Audio-Haptic Signal Mixing to Prevent Amplifier Clipping
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Solution Overview
Problem
Existing audio-haptic systems face challenges in simultaneously generating effective audio and haptic feedback without overdriving haptic actuators, which can lead to amplifier clipping and degradation of haptic performance, often requiring additional loudspeakers or expensive multi-function transducers.
Innovation Solution
An audio-haptic signal generator that includes a controller and mixer, processing audio signals based on haptic and amplifier states to avoid clipping, using techniques like signal delay, gain adjustment, and phase modification, allowing simultaneous output of combined audio and haptic signals without degrading haptic performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If audio and haptic signals are combined and output simultaneously through a haptic actuator, then system complexity is reduced by eliminating separate loudspeakers, but amplifier clipping occurs and haptic performance degrades
Solution Approach 1:
The system dynamically adjusts the audio signal characteristics (delay, gain, phase) based on the haptic signal properties and amplifier state. This dynamic adaptation allows the audio signal to be modified in real-time to prevent clipping while maintaining haptic performance, resolving the contradiction between system simplicity and performance reliability
Solution Approach 2:
The controller modifies key parameters of the audio signal including time delay, gain amplitude, and phase angle based on the haptic signal characteristics and amplifier operating state. By changing these parameters adaptively, the system prevents amplifier clipping while maintaining both audio quality and haptic performance, eliminating the need for separate loudspeakers
2Adaptability or versatility
If the audio signal is amplified along with the haptic signal, then a single transducer can provide both audio and haptic output, but the haptic actuator is overdriven causing amplifier clipping
Solution Approach 1:
The system applies partial action by selectively amplifying only the necessary components of the audio signal while controlling the overall power output. The audio signal is processed with adjusted gain and delayed timing so that it combines with the haptic signal without causing excessive power demand that would lead to clipping, enabling single-transducer multi-functionality while preventing power overload
Solution Approach 2:
The system uses feedback from the amplifier state and haptic signal characteristics to continuously adjust the audio signal processing parameters. This closed-loop control ensures that the combined signal remains within the amplifier's power capabilities, preventing clipping while maintaining the versatility of using a single transducer for both audio and haptic output
Data Source
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AI summary
An audio-haptic signal generator for a haptic system including an amplifier coupled to a haptic actuator is described. The audio-haptic signal generator includes an audio input configured to receive an audio signal; a haptic input configured to receive a haptic signal and a controller configured to receive to at least one of the haptic signal, an amplifier state and a haptic actuator state. A mixer is coupled to the audio input and the haptic input. The mixer has an output configured to be coupled to a haptic actuator. The controller controls the mixer to process the audio signal dependent on at least one of a characteristic of the haptic signal, an amplifier state, and a haptic actuator state. The mixer is configured to mix the haptic signal and processed audio signal on to output the mixed haptic signal and processed audio signal.