Virtual Sensors for Advanced Controllers in Rehabilitation Robotics

Abstract

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.

Design, Implementation, Interfacing and Control of Internet of Robot Things for Assisting Robot

“…Where the error minimization result in acceptable therapy trajectories. Table (5) illustrates the error presented in joint motor responses before and after using the spring system. The above table illustrate the oscillation minimization in robot joints through the presence of the load, that means the designed spring system is working effectively, where it increases the required torque by the first joint motor in the execution phase and damping the links motion through the retraction phase, all of these results overcome via the power of the PD fuzzy controller that can overcome the oscillation with wide range of universe of discourse in input and output signals.…”

“…Aitziber et al, proposed in 2018 the effective sensors, were used as a substitute for the actual force and motion sensors of the proposed assisting robot that used for upper limb recover. These virtual sensors established the required stimulates of force and motion at the contact points, where the person interacts with the assisting arm using the arm mathematical model [5]. In 2018, Monica, et al, provide a control structure used the electromyography signals for drive the joint motion and control the assisting arm.…”

Upper Limb Bionic Orthoses: General Overview and Forecasting Changes

“…Virtual Sensors allow to estimate the robot/user interaction force and motion [129]. It is cheaper and equally effective alternative to standard contact force and motion sensors.…”

Physical Extraction and Feature Fusion for Multi-Mode Signals in a Measurement System for Patients in Rehabilitation Exoskeleton

“…Rehabilitation exoskeletons robot are emerging as important components of the rehabilitation training process for patients affected by hemiplegia and cerebral apoplexy [ 1 , 2 ]. The rehabilitation training system comprises a lower extremity exoskeleton, where the robotics are employed for sensing, control, information fusion and mobile computing [ 3 , 4 , 5 , 6 ]. Accurate data from measurement systems can be provided to the feedback control of exoskeleton system.…”