Archive 02.12.2021

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COVID-19 mobile robot could detect and tackle social distancing breaches

A new strategy to reduce the spread of COVID-19 employs a mobile robot that detects people in crowds who are not observing social-distancing rules, navigates to them, and encourages them to move apart. Adarsh Jagan Sathyamoorthy of the University of Maryland, College Park, and colleagues present these findings in the open-access journal PLOS ONE on December 1, 2021.

Engineers create perching bird-like robot

Like snowflakes, no two branches are alike. They can differ in size, shape and texture; some might be wet or moss-covered or bursting with offshoots. And yet birds can land on just about any of them. This ability was of great interest to the labs of Stanford University engineers Mark Cutkosky and David Lentink—now at University of Groningen in the Netherlands—which have both developed technologies inspired by animal abilities.

Exploring ROS2 using wheeled Robot – #3 – Moving the robot

By Marco Arruda

In this post you’ll learn how to publish to a ROS2 topic using ROS2 C++. Up to the end of the video, we are moving the robot Dolly robot, simulated using Gazebo 11.

You’ll learn:

  • How to create a node with ROS2 and C++
  • How to public to a topic with ROS2 and C++

1 – Setup environment – Launch simulation

Before anything else, make sure you have the rosject from the previous post, you can copy it from here.

Launch the simulation in one webshell and in a different tab, checkout the topics we have available. You must get something similar to the image below:

2 – Create a topic publisher

Create a new file to container the publisher node: moving_robot.cpp and paste the following content:

#include <chrono>
#include <functional>
#include <memory>

#include "rclcpp/rclcpp.hpp"
#include "geometry_msgs/msg/twist.hpp"

using namespace std::chrono_literals;

/* This example creates a subclass of Node and uses std::bind() to register a
 * member function as a callback from the timer. */

class MovingRobot : public rclcpp::Node {
public:
  MovingRobot() : Node("moving_robot"), count_(0) {
    publisher_ =
        this->create_publisher("/dolly/cmd_vel", 10);
    timer_ = this->create_wall_timer(
        500ms, std::bind(&MovingRobot::timer_callback, this));
  }

private:
  void timer_callback() {
    auto message = geometry_msgs::msg::Twist();
    message.linear.x = 0.5;
    message.angular.z = 0.3;
    RCLCPP_INFO(this->get_logger(), "Publishing: '%f.2' and %f.2",
                message.linear.x, message.angular.z);
    publisher_->publish(message);
  }
  rclcpp::TimerBase::SharedPtr timer_;
  rclcpp::Publisher::SharedPtr publisher_;
  size_t count_;
};

int main(int argc, char *argv[]) {
  rclcpp::init(argc, argv);
  rclcpp::spin(std::make_shared());
  rclcpp::shutdown();
  return 0;
}QoS (Quality of Service)

Similar to the subscriber it is created a class that inherits Node. A publisher_ is setup and also a callback, although this time is not a callback that receives messages, but a timer_callback called in a frequency defined by the timer_ variable. This callback is used to publish messages to the robot.

The create_publisher method needs two arguments:

  • topic name
  • QoS (Quality of Service) – This is the policy of data saved in the queue. You can make use of different middlewares or even use some provided by default. We are just setting up a queue of 10. By default, it keeps the last 10 messages sent to the topic.

The message published must be created using the class imported:

message = geometry_msgs::msg::Twist();

We ensure the callback methods on the subscribers side will always recognize the message. This is the way it has to be published by using the publisher method publish.

3 – Compile and run the node

In order to compile we need to adjust some things in the ~/ros2_ws/src/my_package/CMakeLists.txt. So add the following to the file:

  • Add the geometry_msgs dependency
  • Append the executable moving_robot
  • Add install instruction for moving_robot
find_package(geometry_msgs REQUIRED)
...
# moving robot
add_executable(moving_robot src/moving_robot.cpp)
ament_target_dependencies(moving_robot rclcpp geometry_msgs)
...
install(TARGETS
  moving_robot
  reading_laser
  DESTINATION lib/${PROJECT_NAME}/
)

We can run the node like below:

source ~/ros2_ws/install/setup.bash
ros2 run my_package

Related courses & extra links:

The post Exploring ROS2 using wheeled Robot – #3 – Moving the Robot
appeared first on The Construct.

Exploring ROS2 using wheeled Robot – #3 – Moving the robot

By Marco Arruda

In this post you’ll learn how to publish to a ROS2 topic using ROS2 C++. Up to the end of the video, we are moving the robot Dolly robot, simulated using Gazebo 11.

You’ll learn:

  • How to create a node with ROS2 and C++
  • How to public to a topic with ROS2 and C++

1 – Setup environment – Launch simulation

Before anything else, make sure you have the rosject from the previous post, you can copy it from here.

