SITL: Add script for multi-vehicle sim with AirSim

libraries/SITL/examples/Airsim/follow-copter.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+
+# assume we start the script from the root directory
+ROOTDIR=$PWD
+COPTER=$ROOTDIR/build/sitl/bin/arducopter
+
+GCS_IP=$1
+
+BASE_DEFAULTS="$ROOTDIR/Tools/autotest/default_params/copter.parm,$ROOTDIR/libraries/SITL/examples/Airsim/quadX.parm"
+
+[ -x "$COPTER" ] || {
+	./waf configure --board sitl
+	./waf copter
+}
+
+# start up main rover in the current directory
+$COPTER --model airsim-copter --uartA udpclient:$GCS_IP --uartC mcast: --defaults $BASE_DEFAULTS &
+
+# now start another copter to follow the first, using
+# a separate directory to keep the eeprom.bin and logs separate
+# for increasing the number of copters, change the number in seq
+for i in $(seq 1); do
+    echo "Starting copter $i"
+    mkdir -p copter$i
+
+    SYSID=$(expr $i + 1)
+    FOLL_SYSID=$(expr $SYSID - 1)
+
+    # create default parameter file for the follower
+    cat <<EOF > copter$i/follow.parm
+SYSID_THISMAV $SYSID
+FOLL_ENABLE 1
+FOLL_OFS_X -5
+FOLL_OFS_TYPE 1
+FOLL_SYSID $FOLL_SYSID
+FOLL_DIST_MAX 1000
+EOF
+    pushd copter$i
+    $COPTER --model airsim-copter --uartA tcp:0 --uartC mcast: --instance $i --defaults $BASE_DEFAULTS,follow.parm &
+    popd
+done
+wait