Cruise Control Headway Detection for Large Vehicles
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Solution Overview
Problem
Conventional cruise control systems face reduced accuracy in detecting the position of a preceding vehicle, especially when the vehicle is making a turn, due to the shifting reflection point of radar waves, which is exacerbated by large vehicles.
Innovation Solution
A cruise control apparatus that includes a headway control mechanism to determine if a front vehicle is in the same lane as the own vehicle and adjusts its control methods based on the vehicle type, using a combination of radar and camera data to filter probabilities and reduce temporal variations in detection, thereby improving accuracy for large vehicles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If radar wave reflection is used to detect front vehicle position, then detection range is extended, but detection precision deteriorates when the front vehicle makes a turn due to shifting reflection points
Solution Approach 1:
The patent introduces camera imaging as an intermediary measurement method to complement radar detection. The camera captures the front vehicle's position and orientation, providing an alternative reference that does not suffer from the reflection point shifting problem. This intermediary measurement allows the system to cross-validate and correct radar position data, thereby maintaining detection range while improving position precision during turns.
Solution Approach 2:
The system employs feedback by continuously comparing radar detection results with camera imaging results. When the front vehicle makes a turn, the camera provides feedback on the vehicle's actual position and orientation, allowing the control unit to calculate the deviation from radar measurements and apply corrections. This feedback mechanism resolves the contradiction by maintaining the extended detection range of radar while compensating for its precision deterioration during turns.
2Device complexity
If conventional headway control is applied to large size vehicles, then control simplicity is maintained, but detection accuracy deteriorates due to large distance between center portion and end portions
Solution Approach 1:
The patent applies local quality by differentiating the detection and control approach based on vehicle type. For large size vehicles, the system specifically targets and measures the end portions (front or rear ends) rather than relying solely on the center portion reflection. This localized measurement strategy maintains control system simplicity while improving detection accuracy for large vehicles by focusing on the most relevant parts for safe following distance calculation.
Solution Approach 2:
The system changes the detection parameter from center portion distance to end portion distance when dealing with large size vehicles. The control unit identifies large vehicle types and switches the measurement reference point, thereby maintaining simple control logic while adapting the detection parameter to suit the specific vehicle geometry. This parameter change resolves the contradiction by preserving control simplicity while achieving accurate detection for large vehicles.
3Reliability
If probability-based lane recognition is used, then false recognition of vehicles in adjacent lanes is reduced, but detection accuracy deteriorates when front vehicle lateral position shifts during turns
Solution Approach 1:
The patent merges two different measurement methods: radar-based probability calculation for lane recognition and camera-based direct imaging for position verification. The radar provides probabilistic lane information that filters out vehicles in adjacent lanes, while the camera simultaneously captures the actual position and orientation of the front vehicle. By combining these methods, the system maintains high lane recognition reliability while achieving precise position measurement even when the vehicle lateral position shifts during turns.
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
The system effectively performs cruise control by accurately determining the presence and type of preceding vehicles, reducing erroneous detections and maintaining appropriate following distances, especially when dealing with large vehicles whose position varies significantly.
Implementation Method 1
a vehicle-mounted radar apparatus configured to transmit a radar wave (a laser wave or a millimeter wave, for example) and detect an object present around the vehicle based on a reflected version of the radar wave
Implementation Method 2
receive the radar wave reflected mainly at the center portion of the back side of the front vehicle
Data Source
AI summary
The cruise control apparatus includes a headway control means for making a first determination as to whether or not at least one recognized front vehicle running ahead of an own vehicle is a preceding vehicle present in an own-vehicle lane in which the own vehicle is running, performing a headway control to cause the own vehicle to run following the preceding vehicle when the first determination is affirmative, and a vehicle type recognizing means for recognizing a type of the recognized front vehicle. The headway control means is configured to change a way to perform the headway control depending on the type (vehicle size, for example) of the recognized front vehicle.