scholarly journals A Feasibility Study of a Vibrotactile System based on Electrostatic Actuators for Touch Bar Interfaces: Experimental Evaluations

2021 ◽  
Vol 11 (15) ◽  
pp. 7084
Author(s):  
Taylor Mason ◽  
Jeong-Hoi Koo ◽  
Jae-Ik Kim ◽  
Young-Min Kim ◽  
Tae-Heon Yang
Keyword(s):  
Excitation Frequency ◽  
Prototype System ◽  
Force Output ◽  
Vibrotactile Stimulation ◽  
Vibrotactile Feedback ◽  
Electrostatic Actuators ◽  
Actuation System ◽  
Aluminum Beam ◽  
And Control ◽  
Resonant Actuators

Vibrotactile feedback is a very desirable feature for many touchscreen applications, creating a more engaging and effective user experience. Although it is common in small electronic devices, this feedback is often absent in large touchscreen devices because it is difficult to provide vibration sensations and control the magnitude throughout the display. Because of their long shape (over 20 cm), touch bar displays are susceptible to the same challenges that other large display types face. Thus, there is a need for a vibrotactile actuation system capable of generating a freely positionable and fully controllable point of stimulation with satisfying force output at any point of a touch bar display. This study proposes a new spring boundary condition vibrotactile system as a way to provide such feedback in touch bar interfaces. A prototype system was created using two electrostatic resonant actuators and a thin, narrow aluminum beam to study the effect of different actuator excitation parameters on the beam′s response. By varying the number of actuators excited, magnitude, excitation frequency, and signal duration, a minimum vibration of 24.5 m/s2 could be created in the beam, with the majority of the beam able to exceed 40 m/s2. These results show that a targeted vibrotactile response at a given location in the beam can be achieved and sustained. This demonstrates a promising potential for generating a freely positionable and fully controllable point of vibrotactile stimulation at any point of a touch bar display.

scholarly journals Spatial and Temporal Influences on Discrimination of Vibrotactile Stimuli on The Arm

2018 ◽  
Author(s):  
Valay A Shah ◽  
Maura Casadio ◽  
Robert A Scheidt ◽  
Leigh Mrotek
Keyword(s):  
Performance Feedback ◽  
Closed Loop ◽  
Device Performance ◽  
Vibrotactile Stimulation ◽  
Vibrotactile Feedback ◽  
Loop Control ◽  
User Training ◽  
Non Invasive ◽  
Vibrotactile Perception ◽  
And Control

Body-machine interfaces (BMIs) provide a non-invasive way to use and control external devices such as powered wheelchairs. Vibrotactile stimulation has been proposed as a way for BMIs to provide device performance feedback to the user, thereby reducing visual demands of closed-loop control. To advance the goal of developing a compact, multivariate vibrotactile display for BMIs, we performed two 2-alternative, forced choice experiments to determine the extent to which vibrotactile perception might vary across multiple stimulation sites. The first experiment assessed vibrotactile discrimination of sequentially presented stimuli within each of four dermatomes of the arm (C5, C7, C8, T1) and on the ulnar head. The second compared discrimination when pairs of vibrotactile stimuli were presented simultaneously vs. sequentially both within and across dermatomes. Although the first experiment found small but statistically significant differences across dermatomes C7 and T1, discrimination thresholds at the other three locations did not differ one from another or from those at either C7 or T1. These results suggest that stimuli applied to each of the sites may be able to convey approximately the same amount of information. The second experiment found that sequential delivery of vibrotactile stimuli resulted in better discrimination than simultaneous delivery, independent of whether the pairs were located within the same dermatome or across dermatomes. Taken together, our results suggest that the arm may be a viable site to transfer multivariate information via vibrotactile feedback for body-machine interfaces. However, user training may be needed to overcome the perceptual disadvantage of simultaneous vs. sequentially-presented stimuli.

Subsea Processing and Control System in the GASP Project: Testing of the Prototype System

1992 ◽  
Vol 44 (03) ◽  
pp. 341-349
Author(s):  
H.S. Nordvik ◽  
M.M. Sarshar ◽  
Mike Taylor
Keyword(s):  
Control System ◽  
Prototype System ◽  
And Control

scholarly journals Vibration Analysis and Control of a Vibration Screed System for Asphalt Pavers

2020 ◽  
Vol 25 (3) ◽  
pp. 363-372
Author(s):  
Vanliem Nguyen ◽  
Zhenpeng Wu ◽  
Beiping Zhang ◽  
Zhang Jian Run
Keyword(s):  
Working Conditions ◽  
Vibration Analysis ◽  
Excitation Frequency ◽  
Mean Square ◽  
Dynamic Parameters ◽  
Objective Functions ◽  
Nonlinear Dynamic Model ◽  
Compression Efficiency ◽  
Centre Of Gravity ◽  
And Control

