Wearable Robot Technologies

Compensation technique for environmental and light source power variations applied in a polymer optical fiber curvature sensor for wearable devices

“…For the temperature tests (see Figure 4), the range defined for wearable devices application is between 25°C and 45°C, which is within the interval of thermal comfort presented in (Moreno et al, 2008). Since the sensitivity of the sensor with respect to the angle is higher than 0.05 deg -1 , which is the one obtained for the same sensor in , the variation obtained on the range of interest represent an equivalent angular error lower than 0.5°.…”

“…Since the POF power variation on the temperature range tested is not too large, temperatures within the comfort zone range for wearable applications (Moreno et al, 2008) will not lead to high errors on the sensor response. The comfort zone for wearable applications, as defined in (Moreno et al, 2008), is within the interval between 25 °C and 45 °C, which is the range applied on the temperature tests. A sample with the sensitive zone parameters aforementioned is positioned inside a heater without curvatures on the sensor fiber.…”

“…The range of this test is 48% to 94% due to environmental and operational restrictions, respectively. Since wearable devices such as wearable sensors and exoskeletons can lead to variations of the environmental conditions in the interface between the device and skin (Moreno et al, 2008), the entire test range is of interest for the proposed application.…”

“…However, it can result in a less compact and more intrusive system (Wang et al, 2011). Furthermore, their use may also result in a noisy measurement (Moreno et al, 2008). These disadvantages may also inhibit the application of conventional technologies for angle measurement in wearable devices and in soft robotics applications, which is a growing field of research that employs flexible materials or structures as active or semi-active actuators of robotic devices (Holland et al, 2017).…”

“…However, it presents high sensitivity with magnetic field interferences and need frequent calibration (El-Gohary and McNames, 2012). Other common devices are the potentiometers that usually need mechanical supports precisely assembled Compensation technique for environmental and light source power variations applied in a polymer optical fiber curvature sensor for wearable devices to the joint, which are a widely applied technology to measure angles in active orthosis and exoskeletons (Moreno et al, 2008;Villa-Parra et al, 2015). However, it can result in a less compact and more intrusive system (Wang et al, 2011).…”