Multifunctional Device for Assisting Unskilled People in Hand Movements Through the Haptic Point-Based Approach

2011 ◽  
Author(s):  
Mario Covarrubias ◽  
Monica Bordegoni ◽  
Umberto Cugini
Keyword(s):  
Tool Path ◽  
Force Feedback ◽  
Cutting Tool ◽  
Soft Materials ◽  
Haptic Device ◽  
Hand Movements ◽  
Multifunctional Device ◽  
Wire Cutting ◽  
Cutting Operation ◽  
And Training

This paper describes a multifunctional haptic machine, a device that is used for assisting unskilled people in the assessment and training of hand movements. Sketching, hatching and cutting operations are assisted through the multifunctional device by using the haptic point-based approach. The device has enabled users to haptically interact with a 2D virtual template, which acts as a virtual tool path taking advantages of its force feedback capabilities. For sketching, hatching and cutting operations the haptic device is driven under the user movement and assisted through the Magnetic Goemetry Effect (MGE). Two configurations of the multifunctional device have been analyzed; the cartesian and the RR mechanism attached to the PHANTOM device. For sketching and hatching several pencils and pens colors are available. Regarding the cutting operation, a hot wire cutting tool can be replaced for cutting soft materials as expanded and extruded polystyrene foam. This paper discusses the design concept, kinematics and mechanics of the multifunctional haptic device. A brief test using the device in sketching, hatching and cutting operations is also given.

2D Shape and Force Tracking in Rehabilitation Therapy of Upper Extremities Through a Multimodal Guidance System

2014 ◽  
Author(s):  
Mario Covarrubias ◽  
Alessandro Mansutti ◽  
Monica Bordegoni ◽  
Umberto Cugini
Keyword(s):  
Quantitative Measurement ◽  
Tool Path ◽  
Force Feedback ◽  
Preliminary Test ◽  
Rehabilitation Program ◽  
Upper Extremities ◽  
Guidance System ◽  
Audio Feedback ◽  
Force Tracking ◽  
And Training

This paper describes a shape and force tracking approach aimed for the assessment and training of patients’ upper extremities functionalities, while performing 2D tasks in a post-stroke rehabilitation program. The 2D tasks are assisted by a Multimodal Guidance System (MGS), which consists in a combination of visual, haptic and sound interaction. The device enables users to haptically interact with a virtual template, which acts as a virtual tool path taking advantage of its force feedback capabilities while the patient performs a 2D task, as sketching and hatching operations. Furthermore, the patient receives sound information, which provides audio feedback related to the hand velocity. By tracking the shape and the forces required to complete the tasks according to the visual feedback provided on the computer screen, the system can inform about quantitative measurement of a patients progress. The paper concludes by presenting a preliminary test using the device for sketching and hatching operations.

Tool Path Generation for 5-Axis Rough Cutting Using Haptic Device

2020 ◽  
Vol 14 (5) ◽  
pp. 808-815
Author(s):  
Koichi Morishige ◽  
Satoshi Mori ◽  
◽  
Keyword(s):  
Tool Path ◽  
Cutting Tool ◽  
Control Program ◽  
Target Object ◽  
Tool Path Generation ◽  
Haptic Device ◽  
Numerical Control ◽  
Path Generation ◽  
Haptic Devices ◽  
Tool Paths

CAM software is generally used to generate tool paths for 5-axis controlled machining. However, adjusting its several parameters and settings is difficult. We propose a system for tool path generation to be applied to 5-axis controlled machining. The system allows machining movements to be established by manipulating haptic devices in a virtual environment. Therefore, the cutter location for 5-axis machining can be easily controlled by operating a virtual cutting tool. The contact between the cutting tool and the target shape is reflected to the user through the haptic device. The generated path can be converted into a numerical control program for the actual machining of the target object. We detail the implementation of the proposed interface using two haptic devices and a method of tool path generation that improves rough cutting by smoothing the generated cutting points and simplifying the tool postures. The effectiveness of the developed system is confirmed through machining simulations.