To reduce shaking of a vibration screed system (VSS) and improve the paving performance of an asphalt paver (AP), the root-mean-square (RMS) acceleration responses at points on the front and rear screed floors are analyzed via an experimental method. A 3D nonlinear dynamic model of the VSS is also built to evaluate the influence of the dynamic parameters of the VSS on the compression efficiency, paving quality, and working stability of the AP based on the objective functions of the vertical, pitching, and rolling RMS values at the centre of gravity of the screed. The angular deviations, $alpha$ and $gamma$, of the tamper are then controlled to improve the paving performance. The research results show that the excitation frequency, $f_{t}$, and both angular deviations, $alpha$ and $gamma$, of the tamper strongly affect the paving performance. The compression efficiency is quickly enhanced, while both paving quality and working stability are significantly reduced with increasing the excitation frequency $f_{t}$ and reducing the angular deviations. $alpha$ and $gamma$. and vice versa. Additionally, the screed shaking and paving performance of the AP are remarkably improved by control of the angular deviations, $alpha$ and $gamma$, under different working conditions.

scholarly journals A Dedicated Design Strategy for Active Boring Bar

2019 ◽  
Vol 9 (17) ◽  
pp. 3541 ◽  
Author(s):  
Niccolò Grossi ◽  
Lisa Croppi ◽  
Antonio Scippa ◽  
Gianni Campatelli
Keyword(s):  
Operating Conditions ◽  
Dynamic Characterization ◽  
Control Logic ◽  
Boring Bar ◽  
Actuation System ◽  
Static Equivalence ◽  
And Control ◽  
Cutting System ◽  
Damping Systems ◽  
Critical Aspects

Unstable vibrations (i.e., chatter) onset is one of the main limits to productivity in deep boring bar processes. Active damping systems allow to increase machining stability in different configurations (i.e., tool setup), without requiring cutting system dynamic characterization. Design of an active boring bar involves the development of monitoring system (sensors), actuation system and control logic. While several control logics were evaluated and discussed, few design solutions were presented in the literature, focusing only on building prototypes to demonstrate control logic effectiveness. In the presented work, a deep analysis of the main issues and requirements related to active boring design was carried out and a systematic approach to tackle all the critical aspects was developed. The results of the proposed method are: (i) optimal actuators positioning able to damp vibration along two directions; (ii) preload system design guaranteeing the correct actuator preloading for the operating conditions; (iii) covers design to protect actuators and ensure the dynamic and static equivalence between active and standard boring bar. Following this approach, an active boring bar was designed, realized and tested. The results prove the required equivalence between active and original boring bar and assess the damping effect.

scholarly journals Development of Digital Subterranean Models for Real-Time Open Cut Horizon Control

Resources ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 50
Author(s):  
Andrew D. Strange ◽  
Zak Jecny
Keyword(s):  
Technology Development ◽  
Surface Model ◽  
Prototype System ◽  
Mining Operations ◽  
Digital Mine ◽  
Sensing System ◽  
Mining Machinery ◽  
Strong Motivation ◽  
Ground Penetrating ◽  
And Control

A reliable coal seam sensing system is required to improve the productivity of selective mining in open-cut mining operations. A prototype system based upon commercial ground penetrating radar equipment, which measures coal thickness from the top of an exposed surface down to an underlying coal-interburden interface and generates digital subterranean models of the subsurface seam boundaries, was developed for this purpose. The models can be deployed to commercially available in-cab assistive guidance systems for bulldozers and other mining machinery in existing production processes, and can further contribute to the databases required for remote operation and control in a complete digital mine scenario. The system was evaluated at a production open cut coal mine in Queensland, Australia, with promising results. The benefits reported by operational personnel who evaluated the digital surface model in the mining environment provide strong motivation for ongoing technology development.

Design and Control of a Compact and Flexible Pneumatic Artificial Muscle Actuation System: Part Two—Robust Control

2011 ◽  
Author(s):  
Sai-Kit Wu ◽  
Garrett Waycaster ◽  
Tad Driver ◽  
Xiangrong Shen
Keyword(s):  
Robust Control ◽  
Nonlinear Model ◽  
Sliding Mode ◽  
Artificial Muscle ◽  
Control Approach ◽  
Actuation System ◽  
Highly Nonlinear ◽  
Pressure Dynamics ◽  
System Part ◽  
And Control

A robust control approach is presented in this part of the paper, which provides an effective servo control for the novel PAM actuation system presented in Part I. Control of PAM actuation systems is generally considered as a challenging topic, due primarily to the highly nonlinear nature of such system. With the introduction of new design features (variable-radius pulley and spring-return mechanism), the new PAM actuation system involves additional nonlinearities (e.g. the nonlinear relationship between the joint angle and the actuator length), which further increasing the control difficulty. To address this issue, a nonlinear model based approach is developed. The foundation of this approach is a dynamic model of the new actuation system, which covers the major nonlinear processes in the system, including the load dynamics, force generation from internal pressure, pressure dynamics, and mass flow regulation with servo valve. Based on this nonlinear model, a sliding mode control approach is developed, which provides a robust control of the joint motion in the presence of model uncertainties and disturbances. This control was implemented on an experimental setup, and the effectiveness of the controller demonstrated by sinusoidal tracking at different frequencies.

