The Recursive Dynamics Simulator (ReDySim) is a MATLAB-based recursive solver for dynamic analysis of robotic and multibody systems. It essentially consist of very efficient recursive inverse and forward dynamics algorithms for simulation and control of open and closed-loop multibody systems. ReDySim delves upon the concept of Decoupled Natural Orthogonal Complement (DeNOC) based approach for dynamic modeling. In comparison to commercially available software, dynamic analyses in ReDySim can be performed without creating solid model. ReDySim has capability to incorporate any control algorithm and trajectory planner with utmost ease. These abilities provide flexibility to user/researcher in incorporating their customized algorithms with ease. ReDySim showed considerable improvement over commercial software such as ADAMS, RecurDyn and algorithms available in literature in terms of the computational time and numerical accuracy [1]. The gain in computational time is more as the number of links and joints in the system increase. The algorithms in ReDySim have also been used in RoboAnalyzer, a 3D model based software for robot simulation, developed in Mechanical Engineering Department at IIT Delhi.

Virtual Summer Internship with ReDySim 2021

The details of the internship are available here.


1. Basic Module: Fixed-Base Systems
This module can be used to perform inverse and forward dynamics for fixed-base open- and closed-loop robotic and multibody systems.
Version 1: This version can model only rotary joints. Click here to download.
Version 2: This version can model both rotary and prismatic (sliding) joints. Click here to download
GUI Version: This version has a user-friendly GUI using the MATLAB's App Designer [April 11, 2021]. Click here to download.
2. Specialized Module: Floating-Base Systems
A. Floating-Base Systems: Space Robots
This module can be used to perform inverse and forward dynamics of free-floating systems such as space robots. Click here to download.
B: Floating-Base Systems: Legged Robots
This module can be used to perform inverse and forward dynamics of floating-base systems interacting with environment such as legged robots. Click here to download.
3. Symbolic Module: Open-loop fixed and floating-base Systems
This module can generate equations of motion for open-loop fixed- and floating-base systems in symbolic form. Click here to download.


A team of students and faculty at IIT Jodhpur and Delhi.