Application-specific software module with tests to support standards-based headlight measurement
Today’s headlights include smart illumination, adaptive systems like matrix LED- or laser-based systems, and other technology that dynamically illuminates roadways while meeting the requirements of national safety regulations. Because they distribute light over a large spatial area, with specific and sometimes changing geometries, headlamps must be tested against several visual criteria to ensure proper illumination at all settings. An efficient method for evaluating headlamp performance is to project the light source onto a wall or screen and use a connected imaging colorimeter to capture the entire illumination distribution in a matter of seconds. The complete lighting assembly can then be analyzed in a single image using a number of user-defined criteria in Radiant’s PM-HL™ software module, designed specifically for headlamp evaluation.
Part of the Radiant Vision Systems ProMetric® Software family, the PM-HL solution combines application-specific software and a ProMetric Imaging Colorimeter or Photometer to perform accurate evaluation of headlamp beam patterns. The software module also permits conversion of headlamp beam patterns into roadway illumination distributions. Pre-configured point-of-interest (POI) sets support testing to US and ECE standards, including:
- Illuminance (ECE Reg. 20)
- Intensity (FMVSS108, R112, R123)
Used with a ProMetric Imaging Colorimeter or Photometer, PM-HL can be employed in the lab to derive comprehensive headlamp illuminance and intensity data using a single-image measurement of light on a Lambertian surface to evaluate a complete beam pattern.
- ProMetric Y Series Photometers: Y2, Y16, Y29, Y43
- ProMetric I Series Colorimeters: I2, I8, I16, I29
- PM-AC4001 Metal Halide Illumination Calibration Lamp
- ProMetric Imaging Photometer or Colorimeter
- Windows® 10, 64 bit
- 16-32 GB RAM
- Additional system requirements vary by camera.
PM-HL software interface showing measurement images of headlamp beam patterns. In the top image, the luminous intensity distribution of a headlamp beam pattern is measured on a Lambertian surface. In the bottom image, the “Make Road Illumination Measurement” operation is used to extrapolate the same headlamp beam projected onto a roadway.
Comprehensive Data from Images
Illuminance Distribution Evaluation
Headlight evaluation standards require that a headlamp emit light in specific ways to produce acceptable beam patterns. This evaluation is used both to ensure the effectiveness of the lamp for illuminating the roadway within nationally regulated tolerances, and the quality of the light produced according to internal standards. When the headlamp beam is projected from a known distance onto a flat surface (Lambertian wall or screen), illuminance measurements are taken at physical locations along the plane of the wall to ensure the beam pattern is projected according to standard specifications.
In the past, a common method for measuring these points was to use a handheld illuminance meter to manually test each point on the wall. This process was tedious, and not efficient for measuring many headlamps in succession during production-level quality control. Leveraging Radiant’s ProMetric imaging systems to capture a full beam pattern in a single image, the PM-HL module offers a much simpler solution that speeds up the process of measurement by capturing and evaluating all test points at once.
Includes US and ECE Standard POI Sets
When applied to photometric images captured by a Radiant ProMetric Imaging Colorimeter or Photometer, the “Points of Interest”(POI) tool in PM-HL software equips manufacturers to easily measure all points of a headlamp beam pattern in a matter of seconds. Radiant cameras capture both illuminance and luminous intensity measurements on a Lambertian wall or screen, allowing customers to meet the requirements of a variety of industry standards in one testing environment using a single system.
Sample measurement of the full beam distribution of a car headlamp, as captured in ProMetric Software and viewed in false color (indicating intensity).
In the PM-HL software interface, users can create virtual detectors that report out intensity and color values at every point required for standards-based headlamp evaluation. POI can be drawn in shapes including circles, rectangles, and polygons to mimic the test points for any requirement.
Below is an image of the ECE R112 headlamp standard. To test to this standard using Radiant measurement tools, the user could easily place POI in the ProMetric interface at the exact points (1, 2, 3, and so on) defined here. Each of these points can be configured with pass/fail criteria that can be used to quickly determine whether a headlamp meets a given standard, or needs to be adjusted or rejected.
Headlamp test points defined by ECE R112 headlamp standard. Source: www.unece.org
POI applied to the image of a headlamp beam pattern captured by a Radiant ProMetric imaging system. POI presets applied in PM-HL software match the test point positions specified by ECE R112.
PM-HL software includes POI presets for:
- ECE R20
- ECE R112
- ECE R123
Custom POI can also be created easily to match the test points of other measurement standards.
Beyond beam pattern POI test points, the PM-HL package also includes Road Illumination and Gradient POI tools.
A 2D isometric plot can be used to display the Road Illumination plot, overlaid here with a representation of the road in PM-HL software.
Multiple System Configurations
A PM-HL solution can be applied using any ProMetric Imaging Colorimeter or Photometer, providing multiple options to achieve the pixel resolution, dynamic range, and cost requirements for your application.
Supported by Radiant's global support staff and distributor network, PM-HL is field-proven and has been used to test thousands of lighting assemblies for leading automotive brands worldwide.
PM-HL Module Key Features and Highlights:
- Quickly and economically qualify the illuminance, luminous intensity, luminous flux, chromaticity, and color temperature of lamps and lighting assemblies according to lighting regulations or internal requirements
- Convert between illuminance distribution, luminous intensity distribution, and roadway illumination distribution patterns
- Apply a representation of a road overlaid on the measurement bitmap
- Automatically determine the “beam elbow” datum position and alignment of camera image to that position
- Evaluate ECE Reg 20 test points for left- or right-hand drive
- Simplified pass/fail testing
- Headlamp Analysis Report to document results of evaluations
- Data analysis functions, including bitmaps, isoplots, and cross-sections
PM-HL enables accurate evaluation of headlamp beam patterns and converts headlamp beam patterns into roadway illumination distributions.
- Light source illuminance distribution measurement
- Evaluation of ECE and US regulated test points
- Evaluation of custom test points
- Evaluation of beam pattern cut-off gradients
- Conversion to luminous intensity distribution
- Conversion to roadway illumination distribution