Department of Automatic Control and System Engineering, Faculty of Engineering in Bilbao, University of the Basque Country (UPV/EHU), Plaza Ingeniero Torres Quevedo 1, 48013 Bilbao, Spain.
Neurorehabilitation Area, Health Division, TECNALIA Research and Innovation, Mikeletegi Pasealekua 1-3, Donostia-San Sebastian 20009, Spain.
Sensors (Basel). 2018 Mar 5;18(3):785. doi: 10.3390/s18030785.
In order to properly control rehabilitation robotic devices, the measurement of interaction force and motion between patient and robot is an essential part. Usually, however, this is a complex task that requires the use of accurate sensors which increase the cost and the complexity of the robotic device. In this work, we address the development of virtual sensors that can be used as an alternative of actual force and motion sensors for the Universal Haptic Pantograph (UHP) rehabilitation robot for upper limbs training. These virtual sensors estimate the force and motion at the contact point where the patient interacts with the robot using the mathematical model of the robotic device and measurement through low cost position sensors. To demonstrate the performance of the proposed virtual sensors, they have been implemented in an advanced position/force controller of the UHP rehabilitation robot and experimentally evaluated. The experimental results reveal that the controller based on the virtual sensors has similar performance to the one using direct measurement (less than 0.005 m and 1.5 N difference in mean error). Hence, the developed virtual sensors to estimate interaction force and motion can be adopted to replace actual precise but normally high-priced sensors which are fundamental components for advanced control of rehabilitation robotic devices.
为了正确控制康复机器人设备，测量患者与机器人之间的相互作用力和运动是必不可少的。然而，通常情况下，这是一项复杂的任务，需要使用精确的传感器，这会增加机器人设备的成本和复杂性。在这项工作中，我们开发了虚拟传感器，可以作为用于上肢训练的通用触觉牵引器（UHP）康复机器人的实际力和运动传感器的替代物。这些虚拟传感器使用机器人设备的数学模型和通过低成本位置传感器进行测量，来估计患者与机器人相互作用的接触点处的力和运动。为了展示所提出的虚拟传感器的性能，我们已经在 UHP 康复机器人的先进位置/力控制器中实现并进行了实验评估。实验结果表明，基于虚拟传感器的控制器与使用直接测量的控制器具有相似的性能（平均误差小于 0.005 m 和 1.5 N）。因此，开发用于估计相互作用力和运动的虚拟传感器可以替代通常价格较高的实际精确传感器，这是康复机器人设备高级控制的基本组件。
