ERM Actuator Back-EMF Characterization for Haptic Consistency
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Solution Overview
Problem
Conventional actuators used for generating haptic effects, such as Eccentric Rotating Mass (ERM) devices, face variability in performance characteristics like rise time and brake time due to design, manufacturing, and environmental factors, limiting the ability to substitute actuators without affecting haptic feedback quality or requiring costly reconfiguration.
Innovation Solution
Characterizing ERM actuators using back electromotive force (EMF) to derive operating parameters like rise time, brake time, and revolutions per minute, and using these parameters to generate optimized haptic effect signals, allowing for dynamic adjustment of motor signals to achieve consistent and precise haptic feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional ERM actuators are used for generating haptic effects, then the device can provide basic vibration feedback, but the performance characteristics (rise time, brake time) vary due to design, manufacturing, and environmental factors, limiting substitutability and requiring costly reconfiguration
Solution Approach 1:
The system dynamically adjusts control parameters (voltage, frequency, duty cycle) based on real-time monitoring of actuator performance characteristics. By continuously adapting these parameters, the system compensates for manufacturing variances and environmental changes, maintaining consistent haptic feedback across different actuator instances without requiring manual reconfiguration
Solution Approach 2:
The system implements a feedback mechanism that monitors actuator performance (rise time, brake time, steady-state voltage) and uses this information to adjust control signals. This closed-loop approach ensures that performance variations due to manufacturing tolerances or environmental factors are compensated, maintaining reliable haptic feedback while enabling actuator substitutability
2Manufacturing precision
If actuator performance parameters are manually characterized and configured, then haptic feedback quality can be optimized for specific actuators, but this process is costly and time-consuming, preventing flexible actuator substitution
Solution Approach 1:
The system performs self-characterization by automatically measuring actuator parameters (rise time, brake time, steady-state voltage) through built-in monitoring circuits and algorithms. This eliminates the need for external manual characterization equipment and procedures, enabling rapid actuator substitution without costly reconfiguration while maintaining optimized performance
Solution Approach 2:
The system performs preliminary characterization of actuator parameters during initial system setup or actuator installation, storing these parameters for future use. This preliminary action captures performance characteristics before the actuator is deployed, enabling rapid substitution later without requiring time-consuming manual reconfiguration while maintaining performance optimization
3Device complexity
If fixed control signals are used for ERM actuators, then the control system is simple, but it cannot compensate for performance variations due to manufacturing, temperature, and wear, reducing haptic feedback quality
Solution Approach 1:
The control system transitions from static fixed signals to dynamic adaptive signals that adjust in real-time based on monitored actuator performance. The system continuously modifies control parameters (voltage, frequency, pulse width) according to actual actuator behavior, compensating for manufacturing variations, temperature effects, and wear while maintaining relatively simple hardware architecture
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
This approach enables more precise and effective haptic experiences by optimizing actuator performance, allowing for the use of different actuators without affecting feedback quality and reducing the need for costly reconfiguration, while compensating for manufacturing variances and environmental changes.
Implementation Method 1
an electromagnetic actuator such as an Eccentric Rotating Mass ('ERM') in which an eccentric mass is moved by a motor
Implementation Method 2
The system characterizes the ERM actuator using back electromotive force ('EMF') in order to derive operating parameters
Data Source
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AI summary
A system that generates a haptic effect using an Eccentric Rotating Mass ("ERM") actuator determines a back electromotive force ("EMF") of the ERM actuator and receives a haptic effect signal comprising one or more parameters, where one of the parameters is a voltage amplitude level as a function of time. The system varies the voltage amplitude level based at least on the back EMF, and applies the varied haptic effect signal to the ERM actuator.