TruckSim

Packages

TruckSim is a software package for simulating and analyzing the behavior of heavy trucks and combination vehicles in response to steering, braking, and acceleration inputs. The truck models and some of the smaller combination vehicle models run faster than real-time using ordinary PC's. The basic TruckSim packages require no other software, although full compatibility with other simulation environments such as MATLAB/Simulink, LabView, and ETAS ASCET is included for users who want to extend the models. Additional packages offer extra capabilities.

TruckSim

TruckSim includes the VehicleSim (VS) browser and database, engineering plotter, animator, and vehicle models.

The vehicle models are provided as dynamically linked libraries (DLL's). The same DLL is used for stand-alone runs (the core vehicle model running with no external software), or with Simulink, or LabView, or ASCET, or custom programs written in C. The DLL always runs at high speed, giving results much faster than real-time on typical PCs. Of course, identical behavior is obtained regardless of the simulation environment, because there is just one DLL used in different contexts.

Windows Hardware and Software Compatibility

The software runs on Windows 7, Vista, XP, or 2000, with either 32-bit or 64-bit versions (7, Vista, XP).

The math model VS solver programs are CPU intensive, so fast Intel-compatible machines with at least 1 GB RAM are preferred. However, they work fine with 1 Gz (although 2.4+ GHz is recommended). The hard drive should have at least 1 GB of free disk space. The animator makes use of the video card hardware and requires OpenGL 2.0 hardware support with at least 128 MB video memory (NVIDIA, ATI, or similar cards are needed).

Here are versions of popular external software that can optionally be used to extend the models:

• MATLAB R13.1 and up; new multi-port Simulink support of sensors requires MATLAB R14 and up
• LabVIEW 8.2 and up
• ASCET 5.2 and up
• TNO MF-Tyre 6.1 and up
• TNO MF-Swift 6.1 and up (Optional license required from TNO)
• COSIN FTire Version 2.8 (Optional license required from FTire. Ftire is updated frequently; versions 2.9 and 2.10 do not work; please contact us for information about newer versions.)

Note: 64-bit MATLAB/Simulink works with 64-bit VS Solvers; all of the other packages work with the 32-bit VS solvers. (Both 32-bit and 64-bit versions are provided in the normal installations.)

Extended Models: Cab Mounts and Frame Torsional Compliance

Extended TruckSim models are available with mounted cabs and frame torsional compliance. The cab mounts are important when evaluating ride quality in the cab. The frame torsional compliance is an important factor in determining the load transfer to the tires and therefore it affects handling and other behaviors.

The extra complexity slows the simulation time by about 20% and requires data that might be hard to obtain for many users; this is why the basic models are based on the more simple assumption of torsionally rigid frames.

Vehicle Configurations that are Standard in TruckSim

The overall vehicle configuration is described with a short code based on these rules:

• Each axle is represented with the name I or S , indicating whether the associated suspension is an independent (I) or solid-axle (S) system.
• Axles on a vehicle unit that have no load-equalization linkages are separated by an underscore. For example, a 2-axle vehicle with solid-axle suspensions is represented as S_S.
• Axles that make up a tandem suspension are written with no separator. For example, a 3-axle single-unit vehicle with solid-axle suspensions and a tandem linking axles 2 and 3 is represented as S_SS.
• Hitches between vehicle units are represented with plus signs and surrounding spaces (" + "). For example, a 3-axle combination vehicle with all solid axles is represented as " S_S + S ."
• Programs that include the frame twist (and mounted cab) extra modeling detail have a prefix of "F_", such as "F_S_S."
• Dollies are indicated with a prefix "D" for the unit, such as "S_S + S + DS + S."

Using this notation, the table below lists the 19 configurations that come with TruckSim in the basic package and in the optional package that includes frame torsional flexibility. These 38 models are provided both as 32-bit and 64-bit DLLs for use with corresponding versions of Windows XP, Vista, and Windows 7.

Custom

In addition to the 16 axle-trailer configurations included in TruckSim, you can order other configurations of trailers and axles. The database supports an almost unlimited number of trailer, dolly, and axle combinations, and we can provide the math models to go along with those combinations.

TruckSim RT

TruckSim Real-Time (RT) provides math models compiled to run on "target" computers with real-time operating systems such as QNX or Linux RT. A Windows "host" machine is used for the TruckSim database, animator, and plotter. Files are automatically sent to and received from the target, where the Hardware-in-the-Loop (HIL) testing is controlled.

Input and output files from TruckSim RT can be exchanged with users of offline (Windows, non-RT) TruckSim. This lets you follow the same design and evaluation from preliminary design to HIL evaluation.

TruckSim Source

Source code is available for math model equations, to support custom projects such as driving simulators and advanced software projects. All of the source code for the multibody kinematics and dynamics (machine-generated by VS Lisp, a symbolic multibody program) is provided, along with some of the hand-written library routines for the springs, controllers, etc. A precompiled library file is also provided that provides low-level runtime support for reading input files, processing VS commands, and handling the proprietary 3D VS road model.

Note that you might not need the full source. Even the basic TruckSim package comes with limited source that allows you to extend the models using the VehicleSim application program interface (API).

Driving Simulators (TruckSim DS)

CarSim vehicle math models have been used in many driving simulators, and TruckSim is also being used for advanced driving simulators.

Here are several ways to use TruckSim in a driving simulator.

• The TruckSim DS desktop package includes the basic TruckSim software, plus an RT version of SurfAnim (the animator in TruckSim), plus a real-time block that slows the math model down to "wait" for real time, plus controllers for inexpensive (game) controls for steering, braking, and shifting the transmission. Options for this package include a higher-quality steering system for more accurate steering feel, and additional live animations for mutiple-screen systems.
• TruckSim source and TruckSim RT can be used to replace the math models in existing simulator systems. If the simulators run the math model on a Windows PC, it is often possible to run the regular TruckSim math model DLL's using the VehicleSim API to link between your simulation environment and the TruckSim DLL's.
• TruckSim runtime is an option for companies that develop driving simulators. Using TruckSim source or RT to get started, the math models can be modified as needed and then a multiple-copy license is arranged with Mechanical Simulation for the customized copies.

Be aware that larger, more complicated vehicle models run slower than smaller models. It is still possible to generate TruckSim models for large vehicles that will not run well in real time. The more trailers and axles exist in the model, the slower it runs. All of the models included in TruckSim 7 run faster than real time on a fast PC, but larger custom models might run slower.

TruckSim Information