It is common for reflections to occur in the cockpit of a vehicle. These reflections can create disabling or distracting glare for the driver.
This article describes how to asses the common unwanted reflections found on the windscreen reflected from the Instrument Panel (IP) Topper.
Software Prerequisites
- Ansys Speos 2022 R2 or later
- Access to an Ansys Speos Enterprise License.
Overview
Understand the simulation workflow and key results
In this example, we use Ansys Speos to introduce the Human Factor’s topic. It is important to assess what typical reflections are present to the driver and whether this is for perceived quality, human factors, or display legibility.
Step 1 Data & Speos preparation
In this step, we prepare the geometry for the Speos simulation, ensure the data is refined and apply the neccesary optical boundary conditions such as materials, sensors (eyepoints), sources (environments & luminiated features).
Step 2 Review simulation results
In this is step we carry out Post-Processing, this means analyse the results to indentify unwanted reflections to what is considered the worst case condition and explore the functions of the Speos virtual labs.
Run and Results
Instructions for running the model and discussion of key results
Step 1 Data & Speos preparation
The model is made up of a complete vehicle interior including daylight openings, complete with optical properties, two display sources (cluster & IP Display), two environment sources (HDRi & Ambient) and a sensor for the driver’s eyepoint.
A simulation has been created for this exercise and will only need to be run as seen below using either CPU, HPC or GPU Compute methods.
- Open the file AG_UR.scdocx in Speos
- Right click and Compute the "inverse" simulation (see red box )
Step 2 Review simulation results
- Open the Result 'Inverse.Windscreen.xmp' using the Virtual Human Vision Lab (see red box )
In this exercise, we will be using the Virtual Lighting Controller ( see red box )
You can turn off the sources ( blue box ) and change the amount of flux applied to the sources ( green box )
In this scenario, the environment/ambient light source overpowers the sun intensity. To overcome that, turn the HDR:394 environment source down to 10% and this will reveal a direct reflection of the instrument topper.
The result displays the worst case condition during the daytime where the contrast of the instrument panel reflections reduces the visibility of the environment.
Windscreen zones have been applied in white to identify critical driver viewing zones.
Reflections have been highlighted using yellow and red boxes.
- Turn off the HDR environment source (highlighted in red ). The Natural Light:1594 will show the cockpit reflection from the driver's viewpoint.
It is important to highlight any potential obstructions caused by specular or non-specular materials.
As we can see in the result, the reflections from the instrument panel, displays and steering all reflect into the windscreen. This assessment confirms that the design of the geometry and use of various materials have created unwanted contrast between the reflected components.
- select the file and select 'Open with the Virtual Photometric Lab' to assess the luminance values within this result.
The image below shows the luminance values in a false colour analysis with a scaling set to 10000 cd/m2 and the environment turned off.
- Open the level ( blue box to control the luminance levels (cd/m2)
- Open the Virtual Lighting Control ( red box to control the sources)
- Select the 'Black to White' ( green box to change the true colour to false colour)
- Open the Measures ( orange box to open a measurement plot)
The measurement area above can be reshaped, relocated from the centre in a drag-and-drop method, resized at the corners and positioned using coordinates. (see green box )
You will be able to see the maximum luminance value (see red box )
You can add the new measurements and change the type of measurement from maximum to average to assess the absolute luminance value in the drop-down menu (see orange box below )
In this assessment, you are able to assess how high the luminance reflections are on the windscreen from the instrument panel topper. This allows you to carry out decisions on whether the materials and design of the interior geometry are suitable to avoid unwanted reflections within the vehicle cockpit.
Important Model Settings
Description of important objects and settings used in this model
Important Settings for Simulation Setup
Consider specific simulation settings such as increasing the number of passes (see red box ), this will increase the utilisation of your computer processing and run the simulation for a longer time giving you a better result.
Please note the result shown above has been run with 100 passes.
(FTG) ‘Fast Transmissive Gathering’ is the function (see blue box ) that needs to be selected to control light to transmit through selected surfaces, in particular Glass surfaces. This option will ensure the natural light source to perform in the appropriate method and ensure internal reflections of the Instrument Panel occur.
'Natural Light’ is an Ambient Source (see green box ) that is needed to generate interior reflections whether that be a directional source or not, this will work with Fast Transmissive Gathering.
Important Setting for Pre & Post Processing
(VLC) ‘Virtual Lighting Control’ is the function that allows you to control the illuminated sources within the Speos Labs when analysing the result.
‘Layer by Source’ is a sensor setting that will allow you to use the Virtual Lighting Controller.
Taking the Model Further
Information and tips for users that want to further customize the model
Considerations
- Benchmarking against various materials/trim
- Verify Requirements & Internal Standards
- Use of Windscreen Critical Viewing Zones
Additional Resources
Additional documentation, examples and training material
Relevant Speos Ansys Learning Hub Courses
- Ansys Speos Getting Started
- Optics | Visualization - Learning Guide (sapjam.com)
- Specular Glare Study Tutorial.zip (sapjam.com)
- Night_Time_Reflections.zip (sapjam.com)