Hybrid Vehicle Mode Switching for Low-Adhesion Wheel Slip
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Solution Overview
Problem
Four-wheel drive vehicles with hybrid power systems experience rear wheel spin and get stuck on low-adhesion road surfaces due to reliance on rear-wheel drive in series mode.
Innovation Solution
A control method that switches the vehicle from series mode to idle electric four-wheel drive mode when slipping is detected, utilizing both front and rear drive motors while keeping the engine idle, and allows quick return to series mode post-escape to avoid repeated engine start-stop operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the vehicle operates in series mode on low-adhesion road surfaces, then the engine can drive the front drive motor to generate electricity for the rear drive motor, but rear wheel spin occurs and the vehicle may become stuck
Solution Approach 1:
The system dynamically switches between series mode and parallel mode based on road adhesion conditions. When wheel slip is detected, the control system transitions from series mode (engine generating electricity for motors) to parallel mode (engine directly driving wheels while motors provide additional torque), ensuring optimal traction reliability under varying operating conditions
Solution Approach 2:
The control system changes the operating parameters of the hybrid power system by adjusting the connection state of the clutch and the working mode of the engine and motors. Under low-adhesion conditions, the system changes from electrical power transmission to mechanical power transmission, fundamentally altering the energy flow parameters to prevent wheel spin
2Reliability
If the vehicle switches between series mode and parallel mode frequently, then the escape performance is improved, but the engine experiences repeated start-stop operations reducing driving performance
Solution Approach 1:
The control system performs preliminary actions by maintaining the engine in a ready state during mode transitions and pre-positioning the clutch and motor controllers. This preparation minimizes the time required for mode switching and prevents repeated engine start-stop operations, thereby maintaining driving performance while ensuring escape capability
Solution Approach 2:
The system continuously monitors wheel speed, slip ratio, and powertrain operating parameters to provide real-time feedback to the control system. This feedback mechanism enables intelligent decision-making for mode transitions, switching to parallel mode only when necessary for escape, thus avoiding unnecessary engine restarts and maintaining optimal driving performance
3Device complexity
If the vehicle uses rear-wheel drive in series mode, then the structure is simplified, but the vehicle is prone to wheel spin on low-adhesion surfaces
Solution Approach 1:
The hybrid power system is designed with multi-functionality, capable of operating in both series mode (simplified structure) and parallel mode (enhanced traction). The drive motors serve dual purposes: generating electricity in series mode and providing direct mechanical torque in parallel mode. This universality allows the system to prevent wheel spin on low-adhesion surfaces while maintaining structural simplicity during normal operation
Data Source
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AI summary
Disclosed are a control method and a device (300) for a vehicle with a hybrid power, a storage medium, and a vehicle (400). The control method includes: acquiring a current driving mode and a working condition information of the vehicle (400) in a case that the vehicle is determined to be in a slipping state; determining whether the vehicle (400) satisfies a mode switching condition based on the working condition information; and controlling the vehicle (400) to switch from a series mode to an idle electric four-wheel drive mode in a case that the current driving mode is the series mode and the vehicle (400) satisfies the mode switching condition.