Dynamics of Multibody Haptic Systems

2011 ◽  
Author(s):  
Sara Shayan Amin ◽  
Jo´zsef Ko¨vecses
Keyword(s):  
Mechanical Design ◽  
Performance Measure ◽  
Haptic Interface ◽  
Dynamic Equations ◽  
Design Parameters ◽  
Alternative Formulation ◽  
Haptic Interfaces ◽  
Single Degree Of Freedom ◽  
Essential Requirement ◽  
Haptic Devices

An essential requirement in haptics is accuracy and transparency of the haptic interface. Haptic devices are usually lightweight robotic systems with which a human operator interacts. In the current literature, dynamic analyses of haptic devices are limited to single degree-of-freedom (DoF) point mass models. In this paper, experimental and simulation studies are conducted to investigate the effects of mechanical design parameters on the performance of such devices. For this purpose two commonly used haptic devices were considered: a two-DoF PANTOGRAPH and a three-DoF PHANToM. The results show that dynamic coupling between the rendered (controlled) and free directions of motion can influence the desired performance. An alternative formulation is outlined in which dynamic behavior of a haptic interface is modeled as a multibody system. The dynamic equations are separated to two sets of equations associated with the rendered and admissible motions. Effects of time delay and discretization stemming from digital realization of the virtual environment can be analyzed using the rendered dynamic equations, while the equations associated with the admissible motions can serve as a basis for performance measure. This formulation can be efficiently used for the complex nonlinear dynamics and stability analyses of haptic interfaces and can provide essential details on the performance of these devices. Stability analysis of a two-DoF five-bar linkage is presented as an example using the proposed formulation.

A Method for Selecting Velocity Filter Cutoff Frequency for Maximizing Impedance Width Performance in Haptic Interfaces

2013 ◽  
Author(s):  
Vinay Chawda ◽  
Ozkan Celik ◽  
Marcia K. O’Malley
Keyword(s):  
Cutoff Frequency ◽  
Haptic Interface ◽  
Haptic Interfaces ◽  
Simulation Experiments ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Simulation Based ◽  
Position Data ◽  
Simulation Results ◽  
Velocity Filtering

This paper analyzes the effect of velocity filtering cut-off frequency on the Z-width performance in haptic interfaces. Finite Difference Method (FDM) cascaded with a lowpass filter is the most commonly used technique for estimating velocity from position data in haptic interfaces. So far, there is no prescribed method for obtaining the FDM+filter cut-off frequency that will maximize the Z-width performance. We present a simulation based method to demonstrate that there exists such an ideal FDM+filter cut-off frequency, and that it can be predicted by numerical simulation. Experiments are conducted on a single degree-of-freedom linear haptic interface to validate the simulation results.

A Method for Selecting Velocity Filter Cut-Off Frequency for Maximizing Impedance Width Performance in Haptic Interfaces

2014 ◽  
Vol 137 (2) ◽  
Author(s):  
Vinay Chawda ◽  
Ozkan Celik ◽  
Marcia K. O'Malley
Keyword(s):  
Haptic Interface ◽  
Haptic Interfaces ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Simulation Based ◽  
Low Pass ◽  
Position Data ◽  
Velocity Filtering

This paper analyzes the effect of velocity filtering cut-off frequency on the Z-width performance of haptic interfaces. Finite difference method (FDM) cascaded with a low pass filter is the most commonly used technique for estimating velocity from position data in haptic interfaces. So far, there is no prescribed method for obtaining the FDM + filter cut-off frequency that will maximize Z-width performance. We present a simulation based method to demonstrate that there exists such an ideal FDM + filter cut-off frequency, and that it can be predicted by numerical simulation based on an identified model of a haptic interface. Experiments are conducted on a single degree-of-freedom (DOF) linear haptic interface to validate the simulation results.

“IRIS” A Computerized High Head Pump Turbine Design System

1977 ◽  
Vol 99 (3) ◽  
pp. 567-577
Author(s):  
S. Chacour ◽  
J. E. Graybill
Keyword(s):  
Mechanical Design ◽  
Design Parameters ◽  
Design System ◽  
Performance Requirements ◽  
Manufacturing Process Planning ◽  
Depth Analysis ◽  
High Head ◽  
Critical Components ◽  
Limited Input Data ◽  
Turbine Design

“IRIS” is a computerized design and structural optimization system capable of generating all the major hydraulic and mechanical design parameters of high head pump/turbines from limited input data. The program will size the unit and select the proper hydraulic passage configuration according to performance requirements and optimize the dimensions of all the major components, generate command tapes used by a numerically controlled flame cutter, estimate cost, and issue manufacturing process planning. It also generates finite element models for the “in depth” analysis of critical components.

