Set explicit ArduSub simulation speedup

[yeseorizi]

Summary

Pass an explicit --speedup 1 argument when DAVE starts ArduSub for all three BlueROV2 configurations.

Problem

In the tested ARM64 SITL build, starting ardusub without an explicit speedup left SIM_SPEEDUP at -1. After Gazebo JSON sensor input started, ArduSub terminated with SIGFPE in AP_Logger_File::periodic_1Hz().

GDB placed the exception in the logger path. The relevant ArduPilot code multiplies an unsigned timeout by the SITL speedup value, so the negative default creates an invalid boundary in this environment.

Thread 1 "ardusub" received signal SIGFPE, Arithmetic exception.
AP_Logger_File::periodic_1Hz()

Change

Add the explicit real-time speed factor to the existing ArduSub command:

ardusub --speedup 1 ...

The change is applied consistently to:

• bluerov2
• bluerov2_heavy
• bluerov2_heavy_multibeam_sonar

No vehicle parameters, controller settings, or bridge interfaces are changed.

Reproduction

Launch any of the BlueROV2 variants with ArduSub enabled and wait for the Gazebo JSON connection:

ros2 launch dave_demos dave_robot.launch.py \
  namespace:=bluerov2 world_name:=dave_ocean_waves \
  paused:=false gui:=true headless:=true use_ardusub:=true

The reproduced baseline received JSON sensor data and then raised SIGFPE in the ArduSub logger.

Validation

The candidate was installed into the DAVE ARM64 Docker environment with ROS 2 Lyrical and Gazebo Jetty. Each BlueROV2 variant completed one bounded headless control run:

Variant	JSON input	MAVROS samples	Armed	6 s control response	Disarmed	ArduSub FPE
bluerov2	PASS	4/4 connected	PASS	+1.698 m X	PASS	0
bluerov2_heavy	PASS	4/4 connected	PASS	+1.126 m X	PASS	0
bluerov2_heavy_multibeam_sonar	PASS	4/4 connected	PASS	+0.819 m X	PASS	0

These results establish the simulated JSON/MAVROS/control connection in the tested environment. They do not establish controller tuning, physical safety, or real-vehicle accuracy.

Repository checks:

python3 -m py_compile \
  models/dave_robot_models/config/bluerov2/robot_config.py \
  models/dave_robot_models/config/bluerov2_heavy/robot_config.py \
  models/dave_robot_models/config/bluerov2_heavy_multibeam_sonar/robot_config.py

pre-commit run --files <the three robot_config.py files>
# Passed

git diff --check
# Passed

Checklist

• The change is limited to the ArduSub speedup argument.
• All three modified Python files compile.
• All three BlueROV2 variants completed a bounded control run.
• Repository hooks passed.