(lzb.oncoming) do + local a = advtrains.get_acceleration(train, 1) --should be negative + local v0 = train.velocity + local v1 = it.spd + if v1 and v1 <= v0 then + local f = (v1-v0) / a + local s = v0*f + a*f*f/2 + + local st = s + params.ADD_SLOW + if v0 > 3 then + st = s + params.ADD_FAST + end + if v0<=0 then + st = s + params.ADD_STAND + end + + local i = advtrains.path_get_index_by_offset(train, it.idx, -st) + + --train.debug = dump({v0f=v0*f, aff=a*f*f,v0=v0, v1=v1, f=f, a=a, s=s, st=st, i=i, idx=train.index}) + if i <= train.index then + -- Gotcha! Braking... + train.ctrl.lzb = 1 + --train.debug = train.debug .. "BRAKE!!!" + return + end + + i = advtrains.path_get_index_by_offset(train, i, -params.ZONE_ROLL) + if i <= train.index and v0>1 then + -- roll control + train.ctrl.lzb = 2 + return + end + i = advtrains.path_get_index_by_offset(train, i, -params.ZONE_HOLD) + if i <= train.index and v0>1 then + -- hold speed + train.ctrl.lzb = 3 + return + end + end + end + train.ctrl.lzb = nil +end + +local function invalidate(train) + train.lzb = { + trav = atfloor(train.index), + data = {}, + oncoming = {}, + } +end + +function advtrains.lzb_invalidate(train) + invalidate(train) +end + +-- Add LZB control point +-- udata: User-defined additional data +function advtrains.lzb_add_checkpoint(train, index, speed, callback, udata) + local lzb = train.lzb + local pos = advtrains.path_get(train, index) + table.insert(lzb.oncoming, { + pos = pos, + idx = index, + spd = speed, + fun = callback, + data = udata, + }) +end + + +advtrains.te_register_on_new_path(function(id, train) + invalidate(train) + look_ahead(id, train) +end) + +advtrains.te_register_on_update(function(id, train) + if not train.path or not train.lzb then + atprint("LZB run: no path on train, skip step") + return + end + look_ahead(id, train) + apply_control(id, train) +end, true) diff --git a/advtrains/trainlogic.lua b/advtrains/trainlogic.lua index 523e51d..ce9ec8b 100644 --- a/advtrains/trainlogic.lua +++ b/advtrains/trainlogic.lua @@ -585,9 +585,9 @@ local function mknodecallback(name) table.insert(callt, func) end end - return callt, function(pos, id, train, index) + return callt, function(pos, id, train, index, paramx1, paramx2, paramx3) for _,f in ipairs(callt) do - f(pos, id, train, index) + f(pos, id, train, index, paramx1, paramx2, paramx3) end end end @@ -597,6 +597,14 @@ end local callbacks_enter_node, run_callbacks_enter_node = mknodecallback("enter") local callbacks_leave_node, run_callbacks_leave_node = mknodecallback("leave") +-- Node callback for approaching +-- Might be called multiple times, whenever path is recalculated +-- signature is function(pos, id, train, index, lzbdata) +-- lzbdata: arbitrary data (shared between all callbacks), deleted when LZB is restarted. +-- These callbacks are called in order of distance as train progresses along tracks, so lzbdata can be used to +-- keep track of a train's state once it passes this point +local callbacks_approach_node, run_callbacks_approach_node = mknodecallback("approach") + local function tnc_call_enter_callback(pos, train_id, train, index) --atdebug("tnc enter",pos,train_id) @@ -621,6 +629,18 @@ local function tnc_call_leave_callback(pos, train_id, train, index) run_callbacks_leave_node(pos, train_id, train, index) end +function advtrains.tnc_call_approach_callback(pos, train_id, train, index, lzbdata) + --atdebug("tnc approach",pos,train_id, lzbdata) + local node = advtrains.ndb.get_node(pos) --this spares the check if node is nil, it has a name in any