F1TENTH autonomous grand prix (ICRA'23 London) - ForzaETH

Launching in ICRA STACK

Launch headtohead with spliner:

roslaunch stack_master headtohead.launch LU_table:=NUCX_hangar_pacejka overtake_mode:=spliner od_mode:=sami

After successful launch, you should see the following messages in the command line:

• [OBS PSpliner] Waiting for messages and services...
• [Planner] Dynamic Spline Server Launched...
• [OBS PSpliner] Ready!

Dnyamic Reconfigurable State Machine Parameter Overview

Launch rqt and go into dynamic_statemachine_server

Parameters

• lateral_width_gb_m: the distance in [m] at which the statemachine considers an obstacle to be blocking the global trajectory.
• lateral_width_ot_m: the distance in [m] at which the statemachine considers an obstacle to be blocking the overtaking trajectory.
• splini_hyst_timer_sec: hysterisis time in [s] from which the statemachine waits until an overtake state can be entered again.
• splini_ttl time to live in [s] that caches the last splines s.t. we finish driving the spline even when switching to trailing state.
• ftg_speed_mps: threshold speed in [m/s] at which FTG is triggered to overtake with FTG when in a trailing zone and we are blocked.
• ftg_timer_sec: time to await in [s] until we enter FTG.
• ftg_active: flag to activate the FTG based overtake.

Dnyamic Reconfigurable Spliner Parameter Overview

Launch rqt and go into dynamic_spliner_tuner_node

Parameters

• evasion_dist: the apex distance of the spline in [m].
• obs_traj_tresh: the threshold in [m] at which spliner considers obstacles, orthogonal to the raceline.
• spline_bound_mindist: minimum distance in [m] that the spline must be distanced to the track boundaries. If a single point of the spline is closer to the boundaries than the treshold, then the spline is aborted.
• pre_apex_distX: spline point that is infront of the apex. The spline consists of 7 points in frenet space. the further the distX params are set, the smoother the trajectory.
• post_apex_distX: spline point that is behind of the apex. You might want to have an asymetric spline, to cut off the opponent.
• kd_obs_pred: the gain parameter at which we propagate the d of the opponent back to the raceline.
• fixed_pred_time: the time in [s] at which we forward propagate the opponent linearly.

Troubleshooting

No spline found

Lower the evasion_dist and the spline_bound_mindist but keep in mind that collisions are more likely.

Our opponent cuts our raceline

Increase the lateral_width_gb_m and obs_traj_tresh. Optionally you can also increase the motion prediction by increasing the propagation time fixed_pred_time.

These three params are dependant on the opponents behaviour:

• If the opponent has a similar raceline as us in the overtaking zones, then the params are not that important.
• If it is parallel to our raceline the lateral_width_gb_m and obs_traj_tresh should be larger than the distance of the racelines.
• If it cuts our raceline in a shallow angle the lateral_width_gb_m and obs_traj_tresh should be chosen very large as well as higher motion propagation fixed_pred_time. However if we assume the opponent will overshoot after cutting our raceline, then a low lateral_width_gb_m will let us go into global trajectory tracking state quickly (once the opponent has overshot).

In a non overtaking zone with an obstacle we are trapped

• Enable ftg in statemachine

We don't seem to be using spliner waypoints fast enough

• Set down the splini_hyst_timer_sec

Ghost splines come up

• When we have a very short circuit, splines of the previous lap can still be cached. Hence set down splini_ttl.

---

Go back to the checklist index