Sharif Digital Repository

Multi-sensor tracking is widely used for augmentation of tracking accuracy using data fusion. A basic requirement for such applications is the real time temporal synchronization and spatial registration of two sensory data. In this study a new method for time and space coordination of two tracking sensor measurements has been presented. For spatial registration we used a body coordinate system and then applied the effect of the level arm. The time synchronization was done based on least mean square (LMS) error method. This method was implemented to synchronize the position and orientation of an object using Inertial (1IMU) and Optical (Optotrak) tracking systems. The results of synchronized... 

This paper discusses the mission requirements and design constraints for an Unmanned Martian research aircraft based on a tailor-made classical airplane design methodology. First, the exploration mission is described using the information from previous real-world experiences and the desired payload is proposed accordingly. The environmental conditions that dictate severe constraints to the design space are characterized afterwards. The conventional airplane design cycle is modified to address the lack of statistical data and to define a proper design recycling criteria. Eventually, the outcome is presented in the form of a novel configuration that is well suited to carry out the specified... 

In recent years, robotic rehabilitation has been utilized in treatment and recovery of patients with disabilities. In this paper, a novel design and kinematic analysis of a 4-DOF robot for upper-limb rehabilitation are proposed. The main novelty of this design is its mechanism for wrist and fingers motions which is added to the shoulder and elbow mechanism without any noticeable weight increase in the moving parts of the robot. For this purpose, a cable driven mechanism is implemented at the robot end-effector to move the wrist and fingers parts, and the corresponding actuators are placed at the base of the robot. © 2018 IEEE  

This paper describes latest results obtained on modeling, simulation and controller design of an insect-like Flapping Wing Micro Air Vehicle (FWMAV). Because of the highly nonlinear and time varying nature of insect flight and the inability to find an equilibrium point, linearization of the model without compromising the accuracy is not possible. Therefore, to address the problem of designing a controller capable of stabilizing and controlling the FWMAV around a hovering point, a metaheuristic optimization approach is proposed, based on the time averaging theorem. The results show that a controller, designed using the proposed method, is capable of stabilizing the FWMAV effectively around... 

System Identification is a key technology for the development and integration of modern engineering systems including unconventional flying vehicles. These systems are highly parametric with complex dynamics and nonlinearities. Ducted fans are special class of these vehicles that can take off vertically, hover and cruise at very low speed. In this paper, an exact equivalent linear system is found from the non-linear dynamic model of a ducted fan by use of frequency response identification. Here, power spectral density analysis is performed, using CIFER software, to evaluate the input-output responses in hover and to derive the transfer functions based on the coherence criterion. Then,... 

Although numerous molecular methods for spinal muscular atrophy (SMA) detection have been exploited, most of hem are laborious, time consuming and costly. Recently, gold nanoparticles (AuNPs) have attracted attention in the field of colourimetric bioanalysis, because AuNP aggregation can be tracked with the naked eye as well as ultraviolet-visible (UV-vis) peak analysis. Here, based on a non-cross linking platform, a colourimetric-based method was used to evaluate the capability of thiolated oligo-AuNPs (Au nanoprobes) to distinguish between normal individuals, carriers and those with SMA. In this platform, removal of the repulsive force of the Au nanoprobes using high salt concentration... 

This paper proposes a new method to improve accuracy and real-time performance of inertial joint angle estimation for upper limb rehabilitation applications by modeling body acceleration and adding low-cost markerless optical position sensors. A method based on a combination of the 3D rigid body kinematic equations and Denavit-Hartenberg (DH) convention is used to model body acceleration. Using this model, body acceleration measurements of the accelerometer are utilized to increase linearization order and compensate for body acceleration perturbations. To correct for the sensor-to-segment misalignment of the inertial sensors, position measurements of a low-cost markerless position sensor are... 

Exercise therapy is considered as one of the main rehabilitation treatments for post-stroke patients, especially by utilizing modern technologies, such as virtual and/or augmented reality. However, in order to design an appropriate exercise program, which prolongs the exercise duration and maximize the patient's improvement, the fatigue status needs to be detected and used for the program adjustment. In the previous fatigue recognition works, only exercises for healthy and athlete subjects have been taken into account. In this paper, fatigue status classification has been accomplished in a rehabilitation exercise for poststroke patients. To do so, the reaching task, as a basic rehabilitation... 

As balance is the foundation for all voluntary motor skills, considerable research has been conducted to evaluate postural control in patients with low back pain (LBP). Although reliability is a population-specific property, to the authors' knowledge, there has been no study to determine the test-retest reliability of the center of pressure (COP) measures in the general population of LBP patients. As many as 11 patients with a history of nonspecific LBP randomly completed postural measurements with three levels of difficulty (rigid surface-eyes open, rigid surface-eyes closed, and foam surface-eyes closed) in two sessions. The COP data were used to calculate standard deviation of amplitude,... 

Background: Performance indices provide quantitative measures for the quality of motion, and therefore, assist in analyzing and monitoring patients' progress. Measurement of performance indices requires costly devices, such as motion capture systems. Recent developments of sensors for game controllers, such as Microsoft Kinect, have motivated many researchers to develop affordable systems for performance measurement applicable to home and clinical care. In this work, the capability of Kinect in finding motion performance indices was assessed by analyzing intra-session and inter-session test-retest reliability. Method: Eighteen stroke patients and twelve healthy subjects participated in this...