case + local mregnode=minetest.registered_nodes[node.name] + if mregnode and mregnode.advtrains and mregnode.advtrains.on_train_approach then + mregnode.advtrains.on_train_approach(pos, train_id, train, index, lzbdata) + end + + -- call other registered callbacks + run_callbacks_approach_node(pos, train_id, train, index, lzbdata) +end + advtrains.te_register_on_new_path(function(id, train) train.tnc = { diff --git a/advtrains/wagons.lua b/advtrains/wagons.lua index 5b15c70..381f835 100644 --- a/advtrains/wagons.lua +++ b/advtrains/wagons.lua @@ -846,8 +846,8 @@ function wagon:show_bordcom(pname) local i=1
while train.lzb.oncoming[i] do
local oci = train.lzb.oncoming[i]
- if oci.pos then
- if advtrains.interlocking.db.get_sigd_for_signal(oci.pos) then
+ if oci.udata and oci.udata.signal_pos then
+ if advtrains.interlocking.db.get_sigd_for_signal(oci.udata.signal_pos) then
form = form .. "button[4.5,8;5,1;ilrs;Remote Routesetting]"
break
end
diff --git a/advtrains_interlocking/approach.lua b/advtrains_interlocking/approach.lua new file mode 100644 index 0000000..630ebfe --- /dev/null +++ b/advtrains_interlocking/approach.lua @@ -0,0 +1,113 @@ +-- Interlocking counterpart of LZB, which has been moved into the core... +-- Registers LZB callback for signal management. + +--[[ +usage of lzbdata: +{ + travsht = boolean indicating whether the train will be a shunt move at "trav" + travspd = speed restriction at end of traverser + travwspd = warning speed res.t +} +]] + +local SHUNT_SPEED_MAX = advtrains.SHUNT_SPEED_MAX + +local il = advtrains.interlocking + +local function get_over_function(speed, shunt) + return function(pos, id, train, index, speed, lzbdata) + if speed == 0 and minetest.settings:get_bool("at_il_force_lzb_halt") then + atwarn(id,"overrun LZB 0 restriction (red signal) ",ent.pos) + -- Set train 1 index backward. Hope this does not lead to bugs... + train.index = index - 0.5 + train.velocity = 0 + train.ctrl.lzb = 0 + minetest.after(0, advtrains.invalidate_path, id) + else + train.speed_restriction = speed + train.is_shunt = shunt + end + end +end + +advtrains.tnc_register_on_approach(function(pos, id, train, index, lzbdata) + + --atdebug(id,"IL ApprC",pos,index,lzbdata) + --train.debug = advtrains.print_concat_table({train.is_shunt,"|",index,"|",lzbdata}) + + local pts = advtrains.roundfloorpts(pos) + local cn = train.path_cn[index] + local travsht = lzbdata.travsht + + if travsht==nil then + travsht = train.is_shunt + end + + local travspd = lzbdata.travspd + local travwspd = lzbdata.travwspd + + -- check for signal + local asp, spos = il.db.get_ip_signal_asp(pts, cn) + + -- do ARS if needed + if spos then + --atdebug(id,"IL Spos (ARS)",spos,asp) + local sigd = il.db.get_sigd_for_signal(spos) + if sigd then + il.ars_check(sigd, train) + end + end + --atdebug("trav: ",pos, cn, asp, spos, "travsht=", lzb.travsht) + local lspd + if asp then + --atdebug(id,"IL Signal",spos,asp) + local nspd = 0 + --interpreting aspect and determining speed to proceed + if travsht then + --shunt move + if asp.shunt.free then + nspd = SHUNT_SPEED_MAX + elseif asp.shunt.proceed_as_main and asp.main.free then + nspd = asp.main.speed + travsht = false + end + else + --train move + if asp.main.free then + nspd = asp.main.speed + elseif asp.shunt.free then + nspd = SHUNT_SPEED_MAX + travsht = true + end + end + -- nspd can now be: 1. !