SAE Doc J3262 DEC2023 Active Safety Systems Sensor Calibration Terms and Definitions
CHASSIS GEOMETRIC CENTERLINE – Reference- SAE J3262 DEC2023
- A line that intersects the center of the rear axle and center of the front axle.
VEHICLE TRIM HEIGHT – Reference- SAE J3262 DEC2023
- A vertical dimension that specifies the location of a fixed point on the vehicle body or chassis relative to the ground.
VEHICLE TRIM HEIGHT AXIS– Reference- SAE J3262 DEC2023
- A vector that is normal to the chassis plane.
VEHICLE THRUST LINE – Reference- SAE J3262 DEC2023
- The vector of the longitudinal force generated by the vehicle’s powertrain that originates from the center of the non-steering rear axle.
- NOTE: The vehicle thrust line is equal to the numerical difference between the two individual rear toe angles and can be thought of as an imaginary line that is 90° from the non-steering rear axle when the individual rear toe angles are balanced. Refer to SAE J670, Section 3 for more detail regarding the vehicle coordinate system.
VEHICLE THRUST ANGLE (SAE J3262 DEC2023)
- The nominal angular difference between the chassis geometric centerline and the vehicle thrust line.
ADAS SENSOR ADJUSTMENT PROCEDURE – Reference- SAE J3262 DEC2023
- A procedure that consists of mechanically changing the orientation of an ADAS sensor or component.
- EXAMPLE: This can be part of sensor installation or repair to the vehicle.
ADAS SENSOR CALIBRATION PROCEDURE – Reference- SAE J3262 DEC2023
- A procedure for correcting a sensor to a trusted reference input.
- NOTE: An ADAS sensor calibration procedure may consist of a dynamic and/or a static component. ADAS sensor adjustment and installation may be part of or preparatory to ADAS sensor calibration.
DYNAMIC CALIBRATION PROCEDURE – Reference- SAE J3262 DEC2023
- An ADAS sensor calibration procedure that consists of driving the subject vehicle in an environment that includes a set of specified features or objects.
- NOTE: Procedures, driving criteria, and environmental features/objects are typically specified by relevant sensor/system manufacturers/providers.
STATIC CALIBRATION PROCEDURE – Reference- SAE J3262 DEC2023 (SAE J3262 DEC2023)
- An ADAS sensor calibration procedure that consists of presenting one or more targets or objects in defined locations relative to the nonmoving vehicle as specified.
- NOTE: Procedures and target locations are typically specified by relevant sensor/system manufacturers/providers.
STATIC CALIBRATION CLEAR SPACE – Reference- SAE J3262 DEC2023
- A physical space within the sensor’s field of view that must be devoid of all objects, other than the calibration target, that might interfere with the sensor’s calibration.
TARGET PLACEMENT LOCATION COORDINATES – Reference- SAE J3262 DEC2023
- The coordinates of the placement location(s) of the target(s) with respect to a coordinate origin.
- NOTE: Coordinate origin may vary according to procedure.
PRE-CALIBRATION RATIONALE – Reference- SAE J3262 DEC2023
- The explanation of the technical goals that need to be achieved during the calibration procedure.
- NOTE: An understanding of the pre-calibration rationale helps the technician perform the calibration more efficiently.
CALIBRATION PROCEDURE PREREQUISITES – Reference- SAE J3262 DEC2023
- A set of tasks performed prior to calibration.
- EXAMPLE: Prerequisites may involve ensuring a proper environment (proper lighting, level floor, minimal reflections, etc.), proper vehicle stance (ride height, tire pressure, vehicle load, wheel alignment, fluid levels, etc.), and proper state of repair (system readiness, compliant accessories, proper installation/mounting of sensors, etc.).
CALIBRATION REPORT – Reference- SAE J3262 DEC2023
- A comprehensive collection of data or elements involved with the calibration process that is produced at the end of a calibration procedure.
- EXAMPLE: A calibration report may include but is not limited to the following: serial numbers of tools used, date/time stamps, technician ID, pre-calibration health check, ride height, misalignment angles, sensors/systems/angles calibrated, pass/fail status, measurement tolerance, vehicle identification number, vehicle data/description, etc.
- NOTE: Multiple calibration reports may be produced from a calibration procedure, such as data from multiple sensors and/or previous calibrations.
ADAS STATE OF HEALTH – Reference- SAE J3262 DEC2023
- Operational status of the vehicle’s ADAS sensors and computer modules and vehicle sensors and computer modules that provide input to ADAS.
CALIBRATION MISALIGNMENT ANGLES
- The angle between the aim of an ADAS sensor in one or more dimensions with respect to the desired reference direction.
- NOTE: There may be multiple misalignment angles for a given sensor.
