Vehicle Controller Torque Waveform Synchronization
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Solution Overview
Problem
Users of electric vehicles and hybrid vehicles with electric motors may find the flat torque characteristics unsatisfying, as they lack the sense of beating associated with traditional internal combustion engines, leading to an unnatural driving experience.
Innovation Solution
A vehicle controller system that synchronizes the torque output of the electric motor with the engine's combustion cycle, using a sense-of-beating producer to derive a target torque that mimics the engine's torque waveform, ensuring the overall torque output mimics the periodic fluctuation of an engine, thereby replicating the sense of beating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the electric motor outputs flat torque, then the torque characteristics are smooth and consistent, but the user does not feel a sense of beating similar to an engine
Solution Approach 1:
The patent applies periodic action by making the electric motor generate torque that fluctuates periodically according to the engine combustion cycle. The controller causes the motor to output torque with peaks and valleys that correspond to the four-stroke combustion process (intake, compression, power, exhaust), creating a periodic torque pattern that mimics engine beating while maintaining overall torque requirements.
Solution Approach 2:
The patent changes the torque parameter of the electric motor from a constant flat output to a variable periodic output. By dynamically adjusting the motor torque according to the combustion cycle phase, the system transforms the steady-state torque characteristic into a time-varying torque profile that reproduces the beating sensation of traditional engines.
2Ease of operation
If the torque output is increased and decreased to create beating sensation, then the sense of beating is improved, but the torque control complexity increases
Solution Approach 1:
The patent employs feedback by using the actual engine combustion cycle information (crank angle, stroke phase) as input to control the electric motor torque. The controller continuously monitors the combustion cycle progress and adjusts the motor torque in real-time based on this feedback, ensuring the torque fluctuation is precisely synchronized with the combustion events.
Solution Approach 2:
The patent introduces a torque control unit as an intermediary between the engine combustion process and the electric motor. This control unit translates the combustion cycle information into appropriate motor torque commands, acting as a mediator that converts the periodic combustion events into corresponding periodic torque outputs from the motor.
3Stability of the object's composition
If the electric motor and engine share torque output, then the overall torque fluctuation is reduced, but the sense of beating becomes milder and less natural
Solution Approach 1:
The patent applies asymmetry by making the electric motor torque distribution asymmetric relative to the engine torque. Instead of equal or balanced torque sharing, the motor provides supplementary torque that is strategically varied to compensate for the smoothing effect. The motor torque is higher during combustion strokes and lower during non-combustion strokes, creating an asymmetric pattern that restores the beating sensation.
Solution Approach 2:
The patent uses the electric motor torque as a counterweight to the smoothing effect of torque sharing. By introducing periodic torque fluctuations from the motor that are out of phase with the engine torque variations, the system counteracts the stabilizing effect and restores the desired beating sensation in the total torque output.
Data Source
AI summary
A vehicle controller for a vehicle including a drive source including an electric motor includes: a sense-of-beating producer configured to acquire a total required torque which is a required torque of the entire vehicle and configured to derive a total target torque corresponding to the total required torque as applied to a predetermined engine combustion cycle; and a target motor torque deriver configured to, based on the total target torque, derive a target motor torque for torque control of the electric motor. The vehicle controller controls the electric motor based on the target motor torque.