Cantilever Snap-Fit Performance Analysis for Haptic Evaluation

2011 ◽  
Vol 133 (12) ◽  
Author(s):  
Jingjing Ji ◽  
Kok-Meng Lee ◽  
Shuyou Zhang
Keyword(s):  
Force Feedback ◽  
Approximate Solutions ◽  
Algebraic Model ◽  
Haptic Device ◽  
Real Time Control ◽  
Time Control ◽  
Parametric Effects ◽  
Realistic Force ◽  
Design Options ◽  
Algebraic Solutions

This paper investigates the parametric effects, which include material properties, hook shape, and shear deformation, on the force/deflection relationship governing the assembly/disassembly processes of a snap-fit for developing embedded algebraic solutions to achieve realistic force feedback through a haptic device. For this purpose, an algebraic model, which isolates individual parametric factors that contribute to the cantilever hook deflection, has been derived for examining assumptions commonly made to simplify models for design optimization and real-time control. The algebraic model has been verified by comparing computed results against those simulated using ANSYS FEA workbench and published approximate solutions. Additionally, the model has been validated by comparing the friction coefficients of three different snap-fit designs (with same materials), which closely agree within 5% of their root-mean-square value. Implemented on a commercial PHANTOM haptic device, we demonstrate the effectiveness of the model as embedded algebraic solutions for haptic rendering in design. Nine individuals participated in evaluating a set of design options with different parameter settings; 78% of whom chose the optimal theoretical solution by feeling the feedback force. These findings demonstrate that the design confidence of assembly robustness can be enhanced through a relatively accurate virtual force feedback.

scholarly journals Adaptive Balancing of Robots and Mechatronic Systems

2018 ◽  
Author(s):  
Liviu Ciupitu
Keyword(s):  
Exact Solutions ◽  
Real Time ◽  
Solid Mechanics ◽  
Vertical Plane ◽  
Approximate Solutions ◽  
Real Time Control ◽  
Mechatronic Systems ◽  
Static Loads ◽  
Time Control ◽  
Romanian Academy

Present paper is dealing with the adaptive static balancing of robot or other mechatronic arms that are moving in vertical plane and whose static loads are variable, by using counterweights and springs. Some simple passive and approximate solutions are proposed and an example is shown. The active and exact solutions by using adaptive real time control in the case of unknown variation of static loads are simulated on VIPRO platform developed at Institute of Solid Mechanics of Romanian Academy.

scholarly journals Teleoperation Control Design with Virtual Force Feedback for the Cable-Driven Hyper-Redundant Continuum Manipulator

2020 ◽  
Vol 10 (22) ◽  
pp. 8031
Author(s):  
Long Qin ◽  
Fanghao Huang ◽  
Zheng Chen ◽  
Wei Song ◽  
Shiqiang Zhu
Keyword(s):  
Force Feedback ◽  
Inverse Kinematic ◽  
Real Time Control ◽  
Kinematics Model ◽  
Time Control ◽  
Virtual Force ◽  
Control Scheme ◽  
Continuum Manipulators ◽  
Transmission Structure ◽  
And Control

Hyper-redundant continuum manipulators present dexterous kinematic skills in complicated tasks and demonstrate promising potential in underground exploration, intra-cavity inspection, surgery, etc. However, the hyper-redundancy, which endows much dexterity and flexibility, brings a huge challenge to the kinematics solution and control of the continuum manipulators. Due to the pseudoinverse calculation of high-order Jacobian matrix or iteration, many inverse kinematic solution approaches of continuum manipulators are very time-consuming, which extremely limit their applicability in real-time control. Additionally, it is often difficult for the manipulators to perform the tasks well in complex scenarios due to lack of human intervention. Therefore, in this paper, a simplified kinematics model of a typical hyper-redundant manipulator is proposed based on its unique geometry relationships, where the mapping relationships between the actuators’ rotation and the end-effector’s position are derived through the analysis of its driving subsystem and motion subsystem, in particular the joint modules. To perform the tasks of manipulators with the help of operators, a teleoperation control scheme with modified wave transmission structure is designed to achieve the guaranteed stability and improved transparency, and the leader’s trajectory and generated force feedback are the transmitted signals in the communication channel. Specifically, a virtual force feedback generation algorithm is developed in the teleoperation control scheme via the processing tracking errors, which can improve the operators’ assistance and perception during the teleoperation process. The practical experiments with comparative wave variable structures in two different sets are implemented to verify the effectiveness of proposed kinematics model and control scheme.

scholarly journals Application of the Novint Falcon haptic device as an actuator in real-time control

2013 ◽  
Vol 4 (3) ◽  
Author(s):  
Daniel J. Block ◽  
Mark B. Michelotti ◽  
Ramavarapu S. Sreenivas
Keyword(s):  
Embedded System ◽  
High Speed ◽  
Force Feedback ◽  
Low Cost ◽  
Small Scale ◽  
Input Device ◽  
Real Time Control ◽  
Modeling And Control ◽  
Time Control ◽  
Viable Solution

AbstractThis paper describes the development of an embedded system whose purpose is to control the Novint Falcon as a robot, and to develop a control experiment that demonstrates the use the Novint Falcon as a robotic actuator. The Novint Falcon, which is a PC input device, is “haptic” in the sense that it has a force feedback component. Its relatively low cost compared with other platforms makes it a good candidate for academic application in robot modeling and control. An embedded system is developed to interface with the multiple motors and sensors present in the Novint Falcon, which is subsequently used to control three independent Novint Falcons for a “ballon- plate” experiment. The results show that the device is a viable solution for high-speed actuation of small-scale mechanical systems.

