balisujohn / pypose

To connect classic robotics with modern learning methods seamlessly.

PyPose: A Library for Robot Learning with Physics-based Optimization

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Deep learning has had remarkable success in robotic perception, but its data-centric nature suffers when it comes to generalizing to ever-changing environments. By contrast, physics-based optimization generalizes better, but it does not perform as well in complicated tasks due to the lack of high-level semantic information and the reliance on manual parametric tuning. To take advantage of these two complementary worlds, we present PyPose: a robotics-oriented, PyTorch-based library that combines deep perceptual models with physics-based optimization techniques. Our design goal for PyPose is to make it user-friendly, efficient, and interpretable with a tidy and well-organized architecture. Using an imperative style interface, it can be easily integrated into real-world robotic applications.

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Current Features

LieTensor

• Lie group: SO3, SE3, Sim3, RxSO3
• Lie algebra: so3, se3, sim3, rxso3

Modules

• System
• IMUPreintegration
• ......

Second-order Optimizers

• GaussNewton
• LevenbergMarquardt
• ......

Want more features? Create an issue here to requst new features.

PyPose is highly efficient and supports parallel computing for Jacobian of Lie group and Lie algebra. See following comparison.

Efficiency comparisons of Lie group operations on CPU and GPU (we take Theseus performance as 1×).

More information about efficiency comparison goes to our paper for PyPose.

Getting Started

Installation

Install from pypi

pip install pypose

From source

git clone https://github.com/pypose/pypose.git && cd pypose
python setup.py develop

For early users

1. Requirement:

On Ubuntu, MasOS, or Windows, install PyTorch, then run:

pip install -r requirements/main.txt

2. Install locally:

git clone  https://github.com/pypose/pypose.git
cd pypose && python setup.py develop

3. Run tests

pytest

For contributors

1. Make sure the above installation is correct.

2. Go to CONTRIBUTING.md

Examples

1. The following code sample shows how to rotate random points and compute the gradient of batched rotation.

>>> import torch, pypose as pp

>>> # A random so(3) LieTensor
>>> r = pp.randn_so3(2, requires_grad=True)
    so3Type LieTensor:
    tensor([[ 0.1606,  0.0232, -1.5516],
            [-0.0807, -0.7184, -0.1102]], requires_grad=True)

>>> R = r.Exp() # Equivalent to: R = pp.Exp(r)
    SO3Type LieTensor:
    tensor([[ 0.0724,  0.0104, -0.6995,  0.7109],
            [-0.0395, -0.3513, -0.0539,  0.9339]], grad_fn=<AliasBackward0>)

>>> p = R @ torch.randn(3) # Rotate random point
    tensor([[ 0.8045, -0.8555,  0.5260],
            [ 0.3502,  0.8337,  0.9154]], grad_fn=<ViewBackward0>)

>>> p.sum().backward()     # Compute gradient
>>> r.grad                 # Print gradient
    tensor([[-0.7920, -0.9510,  1.7110],
            [-0.2659,  0.5709, -0.3855]])

2. This example shows how to estimate batched inverse of transform by a second-order optimizer. Two usage options for a scheduler are provided, each of which can work independently.

>>> import torch, pypose as pp
>>> from pp.optim import LM
>>> from pp.optim.strategy import Constant
>>> from pp.optim.scheduler import StopOnPlateau

>>> class InvNet(nn.Module):

        def __init__(self, *dim):
            super().__init__()
            init = pp.randn_SE3(*dim)
            self.pose = pp.Parameter(init)

        def forward(self, input):
            error = (self.pose @ input).Log()
            return error.tensor()

>>> device = torch.device("cuda")
>>> input = pp.randn_SE3(2, 2, device=device)
>>> invnet = InvNet(2, 2).to(device)
>>> strategy = Constant(damping=1e-4)
>>> optimizer = LM(invnet, strategy=strategy)
>>> scheduler = StopOnPlateau(optimizer, steps=10, patience=3, decreasing=1e-3, verbose=True)

>>> # 1st option, full optimization
>>> scheduler.optimize(input=input)

>>> # 2nd option, step optimization
>>> while scheduler.continual:
        loss = optimizer.step(input)
        scheduler.step(loss)

>>> # Note: remove one of the above options for usage!

For more usage, see Documentation. For more applications, see Examples.

Citing PyPose

If you use PyPose, please cite the paper below. You may also download it here.

@article{wang2022pypose,
  title   = {{PyPose: A Library for Robot Learning with Physics-based Optimization}},
  author  = {Chen Wang, Dasong Gao, Kuan Xu, Junyi Geng, Yaoyu Hu, Yuheng Qiu, Bowen Li, Fan Yang, Brady Moon, Abhinav Pandey, Aryan, Jiahe Xu, Tianhao Wu, Haonan He, Daning Huang, Zhongqiang Ren, Shibo Zhao, Taimeng Fu, Pranay Reddy, Xiao Lin, Wenshan Wang, Jingnan Shi, Rajat Talak, Han Wang, Huai Yu, Shanzhao Wang, Ananth Kashyap, Rohan Bandaru, Karthik Dantu, Jiajun Wu, Luca Carlone, Marco Hutter, Sebastian Scherer},
  journal = {arXiv preprint arXiv:2209.15428},
  year    = {2022}
}