Vehicle Torque Control via Axle Request Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing engine control systems face drivability issues due to the indirect relationship between driver input and engine torque, particularly when transmission shifting and torque converter clutch engagement occur, leading to unintended torque changes independent of driver input.
Innovation Solution
A system comprising an axle torque determination module, an engine torque determination module, and an engine torque control module that directly controls engine torque based on axle torque requests, accounting for transmission losses and turbine speed, to improve drivability by aligning torque output with driver input.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional engine control systems use indirect torque control methods, then the system complexity is reduced, but drivability deteriorates due to unintended torque changes during transmission shifts and torque converter clutch engagement
Solution Approach 1:
The control system continuously monitors actual engine torque output and compares it with the desired torque request. When deviations are detected (such as during transmission shifts or torque converter clutch engagement), the system adjusts fuel injection and spark timing in real-time to compensate for the deviations and maintain torque output aligned with driver input.
Solution Approach 2:
The system dynamically adjusts multiple engine parameters including fuel injection quantity, injection timing, spark timing, and air intake volume based on real-time operating conditions. These parameter changes enable the engine to maintain optimal torque output characteristics across different transmission states and torque converter clutch engagement states.
2Speed
If engine torque is controlled based on indirect parameters, then the control response is slower, but the system is simpler to implement
Solution Approach 1:
The control system pre-calculates the required fuel injection quantity and spark timing based on the desired torque request and current engine operating conditions. This preliminary preparation allows the system to execute torque adjustments rapidly when transmission shifts or torque converter clutch engagement occurs, without waiting for error accumulation.
Solution Approach 2:
Real-time feedback from torque sensors and transmission control units enables the system to detect torque deviations immediately and trigger corrective fuel injection and spark timing adjustments, achieving fast torque response through closed-loop control.
3Power
If the throttle area is increased to increase air flow and torque output, then the torque production increases, but the control precision deteriorates during transient conditions
Solution Approach 1:
Instead of relying solely on throttle area changes, the system directly controls multiple parameters including fuel injection quantity, injection timing, and spark timing to achieve precise torque control. This multi-parameter approach maintains torque control precision even during rapid transient conditions when throttle response may be sluggish.
Solution Approach 2:
The system replaces purely mechanical throttle-based torque control with an electronically controlled fuel injection and ignition system. This substitution enables more precise and rapid torque adjustment by directly controlling the combustion process through electronic actuators rather than relying on mechanical throttle linkage and air flow dynamics.
Data Source
AI summary
A system according to the principles of the present disclosure includes an axle torque determination module, an engine torque determination module, and an engine torque control module. The axle torque determination module determines an axle torque request based on a driver input and a vehicle speed. The engine torque determination module determines an engine torque request based on the axle torque request and at least one of a turbine speed and whether a clutch of a torque converter is applied. The engine torque control module controls an amount of torque produced by an engine based on the engine torque request.