# towr
**Repository Path**: robomark/towr
## Basic Information
- **Project Name**: towr
- **Description**: A light-weight, Eigen-based C++ library for trajectory optimization for legged robots.
- **Primary Language**: Unknown
- **License**: BSD-3-Clause
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No
## Statistics
- **Stars**: 0
- **Forks**: 0
- **Created**: 2020-03-18
- **Last Updated**: 2020-12-19
## Categories & Tags
**Categories**: Uncategorized
**Tags**: None
## README
[
](https://ieeexplore.ieee.org/document/8283570 "Go to RA-L paper")
*A light-weight and extensible C++ library for trajectory optimization for legged robots.*
[](http://build.ros.org/view/Mdev/job/Mdev__towr__ubuntu_bionic_amd64/)
[](http://docs.ros.org/kinetic/api/towr/html/)
[](http://wiki.ros.org/towr)
[](https://www.codefactor.io/repository/github/ethz-adrl/towr)
[](https://tldrlegal.com/license/bsd-3-clause-license-%28revised%29#fulltext)
A base-set of variables, costs and constraints that can be combined and extended to formulate trajectory optimization problems for legged systems. These implementations have been used to generate a variety of motions such as monoped hopping, biped walking, or a complete quadruped trotting cycle, while optimizing over the gait and step durations in less than 100ms ([paper](https://ieeexplore.ieee.org/document/8283570/)).
Features:
:heavy_check_mark: Inuitive and efficient formulation of variables, cost and constraints using [Eigen].
:heavy_check_mark: [ifopt] enables using the high-performance solvers [Ipopt] and [Snopt].
:heavy_check_mark: Elegant rviz visualization of motion plans using [xpp].
:heavy_check_mark: [ROS]/[catkin] integration (optional).
:heavy_check_mark: Light-weight ([~6k lines](https://i.imgur.com/gP3gv34.png) of code) makes it easy to use and extend.
Install •
Run •
Develop •
Contribute •
Publications •
Authors
[
](https://youtu.be/0jE46GqzxMM "Show more examples on Youtube")
## Install
The easiest way to install is through the [ROS binaries](http://wiki.ros.org/towr):
```bash
sudo apt-get install ros--towr-ros
```
In case these don't yet exist for your distro, there are two ways to build this code from source:
* [Option 1](#towr-with-cmake): core library and hopper-example with pure [CMake].
* [Option 2](#towr-ros-with-catkin) (recommended): core library & GUI & ROS-rviz-visualization built with [catkin] and [ROS].
#### Building with CMake
* Install dependencies [CMake], [Eigen], [Ipopt]:
```bash
sudo apt-get install cmake libeigen3-dev coinor-libipopt-dev
```
Install [ifopt], by cloning the repo and then: ``cmake .. && make install`` on your system.
* Build towr:
```bash
git clone https://github.com/ethz-adrl/towr.git && cd towr/towr
mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
make
sudo make install # copies files in this folder to /usr/local/*
# sudo xargs rm < install_manifest.txt # in case you want to uninstall the above
```
* Test ([hopper_example.cc](towr/test/hopper_example.cc)): Generates a motion for a one-legged hopper using Ipopt
```bash
./towr-example # or ./towr-test if gtest was found
```
* Use: You can easily customize and add your own constraints and variables to the optimization problem.
Herefore, add the following to your *CMakeLists.txt*:
```cmake
find_package(towr 1.2 REQUIRED)
add_executable(main main.cpp) # Your custom variables, costs and constraints added to TOWR
target_link_libraries(main PUBLIC towr::towr) # adds include directories and libraries
```
#### Building with catkin
We provide a [ROS]-wrapper for the pure cmake towr library, which adds a keyboard interface to modify goal state and motion types as well as visualizes the produces motions plans in rviz using [xpp].
* Install dependencies [CMake], [catkin], [Eigen], [Ipopt], [ROS], [xpp], [ncurses], [xterm]:
```bash
sudo apt-get install cmake libeigen3-dev coinor-libipopt-dev libncurses5-dev xterm
sudo apt-get install ros--desktop-full ros--xpp
```
* Build workspace:
```bash
cd catkin_workspace/src
git clone https://github.com/ethz-adrl/ifopt.git
git clone https://github.com/ethz-adrl/towr.git
cd ..
catkin_make_isolated -DCMAKE_BUILD_TYPE=Release # or `catkin build`
source ./devel_isolated/setup.bash
```
* Use: Include in your catkin project by adding to your *CMakeLists.txt*
```cmake
add_compile_options(-std=c++11)
find_package(catkin COMPONENTS towr)
include_directories(${catkin_INCLUDE_DIRS})
target_link_libraries(foo ${catkin_LIBRARIES})
```
Add the following to your *package.xml*:
```xml
towr
```
## Run
Launch the program using
```bash
roslaunch towr_ros towr_ros.launch # debug:=true (to debug with gdb)
```
Click in the xterm terminal and hit 'o'.
