Hybrid Vehicle Torque Control Logic
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Solution Overview
Problem
Conventional methods for calculating driver request torque in hybrid electric vehicles often result in delayed responses due to calculating zero or negative torque values when the accelerator pedal is slightly depressed, leading to inadequate acceleration and deceleration performance.
Innovation Solution
The method involves monitoring vehicle speed and accelerator pedal position, calculating driver request torque by recognizing acceleration intention even at low pedal positions, and applying up/down torque rate limit logic to prevent torque discontinuity and improve acceleration and driving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the driver request torque is calculated as zero or negative when the accelerator pedal is slightly depressed, then the calculation follows the conventional method, but the response to driver request is delayed
Solution Approach 1:
The patent applies preliminary action by setting the minimum driver request torque to 0 Nm in advance before actual acceleration occurs. When the accelerator pedal opening degree is greater than 0%, the system proactively calculates torque as positive rather than waiting for threshold conditions, ensuring immediate response to driver input without delayed calculation
2Speed
If the minimum driver request torque is set to 0 Nm when APS > 0%, then the acceleration response is improved, but torque discontinuity may occur
Solution Approach 1:
The patent applies dynamics by implementing up/down torque rate limit logic that dynamically adjusts torque changes based on current driving conditions. The system calculates maximum and minimum torque rates based on vehicle speed, current torque, and other parameters, allowing torque to change smoothly within defined rates rather than making abrupt transitions, thus maintaining both rapid response and torque continuity
Solution Approach 2:
The patent applies parameter changes by modifying the torque calculation parameters based on accelerator pedal position. When APS > 0%, the minimum torque parameter is changed from negative values to 0 Nm, and the system dynamically adjusts torque rate limits based on vehicle speed and current operating conditions, ensuring smooth transitions while maintaining acceleration performance
Data Source
AI summary
The present invention provides a method of controlling a driver request torque in a hybrid electric vehicle, in which a driver request torque is calculated by determining that a driver has an intention to accelerate, if an accelerator opening degree detected by an accelerator pedal position sensor (APS) is greater than 0% when the accelerator pedal is depressed by the driver who intends to re-accelerate after coasting or decelerating, and a torque discontinuity, which may be caused when the APS is turned on→off→on according to the depression operation of the accelerator pedal by the driver, is controlled using an up/down torque rate limit logic, thus preventing deterioration of driving performance.For this purpose, the present invention provides a method of controlling a driver request torque in a hybrid electric vehicle, the method including: monitoring a vehicle speed; calculating a maximum torque with respect to the vehicle speed; monitoring an APS; and calculating a driver request torque by determining that a driver has an intention to accelerate and recognizing a minimum request torque as 0 Nm, if an opening degree of the APS is greater than 0%.