Idle Measurement
In the Idle Measurement Test, the open-circuit velocity of the vibrotactile actuators is measured under unloaded conditions. During this test, the actuator operates as freely as possible within the frequency range of 20-1000 Hz. It is secured within a metal frame using strings and springs to minimize external constraints and to restrict the movement to one degree of freedom (DOF).
The actuator is driven with a controlled frequency, waveform and amplitude in the case of Linear Resonant Actuators (LRA), or with a controlled DC voltage for Eccentric Rotating Mass Actuators (ERM). The movement occurs perpendicular to the metal frame, aligned with the actuator's natural direction of movement. Acceleration data is captured using an analog accelerometer to ensure accurate measurement.
Blocked Measurement
In the Blocked Measurement Test, the short-circuit force of vibrotactile actuators is measured under maximum load conditions. For this test, the actuator is mounted on a force sensor, which is firmly attached to a testbench table designed to apply a high-mass load.
Similar to the Idle Measurement Test, a frequency sweep is conducted from 20-1000 Hz. The actuator is driven with a controlled frequency, waveform and amplitude in the case of LRAs, or with a controlled DC voltage for ERMs. The movement occurs perpendicular to the testbench, aligned with the actuator's natural direction of movement. Force data is collected using an analog force sensor to ensure accurate and reliable measurement.
