A Recursive Formulation for Real-Time Dynamic Simulation of Mechanical Systems

1991 ◽  
Vol 113 (2) ◽  
pp. 158-166 ◽  
Author(s):  
Dae-Sung Bae ◽  
Ruoh-Shih Hwang ◽  
Edward J. Haug
Keyword(s):  
Real Time ◽  
Dynamic Simulation ◽  
Recursive Algorithm ◽  
Equations Of Motion ◽  
Mechanical Systems ◽  
Time Dynamic ◽  
Time Simulation ◽  
Kinematic Loops ◽  
Multi Body ◽  
Recursive Equations

A new recursive algorithm for real-time dynamic simulation of mechanical systems with closed kinematic loops is presented. State vector kinematic relations that represent translational and rotational motion are defined to simplify the formulation and to relieve computational burden. Recursive equations of motion are first derived for a single loop multi-body system. Faster than real-time performance is demonstrated for a closed loop manipulator, using an Alliant FX/8 multiprocessor. The algorithm is extended to multi-loop, multi-body systems for parallel processing real-time simulation in companion papers [1, 2] where performance of the algorithm on a shared memory multi-processor is compared with that achieved with other dynamic simulation algorithms.

A Recursive Formulation for Real-Time Dynamic Simulation

1988 ◽  
Author(s):  
D.-S. Bae ◽  
R. S. Hwang ◽  
E. J. Haug
Keyword(s):  
Real Time ◽  
Dynamic Simulation ◽  
Recursive Algorithm ◽  
Equations Of Motion ◽  
Design Tool ◽  
Real Time Simulation ◽  
Time Dynamic ◽  
Time Simulation ◽  
Design Variation ◽  
Multi Body

Abstract A new recursive algorithm for real-time, interactive dynamic simulation, animated graphics, and design variation analysis is presented for mechanical systems with closed loops. State vector kinematic relations that represent translational and rotational motion are defined, to simplify the formulation and to relieve computational burden. Recursive equations of motion are first derived for a single loop multi-body system. Faster than real-time performance is demonstrated for a closed loop robot, using an Alliant FX/8 multiprocessor. The algorithm is extended to multi-loop, multi-body systems for parallel processing real-time simulation in companion papers [1,2]. Performance of the algorithm on a shared memory multi-processor is compared with that achieved with other dynamic simulation algorithms. A vehicle example is used to demonstrate efficiency of the algorithm for real-time simulation and graphics rendering in a network environment, for use as an interactive design tool.

Parallel Processing for Real-Time Dynamic System Simulation

1988 ◽  
Author(s):  
R. S. Hwang ◽  
D.-S. Bae ◽  
E. J. Haug ◽  
J. G. Kuhl
Keyword(s):  
Parallel Processing ◽  
Real Time ◽  
Equations Of Motion ◽  
Companion Paper ◽  
Time Dynamic ◽  
Closed Loop Systems ◽  
Time Simulation ◽  
Efficiency And Effectiveness ◽  
Generalized Force ◽  
Recursive Dynamics

Abstract A parallel processing algorithm based on the recursive dynamics formulation presented in a companion paper [1] is developed for multiprocessor implementation. Lagrange multipliers associated with cut-joint constraints for closed loop systems are eliminated systematically, resulting to a minimal set of equations of motion. Concurrent generation of the system inertia matrix and the generalized force vector is exploited. A new computational structure for dynamic analysis is proposed for real-time parallel processing. Real-time simulation of a vehicle is performed to illustrate efficiency and effectiveness of the algorithm, even for interactive man-in-the-loop simulation.