YAW ANGLE – Reference- SAE J3262 DEC2023
- Nominal angular value referenced to rotation about a vector that is normal to the chassis plane.
- NOTE: Refer to SAE J670, Section 3 for more detail regarding the vehicle coordinate system. This angle is sometimes referred to as the “heading.”
ROLL ANGLE – Reference- SAE J3262 DEC2023
- Nominal angular value referenced to rotation about the chassis geometric centerline or vehicle body centerline axis.
- NOTE: Refer to SAE J670, Section 3 for more detail regarding the vehicle coordinate system.
3.20 PITCH ANGLE – Reference- SAE J3262 DEC2023
- Nominal angular value referenced to rotation about the front or rear axle position axis.
- NOTE: Refer to SAE J670, Section 3 for more detail regarding the vehicle coordinate system.
CALIBRATION THRESHOLD VALUES – Reference- SAE J3262 DEC2023
- Numerical maximum or minimum values for specific parameters that are provided by the relevant sensor/system manufacturer/provider to define pass/fail criteria for given requirements.
- EXAMPLE: A forward-facing radar sensor’s yaw angle may exceed the vehicle manufacturer’s specification.
- NOTE: A given calibration procedure may have other pass/fail criteria or requirements in addition to the calibration threshold values.
OPTICAL TARGETS – Reference- SAE J3262 DEC2023
- Physical objects that direct light to lidar systems or visible-spectrum cameras for calibration.
- NOTE: Patterns are not limited to only those defined below. The critical positioning dimensions should always be described by target setup procedure. Target setup procedure should specify number of targets used, including relative spacing and positioning between the targets.
CIRCULAR PATTERN TARGETS – Reference- SAE J3262 DEC2023
- An optical target that includes a pattern that consists of a series of circles/backgrounds/sections of contrasting colors.
- NOTE: Circular pattern targets should have a defined number of circular or sections of circular patterns, size, and spacing. Circular patterns should have a defined reflectivity and color. Target should have a defined flatness specification. The critical positioning dimensions are roll, pitch, yaw, vertical, and lateral.
CHECKERBOARD TARGETS – Reference- SAE J3262 DEC2023
- An optical target that includes a pattern that consists of a series of rectangles/backgrounds of contrasting colors.
- NOTE: Checkerboard targets should have a defined number of rectangles, size, and spacing. Rectangles should have a defined reflectivity and color. Target should have a defined flatness specification. The critical positioning dimensions are roll, pitch, yaw, vertical, and lateral.
DOT PATTERN TARGETS – Reference- SAE J3262 DEC2023
- An optical target that includes a pattern that consists of a series of dots/backgrounds of contrasting colors.
- NOTE: Dot pattern targets should have a defined number of dots, size, and spacing. Dots should have a defined reflectivity and color. Target should have a defined flatness specification. The critical positioning dimensions are roll, pitch, yaw, vertical, and lateral.
SCATTER CHART TARGETS – Reference- SAE J3262 DEC2023
- A large target consisting of a grid of many small rectangles of various degrees of gray color.
- NOTE: Scatter chart targets should not be confused with X-Y scatter plots. Target should have a defined flatness specification. The critical positioning dimensions are roll, pitch, yaw, vertical, and lateral.
RADAR TARGETS – Reference- SAE J3262 DEC2023
- A physical object designed to direct radar signals back to a radar emitter/receiver.
- NOTE: Critical positioning dimensions should always be described by target setup procedure.
TRIHEDRAL REFLECTOR – Reference- SAE J3262 DEC2023
- A metallic reflector with three triangular sides, each of which is orthogonal to the other two.
- NOTE: Trihedral reflector is sometimes referred to as “corner reflector” by radar industry. These should have a defined size/dimension. The critical positioning dimensions are vertical and lateral.
FLAT PLATE REFLECTOR – Reference- SAE J3262 DEC2023
- A flat panel constructed from a material capable of reflecting radar emissions.
- NOTE: Flat plate reflector should have a defined size/dimension and flatness specification. The critical positioning dimensions are pitch and yaw.
DOPPLER SIMULATOR – Reference- SAE J3262 DEC2023
- A device that is capable of simulating a Doppler effect to another radar device.
THERMAL TARGETS – Reference- SAE J3262 DEC2023
- Targets that are designed for calibrating long-wave infrared cameras.
- NOTE: Long-wave infrared cameras are typically used for detecting objects in low-visible-light conditions. Wavelengths typically span 8000 to 14000 nm. Commonly referred to as “night vision cameras.”
- EXAMPLE 1: Heated wire types, which consist of a metal plate with a heated cross pattern wire embedded within it.
- EXAMPLE 2: Heated ceramic plate type behind crosshairs slit.
