SSC-Cruise Control System Speed Offset Strategy
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Solution Overview
Problem
Existing vehicles equipped with start/stop coasting (SSC) and cruise control systems face challenges in entering SSC mode during cruising sections, which limits fuel efficiency improvements due to the need for constant engine operation to maintain speed.
Innovation Solution
A method and apparatus that allow setting a target vehicle speed and an offset vehicle speed, enabling the vehicle to enter SSC mode between these speeds, with the engine stopping and restarting based on predetermined conditions to optimize fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the cruise control system maintains constant vehicle speed, then the vehicle speed stability is improved, but the fuel efficiency deteriorates because the engine cannot stop
Solution Approach 1:
The system dynamically adjusts between two operational modes: traditional cruise control mode (engine running, constant speed) and SSC mode (engine stopped, coasting). The controller switches between these modes based on whether the vehicle speed remains within the offset range, making the system adaptive rather than static. This resolves the contradiction by allowing the system to maintain stability when needed while enabling energy savings when conditions permit.
Solution Approach 2:
The system changes the operational parameters of the engine based on vehicle speed conditions. When speed deviates from the target range (below target - offset), the engine restarts; when speed is within range, the engine stops. This parameter change (engine on/off state) directly addresses the contradiction by adjusting energy consumption based on speed stability requirements.
2Use of energy by moving object
If the engine stops to improve fuel efficiency, then the fuel consumption is reduced, but the vehicle speed control capability deteriorates
Solution Approach 1:
The system performs preliminary action by setting a target vehicle speed and an offset value before entering SSC mode. This pre-establishes the speed range (target ± offset) within which coasting is acceptable, ensuring that speed control capability is maintained through predetermined boundaries even when the engine is stopped. The offset value acts as a buffer that preserves control authority.
Solution Approach 2:
The system continuously monitors vehicle speed and compares it against the target speed and offset range. When speed falls below (target - offset), feedback triggers engine restart to restore speed control. This closed-loop feedback ensures that fuel efficiency improvements from engine stopping do not compromise speed control capability, as the system automatically responds to speed deviations.
3Use of energy by moving object
If the SSC mode is entered during cruising, then the fuel efficiency is improved, but the system complexity increases due to coordination between SSC and cruise control
Solution Approach 1:
The patent merges the cruise control system and SSC system into a unified SSC-cruise control system. The controller integrates both functions, allowing the cruise control's target speed and offset settings to directly govern SSC mode entry and exit. This merging reduces overall system complexity compared to having two separate, independently coordinated systems, while still achieving improved fuel efficiency through SSC operation during cruising.
Data Source
AI summary
A method for controlling driving of an SSC-cruise system is provided. The method includes determining whether a cruising function is operated and receiving a target vehicle speed set by the driver and deriving a first offset vehicle speed from the target vehicle speed, when the cruising function is operated. Additionally, the method includes determining whether a second offset vehicle speed is set by the driver and entering the vehicle into SSC in a driving section between the target vehicle speed and the second offset vehicle speed, in response to determining that the second offset vehicle speed is set.