gary_can

gary_can是负责can收发gary_ros包, 基于linux的socketcan, 实现了can收发和总线监控, 具有断线重连能力, 所有功能被封装为动态链接库供其他包调用.

gary_can包含三部分, 分别是can发送SocketCANSender, can接收SocketCANReceiver 和 can总线监控SocketCANMonitor

Usage

在package.xml中引用gary_can

<depend>gary_can</depend>

在CMakeLists.txt中调用gary_can

find_package(gary_can REQUIRED)
ament_target_dependencies(
        <YOUR_TARGET_NAME>
        ......
        gary_can
)

在代码中引用头文件

#include "gary_can/socket_can_receiver.hpp"
#include "gary_can/socket_can_sender.hpp"

模块介绍

SocketCANSender

SocketCANSender是can发送类, 封装了can非阻塞发送相关功能. 每个SocketCANSender负责一路can总线的发送.

Usage

使用ip link显示的can接口名称实例化SocketCANSender

auto can_sender = std::make_shared<driver::can::SocketCANSender>("can*");

打开socket, 函数成功返回true, 失败返回false

can_sender->open_socket();

或重新指定can接口并打开socket, 函数成功返回true, 失败返回false

can_sender->open_socket("can*");

每次发送前都应检查can_sender->is_opened, 如果是false, 则应执行can_sender->open_socket()直到can_sender->is_opened==true

if (!can_sender->is_opened) {
    //reopen socket
    can_sender->open_socket();
}

使用can_sender->send(frame)向对应的can总线发送数据, 其中参数frame的类型是struct can_frame, 函数执行成功返回true, 失败返回false

struct can_frame frame{};
frame.can_dlc = 8;
//for example, 0x100
frame.can_id = 0x100;
frame.data[0] = 0x00;
// ......
frame.data[7] = 0x00;
if (can_sender->send(frame)) {
    //send succ
} else {
    //send failed
}

SocketCANReceiver

SocketCANReceiver是can接收类, 封装了can非阻塞接收相关功能. 每个SocketCANReceiver负责一路can总线的接收.

Usage

使用ip link显示的can接口名称实例化SocketCANReceiver

auto can_receiver = std::make_shared<driver::can::SocketCANReceiver>("can*");

创建接收socket, 需要指定can总线id, 一个SocketCANReceiver实例可以打开多个不同can总线id的socket, 成功返回true, 失败返回false

can_receiver->open_socket(0x100);
can_receiver->open_socket(0x101);
......
can_receiver->open_socket(0x105);
can_receiver->open_socket(0x106);

每次接收前都应检查can_receiver->is_opened[id], 如果是false, 则应执行can_receiver->open_socket(id)直到can_receiver->is_opened[id]==true

if (!can_receiver[id]->is_opened) {
    //reopen socket
    can_receiver->open_socket(id);
}

使用can_receiver->read(id, &frame)从对应的can总线接收对应id的数据, 其中参数frame的类型是struct can_frame, 函数执行成功返回true, 失败返回false

struct can_frame frame{};
if (can_receiver->read(id, &frame)) {
    //read succ
} else {
    //read failed
}

SocketCANMonitor

SocketCANMonitor是can总线的监控程序, 能够检测总线的多种错误, 并发送自检数据到指定topic. 其能够检测设备离线, 传输干扰, 总线过载, 并回报负载率和每个id的发包频率.

Usage

直接启动节点

ros2 run gary_can socket_can_monitor

作为component加载

ros2 run rclcpp_components component_container
ros2 component load /ComponentManager gary_can gary_can::SocketCANMonitor

注意, SocketCANMonitor是生命周期节点, 当节点启动后, 需要配置才能进入运行状态

ros2 lifecycle set /socket_can_monitor configure
ros2 lifecycle set /socket_can_monitor activate

SocketCANMonitor可配置参数如下

• diagnose_topic: 发送的自检数据主题名称, 默认/diagnostics
• update_freq: 更新频率, 默认10Hz
• monitored_can_bus: 需要监控的can总线名称, 默认为空
• overload_threshold: can过载阈值, 默认为0.8