The precision of a measurement system is the consistency across multiple measurements of the same object. This paper studies the evaluation of the precision of measurement systems that measure on a bounded ordinal scale. A bounded ordinal scale consists of a finite number of categories that have a specific order. Based on an inventory of methods for the evaluation of precision for other types o...

In the medical, behavioral, social, and psychological sciences, latent variables represent unobservable traits that are measured by multiple observed variables. Latent variable models (LVMs) are useful tools for assessing the interrelationships among latent and observed variables. Due to their wide applications, LVMs have attracted significant attention from various fields. However, the majorit...

This manuscript presents a method to calculate and analyze mechanical shock of multi-rigid body system, based on the revised concept center percussion newly derived variable called radius percussion. The objective is improve mechanism’s robustness against shocks that are caused by certain impacts, such as those experienced legged robots from landing jump or making step. In practice, it can be u...

In the 1990s compliant joint actuation was introduced to robotics with the Series Elastic Actuator [1] and the Mechanical Impedance Adjuster [2]. Such concepts provide safer human-robot interaction, can store energy and decrease force control effort [1]. In the following decades, energy efficient actuation with such concepts had high impact in mobile applications such as bipedal robots, since t...

Many mechanical systems can change dimension. r θ l k/2 k/2 y v u v m φ Body 2 1 m v v θ Rake x l θ We are primarily concerned with the problem of determining controllability and the motion planning problem. Slide 1 This motivational slide is intended to illustrate two main points: • Changing dimensions is common, and • There is a natural kinematic/dynamic dichotomy in such problems, which will...

This article presents preliminary stochastic estimates of the multi-variable human ankle mechanical impedance. We employed Anklebot, a rehabilitation robot for the ankle, to provide torque perturbations. Time histories of the torques in Dorsi-Plantar flexion (DP) and Inversion-Eversion (IE) directions and the associated angles of the ankle were recorded. Linear timeinvariant transfer functions ...

This paper describes an electro-mechanical auto-calibration technique for use in capacitive MEMS accelerometers. Auto-calibration is achieved using the combined information derived from an initial measurement of the resonance frequency and the measurement of the pull-in voltages during device operation, with an estimation of process-induced variations in device dimensions from layout and deviat...

Mechanical impedance is an important factor that the central nervous system takes into account while coordinating a motion. This research work thus aims to develop a new measurement for monitoring dynamic changes of mechanical impedance. The method is introduced and validated in the context. The results show that device correctly measures the dynamic force and impedance of an eccentric linear s...

In this paper, we develop a new output feedback, variable structure-like (discontinuous) tracking controller for a class of uncertain, nonlinear, multiinput multi-output, mechanical systems whose dynamics are Þrst-order differentiable. A novel Þlter design and Lyapunov-type stability analysis are used to prove semi-global asymptotic tracking. As a by-product of the proposed framework, we also p...