# How Car Factories Calibrate LIDAR Sensors for Self-Driving Cars > This patent describes a system for car factories to precisely adjust a vehicle's LIDAR sensors using special floor and wall targets, ensuring they accurately map the world for features like self-driving. - **Patent:** US 11391826 - **Original title:** Vehicle LIDAR sensor calibration system - **Owner:** Magna Electronics - **Granted:** 2022 - **Status:** Active - **Times cited:** 4 - **Field:** automotive, consumer_electronics, software, telecommunications ## What it does This calibration system helps car manufacturers accurately set up LIDAR sensors in new vehicles. It uses a horizontal target on the ground and a vertical target, both with distinct patterns of markers, placed in a special 'end of line calibration region' at the factory (Claim 1). When a vehicle is in this spot, its LIDAR sensor detects these markers (Claim 1). By processing the data from the LIDAR, the system figures out the exact positions of these markers relative to the vehicle (Claim 1). Based on these determined locations, the system then calculates any misalignment in the LIDAR sensor's 'roll,' 'pitch,' and 'yaw' (Claim 1). Finally, it adjusts the LIDAR system to correct these misalignments (Claim 1). For example, if a LIDAR sensor is slightly tilted down (pitch) or rotated to the side (yaw), this system can detect that and correct it before the car leaves the factory. ## What it does NOT cover - Does not cover calibration systems that only use a single target (e.g., only horizontal or only vertical), as it requires both a horizontal and a vertical target (Claim 1). - Does not cover calibration performed outside of a vehicle assembly facility's 'end of line calibration region' (Claim 1). - Does not cover systems that calibrate LIDAR sensors without determining misalignment across 'roll,' 'pitch,' and 'yaw' axes (Claim 1). - Does not cover calibration methods that do not rely on light reflecting targets arranged in predetermined patterns (Claim 1). - Does not cover calibration for sensors other than LIDAR, such as cameras or radar, or for LIDAR sensors that do not sense forward of the vehicle (Claim 2). ## The clever bit The novelty lies in using both horizontal and vertical targets with distinct patterns in a factory setting to precisely determine and correct misalignment across all three rotational axes (roll, pitch, and yaw) of a LIDAR sensor, ensuring comprehensive calibration. ## Real-world examples 1. Vehicle assembly lines for autonomous cars 2. Quality control stations for ADAS-equipped vehicles 3. Automotive manufacturing plants producing LIDAR-enabled vehicles ## Why it matters Accurate LIDAR sensor calibration is critical for the safety and performance of advanced driver-assistance systems (ADAS) and autonomous vehicles. If a LIDAR sensor is misaligned, it could misinterpret the distance or position of objects, leading to incorrect decisions by the vehicle's computer. This system ensures that LIDAR sensors are precisely aligned before vehicles are delivered to customers, which is essential for reliable operation of features like adaptive cruise control, automatic emergency braking, and self-parking. ## Frequently asked questions ### What does How Car Factories Calibrate LIDAR Sensors for Self-Driving Cars cover? This patent describes a system for car factories to precisely adjust a vehicle's LIDAR sensors using special floor and wall targets, ensuring they accurately map the world for features like self-driving. ### Who owns patent US 11391826? Magna Electronics owns this patent, granted in 2022. ### When does this patent expire? This patent is expected to expire on September 27, 2038, when the invention enters the public domain. ### What is patent US 11391826 cited by? This patent has been cited by 4 later patents that build on its ideas. ### What problem does this patent solve? Accurate LIDAR sensor calibration is critical for the safety and performance of advanced driver-assistance systems (ADAS) and autonomous vehicles. If a LIDAR sensor is misaligned, it could misinterpret the distance or position of objects, leading to incorrect decisions by the vehicle's computer. This system ensures that LIDAR sensors are precisely aligned before vehicles are delivered to customers, which is essential for reliable operation of features like adaptive cruise control, automatic emergency braking, and self-parking. ### What does this patent NOT cover? Does not cover calibration systems that only use a single target (e.g., only horizontal or only vertical), as it requires both a horizontal and a vertical target (Claim 1). **Full plain-English explainer:** https://patentbrief.org/patent/us/11391826/vehicle-lidar-sensor-calibration-system **Original patent:** https://patents.google.com/patent/US11391826 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [How a Smart LIDAR System Adapts to Noise for Better Distance Sensing](https://patentbrief.org/patent/us/20240045038/noise-adaptive-solid-state-lidar-system) — This patent describes a LIDAR system that uses multiple lasers and detectors, and intelligently adjusts the electrical settings of specific detectors to reduce noise and improve distance measurements in different lighting conditions. - [LiDAR System for Seeing Through Shiny Objects](https://patentbrief.org/patent/us/11041957/systems-and-methods-for-mitigating-effects-of-high-reflectivity-objects-in-lidar) — Toyota's patent on a LiDAR system that can ignore blinding reflections from shiny surfaces to better see what's around a vehicle. - [Lidar System for Spotting Retro-Reflective Objects](https://patentbrief.org/patent/us/12736637/hyper-temporal-lidar-using-multiple-matched-filters-to-determine-target) — This patent describes a lidar system that uses a special signal processing technique to identify objects that reflect light directly back to its source, like road signs or safety vests. - [How Self-Driving Cars Detect Dirty Lidar Sensors](https://patentbrief.org/patent/us/12130389/methods-and-systems-for-detecting-sensor-occlusions) — Waymo's 2024 patent on a self-driving car system that uses two scans from a rotating Lidar sensor to spot dirt or obstructions on its lens. - [How Self-Driving Cars Find Clear Paths Between Objects](https://patentbrief.org/patent/us/10733420/systems-and-methods-for-free-space-inference-to-break-apart-clustered-objects-in) — This patent describes a method for vehicles, especially self-driving ones, to use lidar data and a 3D grid to precisely identify open spaces between obstacles, helping them navigate safely.