Design and evaluation of a high-performance haptic interface

Robotica ◽  
1996 ◽  
Vol 14 (3) ◽  
pp. 321-327 ◽  
Author(s):  
R.E. Ellis ◽  
O.M. Ismaeil ◽  
M.G. Lipsett
Keyword(s):  
High Performance ◽  
Dynamic Range ◽  
Evaluation Criteria ◽  
Haptic Interface ◽  
Human Operator ◽  
Haptic Interfaces ◽  
Environment Design ◽  
Mechanical Constraints ◽  
Computer Controlled ◽  
The Many

SUMMARYA haptic interface is a computer-controlled mechanism designed to detect motion of a human operator without impeding that motion, and to feed back forces from a teleoperated robot or virtual environment. Design of such a device is not trivial, because of the many conflicting constraints the designer must face.As part of our research into haptics, we have developed a prototype planar mechanism. It has low apparent mass and damping, high structural stiffness, high force bandwidth, high force dynamic range, and an absence of mechanical singularities within its workspace. We present an analysis of the human-operator and mechanical constraints that apply to any such device, and propose methods for the evaluation of haptic interfaces. Our evaluation criteria are derived from the original task analysis, and are a first step towards a replicable methodology for comparing the performance of different devices.

Optimal mechanical design of modular haptic devices

2011 ◽  
Author(s):  
Pablo Cerrada ◽  
Jose Brenosa ◽  
Ignacio Galiana ◽  
Javier Lopez ◽  
Manuel Ferre ◽  
...  
Keyword(s):  
Mechanical Design ◽  
Haptic Devices

Integration of qualitative and quantitative reasoning in iterative parametric mechanical design

1992 ◽  
Vol 6 (2) ◽  
pp. 95-109 ◽  
Author(s):  
Von-Wun Soo ◽  
Tse-Ching Wang
Keyword(s):  
Parametric Design ◽  
Mechanical Design ◽  
Qualitative Reasoning ◽  
Quantitative Reasoning ◽  
Design Parameters ◽  
Qualitative And Quantitative ◽  
Compression Spring ◽  
Dependency Network ◽  
Previous Design ◽  
Local Variable

A framework IPD (Iterative Parametric Design) is proposed to assist the iterative parametric mechanical design process. To effectively find a set of satisfiable values for the design parameters the key is to find good heuristics to adjust or tune the parametric values resulting from previous design iterations. We propose that heuristics can come from two aspects by both qualitative and quantitative reasoning. Qualitative reasoning, based on confluences, provides global control over the feasible directions of variable adjustments, while quantitative reasoning, based on the dependency network and perturbation analysis, can be used to propose actual quantity of local variable adjustments. We used the design of a helical compression spring as an example to illustrate the performance of IPD system. We show that IPD can often find a solution faster than those without guidance of qualitative and quantitative reasoning.

Landing efficiency control of a six-degree-of-freedom aircraft model with magnetorheological dampers: Part 1—Modeling

2020 ◽  
pp. 1045389X2094257
Author(s):  
Byung-Hyuk Kang ◽  
Ji-Young Yoon ◽  
Gi-Woo Kim ◽  
Seung-Bok Choi
Keyword(s):  
Lagrange Equation ◽  
Degree Of Freedom ◽  
Magnetorheological Damper ◽  
Dynamic Equations ◽  
Design Parameters ◽  
Coordinate Frame ◽  
Aircraft Model ◽  
Efficiency Control ◽  
Six Degree Of Freedom ◽  
Principal Design

This work presents landing efficiency control of a six-degree-of-freedom aircraft model, which has a controllable landing gear system with magnetorheological damper. Due to lengthy contents, this work is divided into two parts. In Part 1, both the kinematic and dynamic equations of the six-degree-of-freedom aircraft model are derived. After determining the principal design parameters of magnetorheological damper based on commercial Beechcraft Baron B55 (passive oleo-strut type) damper, the kinematic equations are derived using the aircraft body coordinate frame and homogeneous coordinates of the reference frame, while the dynamic equations are derived using Euler–Lagrange equation to represent the heave, roll, and pitch motions of the aircraft model. In Part 2, the landing performance based on landing efficiencies is analyzed through the landing motions using various controllers.

