VeSyMA Suite
Vehicle Systems Modeling and Analysis Libraries

• CAN-bus style controlBus for vehicle data signal distribution
• Multibody ideal manual, automatic or automated manual dual clutch transmission models
• Mapped petrol and diesel engine models including multibody and frictional effects
• Variable fuel tank mass with dynamic centre-of-gravity position and inertia
• 1D independent brake models, from idealised to hybrid compatible, brake-by-wire and single/twin cylinder pseudo-hydraulic models
• Table based DC motor with static and dynamic state-of-charge (SOC) battery models
• 1D drivetrain, including FWD, RWD and 4WD layouts
• Open and closed-loop driver models capable of longitudinal control of vehicles with pre-loaded standard drive cycles: NEDC (complete, urban and extra urban), Artemis (standard and 130) and the FTP 75 (ETA City) cycle

Vehicle template models found within the VeSyMA library depict various configurations of vehicle, from standard single combustion engine vehicles to hybrid electric and fully electric vehicles.

Designed with a modular approach, subsystem models of various media and/or complexity can be used in the same template model, enabling all VeSyMA extension libraries to be compatible with each other. Beyond this, each template shares a common base class itself; different vehicles of varied layout to be compatible at the experiment top level, meaning vehicles can be swapped in and out of experiments and tested back-to-back with ease.

VeSyMA vehicle models are comprised of the following sub-system components:

• 4 Separate wheel/tyre models
• Body model
• Separate front and rear subframe models
• Separate front and rear axle models
• Brakes model
• Driveline model
• Transmission model
• Engine model (where applicable)
• Driveline mounts model
• Engine cooling system (where applicable)
• Front of Engine Accessory Drive (FEAD) model (where applicable)
• Lubrication model (where applicable)
• Fuel tank (where applicable)
• Battery model (where applicable)
• Motor model (where applicable)
• Electric Motor Transmission (where applicable)

• Control system development using detailed physical models of internal combustion engines.
• Supports spark ignition and compression ignition engines as mean-value or crank-angle resolved models.
• Includes turbocharger and supercharger models for forced induction engines.
• Captures the full transient response of the engine (air-flow, Multi-body and 1-D mechanics and thermal effects).
• In-vehicle NVH and performance analysis when coupled to the Powertrain and Vehicle Dynamics libraries.
• Physical fault insertion.
• Reduction of dyno test time.
• Repeatable virtual test conditions.
• Real-time capability.
• Animation is built-in to the models.
• Aftertreatment.

The Mean Value version predicts the cycle averaged air flow and torque produced by the engine.

The cylinder mass flow rates are calculated through an equation based approach allowing the engine capacity to be scaled within reasonable limits. This enables downsizing studies to be carried out using the library.

The combustion and emissions modeling is map based using manifold pressure and engine speed as the primary inputs to the maps with further corrections for spark timing and afr.

This version of the Engine library is particularly suited to driveability analysis where the effect of throttle transients on the driveline behavior are investigated. In addition, this version of the library is also suited to catalyst light-off investigations.

The Crank Angle Resolved version predicts the cyclic variations for air flow and torque. This is an extension to the Mean Value version of the library.

The combustion heat release is modelled though a two-zone predictive model or a Wiebe model with table based coefficients. The table defines the Wiebe model coefficients at different engine speeds, loads and air-fuel ratios. Both Compression and Spark ignition heat release models are available. Port fuel and direct injection are also supported.

The flow though the engine block is dictated by the valve geometry and opening characteristics and the piston-cylinder assembly model. Valve and spark timing effects on the fluid dynamics and combustion model mean that the engine performance can be investigated using this version of the library.

This version of the Engine library is particularly suited to driveline NVH analysis, mount excitations, cranking and detailed friction modeling.

• Double wishbone suspension models with either pushrod/pullrod or direct spring actuation.
• Solid axle with truck arms and panhard rod for NASCAR
• Kinematic models with optional compliance in uprights, tie rods, anti-roll bar links, pushrods, inboard mounts.
• The suspension mechanisms include a full range of adjustment shims, applied in a physically realistic manner by defining shim sizes.
• All the models are optimized to run in real-time to support hardware, software, and driver-in-the-loop simulations.
• Setup calculation experiments give a convenient method for determining the adjustments required for a desired vehicle setup.
• Pacejka tyre models which incorporate tyre pressure and aerodynamics effects.
• A number of aerodynamic models are available to implement the body and wing aerodynamic effect on the chassis.
• Access to all the experiments and driver models available in VeSyMA Suspensions.

