Vehicle Powertrain Control Using Phase-Specific Cost Functions
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Solution Overview
Problem
Current methods for controlling a vehicle's powertrain face challenges in accurately calculating engine torque, leading to reduced shifting feel and potential accidents, as well as increased manpower and complexity in calibrating shifting performance with increasing shift positions, making it difficult to simultaneously control input torque and clutch torque effectively.
Innovation Solution
A method that determines whether the shift phase is torque or inertia phase, configures different cost functions for each phase, and calculates control input changes to minimize these functions, allowing for simultaneous control of input torque, first clutch torque, and second clutch torque, using optimization algorithms to reduce non-linearity and complexity in control software.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If engine torque is calculated by modeling for powertrain control, then control can be implemented without direct measurement, but the calculated torque includes errors that reduce shifting quality and may cause accidents
Solution Approach 1:
The patent implements feedback by using actual shifting behavior and performance data to continuously refine and update the torque calculation model. The controller monitors shifting quality indicators and adjusts the modeled torque values accordingly, transforming the open-loop modeling approach into a closed-loop system that compensates for initial model errors through continuous feedback from actual vehicle operation.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the torque model parameters based on operating conditions and calibration data. Instead of using fixed modeled torque values, the system modifies torque calculation parameters according to actual shifting performance, allowing the model to adapt to different driving scenarios and improve accuracy without requiring direct torque measurement hardware.
2Reliability
If input torque and clutch torque are controlled to be reduced appropriately for smooth shifting, then shifting quality improves, but it is difficult to simultaneously control the two inputs as they continuously change over time
Solution Approach 1:
The patent segments the shifting process into distinct phases (torque phase and inertia phase), allowing different control strategies to be applied to each phase. By dividing the continuous torque control problem into phase-specific sub-problems, the system can manage the complexity of simultaneously controlling input torque and clutch torque through staged, phase-appropriate control actions rather than attempting unified continuous control.
Solution Approach 2:
The patent applies dynamics by implementing adaptive control that responds to real-time changes in torque and clutch state. The control system dynamically adjusts control parameters based on the current phase and measured variables, allowing the control strategy to evolve with the changing operating conditions rather than using fixed control rules, thereby managing complexity through adaptive responsiveness.
3Adaptability or versatility
If the number of shift positions in the transmission is increased, then transmission versatility improves, but the number of shift cases to be calibrated increases, significantly increasing manpower requirements at the early development stage
Solution Approach 1:
The patent applies universality by developing a unified torque model and control strategy that can be applied across multiple shift positions and cases. Instead of creating separate calibration procedures for each shift case, the system uses a generalizable torque model that works across different transmission configurations, allowing the same fundamental approach to handle various shift positions without requiring proportional increases in calibration manpower.
Solution Approach 2:
The patent uses parameter changes to reduce calibration burden by identifying and adjusting key torque model parameters that have the greatest impact across multiple shift cases. By focusing calibration efforts on these critical parameters rather than individual case-specific parameters, the system achieves improved calibration efficiency that scales better with increasing transmission versatility.
Data Source
AI summary
A method of controlling a powertrain of a vehicle is carried out such that during shifting in which a first clutch is released and a second clutch is engaged, whether a current shift phase is a torque phase or an inertia phase is determined. Different cost functions for the torque phase and the inertia phase are predefined. A control input change for minimizing the cost functions in the torque phase and the inertia phase is calculated. At least two among input torque, first clutch torque, or second clutch torque input to a transmission are controlled by applying the control input change calculated for the torque phase and the inertia phase.