dynibo 0.3.0

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dynibo is a fast, lightweight, and reliable library for robot kinematics and dynamics. It loads robot topology from URDF at runtime and provides allocation-free calculations through reusable workspaces. Python and C/C++ interfaces are available on top of the same Rust core.

Features

Fast

Across the benchmarks below, Dynibo runs 1.19–2.51× as fast as Pinocchio for the measured core operations. It is written in Rust and keeps allocation outside the calculation loop. After a Workspace and output buffers are created, the main kinematics and dynamics routines reuse that memory without allocating or resizing.

The table below shows Dynibo's speedup over Pinocchio for core kinematics and dynamics operations.

These Criterion quick-mode results use the same URDF models and joint states on an Intel Core i9-14900K with rustc 1.97.1 and Pinocchio 3.9.0. Setup and allocation are excluded, and speedups use interval medians after subtracting the measured 0.703 ns fixed C ABI overhead. With Pinocchio available through pkg-config, rerun the raw benchmarks with:

cargo bench --features pinocchio-bench --bench pinocchio -- --quick

Lightweight

Dynibo intentionally focuses on the most commonly used robot kinematics and dynamics interfaces:

• forward_kinematics — target-link pose
• jacobian — target-link Jacobian
• jacobian_derivative — time derivative of the target-link Jacobian
• forward_velocity_kinematics — spatial velocity
• forward_acceleration_kinematics — spatial acceleration
• inverse_kinematics — damped least-squares IK
• mass_matrix — joint-space mass matrix
• velocity_product_forces — Coriolis and centrifugal generalized forces
• gravity — gravity compensation with optional external loads
• inverse_dynamics — recursive Newton–Euler inverse dynamics

The API is built around a small set of types: Robot, Workspace, LinkId, Frame, Twist, and Wrench. Rust, Python, C, and C++ interfaces share the same Rust implementation.

Reliable

Dynibo is thoroughly unit-tested. Tests cover finite-difference kinematics, dynamics regressions, branched robots and external loads, inverse kinematics, invalid inputs, workspace ownership and reuse, and allocation-free calculation. An independent Pinocchio oracle also compares complete FK, Jacobian, Jacobian time-derivative, mass matrix, velocity-product forces, gravity, and RNEA outputs over deterministic robot states.

Dependencies

The Rust core has two direct runtime dependencies:

• nalgebra — linear algebra and numerical types
• urdf-rs — URDF parsing

Python wheels bundle the native library and have no runtime Python dependencies.

Quick start

Rust

Add the Cargo package:

cargo add dynibo

Load a URDF, create a reusable workspace, and compute a target-link pose:

use dynibo::{BaseState, Robot};

fn main() -> dynibo::Result<()> {
    let robot = Robot::from_urdf("robot.urdf")?;
    let base = BaseState::fixed();
    let tool = robot.link_id("tool")?;
    let mut workspace = robot.workspace();
    let q = vec![0.0; robot.joint_count()];

    let pose = robot.forward_kinematics(&base, &q, tool, &mut workspace)?;
    println!("translation: {}", pose.translation.vector.transpose());
    Ok(())
}

Python

Install the Python package from PyPI:

python -m pip install dynibo

The Python binding owns its reusable native workspace:

from dynibo import Robot

with Robot.from_urdf("robot.urdf") as robot:
    tool = robot.link_id("tool")
    q = [0.0] * robot.joint_count
    pose = robot.forward_kinematics(q, tool)
    print(pose.translation)

C/C++

Build and install the CMake package from source. This requires Rust with Cargo and CMake 3.16 or newer:

cmake -S . -B build/c -DCMAKE_BUILD_TYPE=Release
cmake --build build/c --parallel
cmake --install build/c --prefix /opt/dynibo

Use the installed package from another CMake project:

find_package(dynibo CONFIG REQUIRED)
target_link_libraries(my_robot PRIVATE dynibo::dynibo)

If dynibo was installed to a custom prefix, configure the consumer with -DCMAKE_PREFIX_PATH=/opt/dynibo (or the prefix you selected).

Examples

Complete Rust, Python, and C examples are available in the examples/ directory. Each example exercises all of the main kinematics and dynamics methods listed above.

Supported models

Dynibo supports runtime-sized tree URDFs with revolute, continuous, prismatic, and fixed joints. It rejects invalid topology and reports structured errors for bad input lengths, model-mismatched handles, and solver failures.

Testing

cargo fmt --all -- --check
cargo clippy --workspace --all-targets --locked -- -D warnings
cargo test --workspace --all-targets --locked

Run the complete local Rust, Python, C, and C++ verification suite with the command below. Pinocchio reference tests are included when Pinocchio is available through pkg-config.

bash ci/test-all.sh

Contributing

Dynibo is still at an early stage, and contributions are welcome. See CONTRIBUTING.md for development setup, required checks, and pull request guidelines.

Citation

If Dynibo is useful in your work, please cite it as:

@software{xue2026dynibo,
  author  = {Xue, Xiaojie},
  title   = {Dynibo: a Fast, Lightweight, and Reliable Robot Kinematics and Dynamics Library},
  year    = {2026},
  version = {0.3.0},
  url     = {https://github.com/xiaojie-xue/dynibo}
}