4. 应用编程示例

以下给出构建一个简单应用的基本步骤。

Note

完整源代码可在 lebai-ros-sdk 源代码中 lebai_tutorials 目录中查看。

4.1. 创建 ROS 2 程序包

ros2 pkg create lebai_tutorials --build-type ament_cmake --dependencies rclpy rclcpp lebai_interfaces

在 package.xml 文件中自行设置 description， maintainer， license 等内容。

4.2. c++ 部分

在 src 目录下，添加 move_example.cc 文件。

touch src/move_example.cc

复制如下内容到 move_example.cc 文件中:

#include <rclcpp/rclcpp.hpp>
#include <lebai_interfaces/srv/move_joint.hpp>
#include <lebai_interfaces/srv/move_line.hpp>
int main(int argc, char **argv)
{
  rclcpp::init(argc, argv);
  std::shared_ptr<rclcpp::Node> node = rclcpp::Node::make_shared("move_example");
  // Create move joint service client.
  rclcpp::Client<lebai_interfaces::srv::MoveJoint>::SharedPtr move_joint_client =
      node->create_client<lebai_interfaces::srv::MoveJoint>("/motion_service/move_joint");
  // Wait for service.
  move_joint_client->wait_for_service();
  RCLCPP_INFO(node->get_logger(), "Move joint service exist.");
  // generate a move joint srv data.
  auto move_joint_req = std::make_shared<lebai_interfaces::srv::MoveJoint::Request>();
  move_joint_req->joint_pose = {-0.515705166127304, -1.383938292070577, 0.9317015810420413, -1.0843326694366626, -0.8334309368181174, -0.7919175817459623};
  move_joint_req->is_joint_pose = 1;
  move_joint_req->common.vel = 0.2;
  move_joint_req->common.acc = 1.0;
  // Call service.
  auto move_joint_result = move_joint_client->async_send_request(move_joint_req);
  if (rclcpp::spin_until_future_complete(node, move_joint_result) ==
      rclcpp::FutureReturnCode::SUCCESS)
  {
    RCLCPP_INFO(node->get_logger(), "Successed to call move joint");
  }
  else
  {
    RCLCPP_ERROR(rclcpp::get_logger("rclcpp"), "Failed to call move joint");
  }
  // Create move line service client.
  rclcpp::Client<lebai_interfaces::srv::MoveLine>::SharedPtr move_line_client =
      node->create_client<lebai_interfaces::srv::MoveLine>("/motion_service/move_line");
  // Wait for service.
  move_line_client->wait_for_service();
  RCLCPP_INFO(node->get_logger(), "Move line service exist.");
  // generate a move line srv data.
  auto move_line_req = std::make_shared<lebai_interfaces::srv::MoveLine::Request>();
  move_line_req->joint_pose = {-1.9979141024218048, -1.1726324385393299, 0.9936360553529241, -1.0942076707586763, -0.849345987492431, -0.8172282647460754};;
  move_line_req->is_joint_pose = 1;
  move_line_req->common.vel = 0.2;
  move_line_req->common.acc = 1.0;
  // Call service.
  auto move_line_result = move_line_client->async_send_request(move_line_req);
  if (rclcpp::spin_until_future_complete(node, move_line_result) ==
      rclcpp::FutureReturnCode::SUCCESS)
  {
    RCLCPP_INFO(node->get_logger(), "Successed to call move line");
  }
  else
  {
    RCLCPP_ERROR(rclcpp::get_logger("rclcpp"), "Failed to call move line");
  }
  rclcpp::shutdown();
  return 0;
}

在 CMakeLists.txt 中添加如下内容：

## after find_package...
add_executable(move_example src/move_example.cc)
ament_target_dependencies(move_example
rclcpp lebai_interfaces)

install(TARGETS
   move_example
   DESTINATION lib/${PROJECT_NAME}
)

您可以尝试编译并运行

# change to your own workspace.
cd lebai_ws
colcon build

# remember you need to run:
# source lebai_ws/install/setup.bash.
# you must run lebai-ros-sdk launch first:
# ros2 launch lebai_lm3_support robot_interface_lm3.launch.py robot_ip:=xxx.xxx.xxx.xxx
ros2 run lebai_tutorials move_example

4.3. python 部分

在 src 目录下，添加 python 模块目录和相应的文件。

cd lebai_tutorials
mkdir scripts
touch scripts/move_example.py
touch scripts/io_example.py
touch scripts/joint_state_subscriber.py

move_example.py 内容如下：

#!/usr/bin/env python3
import rclpy
from rclpy.node import Node
from lebai_interfaces.srv import MoveJoint
from lebai_interfaces.srv import MoveLine
from geometry_msgs.msg import Point
from geometry_msgs.msg import Quaternion

class MoveExample(Node):
   def __init__(self):
      super().__init__('move_example')

