如何获取路口'type'字段？eSBR/NJL广播的路口过滤需求

Hey there! Let me walk you through practical, actionable options to solve your problem of filtering out unregulated junctions (especially vehicle generation points) for your eSBR/NJL implementation:

Option 1: Directly Use TraCI Commands in Veins #

Since Veins relies on TraCI to communicate with SUMO, you can directly send SUMO's CMD_GET_JUNCTION_VARIABLE request to fetch the junction type. Here's how to implement this in your Veins module:

First, a simplified approach using Veins' existing helper methods:

// Inside your Veins application/RSU module
TraCICommandInterface* traci = getParentModule()->getSubmodule("traci")->get<TraCICommandInterface*>();

for (const std::string& junctionId : yourJunctionList) {
    TraCICommandInterface::Junction traciJunction(traci, junctionId);
    // Fetch the junction type via SUMO's attribute
    std::string junctionType = traciJunction.getParameter("type");
    
    // Skip unregulated junctions
    if (junctionType == "unregulated") {
        continue;
    }
    // Add valid junction to your filtered list
    filteredJunctions.push_back(junctionId);
}

If the getParameter method doesn't directly retrieve the type attribute, use low-level TraCI commands for more control:

// Define the TraCI constant if not already available
const uint8_t SUMO_JUNCTION_TYPE = 0x12; 

for (const std::string& junctionId : yourJunctionList) {
    std::string type = traci->genericGetCommand<std::string>(CMD_GET_JUNCTION_VARIABLE, junctionId, SUMO_JUNCTION_TYPE);
    if (type != "unregulated") {
        filteredJunctions.push_back(junctionId);
    }
}

Option 2: Preprocess Your SUMO Road Network #

If your unregulated junctions don't change during simulation, preprocessing your .net.xml file is a more efficient option:

• Manually remove unregulated junctions that act as vehicle generation points from the network file
• Add a custom attribute (e.g., <param key="isVehicleGenerator" value="true"/>) to target junctions, then use Veins' getParameter method to check this flag at runtime.

This avoids repeated TraCI calls and speeds up your simulation.

Option 3: Extend Veins' TraCI Interface for Reusability #

If you need this functionality across multiple modules, extend Veins' TraCICommandInterface::Junction class to add a dedicated getType() method:

1. In TraCICommandInterfaceJunction.h, add the method declaration:

std::string getType() const;

2. In TraCICommandInterfaceJunction.cc, implement it with TraCI commands:

std::string TraCICommandInterface::Junction::getType() const {
    const uint8_t SUMO_JUNCTION_TYPE = 0x12;
    return traci->genericGetCommand<std::string>(CMD_GET_JUNCTION_VARIABLE, id, SUMO_JUNCTION_TYPE);
}

Now you can cleanly call junction.getType() anywhere in your code to filter junctions.

Quick Tips #

• Double-check TraCI constants (like SUMO_JUNCTION_TYPE) – you may need to include SUMO's TraCI headers or define them in your Veins project.
• For vehicle generation points, you might also want to cross-verify if a junction is linked to SUMO flow or route elements, in addition to checking the unregulated type.

内容的提问来源于stack exchange，提问作者browser-bug