Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
54,781
result(s) for
"Motion systems"
Sort by:
Concurrent validation of the Xsens IMU system of lower-body kinematics in jump-landing and change-of-direction tasks
Inertial measurement units (IMUs) allow for measurements of kinematic movements outside the laboratory, persevering the athlete-environment relationship. To use IMUs in a sport-specific setting, it is necessary to validate sport-specific movements. The aim of this study was to assess the concurrent validity of the Xsens IMU system by comparing it to the Vicon optoelectronic motion system for lower-limb joint angle measurements during jump-landing and change-of-direction tasks. Ten recreational athletes performed four tasks; single-leg hop and landing, running double-leg vertical jump landing, single-leg deceleration and push off, and sidestep cut, while kinematics were recorded by 17 IMUs (Xsens Technologies B.V.) and eight motion capture cameras (Vicon Motion Systems, Ltd). Validity of lower-body joint kinematics was assessed using measures of agreement (cross-correlation: XCORR) and error (root mean square deviation and amplitude difference). Excellent agreement was found in the sagittal plane for all joints and tasks (XCORR > 0.92). Highly variable agreement was found for knee and ankle in transverse and frontal plane. Relatively high error rates were found in all joints. In conclusion, this study shows that the Xsens IMU system provides highly comparable waveforms of sagittal lower-body joint kinematics in sport-specific movements. Caution is advised interpreting frontal and transverse plane kinematics as between-system agreement highly varied.
Journal Article
Magnetic Levitation Technology for Precision Motion Systems: A Review and Future Perspectives
Precision motion systems are the core of a wide range of manufacturing equipment and scientific instruments, and their motion performance directly determines the quality and speed of the associated manufacturing or metrology processes. Magnetically levitated precision motion systems, where the moving target is supported by magnetic forces and without any mechanical contact, provide advantages of frictionless motion, vacuum compatibility, and contamination-free operation. These features endow the magnetic levitation technology with the capability to deliver excellent overall performance for precision positioning systems. Through decades of research and engineering efforts, significant advances have been made in the actuation, sensing, design, and control of magnetically levitated precision motion systems. This paper provides an introduction to the fundamentals of the feedback control, actuation, and sensing for the magnetic levitation technology, and provides a comprehensive literature review of various magnetically levitated precision positioning systems developed over the past three decades. The final part of this paper identifies several challenges in the design and control of today’s precision motion systems using magnetic levitation and provides an outlook on the possible directions for future research and development.
Journal Article
MCSA-based fault diagnosis for rotary parts in servo motion system: Approach and experimental study
Motor current signature analysis (MCSA), as a non-invasive diagnostic method, is robust to environmental noise and of less sensor cost than vibration-based monitoring. Although large amount of progress has been achieved, little attention is paid to the MCSA-based diagnosis task in the Servo motion systems (SMS). An approach using Park vector demodulation, comb filtering and the ensemble empirical mode decomposition (EEMD) is proposed for cyclic fault event detection in this paper. Experiment studies reveal that the MCSA approach could extract the fault signature under extremely low-speed or noisy working condition, which has potential in the scenarios where the accelerometers placement is limited or affected by interferences.
Journal Article
Human-robot interaction strategies for walker-assisted locomotion
This book presents the development of a new multimodal human-robot interface for testing and validating control strategies applied to robotic walkers for assisting human mobility and gait rehabilitation. The aim is to achieve a closer interaction between the robotic device and the individual, empowering the rehabilitation potential of such devices in clinical applications. A new multimodal human-robot interface for testing and validating control strategies applied to robotic walkers for assisting human mobility and gait rehabilitation is presented. Trends and opportunities for future advances in the field of assistive locomotion via the development of hybrid solutions based on the combination of smart walkers and biomechatronic exoskeletons are also discussed.
Book
Calibration of Weigh-In-Motion systems – metrological assessment of methods for determining reference values
The increasingly common practical application of systems for the dynamic weighing of vehicles in motion makes necessary periodic assessment of correct operation of such systems and calibration of the results obtained from them. This paper presents an experimental study and the obtained measurement results which allow for the determination of reference values essential for the calibration process. It was assumed that Weigh-In-Motion (WIM) systems will be calibrated using the pre-weighed vehicle method. The desired reference values in this case are thus gross weight (Gross VehicleWeight – GVW) and static load of individual test vehicle axles used in the calibration process. The experiments and analysis of results obtained from them presented in this work involve the use of a platform scale for determination of GVW, as well as portable scales or a dynamic low-speed scale (LS-WIM), intended for measurement of the loads of individual axles of vehicles. All of the scales used in the experiments have valid certificates of metrological approval. The results obtained indicate the possibility of significant simplification of the procedure while still maintaining the required accuracy. The simplification proposed involves the possibility of abandoning the GVW measurement on the platform scale, instead determining this value by summing up the load measurements of all the vehicle’s axles obtained on the LS-WIM scale.
Journal Article
Robust optimal output-feedback control of piezoelectric motion systems with composite adaptive hysteresis compensation
This article proposes a robust optimal output-feedback control scheme for solving the optimal tracking problem of a piezoelectric motion system, where the model of the piezoelectric motion system is represented by the linear dynamics with both asymmetric input hysteresis nonlinearities and various bounded disturbances. Different from the existing hysteresis model, the neural network is incorporated in the Prandtl-Ishlinskii model to depict the asymmetric feature of the input hysteresis nonlinearity, a novel fast composite adaptive identification method is proposed to obtain the parameters of the asymmetric input hysteresis model. Based on the identified asymmetric hysteresis model, its inverse is constructed to compensate the asymmetric hysteresis nonlinearities of the piezoelectric motion system, and the boundedness of the inverse compensation error is firstly analyzed. In particular, a robust optimal output-feedback controller with a finite-time extend state observer is designed to achieve the optimal tracking of the piezoelectric motion system in the presence of the unknown states and disturbances. Both the convergence of the hysteresis model parameters and the stability of the closed-loop system are analyzed. Finally, the excellent modeling and identification accuracy of the asymmetric input hysteresis nonlinearities and the satisfactory tracking performance of the proposed control scheme are demonstrated by real-time experiments on a piezoelectric motion stage.
Journal Article