Haptic Wrists: An Alternative Design Strategy Based on User Perception

Author(s):  
Javier Martín ◽  
Joan Savall ◽  
Iñaki Díaz ◽  
Josune Hernantes ◽  
Diego Borro

A new three degree-of-freedom (3DOF) torque feedback wrist is being developed to be added to an existing 3DOF force feedback haptic device. It is difficult to find a satisfactory solution to the mechanical design problem, mainly because of the required large rotational workspace and severe weight constraints. This work proposes an alternative design strategy based on user perception, which allows simplification of the mechanics. The proposed approach consists of substituting the last rotational DOF of the wrist with a pseudohaptic DOF. Thanks to specially designed visuotactile cues, the pseudohaptic DOF is integrated with the active DOF into the same device, being able to generate free motion and collision detection perception to the user. This approach provides for simpler kinematics, lightweight designs, lower inertias, and less friction, which are key advantages for the inclusion of torque feedback into force feedback devices.

Author(s):  
Q. J. Ge ◽  
B. Ravani

Abstract This paper studies planar motion approximation problems from a computational geometric perspective and develop a computational geometric structure that can be used for mechanical motion synthesis. This allows for development of computational algorithms and software systems to support the mechanical design activity. The approach uses an orientable kinematic mapping to transform the mechanical design problem into a curve design problem in the space of the mapping. The curve design problem for synthesis of an analytic motion is carried out by Hermite interpolation. In case of a mechanical linkage, however, the Hermite interpolation is combined with a first-order curve fitting procedure for synthesizing the motion.


2010 ◽  
Vol 44-47 ◽  
pp. 1817-1822
Author(s):  
Yung Chin Lin ◽  
Yung Chien Lin ◽  
Kun Song Huang ◽  
Kuo Lan Su

A novel application to mechanical optimal design is presented in this paper. Here, an evolutionary algorithm, called mixed-integer differential evolution (MIHDE), is used to solve general mixed-integer optimization problems. However, most of real-world mixed-integer optimization problems frequently consist of equality and/or inequality constraints. In order to effectively handle constraints, an evolutionary Lagrange method based on MIHDE is implemented to solve the mixed-integer constrained optimization problems. Finally, the evolutionary Lagrange method is applied to a mechanical design problem. The satisfactory results are achieved, and demonstrate that the evolutionary Lagrange method can effectively solve the optimal mechanical design problem.


Author(s):  
Kun Chen ◽  
Kai Tang

This paper describes the design of a haptic system that allows the interactive modification of cutter orientation during five-axis finishing cuts with the aim of improving the surface finish quality and collision avoidance strategies. The system supports two haptic models that provide three degree of freedom (DOF) force feedback and 6DOF posture sensing. Details of five key functions of the system are given: (1) a rendering conversion that uses 3DOF (instead of five) force feedback haptic representation, (2) an efficient force feedback design that allows accurate results to be obtained from the user’s manipulation, (3) a fast collision detection scheme that achieves real-time feedback, (4) use of active haptic guidance to assist cutter-path generation, and (5) a design that supports both ball-end and flat-end tools with partial optimization.


2013 ◽  
Vol 454 ◽  
pp. 66-69
Author(s):  
Xiao Wei Jiang ◽  
Qiu Lei Du

In view of well- designed showing platform is advantageous to promoting exhibition effect, the author analyzes the developing course of showing platform, and combining the mechanical design problem of existing showing platform which exists in using function, art function and material technique function and others, discusses the mechanical design requirement, the fundamental structure and working principle, the shape design and the color design of showing platform of rotation and vertical reciprocation. Among them the fundamental structure and working principle mainly elaborate the constituent parts of showing platform, the structure characteristics and working manner. Then the possibility is analyzed. On this foundation, the practical application of showing platform of rotation and vertical reciprocation is analyzed.


Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 640
Author(s):  
Linshuai Zhang ◽  
Shuoxin Gu ◽  
Shuxiang Guo ◽  
Takashi Tamiya

A teleoperated robotic catheter operating system is a solution to avoid occupational hazards caused by repeated exposure radiation of the surgeon to X-ray during the endovascular procedures. However, inadequate force feedback and collision detection while teleoperating surgical tools elevate the risk of endovascular procedures. Moreover, surgeons cannot control the force of the catheter/guidewire within a proper range, and thus the risk of blood vessel damage will increase. In this paper, a magnetorheological fluid (MR)-based robot-assisted catheter/guidewire surgery system has been developed, which uses the surgeon’s natural manipulation skills acquired through experience and uses haptic cues to generate collision detection to ensure surgical safety. We present tests for the performance evaluation regarding the teleoperation, the force measurement, and the collision detection with haptic cues. Results show that the system can track the desired position of the surgical tool and detect the relevant force event at the catheter. In addition, this method can more readily enable surgeons to distinguish whether the proximal force exceeds or meets the safety threshold of blood vessels.


Robotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 21
Author(s):  
Francesco Samani ◽  
Marco Ceccarelli

TORVEastro robot design is presented with a built prototype in LARM2 (Laboratory of Robot Mechatronics) for testing and characterizing its functionality for service in space stations. Several robot astronauts are designed with bulky human-like structures that cannot be convenient for outdoor space service in monitoring and maintenance of the external structures of orbital stations. The design features of TORVEastro robot are discussed with its peculiar mechanical design with 3 arm-legs as agile service robot astronaut. A lab prototype is used to test the operation performance and the feasibility of its peculiar design. The robot weighs 1 kg, and consists of a central torso, three identical three-degree of freedom (DoF) arm–legs and one vision system. Test results are reported to discuss the operation efficiency in terms of motion characteristics and power consumption during lab experiments that nevertheless show the feasibility of the robot for outdoor space applications.


Author(s):  
Samuel N. Cubero

This chapter describes the mechanical design, manufacture and performance of a three-degree-of-freedom manipulator arm and gripper that can be attached to a mobile vehicle or electric scooter. Known by the acronym “ESRA”, or “Electric Scooter Robot Arm”, this device can be remotely or automatically controlled to pick up and retrieve heavy objects, such as books or grocery products, from high shelves or difficult-to-reach locations. Such tasks are often considered to be arduous or even impossible for the frail elderly and people with disabilities. This chapter describes one example of how the combination of mechanical and electronic engineering technology can be used to perform physically strenuous tasks and enable the frail elderly and people with disabilities to enjoy a greater degree of self-sufficiency, independence and physical productivity. It includes the design process for robotic arm manipulators and actuators. It also provides a brief overview of existing “state of the art” robotic and machine vision technologies, and how these can be used to perform many everyday domestic or household chores.


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