Information about how to tune the paramters can be found [here](http://docs.ros.org/api/towr/html/group__Parameters.html).
## Develop
#### Library overview
* The relevant classes and parameters to build on are collected [modules](http://docs.ros.org/api/towr/html/modules.html).
* A nice graphical overview as UML can be seen [here](http://docs.ros.org/api/towr/html/inherits.html).
* The [doxygen documentation](http://docs.ros.org/api/towr/html/) provides helpul information for developers.
#### Problem formulation
* This code formulates the variables, costs and constraints using ifopt, so it makes sense to briefly familiarize with the syntax using [this example].
* A minimal towr example without ROS, formulating a problem for a one-legged hopper,
can be seen [here](towr/test/hopper_example.cc) and is great starting point.
* We recommend using the ROS infrastructure provided to dynamically visualize, plot and change the problem formulation. To define your own problem using this infrastructure, use this [example](towr_ros/src/towr_ros_app.cc) as a guide.
#### Add your own variables, costs and constraints
* This library provides a set of variables, costs and constraints to formulate the trajectory optimization problem. An [example formulation](towr/include/towr/nlp_formulation.h) of how to combine these is given, however, this formulation can probably be improved. To add your own e.g. constraint-set, define a class with it's values and derivatives, and then add it to the formulation ```nlp.AddConstraintSet(your_custom_constraints);``` as shown [here](towr/test/hopper_example.cc).
#### Add your own robot
* Want to add your own robot to towr? Start [here](http://docs.ros.org/api/towr/html/group__Robots.html).
* To visualize that robot in rviz, see [xpp].
## Contribute
We love pull request, whether its new constraint formulations, additional robot models, bug fixes, unit tests or updating the documentation. Please have a look at [CONTRIBUTING.md](CONTRIBUTING.md) for more information.
See here the list of [contributors](https://github.com/ethz-adrl/towr/graphs/contributors) who participated in this project.
## Publications
All publications underlying this code can be found [here](https://www.alex-winkler.com).
The core paper is:
@article{winkler18,
author = {Winkler, Alexander W and Bellicoso, Dario C and
Hutter, Marco and Buchli, Jonas},
title = {Gait and Trajectory Optimization for Legged Systems
through Phase-based End-Effector Parameterization},
journal = {IEEE Robotics and Automation Letters (RA-L)},
year = {2018},
month = {July},
pages = {1560-1567},
volume = {3},
doi = {10.1109/LRA.2018.2798285},
}
A broader overview of the topic of Trajectory optimization and derivation of
the Single-Rigid-Body Dynamics model used in this work:
[DOI 10.3929/ethz-b-000272432](https://doi.org/10.3929/ethz-b-000272432)
## Authors
[Alexander W. Winkler](https://www.alex-winkler.com) - Initial Work/Maintainer
The work was carried out at the following institutions:
[
](https://www.ethz.ch/en.html "ETH Zurich") [
](http://www.adrl.ethz.ch/doku.php "Agile and Dexterous Robotics Lab") [
](http://www.rsl.ethz.ch/ "Robotic Systems Lab")
[A. W. Winkler]: https://awinkler.github.io/publications.html
[CMake]: https://cmake.org/cmake/help/v3.0/
[std_msgs]: http://wiki.ros.org/std_msgs
[roscpp]: http://wiki.ros.org/roscpp
[message_generation]: http://wiki.ros.org/message_generation
[rosbag]: http://wiki.ros.org/rosbag
[HyQ]: https://www.iit.it/research/lines/dynamic-legged-systems
[ANYmal]: http://www.rsl.ethz.ch/robots-media/anymal.html
[ROS]: http://www.ros.org
[xpp]: http://wiki.ros.org/xpp
[ifopt_core]: https://github.com/ethz-adrl/ifopt
[ifopt]: https://github.com/ethz-adrl/ifopt
[Ipopt]: https://projects.coin-or.org/Ipopt
[ncurses]: http://invisible-island.net/ncurses/man/ncurses.3x.html
[xterm]: https://linux.die.net/man/1/xterm
[Snopt]: http://www.sbsi-sol-optimize.com/asp/sol_product_snopt.htm
[rviz]: http://wiki.ros.org/rviz
[catkin]: http://wiki.ros.org/catkin
[catkin tools]: http://catkin-tools.readthedocs.org/
[Eigen]: http://eigen.tuxfamily.org
[this example]: https://github.com/ethz-adrl/ifopt/blob/master/ifopt_core/test/ifopt/test_vars_constr_cost.h