Development of Haptic-Enabled Virtual Reality Applications for Engineering, Medicine and Art

2015 ◽  
Author(s):  
Hugo I. Medellín-Castillo ◽  
Germánico González-Badillo ◽  
Eder Govea ◽  
Raquel Espinosa-Castañeda ◽  
Enrique Gallegos
Keyword(s):  
Virtual Reality ◽  
Virtual Environment ◽  
Force Feedback ◽  
Research Work ◽  
Three Dimensional ◽  
Haptic Device ◽  
The Other ◽  
Virtual Objects ◽  
Other Hand ◽  
And Training

The technological growth in the last years have conducted to the development of virtual reality (VR) systems able to immerse the user into a three-dimensional (3D) virtual environment where the user can interact in real time with virtual objects. This interaction is mainly based on visualizing the virtual environment and objects. However, with the recent beginning of haptic systems, the interaction with the virtual world has been extended to also feel, touch and manipulate virtual objects. Virtual reality has been successfully used in the development of applications in different scientific areas ranging from basic sciences, social science, education and entertainment. On the other hand, the use of haptics has increased in the last decade in domains from sciences and engineering to art and entertainment. Despite many developments, there is still relatively little knowledge about the confluence of software, enabling hardware, visual and haptic representations, to enable the conditions that best provide for an immersive sensory environment to convey information about a particular subject domain. In this paper, the state of the art of the research work regarding virtual reality and haptic technologies carried out by the authors in the last years is presented. The aim is to evidence the potential use of these technologies to develop usable systems for analysis and simulation in different areas of knowledge. The development of three different systems in the areas of engineering, medicine and art is presented. In the area of engineering, a system for the planning, evaluation and training of assembly and manufacturing tasks has been developed. The system, named as HAMS (Haptic Assembly and Manufacturing System), is able to simulate assembly tasks of complex components with force feedback provided by the haptic device. On the other hand, in the area of medicine, a surgical simulator for planning and training orthognathic surgeries has been developed. The system, named as VOSS (Virtual Osteotomy Simulator System), allows the realization of virtual osteotomies with force feedback. Finally, in the area of art, an interactive cinema system for blind people has been developed. The system is able to play a 3D virtual movie for the blind user to listen to and touch by means of the haptic device. The development of these applications and the results obtained from these developments are presented and discussed in this paper.

Pantograph Mechanism for Increasing the Working Area in a Haptic Guidance Device for Sketching, Hatching and Cutting Tasks

2012 ◽  
Author(s):  
Mario Covarrubias ◽  
Monica Bordegoni ◽  
Umberto Cugini ◽  
Elia Gatti ◽  
Alessandro Mansutti
Keyword(s):  
Large Scale ◽  
Force Feedback ◽  
Low Cost ◽  
Haptic Device ◽  
Haptic Guidance ◽  
Cutting Operation ◽  
Manual Tasks ◽  
Specific Disorders ◽  
Design Construction ◽  
Guidance Device

The paper presents the design, construction, validation and testing of a Haptic Guidance Device whose aim is to provide dynamic assistance while performing manual activities such as drawing, hatching and cutting. A commercial phantom haptic device was modified by adding a pantograph mechanism in order to increase the haptic working area. The force feedback workspace provided by the phantom device is quite limited, 160 W × 120 H mm. This workspace sometimes is not enough to reproduce manual tasks in a large-scale area as is often required in several educational activities (e.g. sketching, hatching and cutting tasks). In this paper is evaluated a low cost solution for increasing the haptic working area provided by the phantom device. The pantograph mechanism has been linked with the haptic device in order to increase the working area in a 2:1 scale. The users hand moves a pen linked to the device through 2D predefined shapes in which the pens position have been tracked in 2D coordinates at 25 kHz in order to record all the data for the posterior analysis. The haptic guidance device is also equipped with a cutting system using hot wire for physically producing the drawn shape as a piece of polystyrene foam. The haptic guidance device has been tested by people with specific disorders affecting coordination such as Down syndrome and mental retardation under the supervision of their teachers and care assistants. The results of the study prove that higher performance levels can be achieved while performing manual tasks as sketching, hatching and cutting operation using the haptic guidance device.

A Generic, Geometric Approach to Accurate Machining-Error Predictions for 3-Axis CNC Milling of Sculptured Surface Parts: Part I — Modeling and Formulation

2006 ◽  
Author(s):  
Zezhong C. Chen ◽  
Wei Cai
Keyword(s):  
Tool Path ◽  
Cutting Tool ◽  
Geometric Model ◽  
Research Work ◽  
Geometric Approach ◽  
Cnc Machining ◽  
Sculptured Surface ◽  
Machining Error ◽  
Machining Errors ◽  
Tool Surface

