Traction Machine Coupling Control via Torque Thresholds
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Solution Overview
Problem
Existing methods for controlling the coupling and decoupling of traction machines in hybrid vehicles often result in permanent coupling, leading to energy losses and increased vehicle consumption due to torque losses at high speeds.
Innovation Solution
A method that determines when a torque setpoint exceeds or falls below predetermined thresholds, calculating specific parameters to authorize coupling or decoupling, thereby optimizing power supply and reducing torque losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the traction machine is permanently coupled to the wheel set, then the vehicle can supply power during acceleration, but energy losses occur due to torque losses at high speed
Solution Approach 1:
The patent applies dynamics by making the coupling state of the traction machine variable rather than fixed. The control system dynamically adjusts the coupling/decoupling state based on real-time operating conditions (accelerator pedal position, brake pedal position, vehicle speed, road inclination, and torque setpoint evolution). This allows the system to transition between coupled and decoupled states optimally, supplying power during acceleration when needed and reducing energy losses during high-speed cruising when the traction machine would generate torque losses.
2Loss of energy
If the traction machine is decoupled to reduce energy losses, then vehicle consumption improves, but power supply capability during acceleration is reduced
Solution Approach 1:
The patent applies preliminary action by monitoring the evolution of the torque setpoint over time before making coupling/decoupling decisions. The control system calculates parameters based on the torque setpoint history and anticipates future power needs. This allows the system to maintain coupling in advance when acceleration is anticipated (based on torque setpoint trends) while still benefiting from decoupling during sustained low-torque conditions, thus balancing energy efficiency with power supply capability.
3Speed
If coupling/decoupling decisions are made quickly, then responsiveness to driver input is improved, but premature coupling may occur before stable operating conditions are reached
Solution Approach 1:
The patent applies feedback by continuously monitoring multiple parameters (accelerator pedal position, brake pedal position, vehicle speed, road inclination, and torque setpoint evolution) and using this feedback to make informed coupling/decoupling decisions. The control system calculates specific parameters based on the torque setpoint evolution and compares them against predetermined thresholds. This feedback mechanism ensures that coupling decisions are made with sufficient information about the current and evolving operating conditions, preventing premature coupling while maintaining responsive control.
Data Source
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Figure 3A
AI summary
In this method for controlling the coupling/decoupling of a traction machine of a motor vehicle to/from at least one wheel assembly, steps are carried out that allow the determination (120) of a moment (t_C1) when a torque set point (Croue_cons) to be applied to at least one wheel assembly of the vehicle is higher (110) than a pre-determined coupling threshold (C1) or higher than a pre-determined decoupling threshold, followed by the calculation (140) of a first parameter (PT1) and/or a second parameter (PS2) depending on said moment (t_C1), and the authorisation (160) of the coupling/decoupling when said first parameter (PT1) is higher (150) than a first pre-determined value (t1) and/or when said second parameter (PS1) is higher (150) than a second pre-determined value (S1).