The VeSyMA Motorsports Library provides a comprehensive collection of double wishbone suspension configurations for open-wheel racing applications such as Formula 1, IndyCar and similar vehicle configurations. The models include options for pushrod and pullrod actuation with numerous inboard suspension arrangements.

The inboard suspension models comprise combinations of ride springs, dampers, heave springs, monoshock, inerter and anti-roll systems as well as the rocker mechanism. These optimised suspension models enable real-time running without additional detailed work by the user.

All the suspension models supplied in VeSyMA Motorsports feature a full range of adjustments, which are implemented in a physically realistic manner by the addition of adjustable size shims. The mechanisms also include spring preload adjusters. Setup calculation experiments will automatically determine the adjustments and preloads necessary to achieve a specified setup target.

Geometry records are used in the suspension models for convenient parameterization through a single interface. The library provides a simple tool to easily allow the setup results to be captured into a new geometry record. This method allows the user to quickly change the geometry and setup applied to a vehicle model.

VeSyMA Motorsports includes support for NASCAR where the front suspension model is a double wishbone suspension with outboard springs and dampers but using the same optimized real-time capable model as the other versions of the library. The rear truck arm suspension model has been developed and optimized to be real-time capable.

The library includes generalized setup procedures with methods to enable the customization of the experiments to tailor them to match your own teams process. These experiments allow the tuning of corner weights, frame heights and wheel angles (toe and camber).

For sports car racing and high performance applications the library provides double wishbone suspension configurations with direct acting springs, dampers and anti-roll bars.

All the suspension models supplied in VeSyMA Motorsports feature a full range of adjustments, which are implemented in a physically realistic manner by the addition of adjustable size shims. The mechanisms also include spring preload adjusters. Setup calculation experiments will automatically determine the adjustments and preloads necessary to achieve a specified setup target, these are available for both half car and full chassis models.

Geometry records are used in the suspension models for convenient parameterization through a single interface. The library provides a simple tool to easily allow the setup results to be stored in a new record. This method allows the user to quickly change the geometry and setup applied to a vehicle model.

This library provides vehicle body models specifically for motorsports applications, which include ballast locations and aerodynamics models with separate body, front and rear wings. The aerodynamic examples use either single coefficients or lookup tables for convenient parameterization, but the templates and components can be used and modified should a more complex aerodynamic model be required.

• Detailed powertrain modeling with efficient simulation as a mulitbody system.
• Includes engine, transmission, driveline and chassis models for complete vehicle simulation.
• Build complex mechanical systems from individual elements such as bearings, shafts, gears, clutches, joints and mounting systems.
• Evaluate 3D gear mesh forces, bearing loads and losses.
• Shafts with a large number of linear and nonlinear compliance characteristics.
• Longitudinal chassis models with Pacejka tyre slip and simple suspension with pitch and bounce.
• Compatible with Vehicle Dynamics library, Engines, Powertrain and SmartElectricDrives libraries.
• 3D Effects (torque reactions, gyroscopic effects etc.).
• Faster simulation performance than Standard multibody library.
• Flexible implementation.
• Highly configurable with wide range of component fidelity.

The library is applied in many different applications as follows:

• Vehicle performance, fuel economy and drivability assessment capturing the full motion of the powertrain
• Hardware specification – complete torsional characteristic of transmission and driveline
• Conceptual architecture design – efficiency studies
• Control system optimization using detailed physical models of the complete vehicle
• Modal analysis of the powertrain* for predicting torsional excitation modes i.e. shuffle
• Shift quality and feel – detailed components for capturing the dynamics of the gear shifting system
• Powertrain-chassis interaction – PTDynamics is fully compatible with the Vehicle Dynamics library allowing the interaction between the chassis and powertrain to be analyzed

• Engines: Mapped based engine model for torque generation, emissions and fuel consumption calculation. Simple engine controllers also included for idle speed and fuelling control.
• Transmission: Torque converts, Retarders, shift mechanisms including synchronizers, detents and shift barrels. Powertrain mounts are included with various DOF’s and compliance characteristics.
• Drivelines: Collection of examples and experiments assembled from examples models from the shafts, joints and differentials packages.
• Chassis: Simple chassis with pitch, and roll Degrees of freedom as well as linear and pacejka tyre models are included for longitudinal dynamics. Various road definitions are also included.
• Clutches: Numerous components for modelling torque transfer in a wide range of coupling elements. Wet and dry Multi-plate, Cone, Band and dog elements are all included ranging from simple to complex geometry defined responses.
• Differentials: Templates and examples of gear bearing and shaft arrangements for a wide variety of differential arrangements (open and torsen) including slip control devices.
• Gears: Gear mesh models with 3D force calculations with optional backlash, mesh stiffness and efficiency for spur and helical gears. Numerous planetary configurations are also included configurable for different levels of fidelity. Simple chain drive models are also included.
• Joints: Multibody models of a wide range of joints found within power transmission systems including constant velocity, universal and plunging joints.
• Shafts: Numerous options for uniform and composite shafts are included with a wide variety of torsional characteristics from rigid and simple linear to non-linear plastically deformable characteristics are included using a computationally efficient MultiBody approach.
• Linearization: Linear systems analysis package with functions for natural frequency analysis and plotting.
• Brakes: Simple disc brake models are included.
• Drivers: Open and closed loop drivers available for drive cycle and simple source manoeuvres as well as specific TipIn and idiot start tests.

