EV One-Pedal Rocking Control for Stuck Vehicle Extrication
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Solution Overview
Problem
Mechanical transmissions in internal combustion engine vehicles face significant delays and wear when switching between forward and reverse gears, reducing the efficiency of rocking techniques to extricate vehicles from stuck conditions, and fully automated systems may not provide desired control or account for varying stuck conditions.
Innovation Solution
An electric vehicle controller manages the application of forward and reverse torque to the drive wheels based on accelerator pedal inputs, enabling instantaneous switching between forward and reverse torque without physical gearing changes, allowing a user-friendly one-pedal rocking mode for extrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If mechanical transmission switching between forward and reverse gears is used to rock the vehicle, then the vehicle can be extricated from stuck conditions, but significant delay occurs in switching gears which reduces efficiency
Solution Approach 1:
The patent replaces the mechanical transmission system with an electric motor system that can switch between forward and reverse torque instantaneously. The electric motor controller directly controls the motor to apply forward or reverse torque to the drive wheels without requiring physical gear changes, eliminating the inherent delay in mechanical transmission systems.
Solution Approach 2:
The patent implements dynamic torque control where the electric motor can rapidly change the direction of torque application based on real-time sensor feedback and controller decisions. This dynamic control allows the system to adapt instantly to the vehicle's movement status and extrication needs, unlike static mechanical gear systems.
2Productivity
If mechanical transmission switching between forward and reverse gears is used to rock the vehicle, then the vehicle can be extricated from stuck conditions, but significant wear and damage occurs to the transmission
Solution Approach 1:
The patent eliminates the mechanical transmission system entirely by using an electric motor with electronic control. This substitution removes the mechanical components (gears, shafts, synchronizers) that are subject to wear and damage during frequent forward-reverse switching, thereby improving transmission durability and reliability.
Solution Approach 2:
The electric motor system provides self-protection through electronic control limits and sensor feedback. The controller monitors the extrication process and can automatically adjust or terminate torque application to prevent excessive stress on vehicle components, ensuring the system serves itself in protecting against damage.
3Ease of operation
If automated transmission switching is implemented for rocking mode, then gear shifting is automated, but operator control over the rocking motion is reduced
Solution Approach 1:
The patent implements a dynamic control system that can operate in multiple modes. The operator can select between fully automated rocking mode and manual control mode, or a hybrid mode where the operator has partial control. This dynamic adaptability allows the system to adjust its automation level based on the operator's preferences and the specific extrication situation.
Solution Approach 2:
The electric motor controller serves multiple functions: it can fully automate the rocking sequence, allow manual operator control, or provide a collaborative interface where the operator initiates commands and the system executes with automatic adjustments. This multi-functionality ensures both ease of operation and operator control flexibility can be achieved.
4Device complexity
If mechanical transmission is used for rocking, then the system is simple, but the rocking efficiency is reduced due to inherent switching delays
Solution Approach 1:
The patent replaces the simple but slow mechanical transmission system with a more complex electric motor and electronic control system. This substitution trades mechanical simplicity for electronic intelligence, enabling instantaneous torque direction changes and precise control, thereby dramatically improving rocking efficiency despite increased system complexity.
Data Source
AI summary
A “one-pedal rocking mode” for extricating an electric vehicle from a stuck condition is implemented by: receiving, via a human-machine interface (HMI) of the electric vehicle, an indication of a user selection to activate the one-pedal rocking mode; operating the electric vehicle in the one-pedal rocking mode responsive to detecting movement of an accelerator pedal of the electric vehicle; controlling at least one electric motor of the electric vehicle to: (i) apply a forward torque to corresponding drive wheels when the accelerator pedal is in a first pedal position that exceeds a forward threshold, (ii) apply a reverse torque to the corresponding drive wheels when the accelerator pedal is in a second pedal position that is less than or equal to the forward threshold; and exiting the one-pedal rocking mode by switching operations of the electric vehicle to a second operating mode responsive to detecting an exit condition.