In CNC machining, machining errors are usually caused by some of the sources such as cutting tool deflection, cutting tool wear, machine tool vibration, improper coolant/lubrication, and negative thermal effect. To increase product accuracy, much research has been carried out on the prediction of machining errors. However, in milling of sculptured surface parts, due to their curved shapes, the geometries of cutting tools do not match the parts’ surfaces well if the tools cut along the tool paths on the surfaces in a point-to-point way. As a consequence, machining error is inevitable, even if there is no other source of error in ideal machining conditions. To predict machining errors caused by this tool-surface mismatch, several methods have been proposed. Some of them are simple, and some represent the geometry of machined surfaces using cutter-swept surfaces. But none of these methods is accurate and practical. In this research work, a generic, geometric approach to predicting machining errors caused by the tool-surface mismatch is proposed for 3-axis sculptured surface milling. First, a new geometric model of the furrow formed by an APT tool moving between two neighboring cutter contact (CC) points is built. Second, the mathematical formula of cutting circle envelopes is derived. Then an algorithm for calculating machining errors in each tool motion is provided. Finally, this new approach is applied to two practical parts for the accurate machining-error predictions, and these predictions are then compared to the inaccurate predictions made by two established methods to demonstrate the advantages of this approach. This approach can be used in tool path planning for high precision machining of sculptured surface parts.

Design of a Novel Parallel Mechanism for Haptic Device

2021 ◽  
pp. 1-63
Author(s):  
Jin Lixing ◽  
Duan Xingguang ◽  
Li Changsheng ◽  
Shi Qingxin ◽  
Wen Hao ◽  
...  
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Force Feedback ◽  
Parallel Architecture ◽  
General Purpose ◽  
Haptic Device ◽  
Haptic Devices ◽  
Modeling And Optimization ◽  
Teleoperation Systems

Abstract This paper presents a novel parallel architecture with seven active degrees of freedom (DOFs) for general-purpose haptic devices. The prime features of the proposed mechanism are partial decoupling, large dexterous working area, and fixed actuators. The detailed processes of design, modeling, and optimization are introduced and the performance is simulated. After that, a mechanical prototype is fabricated and tested. Results of the simulations and experiments reveal that the proposed mechanism possesses excellent performances on motion flexibility and force feedback. This paper aims to provide a remarkable solution of the general-purpose haptic device for teleoperation systems with uncertain mission in complex applications.

Development of Multi-Axis Laser-Assisted Milling Device

2017 ◽  
Author(s):  
Dong-Hyeon Kim ◽  
Wan-Sik Woo ◽  
Won-Shik Chu ◽  
Sung-Hoon Ahn ◽  
Choon-Man Lee
Keyword(s):  
Heat Source ◽  
Tool Path ◽  
Cutting Tool ◽  
Field Studies ◽  
Flat Surfaces ◽  
Laser Heat ◽  
Complex Shapes ◽  
Laser Heat Source ◽  
Removal Processes ◽  
Machining Productivity

Laser-assisted machining (LAM) process is an effective method to facilitate material removal processes for difficult-to-cut materials. In LAM process, the mechanical strength of various materials is reduced by a laser heat source focused in front of the cutting tool during machining. Since the laser heat source is located ahead of the cutting tool, the workpiece is preheated by the heat source. This enables difficult-to-cut materials to be machined more easily with low cutting energy, increasing the machining productivity and accuracy. It is difficult to apply laser-assisted milling (LAMilling) to workpieces having complex shapes, because it is not easy to control laser preheating and the cutting tool path for three-dimensionally shaped workpieces. LAMilling has only been used in limited fields such as single-direction machining of flat surfaces. To apply this process in the industrial field, studies on workpieces having various shapes are needed. This study aims to develop a laser-assisted milling device having multiple axes and to investigate the machining characteristics of several difficult-to-cut materials.

Some Theory and Algorithms Pertaining to Machinability and Visibility

Manufacturing ◽  
2002 ◽  
Author(s):  
Mahadevan Balasubramaniam ◽  
Taejung Kim ◽  
Sanjay Sarma
Keyword(s):  
Path Planning ◽  
Tool Path ◽  
Cutting Tool ◽  
Machining Process ◽  
Planning Problem ◽  
Topological Connectivity ◽  
Almost All ◽  
Feasible Space ◽  
Path Planning Problem ◽  
Theoretical Results

In previous work, we and others have developed visibility-based tool path generation schemes. Almost all previous research implicitly assumes that all visible parts are machinable. Though usually true practice, this assumption hides several subtleties inherent to the geometry of the machining process. Here, we define machinability in a stricter sense, as a generalization of the robotic path planning problem. Then, we define various “tight” necessary conditions for strict machinability, and show the connections between these conditions. After demonstrating the richness of the information contained in visibility, we show how to compute visibility effectively. Visible directions constitute an approximate feasible configuration space of a cutting tool. We also address questions pertaining to the topological connectivity of the feasible space. The theoretical results of this paper lay down a firmer foundation of machining path planning.

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