Low-level CAN interface for real-time Hubo operation on Linux
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HuboCan
HuboCmd
HuboPath
HuboQt
HuboRT
HuboState
cmake
devices
instructions
misc
src
.gitignore
CMakeLists.txt
LICENSE
README.md
setup.sh

README.md

HuboCan

⚠️ Due to unfortunate circumstances, this project is no longer supported, and its development is incomplete in a few respects. If you are interested in continuing the development effort, you are welcome to contact the original creator greyxmike@gmail.com

A complete framework for real-time operation of Hubo on Linux. This single framework is intended to work seamlessly for every version of Hubo which currently exists and which may exist in the future (pending software updates).

Basic Usage

Installation

Dependencies

This package currently has two (and an optional third) external dependencies:

  1. Ach for interprocess communication
  2. Eigen for fancy matrix operations
  3. (Optional) Qt for user interface creation

Installation script

For your convenience, a bash script is already written which will automatically install the dependenceis for you as long as you have an internet connection during the installation. The script is called setup.sh and resides in the root of the source tree. Of course it also handles building and installing the HuboCan package.

You are strongly encouraged to run setup.sh from the same directory that it resides in, because it will create its own build directory relative to the current working directory of the terminal.

There are two modes of installation for the HuboCan package. One is meant to be used on the internal computer of the physical robot. The other is meant to be used on remote workstations

Robot installation

Simply run the setup script as follows:

$ ./setup robot <robot_type>

Replace <robot_type> with either Hubo2Plus or DrcHubo depending on which version of Hubo you have.

Workstation installation

Simply run the setup script as follows:

$ ./setup workstation

You do not need to specify a version of the robot for a workstation install, because the robot will inform you which version it is when you connect to it. So the same workstation can be used to operate a Hubo2Plus or a DrcHubo with no changes whatsoever necessary.

Uninstall

Simply run the setup script as follows:

$ ./setup uninstall

The script will automatically identify whether you originally did a 'robot' installation or a 'workstation' installation and then remove libraries, headers, and startup scripts as appropriate. Adding the argument 'purge' will also remove the entire /opt/hubo directory, but this is not recommended unless you want to completely remove all HuboCan files from your computer.

Code Description

This source code compiles into two libraries:

libHuboCan -- This is the central library to the HuboCan framework. Linking this library grants access to all the key features available.

libHuboQt -- This library provides some Qt-widget and window interfaces for human interaction with the HuboCan framework. These plugins are designed to be either run in their own windows or made into plugins for any Qt-based framework.

There are five namespaces used in the HuboCan library:

Namespace Description Class list
HuboCan This is the foundational namespace of the library which deals with low-level CAN protocol and hardware interface CanPump, CanDevice, HuboDescription, HuboJmc, HuboJoint, HuboSensor
HuboCmd This namespace deals with sending and receiving real-time control commands (i.e. commands which must be updated every control cycle) to the lowest layer of the framework Commander, Aggregator, AuxSender, AuxReceiver
HuboState This namespace is used to collect state data which gets published by the hardware interface level of the HuboCan framework, and can be used to synchronize a process with the low-level control cycle State, HuboData
HuboPath This namespace provides tools for creating, interpolating, and running trajectories on Hubo (as well as interrupting and reversing trajectories while they are running) Operator, Player, Trajectory
HuboRT (Real Time) This namespace contains the tools which are used for creating real-time processes and managing those processes, as well as their Ach channels Daemonizer, Manager, ManagerReq

HuboQt Namespace

ManagerWidget

This widget is designed to expose the most basic features of the HuboRT::ManagerReq class. In other words, it provides an interface to the Manager process that runs on Hubo, allowing you to create/destroy Ach channels and launch/stop/kill processes remotely without needing to SSH. This also provides a convenient interface for managing Ach Networking Daemons by simply clicking Reconnect/Disconnect. This widget is intended to be the "front page" of any Qt-based operating software for Hubo.