• Full vehicle dynamic experiments featuring open and closed loop manoeuvres
• Pacejka MF 6.1/6.2 tyre models with F-Tyre support (option for multi-threading)
• 4/7 post rig experiments plus K&C tests
• Full multibody parameterised suspension linkage models
• Lumped linkage compliance models
• Individual mounting bushes for linkages and anti-roll bars
• 3D road models including both high and low frequency/amplitude features
• Table-based suspensions and aggregate joints support real-time applications
• Closed and Open loop driver models
• Fully built up example vehicle models

To facilitate the development of real-time models, all suspension linkages featured in the Suspensions library have been optimised for performance. Care has been taken to ensure the state selection strategy used in each linkage model provides the fastest possible simulation speed with no dynamic states within the model.

Beyond this, the Suspensions library features innovative aggregate joint models, which are specifically designed idealised joints for real-time applications. Featuring a different concept of force and angle calculation, aggregate joints are more efficient computationally than standard multibody joints.

Also included in the library is the ability to map a multibody suspension linkage and generate a table based approximation. A full complement of data collection experiments alongside the relevant harvesting functions means the process is as simple as designating the desired linkage model to be mapped, setting output data parameters and clicking execute.

Due to the shared parentage with the VeSyMA library, any vehicle model built from the Suspensions library is compatible with the real-time simulator templates found in the Driver-in-the-Loop (DiL) library.

In addition to the compliment of ideal multibody linkages, examples of non-linear compliant and bushed linkages models are also provided. As the linkage model templates have been designed to support both ideal joints and bushed joints in addition to rigid and linear compliance blocks, any linkage model can be fashioned into compliant linkages.

Linear, non-linear and frequency dependent bushes are available in the Suspensions library with a built-in preload tuner, which calculates the preload forces for the bushes to ensure the linkage model the bush is used within initializes with no deflection in the bushes beyond a tolerance the user sets in the tuning process.

Linkage compliance is lumped in the arm mounting and strut mounting points, to enable K&C (kinematic and compliance) effects to be captured. A range of compliance blocks are available for use, ranging from single degree of freedom translational or rotational to full 6 DOF blocks. Both standard compliance blocks using spring dampers, and more computationally efficient quasi-static versions are available.

Individual quarter car and half car kinematics experiments enable optimization of suspension geometry. All commonly used suspension linkages are included as models:

• Multilink Hybrid
• Double Wishbone
• MacPherson
• Multilink (rear/non-steered only)
• Trapezoidal (rear/non-steered only)
• Trailing Arm (rear/non-steered only)

A range of full vehicle experiments are available in the Suspensions library, complete with calibrated driver models and analysis scripts loaded into the experiments as commands. The double lane change, J-Turn and Fishhook experiments comply with the relevant ISO and NHTSA standards. The experiments included are:

• Acceleration test
• Coastdown test
• Braking test
• Braking test on split mue/split friction road surface
• Double lane change test
• Double lane change test on a rough road
• Slalom test
• Slalom test with ESP (Electronic Stability Programme) equipped vehicle
• J-Turn test
• Fishhook test
• Steering ramp test
• Figure of 8 closed loop test
• Banked circle closed loop test
• Rough road with large curbs test

In addition to these tests, a range of vehicle rig experiments are also available:

• 7 Post Rig
• 4 Post Rig with variable normal direction
• Single Post rig
• Lateral pulling force K&C test
• Pull down K&C test
• Full vehicle compliance test

• Enables the use of rFpro track data in Dymola simulations
• Ensures consistency between the driving simulator and offline simulation
• Provides support for both the standard and high definition track models supplied by rFpro
• Includes support for all the tyre contact methods supported by rFpro TerrainServer
• Also provides support for additional gr0und contact points to be retrieved to provide a detailed representation of the surface underneath the vehicle