Variable Creep Torque Control via Brake Torque Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Newer vehicle types, such as two-mode hybrid, battery electric, and fuel cell vehicles face challenges in efficiently applying creep torque while stationary, as the continuous energy usage for maintaining creep torque contradicts the purpose of these non-conventional powertrains.
Innovation Solution
A method that detects the creep torque condition, determines the initial and new brake torque, calculates the rate of change, and adjusts the creep torque applied by the powertrain to minimize energy usage while maintaining the desired creep torque feel, involving a brake system and powertrain system with controllers to manage brake torque and creep torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the electric motor operates continuously to supply creep torque while the vehicle is stopped in gear, then the desired creep torque feel is provided to the driver, but energy consumption increases
Solution Approach 1:
The patent applies dynamics by making the creep torque variable rather than constant. The controller dynamically adjusts the creep torque based on detected brake torque conditions, transitioning from a fixed torque approach to an adaptive one that responds to real-time driver input, thereby reducing energy consumption while maintaining operational effectiveness.
Solution Approach 2:
The patent changes the parameter of creep torque from a constant value to a variable value that depends on brake torque conditions. By monitoring brake torque and adjusting creep torque accordingly (reducing it when brake torque is high, maintaining it when brake torque is low), the system optimizes energy usage while preserving the desired vehicle behavior.
2Stability of the object's composition
If the brakes work against creep torque while the vehicle is stationary, then the vehicle remains stopped, but energy efficiency is reduced
Solution Approach 1:
The patent implements feedback by having the controller continuously monitor brake torque conditions and use this information to adjust creep torque output. This closed-loop control ensures that creep torque is optimized based on actual brake application, preventing energy waste when brakes are heavily applied while maintaining vehicle stability when appropriate.
Solution Approach 2:
The patent applies preliminary anti-action by reducing creep torque in anticipation of or in response to brake application. When the controller detects high brake torque, it proactively reduces or eliminates creep torque to prevent the motor from working against the brakes, thereby avoiding unnecessary energy consumption while maintaining the vehicle's stopped state.
Data Source
AI summary
A vehicle and a method of operation. The method of operating the vehicle may include a method of controlling a creep torque in a vehicle having a powertrain configured to provide variable creep torque. The method may comprise the steps of: detecting a vehicle creep torque condition, determining a brake torque, and adjusting a creep torque applied by the powertrain based on the brake torque.