EV Torque Optimization Using Physics-Based 3D Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional torque control systems for range-extended electrified vehicles (REEVs) with three or more electric motors face computational challenges due to the complexity of four-dimensional optimization problems, which exceed typical processing capabilities.
Innovation Solution
A physics-based dimension reduction strategy that transforms the 4D optimization problem into a 3D optimization problem by determining a torque relationship between two electric motors, using equations like Tc = M*Tb + N, and employing various techniques to select values for M and N, such as radii modification and optimization planes, allowing online solution by an embedded processor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a four-dimensional optimization problem is solved for torque control in electrified vehicles with three or more electric motors, then torque optimization accuracy is improved, but computational complexity and processing requirements increase substantially
Solution Approach 1:
The patent segments the four-dimensional optimization problem into multiple lower-dimensional sub-problems. Specifically, it divides the torque optimization across three electric motors and one torque generating system into separate controllable dimensions, allowing each to be optimized independently or in smaller groups, thereby reducing the overall computational burden while maintaining optimization effectiveness.
Solution Approach 2:
The patent applies dimensionality reduction by transforming the four-dimensional torque optimization problem into a three-dimensional problem through mathematical transformations and constraints. This is achieved by establishing torque relationships between motors (e.g., Tb = M*Tc + N) that reduce the independent variables, making the problem solvable with available processing power while preserving essential optimization characteristics.
2Measurement precision
If a four-dimensional optimization problem is solved for torque control in electrified vehicles, then torque distribution accuracy is improved, but processing time increases
Solution Approach 1:
The optimization problem is segmented into computationally lighter sub-problems that can be solved more quickly. By dividing the torque distribution calculations across multiple independent or semi-independent dimensions, the system achieves accurate torque distribution without requiring excessive processing time for a full four-dimensional solution.
Solution Approach 2:
The patent reduces the problem from four to three dimensions through mathematical transformations, directly decreasing the computational complexity and processing time required. This dimensionality reduction allows the system to maintain torque distribution accuracy while operating within real-time control constraints and available processing power.
3Reliability
If conventional torque control systems are used for electrified vehicles with three or more electric motors, then system reliability is maintained, but computational resources required exceed typical processing capabilities
Solution Approach 1:
The patent successfully reduces the computational dimension from four to three, making the optimization problem solvable with typical embedded processor capabilities while preserving the reliability of torque control. This dimensionality reduction is achieved through establishing torque relationships and constraints that maintain control accuracy without requiring excessive processing power.
Data Source
AI summary
A torque optimization system for an electrified vehicle having an electrified powertrain including three electric motors a, b, and c and an additional torque generating system includes a set of sensors configured to measure a set of operating parameters of the electrified vehicle and a control system configured to determine a torque relationship between electric motors b and c, solving a three-dimensional (3D) optimization problem for the electrified powertrain, the 3D optimization problem defining torques generatable by one of electric motors b and c, electric motor a, and the additional torque generating system, determine torque commands for the three electric motors a, b, and c and the torque generating system based on the solving of the 3D optimization problem, the determined torque relationship, and the set of operating parameters, and control the electrified powertrain based on the determined torque commands.