Launch the simulation in one webshell and in a different tab, checkout the topics we have available. You must get something similar to the image below:

2 – Create a topic publisher

Create a new file to container the publisher node: moving_robot.cpp and paste the following content:

#include <chrono>
#include <functional>
#include <memory>

#include "rclcpp/rclcpp.hpp"
#include "geometry_msgs/msg/twist.hpp"

using namespace std::chrono_literals;

/* This example creates a subclass of Node and uses std::bind() to register a
 * member function as a callback from the timer. */

class MovingRobot : public rclcpp::Node {
public:
  MovingRobot() : Node("moving_robot"), count_(0) {
    publisher_ =
        this->create_publisher("/dolly/cmd_vel", 10);
    timer_ = this->create_wall_timer(
        500ms, std::bind(&MovingRobot::timer_callback, this));
  }

private:
  void timer_callback() {
    auto message = geometry_msgs::msg::Twist();
    message.linear.x = 0.5;
    message.angular.z = 0.3;
    RCLCPP_INFO(this->get_logger(), "Publishing: '%f.2' and %f.2",
                message.linear.x, message.angular.z);
    publisher_->publish(message);
  }
  rclcpp::TimerBase::SharedPtr timer_;
  rclcpp::Publisher::SharedPtr publisher_;
  size_t count_;
};

int main(int argc, char *argv[]) {
  rclcpp::init(argc, argv);
  rclcpp::spin(std::make_shared());
  rclcpp::shutdown();
  return 0;
}QoS (Quality of Service)

Similar to the subscriber it is created a class that inherits Node. A publisher_ is setup and also a callback, although this time is not a callback that receives messages, but a timer_callback called in a frequency defined by the timer_ variable. This callback is used to publish messages to the robot.

The create_publisher method needs two arguments:

  • topic name
  • QoS (Quality of Service) – This is the policy of data saved in the queue. You can make use of different middlewares or even use some provided by default. We are just setting up a queue of 10. By default, it keeps the last 10 messages sent to the topic.

The message published must be created using the class imported:

message = geometry_msgs::msg::Twist();

We ensure the callback methods on the subscribers side will always recognize the message. This is the way it has to be published by using the publisher method publish.

3 – Compile and run the node

In order to compile we need to adjust some things in the ~/ros2_ws/src/my_package/CMakeLists.txt. So add the following to the file:

  • Add the geometry_msgs dependency
  • Append the executable moving_robot
  • Add install instruction for moving_robot
find_package(geometry_msgs REQUIRED)
...
# moving robot
add_executable(moving_robot src/moving_robot.cpp)
ament_target_dependencies(moving_robot rclcpp geometry_msgs)
...
install(TARGETS
  moving_robot
  reading_laser
  DESTINATION lib/${PROJECT_NAME}/
)

We can run the node like below:

source ~/ros2_ws/install/setup.bash
ros2 run my_package

Related courses & extra links:

The post Exploring ROS2 using wheeled Robot – #3 – Moving the Robot
appeared first on The Construct.

NeatNet: A model that can learn people’s tidying up preferences

As robots become increasingly advanced and affordable, more people could start introducing them into their homes. Many roboticists have thus been trying to develop systems that can effectively assist humans with house chores, such as cooking, cleaning and tidying up.

New software allows industrial robots to achieve touch sensitivity and precision close to human hands

Eureka Robotics, a tech spin-off from Nanyang Technological University, Singapore (NTU Singapore), has developed a technology, called Dynamis, that makes industrial robots nimbler and almost as sensitive as human hands, able to manipulate tiny glass lenses, electronics components, or engine gears that are just millimeters in size without damaging them.

An inventory of robotics roadmaps to better inform policy and investment

Much excellent work has been done, by many organizations, to develop ‘Roadmaps for Robotics’, in order to steer government policy, innovation investment, and the development of standards and commercialization. However, unless you took part in the roadmapping activity, it can be very hard to find these resources. Silicon Valley Robotics in partnership with the Industrial Activities Board of the IEEE Robotics and Automation Society, is compiling an up to date resource list of various robotics, AIS and AI roadmaps, national or otherwise. This initiative will allow us all to access the best robotics commercialization advice from around the world, to be able to compare and contrast various initiatives and their regional effectiveness, and to provide guidance for countries and companies without their own robotics roadmaps.

Another issue making it harder to find recent robotics roadmaps is the subsumption of robotics into the AI landscape, at least in some national directives. Or it may appear not as robotics but as ‘AIS’, standing for Autonomous Intelligent Systems, such as in the work of OCEANIS, the Open Community for Ethics in Autonomous aNd Intelligent Systems, which hosts a global standards repository. And finally there are subcategories of robotics, ie Autonomous Vehicles, or Self Driving Cars, or Drones, or Surgical Robotics, all of which may have their own roadmaps. This is not an exhaustive list, but with your help we can continue to evolve it.

Do you know of robotics roadmaps not yet included? Please share them with us. 

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