Engine Torque Control for Transmission Upshift Disturbance
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Solution Overview
Problem
Existing engine control systems cause acceleration disturbances during transmission upshifts due to the decrease in output torque during the torque phase, leading to a delay in vehicle acceleration known as a 'torque hole', as they typically increase engine torque during the inertia phase rather than the torque phase.
Innovation Solution
A control system that includes a torque phase detection module, a torque request generation module, and an engine torque control module, which increases engine torque during the torque phase of the upshift and controls it to a final torque during the inertia phase, ensuring smoother acceleration throughout both phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If engine torque is increased during the inertia phase of upshift (conventional control), then transmission gear switching is completed, but acceleration disturbance and torque hole occur during the torque phase
Solution Approach 1:
The control system increases engine torque during the torque phase (before the inertia phase) rather than during the inertia phase. This preliminary action of increasing torque before the actual gear switching eliminates the torque hole and acceleration disturbance that would otherwise occur during the torque phase, while still completing the upshift in a timely manner.
2Productivity
If transmission upshift is performed with conventional torque control, then gear ratio changes from higher to lower, but output torque decreases during torque phase causing acceleration disturbance
Solution Approach 1:
The control system applies preliminary anti-action by increasing engine torque during the torque phase to counteract the decrease in output torque that occurs during upshift. This compensatory torque increase prevents the acceleration disturbance and torque hole that would normally result from the transmission torque decrease, while allowing the upshift to complete at normal speed.
Data Source
AI summary
A control system for an engine includes a torque phase detection module, a torque request generation module, and an engine torque control module. The torque phase detection module detects a start of a torque phase of an upshift of a transmission coupled to the engine. The torque request generation module generates an engine torque request at the start of the torque phase of the transmission upshift. The engine torque control module controls engine torque during the torque phase of the transmission upshift based on the engine torque request.