Vehicle Torque Control Using Integral-Based Backlash Elimination
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Solution Overview
Problem
Existing vehicle control systems fail to effectively suppress rattling noise in gears due to the limitation of torque control, which can occur before the gear backlash is fully eliminated, especially when the driver's accelerator pedal operation changes.
Innovation Solution
A vehicle controller that includes a target driving torque setting unit, an output driving torque acquisition unit, a control unit, a calculation unit, and a determination unit. The controller calculates the temporal integral of the output or required driving torque after a switch in torque direction and limits the target driving torque until a predetermined integral value is reached, ensuring the gear backlash is fully eliminated before torque limitation is lifted.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If time counting is used to determine when torque limitation ends, then the control is simple and responsive, but the backlash may not be fully eliminated resulting in acceleration shock
Solution Approach 1:
The patent changes the control parameter from simple time counting to temporal integral of driving torque. The calculation unit computes the temporal integral of driving torque during the torque limitation period, and the determination unit terminates limitation when this integral reaches a threshold value. This parameter transformation ensures that the termination condition reflects the actual physical state of backlash elimination rather than just elapsed time.
2Object-affected harmful factors
If torque limitation is applied to suppress acceleration shock, then gear backlash is eliminated, but rattling noise occurs if limitation ends too early
Solution Approach 1:
The patent implements feedback control by continuously monitoring the temporal integral of driving torque and using this information to adjust the torque limitation termination decision. The determination unit receives feedback from the calculation unit about the current integral value and compares it against the threshold, dynamically deciding when to terminate limitation based on actual torque accumulation rather than predetermined time.
3Reliability
If temporal integral of driving torque is calculated to determine torque limitation termination, then backlash elimination is ensured, but control complexity increases
Solution Approach 1:
The patent introduces a temporal integral calculation as an intermediary mechanism between the simple time-based control and the complex physical state monitoring. Rather than directly monitoring complex gear mesh states, the system uses the integrable property of driving torque as an intermediary indicator that correlates with backlash elimination progress, simplifying the overall control architecture while maintaining reliability.
Data Source
AI summary
In a vehicle controller, when output driving torque switches between positive and negative, a target driving torque setting unit executes a torque limiting process that limits the absolute value of the target driving torque to a predetermined limit value or less, and the target driving torque setting unit ends the torque limiting process based on a determination by a determination unit that a temporal integral has reached a predetermined value.