Mechanical Simulation Corporation has released the 2019.1 versions of its CarSim and TruckSim vehicle dynamics simulation tools, which provide high-fidelity math models that reproduce physical test results, while also being claimed to run fast enough on the computer to support real-time simulation with hardware in the loop.
With the growing need by the automotive industry to improve support for Advanced Driver Assistance Systems (ADAS) and autonomous vehicles, there is a corresponding need to provide simulation of complicated intersections, urban environment and test facilities. CarSim and TruckSim have built-in support for multiple road surfaces, but there are other sources for 3D ground information that use a polygon-mesh description of the ground, and which are available in file formats such as FBX and OpenDRIVE. In order to make use of these resources, Mechanical Simulation has introduced VS Terrain in its 2019 versions, a new ground model which provides an efficient interface between a vehicle’s tyre points of contact and the ground.
According to Baker Searles, senior software development engineer at Mechanical Simulation Corporation, “The use of standard geometry formats combined with optimised 3D collision algorithms provide many new opportunities for vehicle testing.”
The terrain data is loaded in a compact format for use by the vehicle model to find contact information such as slope, rolling resistance and friction. Users can also install their own functions to include custom terrain data and algorithms.
There is also a growing need for highly realistic displays of scenarios, as they would be viewed by on-board cameras. According to Searles, “The video displays for the simulation are used both for evaluating performance of on-board controllers, and possibly for ‘machine learning’ for the controllers to view hundreds of thousands of simulation conditions.”
There has been a growing interest in connecting with sophisticated game engines such as Epic’s Unreal Engine, which is capable of providing realistic camera views for day and night lighting conditions, rain and snow. Mechanical Simulation provides a plugin for Unreal that includes the CarSim and TruckSim vehicle modules.
When simulating ADAS and autonomous driving scenarios, there is often a need to work simultaneously with Unreal and Simulink. Brad Porter, Senior Software Engineer, created the VehicleSim Dynamics Plugin for Unreal Engine and the VS Connect communication library to meet this need.
According to Porter, “Combining the features of our Unreal plugin, VS Connect, and VS Terrain allows us to link the Unreal and Simulink simulations together and simultaneously simulate multiple CarSim and TruckSim vehicles in either or both environments.”
The data synchronization capabilities of VS Connect also allow users to implement controller logic in either or both environments. As Porter adds, “For example, a CarSim vehicle can be simulated within Unreal while its controller logic resides in a Simulink model.”