=0: new speed restriction, 2. =0: stop here or 3. nil: keep travspd + if nspd then + if nspd == -1 then + travspd = nil + else + travspd = nspd + end + end + + local nwspd = asp.info.w_speed + if nwspd then + if nwspd == -1 then + travwspd = nil + else + travwspd = nwspd + end + end + --atdebug("ns,wns,ts,wts", nspd, nwspd, travspd, travwspd) + lspd = travspd + if travwspd and (not lspd or lspd>travwspd) then + lspd = travwspd + end + + local udata = {signal_pos = spos} + local callback = get_over_function(lspd, travsht) + advtrains.lzb_add_checkpoint(train, index, lspd, callback) + end + lzbdata.travsht = travsht + lzbdata.travspd = travspd + lzbdata.travwspd = travwspd +end) diff --git a/advtrains_interlocking/init.lua b/advtrains_interlocking/init.lua index 37f962b..a2f5882 100644 --- a/advtrains_interlocking/init.lua +++ b/advtrains_interlocking/init.lua @@ -22,7 +22,7 @@ dofile(modpath.."tcb_ts_ui.lua") dofile(modpath.."route_ui.lua") dofile(modpath.."tool.lua") -dofile(modpath.."lzb.lua") +dofile(modpath.."approach.lua") dofile(modpath.."ars.lua") dofile(modpath.."tsr_rail.lua") diff --git a/advtrains_interlocking/lzb.lua b/advtrains_interlocking/lzb.lua deleted file mode 100644 index 8541525..0000000 --- a/advtrains_interlocking/lzb.lua +++ /dev/null @@ -1,292 +0,0 @@ --- lzb.lua --- Enforced and/or automatic train override control, obeying signals - -local function approach_callback(parpos, train_id, train, index) - local pos = advtrains.round_vector_floor_y(parpos) - - local node=pnode or advtrains.ndb.get_node(pos) - local ndef=minetest.registered_nodes[node.name] - if ndef and ndef.advtrains and ndef.advtrains.on_train_approach then - ndef.advtrains.on_train_approach(pos, train_id, train, index) - end -end - - ---[[ -Documentation of train.lzb table -train.lzb = { - trav = Current index that the traverser has advanced so far - travsht = boolean indicating whether the train will be a shunt move at "trav" - travspd = speed restriction at end of traverser - travwspd = warning speed res.t - oncoming = table containing oncoming signals, in order of appearance on the path - { - pos = position of the signal (not the IP!). Can be nil - idx = where this is on the path - spd = speed allowed to pass (determined dynamically) - npr = <boolean> "No permanent restriction" If true, this is only a punctual restriction. - speed_restriction is not set then, and train can accelerate after passing point - This is (as of Nov 2017) used by "lines" to brake the train down to 2 when approaching a stop - The actual "stop" command is given when the train passes the rail (on_train_enter callback) - } -} -each step, for every item in "oncoming", we need to determine the location to start braking (+ some safety margin) -and, if we passed this point for at least one of the items, initiate brake. -When speed has dropped below, say 3, decrease the margin to zero, so that trains actually stop at the signal IP. -The spd variable and travsht need to be updated on every aspect change. it's probably best to reset everything when any aspect changes - -The traverser stops at signals that result in spd==0, because changes beyond there are likely. -]] - -local il = advtrains.interlocking - -local params = { - BRAKE_SPACE = 10, - AWARE_ZONE = 50, - - ADD_STAND = 2.5, - ADD_SLOW = 1.5, - ADD_FAST = 7, - ZONE_ROLL = 2, - ZONE_HOLD = 5, -- added on top of ZONE_ROLL - ZONE_VSLOW = 3, -- When speed is <2, still allow accelerating - - DST_FACTOR = 1.5, - - SHUNT_SPEED_MAX = advtrains.SHUNT_SPEED_MAX, -} - -function advtrains.interlocking.set_lzb_param(par, val) - if params[par] and tonumber(val) then - params[par] = tonumber(val) - else - error("Inexistant param or not a number") - end -end - - -local function look_ahead(id, train) - - local acc = advtrains.get_acceleration(train, 1) - local vel = train.velocity - local brakedst = ( -(vel*vel) / (2*acc) ) * params.DST_FACTOR - - local brake_i = advtrains.path_get_index_by_offset(train, train.index, brakedst + params.BRAKE_SPACE) - --local aware_i = advtrains.path_get_index_by_offset(train, brake_i, AWARE_ZONE) - - local lzb = train.lzb - local trav = lzb.trav - local travspd = lzb.travspd - local travwspd = lzb.travwspd - local lspd - - --train.debug = lspd - - while trav <= brake_i and (not lspd or lspd>0) do - trav = trav + 1 - local pos = advtrains.path_get(train, trav) - local pts = advtrains.roundfloorpts(pos) - local cn = train.path_cn[trav] - -- check offtrack - if trav > train.path_trk_f then - lspd = 0 - table.insert(lzb.oncoming, { - idx = trav-1, - spd = 0, - }) - else - -- run callback, if exists - approach_callback(pos, id, train, trav) - - -- check for signal - local asp, spos = il.db.get_ip_signal_asp(pts, cn) - - -- do ARS if needed - if spos then - local sigd = il.db.get_sigd_for_signal(spos) - if sigd then - il.ars_check(sigd, train) - end - end - --atdebug("trav: ",pos, cn, asp, spos, "travsht=", lzb.travsht) - if asp then - local nspd = 0 - --interpreting aspect and determining speed to proceed - if lzb.travsht then - --shunt move - if asp.shunt.free then - nspd = params.SHUNT_SPEED_MAX - elseif asp.shunt.proceed_as_main and asp.main.free then - nspd = asp.main.speed - lzb.travsht = false - end - else - --train move - if asp.main.free then - nspd = asp.main.speed - elseif asp.shunt.free then - nspd = params.SHUNT_SPEED_MAX - lzb.travsht = true - end - end - -- nspd can now be: 1. !=0: new speed restriction, 2. =0: stop here or 3. nil: keep travspd - if nspd then - if nspd == -1 then - travspd = nil - else - travspd = nspd - end - end - - local nwspd = asp.info.w_speed - if nwspd then - if nwspd == -1 then - travwspd = nil - else - travwspd = nwspd - end - end - --atdebug("ns,wns,ts,wts", nspd, nwspd, travspd, travwspd) - lspd = travspd - if travwspd and (not lspd or lspd>travwspd) then - lspd = travwspd - end - - table.insert(lzb.oncoming, { - pos = spos, - idx = trav, - spd = lspd, - sht = lzb.travsht, - }) - end - end - end - - lzb.trav = trav - lzb.travspd = travspd - lzb.travwspd = travwspd - - --train.debug = dump(lzb) - -end - ---[[ -Distance needed to accelerate from v0 to v1 with constant acceleration a: - - v1 - v0 a / v1 - v0 \ 2 -s = v0 * ------- + - * | ------- | - a 2 \ a / -]] - -local function apply_control(id, train) - local lzb = train.lzb - - local i = 1 - while i<=#lzb.oncoming do - if lzb.oncoming[i].idx < train.index then - local ent = lzb.oncoming[i] - local nodelete - if not ent.npr then - if ent.spd == 0 and minetest.settings:get_bool("at_il_force_lzb_halt") then - atwarn(train.id,"overrun LZB 0 restriction (red signal) ",ent.pos) - -- Set train 1 index backward. Hope this does not lead to bugs... - train.index = ent.idx - 0.5 - train.velocity = 0 - train.ctrl.lzb = 0 - nodelete = true - else - train.speed_restriction = ent.spd - train.is_shunt = ent.sht - end - end - if not nodelete then - table.remove(lzb.oncoming, i) - end - else - i = i + 1 - end - end - - for i, it in ipairs(lzb.oncoming) do - local a = advtrains.get_acceleration(train, 1) --should be negative - local v0 = train.velocity - local v1 = it.spd - if v1 and v1 <= v0 then - local f = (v1-v0) / a - local s = v0*f + a*f*f/2 - - local st = s + params.ADD_SLOW - if v0 > 3 then - st = s + params.ADD_FAST - end - if v0<=0 