motiondepends

Motiondepends is an open-source framework for describing and analyzing motion-dependent relationships in mechanical and robotic systems. It provides a formal language to express how quantities such as position, velocity, force, and energy depend on one another over time, and it models these relationships as a dependency graph of quantities and relationships.

In motiondepends, nodes represent physical quantities and edges denote functional, differential, or algebraic relationships. The framework can automatically derive equations of motion from a defined graph, and it supports code generation for multiple target languages to enable integration with simulation engines and control pipelines.

Origin and license: Motiondepends originated in the early 2020s through a collaboration of researchers and engineers and is maintained by an open-source community. The project publishes releases on its primary repository under a permissive license, with ongoing contributions and documentation.

Key features include a declarative syntax for defining dependencies, automatic scheduling of state updates, support for differential-algebraic equations, and optional code generators that produce solver-ready routines. It also includes tools for visualizing dependency graphs and motion traces.

Applications include robotics motion planning and control, vehicle dynamics, biomechanics, and education. Users can model linkages, actuators, sensors, and control laws, then simulate how perturbations propagate through the system.

Limitations and development: the accuracy of models depends on the quality of the specified relationships and numerical solvers. The project emphasizes interoperability and continues to expand its language, solvers, and integration with external tools.

See also and references: See also dependency graphs, differential-algebraic equations, motion planning, and system dynamics. For more information, consult the official documentation and the GitHub repository.