The Development of an Experimental Force Feedback Dynamometer to Investigate the Real Time Control of an Oscillating Wave Surge Converter

2013 ◽  
Author(s):  
Daniel Banks ◽  
Jos van ’t Hoff ◽  
Kenneth Doherty
Keyword(s):  
Force Feedback ◽  
Position Control ◽  
Experimental Testing ◽  
Control Strategies ◽  
Small Scale ◽  
Real Time Control ◽  
Time Control ◽  
Scale Models ◽  
Damping Torque ◽  
And Control

An Oscillating Wave Surge Converter (OWSC) is a Wave Energy Converter (WEC) that consists of a bottom-hinged flap which oscillates due to wave action. Extensive research has been performed on this type of WEC through small scale experimental wave tank tests. One of the key challenges of experimental testing is replicating the characteristics of the Power Take-Off (PTO) system of the equivalent full scale WEC. Many scale models rely on simplified mechanical designs to simulate a PTO system. This can often restrict the experimental research into the influence of PTO design and control strategies of WECs. In order to model PTO systems and control strategies more accurately other tools are needed. This paper describes the design and build of a PLC controlled Force Feedback Dynamometer (FFD) system that enables the testing of more sophisticated control strategies applicable to an OWSC through fast application of a variable PTO damping torque. A PLC system is shown to be a viable control for PTO strategy investigations through velocity triggered damping levels. Examples of both PTO and position control strategies are presented.

scholarly journals A Six Degree-of-Freedom Haptic Device Based on the Orthoglide and a Hybrid Agile Eye

2006 ◽  
Author(s):  
Damien Chablat ◽  
Philippe Wenger
Keyword(s):  
Degrees Of Freedom ◽  
Degree Of Freedom ◽  
Haptic Device ◽  
Parallel Mechanisms ◽  
Real Time Control ◽  
Time Control ◽  
Rotational Motions ◽  
Six Degree Of Freedom ◽  
Rotary Motor ◽  
Three Degrees Of Freedom

This paper is devoted to the kinematic design of a new six degree-of-freedom haptic device using two parallel mechanisms. The first one, called orthoglide, provides the translation motions and the second one, called agile eye, produces the rotational motions. These two motions are decoupled to simplify the direct and inverse kinematics, as it is needed for real-time control. To reduce the inertial load, the motors are fixed on the base and a transmission with two universal joints is used to transmit the rotational motions from the base to the end-effector. Two alternative wrists are proposed (i), the agile eye with three degrees of freedom or (ii) a hybrid wrist made by the assembly of a two-dof agile eye with a rotary motor. The last one is optimized to increase its stiffness and to decrease the number of moving parts.

scholarly journals Haptic Manipulation of Serial-Chain Virtual Mechanisms

2005 ◽  
Vol 128 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Daniela Constantinescu ◽  
Septimiu E. Salcudean ◽  
Elizabeth A. Croft
Keyword(s):  
Singular Value Decomposition ◽  
Virtual World ◽  
Force Feedback ◽  
Singular Value ◽  
Haptic Device ◽  
Serial Chain ◽  
Numerical Performance ◽  
Realistic Force ◽  
Value Decomposition ◽  
Virtual Joints

This paper presents an approach for providing realistic force feedback to users manipulating serial-chain virtual mechanisms. In the proposed approach, a haptic device controller is designed that penalizes users’ motion along the directions resisted by the virtual joints. The resisted directions span the nullspace the Jacobian of the virtual mechanism computed at the users’ hand, and are derived via a singular value decomposition-based algorithm. Haptic numerical performance is achieved by computing the resisted directions on the graphics processor, and by using them on the haptics processor to derive the control signal that restricts users’ motion as required by the virtual joints. The performance of the proposed approach is validated through experimental manipulations of links with unrestricted and with restricted motion within a planar virtual world.

A Real Time Control Architecture for Continuously Managing Patients in a Care Unit

1995 ◽  
Vol 34 (05) ◽  
pp. 475-488
Author(s):  
B. Seroussi ◽  
J. F. Boisvieux ◽  
V. Morice
Keyword(s):  
Real Time ◽  
Linear Time ◽  
Treatment Plan ◽  
Control Architecture ◽  
Real Time Control ◽  
Time Representation ◽  
Time Control ◽  
Continuous Support ◽  
Definition Of ◽  
Computerized System

Abstract:The monitoring and treatment of patients in a care unit is a complex task in which even the most experienced clinicians can make errors. A hemato-oncology department in which patients undergo chemotherapy asked for a computerized system able to provide intelligent and continuous support in this task. One issue in building such a system is the definition of a control architecture able to manage, in real time, a treatment plan containing prescriptions and protocols in which temporal constraints are expressed in various ways, that is, which supervises the treatment, including controlling the timely execution of prescriptions and suggesting modifications to the plan according to the patient’s evolving condition. The system to solve these issues, called SEPIA, has to manage the dynamic, processes involved in patient care. Its role is to generate, in real time, commands for the patient’s care (execution of tests, administration of drugs) from a plan, and to monitor the patient’s state so that it may propose actions updating the plan. The necessity of an explicit time representation is shown. We propose using a linear time structure towards the past, with precise and absolute dates, open towards the future, and with imprecise and relative dates. Temporal relative scales are introduced to facilitate knowledge representation and access.

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