Real Time Dynamics

Last Update: February 2, 1996 Comments or Suggestions? krumm@iai.fzk.de


Introduction

The simulation of the dynamic behaviour of a mechanism, e.g. a robot, can be very useful for simulating robot motion, the evaluation of kinematic design or the design of suitable control equations for a robot. Basically the term 'Dynamics' can be devided into Direct- or Forward Dynamics, that is, given the desired torques/forces acting on a mechanism the resulting joint accelerations have to be calculated, which are then integrated to get the joint positions and velocities, and Indirect or Inverse Dynamics, that is, given the desired motion of the mechanism, the needed forces/torques are calculated.

Picture on the left shows an example for Direct Dynamics as animated gif.

Real-time dynamic simulation with KISMET

The simulation system KISMET is able to calculate and display the dynamic behaviour of mechanisms (e.g. pendulums, robots etc.) in real-time. The DYNAMICS feature in KISMET covers real-time simulation of:


Now available:(for KISMET Users only): The KISMET Guide to DYNAMICS
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Direct Dynamics:

The movement of a mechanism due to external and/or internal forces is calculated.

Example 1: A pendulum moves due to the gravitational force.

Forces and Torques of a pendulum (JPEG, 58kB)

Example 2: Jumping Jack as an example for branched kinematics.

Jumping Jack (JPEG, 88kB)


Indirect or Inverse Dynamics:

Forces and torques which are necessary to perform a certain movement are calculated.

Example: Simulation of a robot program: The forces and torques necessary to perform the demanded movement of the robot are calculated and diplayed either on-line as force/torque arrows or off-line as a diagram.

Forces and Torques acting on EDITH(JPEG, 145kB)

Diagram Output(JPEG, 279kB)

Pictures above show the EDITH Boom.


Control Systems:

The dynamic behaviour of a robot and its corresponding control-system will be calculated. The user can simulate a complex control system out of control-primitives in order to build a model of the dynamic behaviour of the control-system. Together with the model of the dynamic behaviour of the robot itself a simulation of the whole system (robot and control system) is possible.


See also: [Simulation of Deflections], [Force Feedback]
This page has been hit times since June 14, 1996 and is maintained by
Hans-Georg Krumm krumm@iai.fzk.de
Institut für angewandte Informatik (IAI)
Forschungszentrum Karlsruhe
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