ranger_ros

ranger

ranger mini is the name of the following car

Communicate Flow

The ugv_sdk communicate with the car by can protocol
The ranger_ros package call the function GetRangerState to get the newest machine information, call the SetMotionCommand to set linear velocity 、angle、etc, call the SetMotionMode to change the motion mode
Ranger mini have 4 type of motion mode. see ranger mini manual from agilex develop manuals
pub ranger_ros can set motion mode
subscribe ranger_status can get the robot status

Params

see ranger_base/launch/ranger_mini_base.launch

is_ranger_mini : ranger mini or ranger pro
port_name: can port name , usually is can0
simulated_robot: sim robot for test or not
odom_frame: the odometry frame name in tf
base_frame: the base link frame name in tf
odom_topic_name: the odometry topic name
pub_odom_tf: publish tf transformation of odometry frame or not. if true publish

Build

dependencies:

ROS1 melodic or newer

assume your ros workspace is ~/agilex_ws

# install ugv_sdk
cd ~/agilex_ws/src
git clone https://github.com/agilexrobotics/ugv_sdk.git
cd ugv_sdk
git checkout -b v2.x origin/v2.x
cd ../
catkin_make install --pkg ugv_sdk

# source the packages
source devel/setup.bash

# install ranger_ros
cd ~/agilex_ws/src/
git clone https://github.com/agilexrobotics/ranger_ros.git

# install the ascent library at first
cd ranger_ros/ranger_base/ascent
mkdir -p build && cd build && cmake -DBUILD_TESTING=OFF .. && sudo make install

cd ~/agilex_ws/
catkin_make install # or just catkin_make

# if you catch error:  ranger_msgs/RangerSetting.h: No such file or directory
# then install `ranger_msgs` first
catkin_make install --pkg ranger_msgs

# for install
catkin_make install

Run

# run ranger_ros
cd ~/agilex_ws
source devel/setup.bash
roslaunch ranger_bringup ranger_minimal.launch

use keyboard to control

the default motion mode is Head-Back Ackermann

# if you want to remote control the car by keyboard
sudo apt install ros-$ROS_DISTRO-teleop-twist-keyboard
roslaunch ranger_bringup ranger_teleop_keyboard.launch

Ros Topic Examples

Input: the car linear velocity and the heading angle
Output: total linear velocity, x direction velocity, y direction velocity, angular velocity, central steer angle and rotate radius, .etc

Publish topic to control the car

see ranger_ros/ranger_examples/src/input.cpp for details

////----------------control by ros topic---------------------------------
ros::Publisher motion_mode =
    node.advertise<ranger_msgs::RangerSetting>("/ranger_setting", 1);
ranger_msgs::RangerSetting setting;
setting.motion_mode = ranger_msgs::RangerSetting::MOTION_MODE_ACKERMAN;
motion_mode.publish(setting);

////------------------move by ros topic --------------------------------
ros::Publisher move_cmd =
    node.advertise<geometry_msgs::Twist>("/cmd_vel", 10);
geometry_msgs::Twist cmd;
cmd.linear.x = 0.1;                   // the motor will run at 0.1m/s
cmd.angular.z = 30.0 / 180.0 * M_PI;  // the heading angle of the car

// publish robot state at 50Hz while listening to twist commands
ros::Rate rate(50);
while (ros::ok()) {
    ros::spinOnce();

    // /cmd_vel topic must send at 50Hz, even stop need send 0m/s
    move_cmd.publish(cmd);

    rate.sleep();
}

or publish by command line

# 0 Ackrmann, 1 Slide, 2 Round, 3 Sloping
# 0 前后阿克曼，1 斜移,   2 自旋,  3  侧移
rostopic pub -1 /ranger_setting ranger_msgs/RangerSetting -- '[0, 0, setting_frame]' '1'

rostopic pub /cmd_vel geometry_msgs/Twist --rate 50 '[0.1, 0.0, 0.0]' '[0.0, 0.0, 0.52358]'  # 0.52358 = 30 degree

Subcribe the car output

see ranger_ros/ranger_examples/src/output.cpp for details

ros::Subscriber status_sub = node.subscribe<ranger_msgs::RangerStatus>(
    "/ranger_status", 10, StatusCallback);

void StatusCallback(ranger_msgs::RangerStatus::ConstPtr msg) {
    std::cout << "linear velocity: " << msg->linear_velocity << std::endl;
    std::cout << "angular velocity: " << msg->angular_velocity << std::endl;
    std::cout << "x direction linear velocity: " << msg->x_linear_vel << std::endl;
    std::cout << "y direction linear linear velocity: " << msg->y_linear_vel << std::endl;
    std::cout << "rotate radius: " << msg->motion_radius << std::endl;
    std::cout << "car heading angle: " << msg->steering_angle << std::endl;
    // ...etc
}

or show the data by rostopic

rostopic echo /ranger_status

Sdk API Examples

0. enable can control

robot->Connect("can0");
robot->EnableCommandedMode();

1. set motion mode

see ranger_ros/ranger_examples/src/change_the_mode.cpp for more details

robot->Connect("can0");
robot->EnableCommandedMode();

// 0 Arckmann 1 Slide 2 round, 3 Sloping
// 0 前后阿克曼 1 横移  2 自旋  3 侧移 
robot->SetMotionMode(0);
//  robot->SetMotionMode(1);
//  robot->SetMotionMode(2);
//  robot->SetMotionMode(3);

2. set the movement linear velocity and angle of the car

see ranger_ros/ranger_examples/src/control_the_car.cpp for more details

robot->SetMotionCommand(0.1, 30.0/180.0 * M_PI); // steer angle = 30°

// or write them in a function
void Ackermann() {
  robot->SetMotionMode(0);
  // or
  robot->SetMotionMode(RangerSetting::MOTION_MODE_ACKERMAN);
  l_v = 0.1;                  // m/s
  angle_z = 30 / 180 * M_PI;  // rad
}
void Slide() {
  robot->SetMotionMode(1);
  // or
  robot->SetMotionMode(RangerSetting::MOTION_MODE_SLIDE);
  l_v = 0.1;                  // m/s
  angle_z = 30 / 180 * M_PI;  // rad
}
void Round() {
  robot->SetMotionMode(2);
  // or
  robot->SetMotionMode(RangerSetting::MOTION_MODE_ROUND);
  l_v = 0.1;
  // angle_z is not used
}
void Sloping() {
  robot->SetMotionMode(3);
  // or
  robot->SetMotionMode(RangerSetting::MOTION_MODE_SLOPING);
  l_v = 0.1;
  // angle_z is not used
}

use odometry

subscribe /odom topic

885288421 / ranger_ros