Adaptive Cruise Control Extended Mode Operation
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Solution Overview
Problem
Conventional adaptive cruise control (ACC) systems in heavy-duty vehicles shut off when set-speed cruise control (SSCC) is deactivated, leading to safety issues as they fail to recognize SSCC shutoff due to ACC deceleration events, causing unintended deactivation of ACC and loss of braking control.
Innovation Solution
An adaptive cruise control system that operates in an extended mode, allowing ACC to continue functioning even when SSCC is shut off, using a radar sensor and processor to maintain a predetermined distance from a forward vehicle and apply brakes as necessary, independent of SSCC activation, until an ACC shutoff trigger event is detected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If ACC system shuts off when SSCC is deactivated, then system complexity is reduced, but safety and reliability deteriorate due to unintended deactivation during ACC-initiated deceleration events
Solution Approach 1:
The patent segments the cruise control system into two independent operational modes: SSCC (Set Speed Cruise Control) and ACC (Adaptive Cruise Control). The ACC system is designed to operate independently with its own activation and deactivation logic, rather than being strictly dependent on SSCC state. This segmentation allows ACC to maintain operation during SSCC deactivation when appropriate, resolving the contradiction by enabling ACC to distinguish between driver-initiated and ACC-initiated deceleration events.
Solution Approach 2:
The patent implements feedback mechanisms where the ACC system monitors its own operational state and the reasons for SSCC deactivation. By detecting whether deceleration was ACC-initiated or driver-initiated, the system provides feedback to determine appropriate ACC behavior. This feedback loop prevents unintended ACC deactivation while maintaining system reliability and safety.
2Reliability
If ACC operates independently of SSCC state, then safety and reliability improve, but device complexity increases due to extended operational modes
Solution Approach 1:
The patent introduces dynamic operational characteristics where the ACC system can transition between different states based on real-time conditions. The ACC may operate in normal mode when SSCC is active, or in extended mode when SSCC is deactivated following ACC-initiated deceleration. This dynamic adaptability allows the system to improve safety without requiring completely separate independent systems, thereby limiting the increase in complexity.
Solution Approach 2:
The ACC system is designed with multi-functionality to handle multiple operational scenarios: it can operate during SSCC active state, continue operation after SSCC deactivation (extended mode), and properly deactivate when appropriate. This universal design allows a single ACC system to fulfill multiple functions across different operational contexts, improving reliability without proportionally increasing system complexity.
3Reliability
If ACC continues operation after SSCC deactivation, then braking control and safety are maintained, but loss of time occurs during mode transitions and state management
Solution Approach 1:
The patent implements preliminary action by having the ACC system proactively detect and record the reason for SSCC deactivation before ACC deactivation is considered. The system anticipates potential SSCC shutdown reasons (driver input, fault conditions, etc.) and pre-determines whether ACC should continue operation. This preliminary detection and state recording minimizes processing time during actual mode transitions and prevents time loss through reactive decision-making.
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
Ensures continuous ACC operation during SSCC deactivation, enhancing safety by maintaining braking control and preventing sudden loss of braking force, even when SSCC is disengaged due to ACC-initiated deceleration events.
Implementation Method 1
a radar sensor that detects the position of a forward vehicle relative to a primary vehicle in which the sensor is installed
Data Source
AI summary
When employing an a cruise control system in a commercial or heavy-duty vehicle, an adaptive cruise control (ACC) system (14) is activated upon activation of a vehicle or set-speed cruise control (SSCC) system (16). The ACC (14) remains on, even after SSCC shutoff, to maintain a minimum following distance for a primary vehicle in which the ACC (14) is employed and a forward vehicle. The ACC (14) is deactivated after detection of an ACC shutoff trigger event, which may be driver application of the brakes of the primary vehicle, driver-initiated acceleration for a predefined time period, expiration of a predetermined time period, manual shutoff (e.g., via a switch or button), etc.