Mechatronic Platform Research Articles

Virtual Prototyping of an Electric Power Steering Simulator

This paper presents a simulation tool for an electrical steering system whose aim is twofold: 1) to investigate the possibility of designing a minimum clearance mechatronic platform with sensorless control methods and 2) to evaluate assistance torque control feedback by considering technological specifications and human factor consideration. The choice has been made for a driving simulator having at least a real steering system with an electrical power steering (EPS) device and an adequate motor to reproduce the rack load force resulting from tire/road contact, as in a real driving situation. These components are gathered to form a virtual simulator platform, which serves as a basis for future realization. Our main contributions concern the vehicle's front assembly kinematics modeling and the evaluation of the load rack force resulting from tire/road interaction. In addition, a real application of the most recent virtual sensor algorithms, arising from the sliding-mode observer theory for states and unknown input estimation, is described.

Design and Evaluation of a new mechatronic platform for assessment and prevention of fall risks

BackgroundStudying the responses in human behaviour to external perturbations during daily motor tasks is of key importance for understanding mechanisms of balance control and for investigating the functional response of targeted subjects. Experimental platforms as far developed entail a low number of perturbations and, only in few cases, have been designed to measure variables used at run time to trigger events during a certain motor task.MethodsThis work introduces a new mechatronic device, named SENLY, that provides balance perturbations while subjects carry out daily motor tasks (e.g., walking, upright stance). SENLY mainly consists of two independently-controlled treadmills that destabilize balance by suddenly perturbing belts movements in the horizontal plane. It is also provided with force sensors, which can be used at run time to estimate the ground reaction forces and identify events along the gait cycle in order to trigger the platform perturbation. The paper also describes the customized procedures adopted to calibrate the platform and the first testing trials aimed at evaluating its performance.ResultsSENLY allows to measure both vertical ground reaction forces and their related location more precisely and more accurately than other platforms of the same size. Moreover, the platform kinematic and kinetic performance meets all required specifications, with a negligible influence of the instrumental noise.ConclusionA new perturbing platform able to reproduce different slipping paradigms while measuring GRFs at run time in order to enable the asynchronous triggering during the gait cycle was designed and developed. Calibration procedures and pilot tests show that SENLY allows to suitably estimate dynamical features of the load and to standardize experimental sessions, improving the efficacy of functional analysis.

A mechatronic platform for behavioral analysis on nonhuman primates

In this work we present a new mechatronic platform for measuring behavior of nonhuman primates, allowing high reprogrammability and providing several possibilities of interactions. The platform is the result of a multidisciplinary design process, which has involved bio-engineers, developmental neuroscientists, primatologists, and roboticians to identify its main requirements and specifications. Although such a platform has been designed for the behavioral analysis of capuchin monkeys (Cebus apella), it can be used for behavioral studies on other nonhuman primates and children. First, a state-of-the-art principal approach used in nonhuman primate behavioral studies is reported. Second, the main advantages of the mechatronic approach are presented. In this section, the platform is described in all its parts and the possibility to use it for studies on learning mechanism based on intrinsic motivation discussed. Third, a pilot study on capuchin monkeys is provided and preliminary data are presented and discussed.

A mechatronic platform for human touch studies

The development of a mechatronic tactile stimulation platform for touch studies is presented. The platform was developed for stimulation of the fingertip using textured surfaces, providing repeatable tangential sliding motion of stimuli with controlled indentation force. Particular requirements were addressed to make the platform suitable for neurophysiological studies in humans with particular reference to electrophysiological measurements, but allowing a variety of other studies too, such as psychophysical, tribological and artificial touch ones. The design of the mechatronic tactile stimulator is detailed, as well as the performance in tracking reference trajectories. Using microneurography, we recorded from human tactile afferents and validated the platform compatibility with the exacting demands of electrophysiological methods, comprising the absence of spurious vibrations and the lack of relevant electromagnetic interference.

Engaging High School and Engineering Students: A Multifaceted Outreach Program Based on a Mechatronics Platform

If we aim to enhance the interest of students in engineering and therefore produce the best engineers, it is essential to strengthen the pipeline to high school education. This paper discusses several outreach activities undertaken by the Faculty of Engineering and Faculty of Education, University of Ottawa (UO), Ottawa, ON, Canada, to help the transition between high school and engineering education and to make students aware of the engineering profession. At the heart of these activities is mechatronics education, which demands an interdisciplinary approach, connects to fundamental math and science concepts, and promotes collaborative project-based learning (PBL). Connected to this focus, a multifaceted program of outreach activities has been initiated. The program includes creation of design-simulate-and-build projects by engineering and high school students, as well as an interactive presentation program whereby engineering students connect with high school students through the sharing of projects that they create in their engineering courses. The survey results indicate that for the high school students, these programs promote students' awareness of engineering and how the mathematics and science they take in school connects to engineering concepts. For the engineering students, they are provided with a meaningful context within which to share their projects and explain their own understanding of engineering principles.

Early assessment of neuro-rehabilitation technology: a case study

A novel mechatronic platform for neuro-rehabilitation has been developed, that measures post-stroke functional recovery through whole-body isometric force measurements. An early assessment of the prototype is here presented by using a SWOT survey. The main aim of the analysis was to perform an 'in-progress' assessment of the technology, for identifying its main strengths and limitations in order to successfully manage its introduction on the market. Even though some technical limitations emerged, an overall acceptance of the proposed approach was shown. The data collected gave useful information for bringing technical adjustments to the device and gave indications about its market potential.

