Quanser (Canada)

Building upon the Integer Lattice Gas Automata framework of Blommel and Wagner [Phys. Rev. E97, 023310 (2018)2470-004510.1103/PhysRevE.97.023310], we introduce a simplified, fluctuation-free variant. This approach relies on floating-point numbers and closely mirrors the Lattice Boltzmann Method (LBM), with the key distinction being a different collision operator. This operator, derived from the ensemble average of transition probabilities, generates nonlinear terms. We propose this float lattice gas automata collision as a computationally efficient alternative to traditional and quantum LBM implementations.

The increasing role of technology in the delivery of healthcare services has necessitated the training of engineers with complimentary background in engineering and health sciences.In response to this demand, universities and educational institutions around the globe are beginning to create undergraduate programs in biomedical engineering and developing new curriculums to support such programs.Medical Robotics is a Level 4 compulsory course in McMaster University's new established Electrical and Biomedical Engineering program.This paper provides an overview of a laboratory component which has been co-developed by McMaster University and Quanser Consulting Inc. for this course.First, the motivations for introducing a Medical Robotics course into the Biomedical Engineering curriculum and the desired learning outcomes pursued by the proposed laboratory experiments are discussed.These are followed by a brief introduction of the hardware/software system used in the lab as well as detailed descriptions of four experiments developed to achieve the learning objectives.

Bilateral teleoperation control systems are designed for guaranteed stability against uncertainties in operator and environment dynamics. In this paper, we study the effect of human operator dynamics on the coupled stability by incorporating the operator dynamics in the master–slave network. We will analytically prove and graphically show that for any potentially unstable control architecture, as the operator minimum damping grows, the teleoperation system can stably tolerate a larger range of variations in the environment impedance parameters. More importantly, we will demonstrate how the proposed coupled stability analysis method can be utilized to design stabilizing controllers for enhanced transparency, given a priori knowledge or online estimate of human operator damping.

This work presents a novel path following controller for underactuated unmanned surface vessels (USVs) that is both provably stable and intuitive to tune. The approach consists of a navigation component that computes a desired heading angle to ensure the USV will arrive at the path, and a nonlinear controller to guarantee exponential tracking of surge velocity and heading. Additionally, ultimate boundedness of the unactuated sway velocity is proven. Simulation results are presented to show numerically that the controller works as expected in the ideal case. Outdoor experimental results are presented, using a GPS and compass as sensors, showing the practical feasibility of the approach in the presence of sensor noise, disturbances, and unmodeled dynamics.

Abstract Stroke is one of the major causes of permanent adult disability. Stroke frequently affects motor control of the arm, leading to diffculties in doing activities of daily living. This research focuses on developing an upper limb rehabilitation robotic prototype through user-centered design to aid stroke survivors in rehabilitating their arm. To gather requirements from end users, stroke therapy sessions were observed and a survey of stroke therapists was conducted. End user requirements were evaluated to determine technical targets for the mechanical design of the prototype. Evaluation of the prototype was done with stroke therapists in a focus group and a preliminary biomechanical study. As user-centered design would require more iterations of design, testing and evaluation, this project reports a first step in developing an affordable, portable device, which could increase access to stroke rehabilitation for the arm.

This paper investigates the effect of environmental factors on user performance in a dual-user haptic guidance system. The system under study allows for interaction between both users, the trainee and the trainer, to collaboratively perform a common task in a shared virtual environment. User studies are carried out to experimentally evaluate the users' performance while following square and circular trajectories with two viewpoints of the environment (top view and front view), while the virtual manipulator tool moves in free motion or against forbidden-region virtual fixtures. The performance is measured and statistically evaluated against task completion time, tracking accuracy, and user energy exchange. The studies revealed that changing the environment geometry from a square to a circle results in reduced task completion time and tracking error. Changing the environment viewpoint from top to front decreases the task completion time in both geometries. Forbidden-region virtual fixtures increase energy exchange by both users and decrease task completion time while compromising the tracking performance in the square-following task. However, when visual feedback is removed in the presence of the fixtures, the square tracking performance improves. The results also indicate a strong relationship between user dominance and tracking error only when the experiment is time-limited.

A decentralized fault detection (DFD) scheme warranting mission integrity for leader-to-follower formations of almost-lighter-than-air vehicles (ALTAVs) is proposed. Such DFD allows compensating for concurrent communication network and component-level faults that may significantly impact mission integrity despite the presence of on-board fault detection, isolation and recovery for actuator and sensor faults. The formation of unmanned ALTAVs is beforehand stabilized by a distributed formation guidance scheme that uses neighboring vehicle information. Each ALTAV is equipped with an observer based on simplified models of the neighboring ALTAVs. The observer and the guidance law use the same local information. Residues associated with neighboring vehicle states carry the information as to their normal or abnormal flight conditions, thereby determining whether or not there is a fault in the neighboring vehicles. The observer design is formulated as a mixed H2/Hinfin controller synthesis compensating for exogenous disturbance estimates and accounting for noisy measurements. The minimum detectable fault and the associated threshold are shown to be increasing functions of the relative distance between the formation leader and the follower vehicle at hand, which means that the value of the threshold may vary from one follower to another depending on its relative distance from the leader. Simulations based on high-fidelity nonlinear 6DOF ALTAV models show that the proposed team-level DFD scheme combined with a simple guidance adaptation technique enable quick hard fault/failure detection while preserving leader-to-follower formation geometry requirements.

This paper presents the implementation of a two degree-of-freedom, high-precision, magnetic-levitation-based positioning system. The apparatus employs one permanent magnet linear synchronous motor and is constructed by Quanser Inc. The paper focuses on the design and testing of a nonlinear controller required for actuating the positioning system. The controller is based on feedback linearization and output regulation. Experimental results show that the controller is capable of performing both set-point stabilization and sinusoidal tracking over the complete operating range to within a specified degree of accuracy, with an acceptable amount of overshoot and settling time