Haptic Interface With Hybrid Actuator for Virtual Tissue Cutting

2015 ◽  
Author(s):  
Berk Gonenc ◽  
Hakan Gurocak
Keyword(s):  
Haptic Device ◽  
Haptic Interface ◽  
Haptic Interfaces ◽  
Virtual Training ◽  
Tissue Properties ◽  
Tissue Cutting ◽  
Control Scheme ◽  
Rat Tissue ◽  
Dc Servomotor ◽  
Hybrid Actuator

Surgical training is an important and recent application where haptic interfaces are used to enhance the realism of virtual training simulators. Tissue cutting with surgical scissors is a common interaction mode in the simulations. The haptic interface needs to render a range of tissue properties and resistance forces accurately. In this research, we developed a hybrid haptic device made up of a DC servomotor and a magnetorheological (MR) brake. The motor can provide fast dynamic response and compensate for inertia and friction effects of the device. But it cannot supply high force levels and the sensation of stiff interaction with hard tissues such as tendons. On the other hand, the MR-brake can provide very high and stiff interaction forces yet cannot reflect fast dynamics that are encountered as the virtual scissors go through the tissue. Design details of the hybrid actuator and the haptic device are presented. A control scheme was developed to decompose the actuator command signal into two branches considering each actuator’s capabilities. Virtual tissue cutting experiments were conducted using three different scissor types and four types of rat tissue. Results are presented and discussed. Forces in a wider amplitude range compared to just using a DC motor could be generated by the hybrid actuator. It also enabled simulation of multiple scissor types using the same haptic interface due to the extended force amplitude range.

Flutter of Mistuned Turbomachinery Rotors

1984 ◽  
Vol 106 (1) ◽  
pp. 25-33 ◽  
Author(s):  
O. O. Bendiksen
Keyword(s):  
Perturbation Methods ◽  
Arbitrary Order ◽  
Design Parameters ◽  
Complex Conjugate ◽  
Form Complex ◽  
Stable Mode ◽  
Single Degree Of Freedom ◽  
Reduced Frequency ◽  
Left And Right ◽  
The Stability

An investigation of the fundamental aspects of flutter in mistuned turbomachinery rotors is presented. Perturbation methods are used to obtain asymptotic solutions to arbitrary order in the mistuning parameter. These solutions require only the knowledge of the eigensolution of the tuned system, and thus provide efficient formulas for calculating the effect of mistuning without solving a new eigenvalue problem. Numerical results presented for design parameters representative of fan rotors indicate that a critical reduced frequency exists, below which mistuning alone cannot stabilize the rotor. The sensitivity of the stability boundaries to mistuning was found to depend fundamentally on relations between the left and right eigenvectors. For systems where the left and right eigenvectors form complex conjugate pairs, mistuning cannot destabilize the system unless the reduced frequency of the least stable mode is decreased by the perturbation. In general, only cascades and rotors with a single degree-of-freedom per blade belong to this class.

Dynamic Modeling of Powder Delivery Systems in Gravity-Fed Powder Feeders

2005 ◽  
Vol 128 (1) ◽  
pp. 337-345 ◽  
Author(s):  
Heng Pan ◽  
Robert G. Landers ◽  
Frank Liou
Keyword(s):  
System Dynamics ◽  
Delivery System ◽  
Mechanical Design ◽  
Three Dimensional ◽  
Low Flow ◽  
Order System ◽  
Tube Length ◽  
Design Parameters ◽  
Simulation Studies ◽  
Transport Delay

This paper presents an approach for modeling powder delivery system dynamics in low flow rate applications. Discrete particle modeling (DPM) is utilized to analyze the motion of individual powder particles. In DPM, an irregular bouncing model is employed to represent the powder dispersion in the powder delivery system induced by non-spherical particle-wall collisions. A three-dimensional friction collision model is utilized to simulate the interactions between particles and the powder delivery system walls. The modeling approach is experimentally verified and simulation studies are conducted to explore the effect of powder delivery system mechanical design parameters (i.e., tube length, diameter, and angle, number of tubes and meshes, and mesh orientation and size) on the powder flow dynamics. The simulation studies demonstrate that the powder delivery system dynamics can be modeled by a pure transport delay coupled with a first order system.

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