Posterior probability profiles for the automated assessment of the recovery of patients with stroke from activity of daily living tasks

Assessing recovery after stroke has been so far a time consuming procedure in which trained clinicians are required. A demand for automated assessment techniques arises due to the increasing number of patients with stroke and the continuous growth of new treatment options. In this study, we investigate the applicability of isometric force and torque measurements in activity of daily living tasks to assess the functional recovery after stroke in an automated way. A new hybrid filter-wrapper feature subset technology was developed for a new mechatronic platform with the aim to identify the most important features and sensors that can distinguish normal controls from patients with stroke. We compared 3 different classification algorithms to make the distinction: k-nearest neighbors, kernel density estimation and least-squares support vector machines. Based on isometric force and torque measurements obtained from 16 patients with a first-ever ischemic or haemorrhagic stroke within the middle cerebral artery territory, we computed for each subject the probability to belong to the class of normal subjects. These probabilities were computed during a period of 6 months post-stroke to quantify the level of recovery during this period. The posterior probabilities were validated by means of a correlation study with the Lindmark modified Fugl-Meyer assessment. Patients with stroke and normal controls could be distinguished with an accuracy of 98.25% by means of kernel density estimation. The posterior probability profiles had a correlation of 76.6% and 80.29% with the global score of the Lindmark modified Fugl-Meyer scale and 'part A', the upper extremity subscore, respectively. This degree of correlation was as high as obtained with supervised scoring techniques such as the Barthel index. This study shows that the assessment of recovery after stroke can be automated by means of posterior probability profiles due to their high correlation with the Fugl-Meyer assessment. The posterior probability profiles confirm the importance of a recovery within the first weeks after stroke to obtain a higher recovery plateau compared to later changes in recovery.

Robust motion control design for dual-axis motion platform using evolutionary algorithm

This paper presents a new approach to deal with the dual-axis control design problem for a mechatronic platform. The cross-coupling effect leading to contour errors is effectively resolved by incorporating a neural net-based decoupling compensator. Conditions for robust stability are derived to ensure the closed-loop system stability with the decoupling compensator. An evolutionary algorithm possessing the universal solution seeking capability is proposed for finding the optimal connecting weights of the neural compensator and PID control gains for the X and Y axis control loops. Numerical studies and a real-world experiment for a watch cambered surface polishing platform have verified performance and applicability of our proposed design.

A mechatronic platform for early diagnosis of neurodevelopmental disorders

Neurodevelopmental engineering is a new interdisciplinary research area at the intersection of developmental neuroscience and biomedical engineering, mainly concerned with quantitative analysis and modeling of human behaviour during neural development. Along such a line, our research focuses on early diagnosis of neurodevelopmental disorders such as autism, typically diagnosed after 2–3 years of age. With the purpose of beating new paths in the emerging field of neurodevelopmental engineering, we propose a novel approach to the assessment of basic patterns of goal-directed actions in developing babies, in the 0–24 months of age range, both under laboratory and naturalistic conditions. In particular, we propose novel mechatronic devices, either wearable or embedded into toys, for ecological, unobtrusive assessment of infant behavior. Guidelines for the design of a particular toy embedding both kinematics and force-sensing capabilities as well as of experimental scenarios where similar instrumented toys can be deployed are provided. Preliminary experiments for the technical validation of an early prototype in ecological conditions are also presented.

A Computational Mechatronics Approach for the Analysis, Synthesis and Design of a Simple Active Biped Robot: Theory and Experiments

Biped walking is a quite complex process that has been mastered only by human beings. Transferring this skill to a robot requires implementing advanced techniques in every aspect. To this end, a computational mechatronics platform was integrated to run the scheme for the analysis, synthesis and design to achieve planar biped walking. The result is an advanced computational tool that integrates advanced modeling and control as well as path planning techniques along with hardware-in-the-loop for perhaps the simplest biped robot. An experimental underactuated three-degree-of-freedom (two active and one passive) active biped robot yields encouraging results; that is, achieving biped walking with this simple device requires adding a telescopic support leg. Considering a more complete dynamic model to take into account frictional and contact forces.

Interactive motion control using Ch – an embeddable C/C++ interpreter

A flexible agile assembly system requires an open architecture integration environment that is mechatronic device and computer platform independent. An interactive environment allows the users to step through programs and acquire immediate feedback from the system and is most suitable for the development of mechatronic systems used on the shop floor. Ch, an embeddable C/C++ interpreter, was developed for mechatronic‐independent task‐level programming. An experimental mechatronic system with an IBM 7575 Robotic Arm and a National Instruments' motion control board has been developed to demonstrate the capabilities and the ease in integrating mechatronic devices in Ch, which is freely available for downloading.

A Computational Mechatronics Approach for the Analysis, Synthesis and Design of a Simple Active Biped Robot: Theory and Experiments

Biped walking is a quite complex process that has been mastered only by human beings. Transferring this skill to a robot requires implementing advanced techniques in every aspect. To this end, a computational mechatronics platform was integrated to run the scheme for the analysis, synthesis and design to achieve planar biped walking. The result is an advanced computational tool that integrates advanced modeling and control as well as path planning techniques along with hardware‐in‐the‐loop for perhaps the simplest biped robot. An experimental underactuated three‐degree‐of‐freedom (two active and one passive) active biped robot yields encouraging results; that is, achieving biped walking with this simple device requires adding a telescopic support leg. Considering a more complete dynamic model to take into account frictional and contact forces.