Real-time analysis of mobile machines using sparse matrix technique

2016 ◽  
Vol 230 (4) ◽  
pp. 615-625 ◽  
Author(s):  
Ezral Baharudin ◽  
Asko Rouvinen ◽  
Pasi Korkealaakso ◽  
Marko K Matikainen ◽  
Aki Mikkola
Keyword(s):  
Real Time ◽  
Sparse Matrix ◽  
Equations Of Motion ◽  
Numerical Procedure ◽  
Augmented Lagrangian Methods ◽  
Time Dynamic ◽  
Real Time Analysis ◽  
Simulation Techniques ◽  
Time Simulation ◽  
High Level

The use of modern multibody simulation techniques enables the description of complex products, such as mobile machinery, with a high level of detail while still solving the equations of motion in real time. Using the appropriate modelling and implementation techniques, the accuracy of real-time simulation can be improved considerably. Conventionally, in multibody system dynamics, equations of motion are implemented using the full matrices approach that does not consider the sparsity feature of matrices. With this implementation approach, numerical efficiency decreases when sparsity increases. In this study, a numerical procedure based on semi-recursive and augmented Lagrangian methods for real-time dynamic simulation is introduced. To enhance computing efficiency, an equation of motion is implemented by employing the sparse matrix technique.

Modelling of off-road wheeled vehicles for real-time dynamic simulation

2021 ◽  
Vol 97 ◽  
pp. 45-58
Author(s):  
Albert Peiret ◽  
Eric Karpman ◽  
László L. Kovács ◽  
József Kövecses ◽  
Daniel Holz ◽  
...  
Keyword(s):  
Real Time ◽  
Dynamic Simulation ◽  
Time Dynamic ◽  
Wheeled Vehicles

A Network Implementation of Real-Time Dynamic Simulation With Interactive Animated Graphics

1988 ◽  
Author(s):  
M. W. Dubetz ◽  
J. G. Kuhl ◽  
E. J. Haug
Keyword(s):  
Real Time ◽  
Dynamic Simulation ◽  
High Speed ◽  
Dynamic Performance ◽  
Data Communication ◽  
Computing System ◽  
Data Sets ◽  
Parallel Processor ◽  
Network Computing ◽  
Time Dynamic

Abstract This paper presents a network based implementation of real-time dynamic simulation methods. An interactive animated graphics environment is presented that permits the engineer to view high quality animated graphics rendering of dynamic performance, to interact with the simulation, and to study the effects of design variations, while the simulation is being carried out. An industry standard network computing system is employed to interface the parallel processor that carries out the dynamic simulation and a high speed graphics processor that creates and displays animated graphics. Multi-windowing and graphics processing methods that are employed to provide visualization and operator control of the simulation are presented. A vehicle dynamics application is used to illustrate the methods developed and to analyze communication bandwidth requirements for implementation with a compute server that is remote from the graphics workstation. It is shown that, while massive data sets are generated on the parallel processor during realtime dynamic simulation and extensive graphics data are generated on the workstation during rendering and display, data communication requirements between the compute server and the workstation are well within the capability of existing networks.

Performance of a Track Geometry Car-Based Real-Time Dynamics Simulator Using Multiple Vehicle Types

2003 ◽  
Author(s):  
Clifford S. Bonaventura ◽  
Joseph W. Palese ◽  
Allan M. Zarembski
Keyword(s):  
Real Time ◽  
Dynamic Model ◽  
Dynamic Simulation ◽  
Simulation System ◽  
Time Dynamic ◽  
Track Geometry ◽  
Time Dynamics ◽  
Rail Vehicle ◽  
Empty Condition ◽  
Traveling Speed

A real-time dynamic simulation system designed to identify sections of track geometry that are likely to cause unsafe rail vehicle response is discussed. Known as TrackSafe, this system operates onboard a track geometry vehicle where the geometry measurements are passed as inputs to the dynamic model of one or more rail vehicle types. In order to comprehensively analyze the effect of the existing geometry on rail vehicle behavior, the system is capable of simultaneously simulating the response of several vehicle models, each over a range of traveling speeds. The resulting response predictions for each modeled vehicle and each simulated traveling speed are used to assess the track geometry condition and to identify locations leading to potentially unsafe response. This paper presents the latest work in the development of TrackSafe, specifically, the development and testing of eight new vehicle models is presented. The new car types modeled include a box car, flat car, and both a long and short tank car. Each can be simulated in a fully loaded or empty condition. Accuracy of the models is discussed in detail.

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