Measurement of Force and Displacement for the Tribological Analysis of MEMS

2005 ◽  
Author(s):  
Joshua S. Wiehn ◽  
Michael T. Dugger ◽  
Thomas E. Buchheit
Keyword(s):  
Friction And Wear ◽  
Microelectromechanical Systems ◽  
Mems Devices ◽  
Force Output ◽  
Electrostatic Actuators ◽  
Friction Forces ◽  
Tangential Forces ◽  
Tribological Analysis ◽  
Output Characteristics ◽  
Force Calibration

The tribological interfaces in microelectromechanical systems (MEMS) pose a significant hurdle in the advancement of MEMS. In order to gain a better understanding of these tribological interfaces, meaningful friction and wear measurements of MEMS devices must be made at loads and speeds relevant to MEMS operation. Devices containing isolated tribological contacts from which quantitative friction forces can be extracted have been developed. Since independent in-plane measurement of forces are not available for structures that are on the order of microns thick, the normal and tangential forces between structures are typically estimated based on the calculation of the force output of electrostatic actuators, and the force required to bend compliant suspensions. We will discuss the uncertainties associated with the measurement of applied and friction forces in MEMS tribometers, and metrology needs for improved tribological analysis of dynamic microsystems. We will also present a method of independent force calibration in these devices, and compare measured output characteristics with those predicted from mechanics and electrostatics.

Design of a Compliant Industrial Gripper Driven by a Bistable Shape Memory Alloy Actuator

2020 ◽  
Author(s):  
Dominik Scholtes ◽  
Stefan Seelecke ◽  
Gianluca Rizzello ◽  
Paul Motzki
Keyword(s):  
Shape Memory ◽  
High Energy ◽  
Industrial Applications ◽  
High Energy Density ◽  
Small Scale ◽  
Monitoring And Control ◽  
Actuation System ◽  
First Results ◽  
Functional Prototype ◽  
And Control

Abstract Within industrial manufacturing most processing steps are accompanied by transporting and positioning of workpieces. The active interfaces between handling system and workpiece are industrial grippers, which often are driven by pneumatics, especially in small scale areas. On the way to higher energy efficiency and digital factories, companies are looking for new actuation technologies with more sensor integration and better efficiencies. Commonly used actuators like solenoids and electric engines are in many cases too heavy and large for direct integration into the gripping system. Due to their high energy density shape memory alloys (SMA) are suited to overcome those drawbacks of conventional actuators. Additionally, they feature self-sensing abilities that lead to sensor-less monitoring and control of the actuation system. Another drawback of conventional grippers is their design, which is based on moving parts with linear guides and bearings. These parts are prone to wear, especially in abrasive environments. This can be overcome by a compliant gripper design that is based on flexure hinges and thus dispenses with joints, bearings and guides. In the presented work, the development process of a functional prototype for a compliant gripper driven by a bistable SMA actuation unit for industrial applications is outlined. The focus lies on the development of the SMA actuator, while the first design approach for the compliant gripper mechanism with solid state joints is proposed. The result is a working gripper-prototype which is mainly made of 3D-printed parts. First results of validation experiments are discussed.

scholarly journals A new active asymmetry monitoring and control technique applied to critical aircraft flap control system failures

2019 ◽  
Vol 304 ◽  
pp. 04011
Author(s):  
Dario Belmonte ◽  
Matteo Davide Lorenzo Dalla Vedova ◽  
Gaetano Quattrocchi
Keyword(s):  
Control System ◽  
Flight Control ◽  
Angular Position ◽  
Control Technique ◽  
Monitoring And Control ◽  
Active Monitoring ◽  
Actuation System ◽  
Left And Right ◽  
And Control ◽  
Current Monitoring

Asymmetry limitation requirements between left and right wing flap surfaces play an important role in the design of the implementation of the secondary flight control system of modern airplanes. In fact, especially in the case of sudden breaking of one of the torsion bars of the flap transmission line, the huge asymmetries that can rapidly develop could compromise the lateral-directional controllability of the whole aircraft (up to cause catastrophic occurrences). Therefore, in order to guarantee the aircraft safety (especially during take-off and landing flight phase in which the effects of asymmetries could generate uncontrollable aircraft attitudes), it is mandatory to timely detect and neutralize these asymmetries. The current monitoring techniques generally evaluate the differential angular position between left and right surfaces and, in most the events, limit the Flaps Control System (FCS) asymmetries, but in severe fault conditions (e.g. under very high aerodynamic loads), unacceptable asymmetries could be generated, compromising the controllability of the aircraft. To this purpose, in this paper the authors propose a new active monitoring and control technique capable of detecting the increasing angular error between the different flap surfaces and that, after stopping the whole actuation system, acts on the portion of the actuation line still connected to the PDU to minimize the FCS asymmetries.

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