   def SendMoveJoint(self):
      move_joint_srv = self.create_client(
            MoveJoint, '/motion_service/move_joint')
      while not move_joint_srv.wait_for_service(timeout_sec=1.0):
            self.get_logger().info('service "move_joint" not available, waiting...')
      req = MoveJoint.Request()
      req.is_joint_pose = True
      req.joint_pose = [-0.516, -1.384, 0.932, -1.084, -0.833, -0.792]
      req.common.vel = 0.1
      req.common.acc = 1.0
      req.common.radius = 0.0
      future = move_joint_srv.call_async(req)
      while rclpy.ok():
            rclpy.spin_once(self)
            if future.done():
               try:
                  future.result()
               except Exception as e:
                  self.get_logger().info(
                        'Service "move_joint" call failed %r' % (e,))
               else:
                  self.get_logger().info(
                        'Service "move_joint" call succeed.')
               break

   def SendMoveLine(self):
      move_line_srv = self.create_client(
            MoveLine, '/motion_service/move_line')
      while not move_line_srv.wait_for_service(timeout_sec=1.0):
            self.get_logger().info('service "move_line" not available, waiting...')
      req = MoveLine.Request()
      req.is_joint_pose = False
      req.cartesian_pose.position.x = 0.022
      req.cartesian_pose.position.y = 0.473
      req.cartesian_pose.position.z = 0.431
      req.cartesian_pose.orientation.x = 0.918
      req.cartesian_pose.orientation.y = 0.128
      req.cartesian_pose.orientation.z = -0.364
      req.cartesian_pose.orientation.w = -0.091
      req.common.vel = 0.1
      req.common.acc = 1.0
      req.common.radius = 0.0
      future = move_line_srv.call_async(req)
      while rclpy.ok():
            rclpy.spin_once(self)
            if future.done():
               try:
                  future.result()
               except Exception as e:
                  self.get_logger().info(
                        'Service "move_line" call failed %r' % (e,))
               else:
                  self.get_logger().info(
                        'Service "move_line" call succeed.')
               break


def Run():
   move_example = MoveExample()
   move_example.SendMoveJoint()
   move_example.SendMoveLine()
   return


def main():
   rclpy.init()
   Run()
   rclpy.shutdown()


if __name__ == '__main__':
   main()

io_example.py 内容如下：

#!/usr/bin/env python3

import rclpy
from rclpy.node import Node
from lebai_interfaces.srv import SetDO
from lebai_interfaces.srv import SetAO


class IOExample(Node):
   def __init__(self):
      super().__init__('io_example')

   def SetDO(self):
      srv = self.create_client(
            SetDO, '/io_service/set_robot_do')
      while not srv.wait_for_service(timeout_sec=1.0):
            self.get_logger().info('service "set_robot_do" not available, waiting...')
      req = SetDO.Request()
      req.pin = 0
      req.value = True
      future = srv.call_async(req)
      while rclpy.ok():
            rclpy.spin_once(self)
            if future.done():
               try:
                  future.result()
               except Exception as e:
                  self.get_logger().info(
                        'Service "set_robot_do" call failed %r' % (e,))
               else:
                  self.get_logger().info(
                        'Service "set_robot_do" call succeed.')
               break

   def SetAO(self):
      srv = self.create_client(
            SetAO, '/io_service/set_robot_ao')
      while not srv.wait_for_service(timeout_sec=1.0):
            self.get_logger().info('service "set_robot_ao" not available, waiting...')
      req = SetAO.Request()
      req.pin = 0
      req.value = 3.0
      future = srv.call_async(req)
      while rclpy.ok():
            rclpy.spin_once(self)
            if future.done():
               try:
                  future.result()
               except Exception as e:
                  self.get_logger().info(
                        'Service "set_robot_ao" call failed %r' % (e,))
               else:
                  self.get_logger().info(
                        'Service "set_robot_ao" call succeed.')
               break


def Run():
   io_example = IOExample()
   io_example.SetDO()
   io_example.SetAO()
   # SendMoveCircle()
   return


def main():
   rclpy.init()
   Run()
   rclpy.shutdown()


if __name__ == '__main__':
   main()

joint_state_subscriber.py 内容如下：

#!/usr/bin/env python3

import rclpy
from rclpy.node import Node
from sensor_msgs.msg import JointState


class JointStateSubscriber(Node):

   def __init__(self):
      super().__init__('joint_state_subscriber')
      self.subscription = self.create_subscription(
            JointState,
            'joint_states',
            self.joint_state_callback,
            10)
      self.subscription  # prevent unused variable warning

   def joint_state_callback(self, msg: JointState):
      self.get_logger().info('Joint position: "%s"' % msg.position)


def main(args=None):
   rclpy.init(args=args)
   joint_state_subscriber = JointStateSubscriber()
   rclpy.spin(joint_state_subscriber)
   joint_state_subscriber.destroy_node()
   rclpy.shutdown()


if __name__ == '__main__':
   main()

在 CMakeLists.txt 中添加如下内容：

## after find_package...
install(PROGRAMS
   scripts/move_example.py
   scripts/io_example.py
   scripts/joint_state_subscriber.py
   DESTINATION lib/${PROJECT_NAME}
)

您可以尝试编译并运行

# change to your own workspace.
cd lebai_ws
colcon build

# remember you need to run:
# source lebai_ws/install/setup.bash.
# you must run lebai-ros-sdk launch first:
# ros2 launch lebai_lm3_support robot_interface_lm3.launch.py robot_ip:=xxx.xxx.xxx.xxx
ros2 run lebai_tutorials move_example.py
ros2 run lebai_tutorials io_example.py
ros2 run lebai_tutorials joint_state_subscriber.py