Quantifying Lidar Sensor Performance through DIN SAE SPEC 91471 Testing Methods
- clemenslinnhoff
- 5 days ago
- 3 min read
Lidar (Light Detection and Ranging) technology is transforming industries, from self-driving cars to environmental conservation. As more sectors adopt lidar, the demand for reliable sensors grows. This is where standardized testing comes into play. The DIN SAE SPEC 91471 offers a structured way to assess lidar performance. In this blog post, we will explore key performance tests, each critical for understanding lidar capabilities.
Understanding DIN SAE SPEC 91471
DIN SAE SPEC 91471 sets the groundwork for evaluating lidar sensors consistently. This standard provides a clear set of tests, allowing manufacturers and users to benchmark performance metrics effectively. Through these assessments, anyone can better understand how lidar sensors function across different environments.
The three main tests outlined are vital for revealing the strengths and weaknesses of lidar systems. For example, the multi-domain test helps assess detection performance across various distances, surface reflectivity levels and orientations, indicating how well a lidar sensor can spot objects under different conditions. This is essential in practical settings, where target surfaces can vary significantly.
The Multi-domain Test
The multi-domain test serves as a foundational assessment within the DIN SAE SPEC 91471 framework. It measures the lidar detection performance against different target reflectivities and orientations. Typically, four different reflectivities are tested: 10%, 50% and 80% Lambertian targets as well as a retro-reflector. The targets are placed at different distances and various angles are considered by introducing yawed and pitched surfaces.
Angular Separability Test
The angular separability test is essential for understanding the lidar sensor's performance in detecting closely spaced and partially occluded objects. The combination of beam resolution and beam divergence of the lidar is evaluated here.
Two targets are placed at the front with a gap between them. An additional target is placed further back in the center of the gap. Angular separability is reached, when the target in the back is detected by the lidar. Consider an autonomous vehicle navigating city streets, where pedestrians and parked cars are often closely situated, this performance insight becomes critical for ensuring safety. A lidar that can maintain accuracy even through small gaps between objects can help prevent accidents.
Radial Separability Test
Complementing the angular separability test, the radial separability test evaluates how well the sensor performs when only part of a target is illuminated. This scenario is common in environments with obstructions, like trees or buildings blocking the view.
In this test, targets at different distances are partially illuminated by on beam, mimicking situations where the target is not fully in the direct line of sight. If a lidar sensor can still accurately distinguish targets at different distances in one beam with multi-returns, it demonstrates a robust performance, offering reliability in complex environments.
The Semi-Automatic Test Bench
A semi-automatic test bench has been developed at Persival to streamline the testing processes defined in DIN SAE SPEC 91471. This advanced setup enhances the accuracy of placing lidar sensors at specific azimuth and elevation angles, achieving a precision of up to 0.01 degrees. Such accuracy is vital for producing reliable results.
Additionally, the test bench includes reference systems that measure distances to targets within millimeters, ensuring optimal alignment during tests.
Generating Ground Truth Data
One major benefit of the semi-automatic test bench is its ability to generate ground truth data. This includes precise details about sensor and target positions and orientations. With accurate data, engineers can rerun the measurements in simulations of sensor models.
These simulations can be analyzed using tools like Persival Simspector, which offers clarity on lidar behavior under diverse conditions. The simulatoin models can be validated by comparing the simulated and actual test measurements with tools like Persival Avelon.
In Closing
Accurately measuring lidar performance according to DIN SAE SPEC 91471 is vital for ensuring sensors can handle the demands of modern applications. Tests like the multi-domain, angular separability, and radial separability provide crucial insights into lidar capabilities. The use of a semi-automatic test bench enhances the reliability of evaluations and facilitates the generation of dependable ground truth data. This can acuallty be used to validate simulation models of the tested lidars.
As technology evolves, methods like those in DIN SAE SPEC 91471 will be essential in advancing lidar capabilities, ensuring safety and efficiency across a range of applications. Understanding and quantifying lidar performance will empower manufacturers and users, paving the way for innovative advancements in this critical technology.
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