Vehicle Driving Force Zero-Crossing Control for Impact Suppression
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Solution Overview
Problem
Existing vehicle driving force controllers face challenges in suppressing impacts during changes in driving force, particularly when the driving force crosses zero, due to high rates of change, which can lead to failures in detecting optimal control timing.
Innovation Solution
A driving force controller with a driving force calculator and controller that determines whether a predicted driving force satisfies a condition involving a near-zero range, imposing rate-of-change limitations to keep the driving force within this range, thereby reducing impacts during zero-crossing events.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the rate of change in instructed driving force is not limited, then the responsiveness to driving commands is improved, but impacts occur in the power source or transmission path when driving force crosses zero
Solution Approach 1:
The system performs preliminary detection of the zero-crossing condition by checking whether the range between current and predicted driving force covers the first range (including zero driving force). Based on this preliminary detection, the controller proactively limits the rate of change before the actual zero-crossing occurs, preventing impact while maintaining responsiveness.
Solution Approach 2:
The controller dynamically adjusts the rate-of-change limitation based on the detected condition. When the first condition is satisfied (zero-crossing predicted), the rate of change is limited; when not satisfied, normal responsive control is maintained. This dynamic adjustment resolves the contradiction between responsiveness and impact prevention.
2Object-affected harmful factors
If the rate of change in instructed driving force is limited, then impacts during zero-crossing are suppressed, but the responsiveness to driving commands deteriorates
Solution Approach 1:
The rate-of-change limitation is applied locally and selectively only when the first condition is satisfied (i.e., when zero-crossing is predicted). In all other situations, the normal rate of change is maintained, ensuring high responsiveness. This localized application resolves the contradiction by limiting impact suppression to specific critical moments.
Solution Approach 2:
The controller changes the parameter of rate-of-change limitation based on the detected condition. When zero-crossing is predicted, the rate of change parameter is reduced to suppress impact; otherwise, it maintains normal values for responsiveness. This parameter adjustment strategy resolves the contradiction between impact suppression and responsiveness.
3Measurement precision
If the control timing detection is not precise, then the control system is simpler, but failures occur in detecting optimal control timing during zero-crossing events
Solution Approach 1:
The system performs preliminary detection of the zero-crossing condition by checking whether the range between current and predicted driving force covers the first range. This preliminary action enables precise control timing detection without complex real-time monitoring, as the prediction mechanism identifies upcoming zero-crossing events in advance.
Solution Approach 2:
The patent introduces an intermediary prediction mechanism that calculates predicted driving force based on current rate of change. This intermediary calculation serves as a mediator between simple current state monitoring and complex real-time zero-crossing detection, achieving precise timing detection with moderate system complexity.
Data Source
AI summary
A driving force controller for vehicle includes a driving force calculator and a driving controller. The driving force calculator calculates an instructed driving force, and includes a first determination unit that determines whether or not a predicted driving force satisfies a first condition. The predicted driving force assumes that the instructed driving force calculated on a first control cycle is changed at a rate of change calculated on the first control cycle, until a second control cycle. The first condition includes that a range between the instructed driving force calculated on the first control cycle and the predicted driving force at least partly cover a first range including a zero driving force. The driving force calculator imposes limitation on the rate of change in the instructed driving force to be calculated in the second control cycle, on the condition that the first condition is satisfied.