Hybrid Vehicle Rear Axle Coupling Strategy for Cornering Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid vehicles with a heat engine driving the front wheels and an independent electric machine driving the rear wheels face motorization and stability issues due to different torque characteristics, leading to potential destabilization and increased energy consumption from frequent coupling and decoupling of the electric machine during cornering.
Innovation Solution
A strategy that automatically controls the coupling of the electric machine to the rear wheels, prohibiting coupling during bends and allowing it only after confirmation of exit from the bend, using detection of lateral acceleration, steering wheel angle, and other vehicle and external data, with validation conditions based on time or distance traveled, to prevent torque variations and ensure stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the electric machine is frequently coupled and decoupled to reduce energy consumption, then energy efficiency is improved, but vehicle stability deteriorates due to torque variations on the rear axle
Solution Approach 1:
The control system applies preliminary anti-action by detecting bend conditions in advance and prohibiting electric machine coupling during these periods. This prevents the harmful torque variations that would destabilize the rear axle during cornering, while still allowing coupling during straight-line driving to reduce energy consumption through friction reduction.
2Power
If the electric machine is coupled during bends to provide torque, then torque availability is improved, but vehicle stability deteriorates due to delicate grip conditions
Solution Approach 1:
The control system extracts the electric machine coupling function during bend conditions, separating this operation from normal driving conditions. By taking out the coupling action during delicate grip conditions, the system avoids adding torque variations that could destabilize the vehicle while maintaining coupling capability during stable straight-line driving.
3Stability of the object's composition
If coupling validation uses strict time or distance conditions, then stability is improved by ensuring bend exit, but response time worsens due to additional validation delays
Solution Approach 1:
The control system applies dynamics by making the validation conditions adaptive rather than fixed. The time delay or distance threshold for validating bend exit can be adjusted based on vehicle speed, bend severity, and other operating parameters, optimizing the balance between ensuring stable coupling conditions and minimizing unnecessary delays.
Data Source
Figure 1~2
AI summary
A strategy concerning the coupling of an electric machine (20) with the rear wheels (22) of a hybrid vehicle comprising a power train provided with a heat engine (2) driving the front wheels (6), said electric machine being equipped with an automatically controlled system for coupling with the rear wheels (22), characterised in that, in case of detection of cornering, it prohibits the coupling of the electric machine (20) with the rear wheels (22) during said cornering, and it allows this coupling to take place only after confirmation of the end of cornering (34), which depends on validation conditions ensuring an end of detection of said cornering for a certain period of time.