Electrified Vehicle Powertrain Alert System Using Switching Frequency Modulation
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Solution Overview
Problem
Electrified vehicles lack effective alert systems that utilize the powertrain to provide audible and inaudible sounds as alerts, which are not integrated with the vehicle's power delivery characteristics, limiting the ability to create sequences of tones for alert notifications.
Innovation Solution
A power characteristic control system that alters the power delivery within the electrified vehicle powertrain by changing switching frequencies during pulse width modulation to emit a sequence of acoustic tones, allowing for both audible and inaudible sounds to be used as alerts, maintaining net power delivery and controllability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the electrified vehicle powertrain operates normally without alert functions, then power delivery efficiency is maintained, but the ability to provide alert notifications is limited
Solution Approach 1:
The powertrain control system is modified to perform dual functions: normal power delivery and alert notification. By utilizing existing powertrain components (electric machines, power converters) for both propulsion and alert sound generation, the system achieves multi-functionality without adding dedicated alert hardware, thus improving versatility while minimizing complexity increase
2Adaptability or versatility
If the switching pattern of power is altered to emit acoustic tones, then alert notification capability is improved, but power delivery stability may be affected
Solution Approach 1:
Alert sounds are generated through periodic modulation of the switching pattern in power converters. By applying periodic switching variations at specific frequencies, the system generates audible acoustic tones without disrupting the overall power delivery function. The periodic nature allows controlled sound emission while maintaining stable average power output to the electric machines
Solution Approach 2:
The system temporarily changes switching frequency parameters in power converters during alert events. By adjusting the switching frequency within acceptable ranges and returning to normal parameters after the alert, the system generates detectable acoustic tones while minimizing impact on power delivery stability. The parameter changes are controlled and reversible, ensuring powertrain performance is restored after alert completion
3Reliability
If acoustic tones are emitted during power delivery, then alert effectiveness is enhanced, but energy efficiency may be reduced
Solution Approach 1:
The powertrain system uses its own operational components (power converters and electric machines) to generate alert sounds without requiring external energy sources or additional actuators. The alert function is achieved by self-utilizing the existing power delivery infrastructure, converting a portion of the power flow into acoustic energy. This self-service approach minimizes additional energy consumption while maintaining alert effectiveness
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables the use of powertrain-generated sounds to provide alert notifications that are perceivable as melodies or sequences, enhancing alert effectiveness without compromising powertrain efficiency or controllability.
Implementation Method 1
The electric machines can drive the electrified vehicles instead of, or in addition to, an internal combustion engine. The electric drivetrain can emit sounds when operating.
Implementation Method 2
The electric machines can drive the electrified vehicles instead of, or in addition to, an internal combustion engine. The electric drivetrain can emit sounds when operating. The individual could instead, or additionally, perceive the sounds as vibrations transmitted through structures of the electrified vehicle.
Data Source
AI summary
A vehicle alert method includes, among other things, in response to an alert event, altering at least one characteristic of power delivered within an electrified vehicle powertrain to provide an alert. A vehicle alert assembly includes, among other things, a power characteristic control system that, in response to an alert event, alters at least one characteristic of power delivered within an electrified vehicle powertrain to provide alert.