Vehicle Acceleration Limit Control for Uphill Rollback Prevention
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Solution Overview
Problem
Existing speed limit control systems, such as MSLA, do not effectively manage acceleration on sloped roads, particularly when a rear-facing car seat is installed, leading to potential vehicle rollback and discomfort for passengers, especially infants, due to inadequate consideration of passenger orientation and slope effects.
Innovation Solution
A vehicle system that calculates an acceleration limit based on passenger information and slope conditions, using a torque calculation controller to determine disturbance torque and output torque, ensuring the vehicle does not roll back while minimizing passenger discomfort by adjusting the drive source's output torque in accordance with the driver's request.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If scaling control is applied to reduce accelerator pedal input for rear-facing car seat passengers, then passenger comfort is improved, but vehicle climbability on uphill roads deteriorates
Solution Approach 1:
The system dynamically changes the acceleration limit parameter based on detected slope conditions. When an uphill slope is detected, the system increases the acceleration limit compared to flat road conditions, allowing sufficient torque for climbing while still limiting acceleration on flat roads to protect rear-facing car seat passengers.
Solution Approach 2:
The acceleration limit is not fixed but dynamically adjusted based on real-time slope detection. The control system continuously monitors road gradient and modifies the acceleration limit accordingly, transitioning between conservative limits on flat roads and permissive limits on uphill sections.
2Object-affected harmful factors
If acceleration limit is strictly controlled to protect rear-facing car seat passengers, then passenger safety is improved, but vehicle ability to climb uphill roads deteriorates
Solution Approach 1:
The system changes the acceleration limit parameter based on slope conditions. On uphill roads, the acceleration limit is increased to allow sufficient torque for climbing, while on flat roads the limit remains strict to protect passengers in rear-facing car seats.
Solution Approach 2:
The acceleration control system dynamically adjusts the acceleration limit based on real-time slope detection, transitioning between protective limits on flat roads and performance-oriented limits on uphill sections.
3Device complexity
If no slope consideration is applied in acceleration control, then system complexity is reduced, but control accuracy on sloped roads deteriorates
Solution Approach 1:
The system introduces a slope detection mechanism as an intermediary that provides road gradient information to the acceleration control system. This additional sensor input enables accurate acceleration control on sloped roads without significantly increasing overall system complexity.
Data Source
AI summary
An embodiment acceleration limit control method includes determining an acceleration limit based on information on a passenger, determining a disturbance torque due to a disturbance, other than a drive source of a vehicle, based on at least a slope, determining a torque limit satisfying the acceleration limit based on the disturbance torque, and determining an output torque to be generated by the drive source based on the torque limit and a driver's requested torque.