计算当前车辆与前车之间的距离

Question

我需要计算当前车辆与前面车辆之间的距离，对于流中的每辆车，运行在边上。

在使用 TraCI 时，我遇到了 getLeader 方法，该方法应该 return 领导者的 ID 和我需要的距离。

但我找不到使用此名称的已实现方法，或在 Overview Extended Variables Retrieval 下列出的任何其他方法，这些方法是在 TraCI 中用 C++ 编写的。

如果有人能帮助我，我将不胜感激。

我成功实施了 getLastStepVehicleIDs to retrieve values from induction loops as advised here。我遵循了相同类型的已实现方法（例如 getJunctionIds），但在这种情况下找不到此类已实现的方法。

Answer 1

TraCICommandInterface.cc中有很多函数可以借鉴。如果不进行测试，实现可能如下所示

std::pair<std:string, double> TraCICommandInterface::getLeader(const double lookahead) {
    TraCIBuffer request;
    request << static_cast<uint8_t>(VAR_LEADER) << nodeId
                    << static_cast<uint8_t>(TYPE_DOUBLE) << lookahead;
    TraCIBuffer response = connection.query(CMD_GET_VEHICLE_VARIABLE, request);

    uint8_t cmdLength; response >> cmdLength;
    if (cmdLength == 0) {
            uint32_t cmdLengthX;
            response >> cmdLengthX;
    }
    uint8_t responseId; response >> responseId;
    ASSERT(responseId == RESPONSE_GET_VEHICLE_VARIABLE);
    uint8_t variable; response >> variable;
    ASSERT(variable == VAR_LEADER);
    std::string id; response >> id;
    uint8_t typeId_r; response >> typeId_r; ASSERT(typeId_r == TYPE_COMPOUND);
    uint32_t compoundLength; response >> compoundLength; ASSERT(compoundLength == 2);
    uint8_t typeId_resp; response >> typeId_resp; ASSERT(typeId_resp == TYPE_STRING);
    std::string leader; response >> leader;
    uint8_t typeId_resp2; response >> typeId_resp2; ASSERT(typeId_resp2 == TYPE_DOUBLE);
    double dist; response >> dist;

    return std::make_pair(leader, dist);
}

计算当前车辆与前车之间的距离

Calculating the distance between the current vehicle and the preceding vehicle

c++

omnet++

veins

sumo