On-Vehicle Radar Mounting Angle Calculation Using Speed Zero Observation Points
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Solution Overview
Problem
Conventional on-vehicle radar apparatuses face challenges in accurately detecting optical axis deviation due to the reflection point not always being on the horizontal plane containing the optical axis, especially with wider vertical view angles, leading to inconsistent speed component measurements.
Innovation Solution
The on-vehicle radar apparatus includes a radar sensor and a mounting angle calculation section, where the radar sensor is mounted at a 90-degree azimuth relative to the vehicle's front-back direction, detecting speed zero observation points to calculate the actual mounting angle and optical axis deviation, using robust estimation methods like trimmed mean to ensure stability and precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the radar sensor has a wider vertical view angle to detect targets at different heights, then the coverage area is improved, but the measurement precision of optical axis deviation deteriorates due to vertical speed components affecting the parameter A
Solution Approach 1:
The invention extracts and utilizes only the horizontal speed component by selecting observation points at the same height as the radar sensor. This isolates the measurement from the harmful vertical speed components that occur with wider vertical view angles, thereby maintaining measurement precision while preserving the ability to detect a wide coverage area.
Solution Approach 2:
The invention transitions from using the ratio of speed errors (parameter A) in the vertical-dominant measurement space to using azimuth angle directly in the horizontal plane. By selecting observation points at the same height and measuring azimuth angles, the system operates in a dimension where vertical speed components do not interfere, resolving the contradiction between wide coverage and precise measurement.
2Adaptability or versatility
If the reflection point is located out of the horizontal plane containing the optical axis, then the radar can detect targets at various heights, but the parameter A becomes non-constant leading to inaccurate optical axis deviation detection
Solution Approach 1:
The invention extracts observation points that satisfy the condition of being at the same height as the radar sensor, thereby isolating measurements to the horizontal plane where vertical speed components are zero. This extraction ensures parameter A remains constant and reliable, while the system maintains versatility by processing data from multiple observation points including those at different heights for comprehensive target detection.
Solution Approach 2:
The invention performs preliminary selection of observation points based on the height condition before conducting optical axis deviation detection. By pre-filtering observation points to those at the same height as the radar sensor, the system ensures that only reliable data with constant parameter A is used for measurement, while maintaining the ability to detect targets at various heights through other means.
3Device complexity
If conventional techniques use the ratio of speed errors (parameter A) for optical axis deviation detection, then the method is simple, but the detection accuracy deteriorates when reflection points are at different heights due to vertical speed components
Solution Approach 1:
The invention changes the measurement dimension from using speed ratio (parameter A) which is affected by vertical components, to using azimuth angle directly in the horizontal plane. This dimensional shift eliminates the influence of vertical speed components while maintaining computational simplicity, as the azimuth angle can be directly obtained from radar detection data without complex calculations.
Solution Approach 2:
The invention substitutes the mechanical calculation of parameter A (ratio of speed errors) with a direct azimuth angle measurement approach. By replacing the speed-ratio-based method with azimuth-angle-based measurement in the horizontal plane, the system achieves both simplicity and precision, as azimuth angles are directly provided by radar systems without requiring complex speed ratio calculations.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for stable and accurate determination of the radar sensor's mounting angle relative to the vehicle, enabling precise detection of optical axis deviation and automatic correction, even when the reflection point is out of the horizontal plane, improving reliability across varying vertical view angles.
Implementation Method 1
a radar sensor 10... transmits and receives a probe wave to detect at least a relative speed to an observation point at which a radar wave is reflected
Implementation Method 2
an observation point at which a radar wave is reflected in the sensing area
Data Source
AI summary
An on-vehicle radar apparatus includes a radar sensor and a mounting angle calculation section that calculates a mounting angle of the radar sensor, and the radar sensor is mounted on a vehicle so that a sensing area includes a direction of 90 degrees relative to a front-back direction of the vehicle and detects a relative speed to an observation point at which the radar wave is reflected in the sensing area and an azimuth at which the observation point is located. The mounting angle calculation section calculates a mounting angle of the radar sensor from an azimuth of a speed zero observation point, the speed zero observation point being the observation point with a relative speed of zero.