HuboPath Namespace

Operator

The Operator class has three major roles: (1) Helping to construct a HuboPath::Trajectory, (2) Sending that Trajectory to the HuboPath::Player in order to execute it on the robot, and (3) Sending instructions to the Player to start, pause, or reverse its current trajectory.

Player

The Player class is designed to provide a framework for receiving, sanity-checking, and executing trajectories in real time. In the future, this class will be upgraded to accept a real-time controller class which will be able to modify trajectories on the fly based on sensor feedback.

Trajectory

The Trajectory class is a container class for handling trajectory data. Currently this only includes jointspace waypoints and limit (position, velocity, and acceleration) checking, but in the future will (hopefully) include control schemes, end effector waypoints, and self-collision checks.

Note: The Trajectory class has a very nice C++ stream operator (std::cout << ) which will print out its contents in a clean and easy-to-read format.

HuboState Namespace

State

The State class reads the data which has been published by the JMC and sensor CanDevices. The data is provided in the form of a templated HuboData class.

You can also use the State class to synchronize the actions of a process to the hardware control loop. The update() function will do a blocking wait (a blocking wait means that it does NOT eat up any computer resources while waiting) up to whatever argument is passed in.

The default argument is 1, so by default it will wait for new state information for up to one second before giving up. Passing in an argument of 0 will have it simply check if a new state has been published, grab it if it has, and return immediately.

HuboData

This is a templated class designed to make it easy to transmit variable-sized data over Ach. Currently three types of data are taking advantage of this class: hubo_joint_state_t, hubo_imu_state_t, and hubo_ft_state_t. The definitions for these data structures can be found in hubo_sensor_c.h.

HuboCan Namespace

CanPump

The purpose of the CanPump class is to provide a skeleton for a real-time CAN-based hardware interface. The CanPump class alone is not able to interface with hardware; rather, that is what the SocketCanPump class (which inherits CanPump) is made for. But SocketCanPump is an implementation specifically made for SocketCan. It is conceivable that not all Hubos (or any other robots which wish to use this framework) will use SocketCan, so the CanPump class exists to provide all the key timing functionality and connection to the rest of the HuboCan framework with no effort. Simply inherit the CanPump class overload the virtual functions _send_frame() and _wait_on_frame() with your hardware implementation.

CanDevice

The CanDevice class gives a blueprint for CanDevices to add to the CanPump. The idea is that a CAN bus will have any number of devices attached to it (in our case, mostly joints and sensors). Each of these devices needs a software class to send frames to (and decode frames from) those physical devices. CanDevice is the blueprint for these software classes. At each control cycle, the CanPump will trigger the update() function on each CanDevice which has been given to it. And every time a CAN frame is received by the CanPump, it will call the decode() function on each CanDevice to give them all the opportunity to read the incoming frames.

HuboJmc

The physical Hubo robot has JMCs (Joint Motor Controllers) which are connected to the CAN bus. Each JMC is considered one device on the CAN bus (whether that JMC controls one, two, or more joints). Different JMC types will have very different implementations, so the HuboJmc class simply serves as a minimalist blueprint for these devices. The many different types of JMCs can be seen in HuboCan/HuboJmc.hpp. This class may serve as a good example of a CanDevice implementation.

HuboSensor (Not yet fully implemented)

In addition to JMCs, the physical robot has sensor devices connected to CAN. HuboSensor represents a minimalist blueprint for various sensor classes (i.e. HuboImu and HuboFt)

HuboDescription

This class is an abstract factory. It reads in a .dd (device description) file and churns out the appropriate CanDevices. When implementing a new CanDevice, it is also important to update the HuboDescription class to be able to correctly read (and transmit, if necessary) your device description (.dd).

It is acceptable to create your own class which inherits HuboDescription, but it would be preferable to make changes directly to HuboDescription so that everyone can benefit from any new device implementations.