then - st = s + params.ADD_STAND - end - - local i = advtrains.path_get_index_by_offset(train, it.idx, -st) - - --train.debug = dump({v0f=v0*f, aff=a*f*f,v0=v0, v1=v1, f=f, a=a, s=s, st=st, i=i, idx=train.index}) - if i <= train.index then - -- Gotcha! Braking... - train.ctrl.lzb = 1 - --train.debug = train.debug .. "BRAKE!!!" - return - end - - i = advtrains.path_get_index_by_offset(train, i, -params.ZONE_ROLL) - if i <= train.index and v0>1 then - -- roll control - train.ctrl.lzb = 2 - return - end - i = advtrains.path_get_index_by_offset(train, i, -params.ZONE_HOLD) - if i <= train.index and v0>1 then - -- hold speed - train.ctrl.lzb = 3 - return - end - end - end - train.ctrl.lzb = nil -end - -local function invalidate(train) - train.lzb = { - trav = atfloor(train.index), - travsht = train.is_shunt, - oncoming = {} - } - -- possible FIX: do not clear LZB control when invalidating. This will be cleared when apply_control is run next time - --train.ctrl.lzb = nil -end - -function advtrains.interlocking.lzb_invalidate(train) - invalidate(train) -end - --- Add an (extra) lzb control point that is not a permanent restriction (see above) --- (permanent restrictions are only to be imposed by signal ip's) -function advtrains.interlocking.lzb_add_oncoming_npr(train, idx, spd) - local lzb = train.lzb - - table.insert(lzb.oncoming, { - idx = idx, - spd = spd, - npr = true, - }) -end - - -advtrains.te_register_on_new_path(function(id, train) - invalidate(train) - look_ahead(id, train) -end) - -advtrains.te_register_on_update(function(id, train) - if not train.path or not train.lzb then - atprint("LZB run: no path on train, skip step") - return - end - look_ahead(id, train) - apply_control(id, train) -end, true) diff --git a/advtrains_interlocking/signal_api.lua b/advtrains_interlocking/signal_api.lua index d43125b..90bfaf4 100644 --- a/advtrains_interlocking/signal_api.lua +++ b/advtrains_interlocking/signal_api.lua @@ -226,9 +226,9 @@ function advtrains.interlocking.signal_on_aspect_changed(pos) local tns = advtrains.occ.get_trains_over(ipos) for id, sidx in pairs(tns) do - local train = advtrains.trains[id] +-- local train = advtrains.trains[id] --if train.index <= sidx then - advtrains.interlocking.lzb_invalidate(train) + minetest.after(0, advtrains.invalidate_path, id) --end end end diff --git a/advtrains_interlocking/tsr_rail.lua b/advtrains_interlocking/tsr_rail.lua index 90e8101..89da290 100644 --- a/advtrains_interlocking/tsr_rail.lua +++ b/advtrains_interlocking/tsr_rail.lua @@ -34,7 +34,7 @@ local adefunc = function(def, preset, suffix, rotation) if train.path_cn[index] == 1 then local pe = advtrains.encode_pos(pos) local npr = advtrains.interlocking.npr_rails[pe] or 2 - advtrains.interlocking.lzb_add_oncoming_npr(train, index, npr) + advtrains.lzb_add_checkpoint(train, index, npr, nil) end end, }, diff --git a/advtrains_line_automation/stoprail.lua b/advtrains_line_automation/stoprail.lua index 2e6072e..e955d76 100644 --- a/advtrains_line_automation/stoprail.lua +++ b/advtrains_line_automation/stoprail.lua @@ -151,7 +151,7 @@ local adefunc = function(def, preset, suffix, rotation) stdata.ars = {default=true} end if stdata.ars and (stdata.ars.default or advtrains.interlocking.ars_check_rule_match(stdata.ars, train) ) then - advtrains.interlocking.lzb_add_oncoming_npr(train, index, 2) + advtrains.lzb_add_checkpoint(train, index, 2, nil) local stn = advtrains.lines.stations[stdata.stn] local stnname = stn and stn.name or "Unknown Station" train.text_inside = "Next Stop:\n"..stnname |