[Feature request]: Load-Based Speed Control for Robots

[mechdrive]

Before proceeding, is there an existing issue or discussion for this?

• I have done a search for similar issues and discussions.

Description

When I am running RMF simulations with robots performing delivery tasks, I want the robot speed to automatically adjust based on whether the robot is carrying a load or not, so that I can simulate more realistic robot behavior where loaded robots move slower for safety and stability, while unloaded robots can move at full speed for efficiency.
This feature will benefit:

• Simulation developers who need realistic robot behavior in their RMF simulations
• Safety researchers who want to test load-dependent robot performance
• Fleet operators who need to understand how load affects robot navigation efficiency
• System integrators who want to implement load-based speed control in real-world deployments

The feature is necessary because current RMF simulations treat all robots the same regardless of their load state, which doesn't reflect real-world robot behavior where loaded robots typically move slower for safety reasons.

Implementation Considerations

Event-Driven Load Detection (Recommended)

• Automatic detection via dispenser/ingestor state changes
• No manual intervention required
• Integrates seamlessly with existing RMF workflow
• Thread-safe and efficient

Integration Points:

• SlotcarCommon speed control system
• RMF fleet adapter for task management
• Gazebo simulation environment
• ROS 2 topic system for state monitoring

Alternatives

Technical Implementation:

• Load Detection: Monitor /dispenser_states and /ingestor_states topics
• Speed Control: Integrate with existing SlotcarCommon speed limit system
• State Management: Maintain LOADED/UNLOADED state with automatic transitions
• Configuration: Allow configurable speed reduction factor (e.g., 70% speed when loaded)

Additional information

Use Cases:

• Warehouse Automation: Robots carrying heavy items should move slower for safety
• Hospital Delivery: Medical supplies require careful handling with reduced speed
• Factory Automation: Loaded robots need to navigate more cautiously
• Research & Development: Testing load-dependent robot behavior

[mxgrey]

I think this is definitely a feature we can consider for the next generation, but the core team won't work on this for the current generation because it's currently too difficult to put user-defined conditional reactive logic into the system.

Until the next generation implementation is available, you can still choose to write your own logic to adjust the speeds of the robots based on events that are happening. The traffic schedule constantly adjusts to changes and delays that happen, so when your robot's load changes you can simply tell the robot itself to drive more slowly, and the Open-RMF traffic schedule will just constantly adjust to that slowdown. If the slowdown is very significant then there's a risk that the traffic planning will be less optimal, but I think in most cases it won't make a qualitative difference.

[mechdrive]

Can I open pr for this in the current branch, as I have implemented this feature in the Humble version