API Reference

trep is a Python module for simulation and trajectory optimization of mechanical systems in generalized coordinates.

The dynamics can be modeled in continuous time as a traditional ODE, or in discrete time using variational integrators.

The central component of trep is the System class. A System is a collection of coordinate frames, forces, potential energies, and constraints that describe a mechanical system in generalized coordinates. The System is capable of calculating the continuous dynamics and the first and second derivatives of the dynamics.

• trep - Core Components
  • System - A Mechanical System
  • Frame – Coordinate Frame
  • Config – Configuration Variables
  • Input – Input Variables
  • Force – Base Class for Forces
  • Potential – Base Class for Potential Energies
  • Constraint – Base Class for Holonomic Constraints
  • MidpointVI - Midpoint Variational Integrator
• trep.potentials - Potential Energies
  • Gravity – Basic Gravity
  • LinearSpring – Linear spring between two points
  • ConfigSpring – Linear Spring acting on a configuration variable
  • NonlinearConfigSpring – Nonlinear spring acting on a configuration variable
• trep.forces - Forces
  • Damping – Damping on Configuration Variables
  • LinearDamper – Linear damper between two points
  • ConfigForce – Apply forces to a configuration variable.
  • BodyWrench – Apply a body wrench to a frame.
  • HybridWrench – Apply a hybrid wrench to a frame.
  • SpatialWrench – Apply a spatial wrench to a frame.
• trep.constraints - Holonomic Constraints
  • Distance - Maintain a specific distance between points
  • PointToPoint - Constrain the origins of two frames together
  • PointOnPlane - Constraint a point to a plane
• trep.discopt - Discrete Optimal Control
  • Discrete LQ Problems
  • DSystem - Discrete System wrapper for Midpoint Variational Integrators
  • DCost - Discrete Trajectory Cost
  • DOptimizer - Discrete Trajectory Optimization
• trep.ros - ROS Tools
  • URDF Import Tool
  • ROSMidpointVI - ROS Midpoint Variational Integrator
• Misc. Components
  • Spline – Spline Objects
  • TapeMeasure – Measuring distances between frames