Multibody Dynamics Simulation




Concurrent Dynamics creates high fidelity Multibody Dynamics Simulation programs to assess dynamics and control performances of mechanisms and robotics. They expedite:

  • Concept Feasibility Evaluation

  • Control System Design and Testing

  • Hardware-in-the-Loop Simulation

  • System Failure Analysis, etc..

NASA-JPL-Robosimian-robot, courtesy of NASA

We have ready-to-use simulations for a variety of vehicles and for different operations. Three simulations are shown below and more are on the space vehicle page and in the works. The model equations in these packages are derived from the Newton-Euler formulation. They deliver extremely accurate results and run significantly faster than programs built by leading commercial codes. Moreover, they can be modified easily to fit user's immediate needs. 

Our simulations run on PC's with Window XP and Window 7/8 equipped with Matlab/Simulink. Their main program

  • Generates minimal state multibody dynamics equations for each vehicle or mechanism being simulated 

  • Solves the dynamics equations efficiently (by order(N) method) so you can concentrate on the design and testing of control systems

  • Connects easily with user defined control systems

  • Permits easy model/ control system parameter modifications to achieve simulation goals quickly

The manual in each package  explains how to define a model file using the tool, buildx.exe. This definition encompass mechanism connectivity, mass property of bodies and wheels, force objects, gravity model selection and dynamics input/output/plot data list. It also shows how to build a nominal control system for the mechanism represented by the model file. It then uses that control system to perform a control task or a number of tasks. 

Write to regarding our simulations. Click pdf below for details on creating the model file using the editor, buildx.exe, and on the mdl file designed for that application and more. 

Arm6x : Simulates a ground fixed 6 joint robotic arm with a nominal position control system. It has a control algorithm to move the arm from one configuration to another. pdf 

OneCylinderEngine:  Simulates a one cylinder engine running under two-stroke and four-stroke modes. Combustion force profile and crank/piston friction forces determine engine performance. pdf 

Inv_Pendulum : Simulates a cart carrying an inverted pendulm. Its conrol system keeps the pendulum upright while moving the cart to a commanded position. pdf 


Back to space vehicle page

Send inquiries to

Interesting Websites:

  1. Multibody System Dynamics- Research Activities ( )
  2. Review of multibody dynamics software ( )



Concurrent Dynamics International
Last modified: June 24, 2018