https://iopscience.iop.org/article/10.1088/1361-665X/ab192a/pdf

Delta-type four-DOF force-feedback device composed of pneumatic artificial muscles and magnetorheological clutch and its application to lid opening

In a virtual reality (VR) space, wearing a head-mounted display can help with the visualization of objects although users cannot experience realistic tactile sensations. Recently, several force feedback devices have been developed, including wearable devices that use straight-fiber-type pneumatic muscles and magnetorheological fluids. This allows the devices to render elastic, frictional, and viscous forces during spatially unrestricted movement. However, during friction and viscosity rendering, the elasticity of the artificial muscle is influenced by the elastic element of the muscle, preventing proper presentation of the force. Therefore, this study proposed a clutch mechanism to switch the force presentation of elastic elements by the contraction of artificial muscles. The mechanism was incorporated into a wearable four-degrees-of-freedom force feedback device, and its elastic, frictional, and viscous force feedback performances were quantitatively assessed via fundamental property experiments. Furthermore, a VR space was constructed to present the operator with force perceptions of virtual elastic, frictional, and viscous objects within that space, and the system’s performance was qualitatively assessed. The results confirmed a reduction in the effect of elastic elements and an improvement in the presentation performance. Additionally, the use of this device in the VR space was confirmed to improve the realism of virtual objects in terms of friction and viscosity.

Development of a Wearable Four-Degrees-of-Freedom Force Feedback Device with a Clutch Mechanism Using Artificial Muscle Contraction

This paper presents the testing of a Magnetorheological brake (MRB) in the braking system of a vehicle. Two techniques are used to determine the capability of the brake system which are the simulation via Matlab Simulink Software and experimental study by using a quarter vehicle test rig. A Proportional-Integral-Derivative (PID) is employed as a wheel speed control as well as to enforce the MRB to produce the required braking torque need by a vehicle. A dynamic test, namely sudden braking test is performed in three rotational speed conditions which are from 127.5 rad/s (1200 rpm) to 31.42 rad/s (300 rpm), 52.37 Rad/s (500 rpm) and 73.31 rad/s (700 rpm) in two different wheel load which are 10 kg and 15 kg, respectively. The behaviours to be assessed are wheel speed response and brake torque produced by the MRB. From the observation, it is concluded that the capability of the MRB in providing the required brake torque is promising and harmony between simulation and experimental response.

The Magnetorheological Fluid: Testing on Automotive Braking System

A series of reduced-order numerical simulations on a specific bluff body type (v-gutters) in a subsonic duct flow is done to assess the unsteady wake dynamics. Two of the v-gutter's geometrical parameters are varied: the v-gutter's base angle (θ) and the size of a slit (ξ) at the leading edge of the v-gutter. Five v-gutter angles are considered (θ,{degree sign} = π/6, π/4, π/3, 5π/12, π/2) and three slit sizes (ξ, mm =0,0.25,0.5) are considered only for a particular θ = [π/6]. High fluctuations in velocity and pressure are seen for the bluffest body in consideration (θ = π/2) with higher drag (cd) and total pressure loss (Δp0). On the other hand, the presence of a slit on a streamlined body (θ = π/6) tends to efficiently stabilize the wake and thus, producing almost a periodic shedding structure with lower cd and Δp0. For θ = [π/6], broadened spectra in vortex shedding are seen with a peak at [fL/u∞] ∼ 0.08. For θ {greater than or equal to} [π/4], a dominant discrete shedding frequency is seen with a gradual spectral decay. Similarly, the effects of ξ on the θ = [π/6] case produce a discrete shedding frequency instead of a broadened one, as told before. The shedding frequency increases to a maximum of [fL/u∞] ∼ 0.26 for the maximum slit size of ξ = 0.5. More insights on the shedding vortices, momentum deficit in the wake, varying energy contents in the flow field, and the dominant spatiotemporal structures are also provided.

https://aip.scitation.org/doi/pdf/10.1063/5.0097235

Unsteady dynamics in a subsonic duct flow with a bluff body

2534 Published By: Blue Eyes Intelligence Engineering & Sciences Publication Retrieval Number E7803068519/19©BEIESP  Abstract: In this paper, an optimized design for hatchback segment of commercial vehicle is considered to find the optimum dimensions for the MR brake, with the help of optimization tools and existing conventional dimensions. An axisymmetric model is generated using COMSOL based on the dimensions available in the existing literature and braking torque is calculated using Bingham plastic model. It is a coupled system i.e. Electric field – Magnetic field – Mechanical action. Initially the existing design from literature survey is taken as base model for the MR brake and the design is changed according to the dimensions found on the basis of the conventional dimensions of disc brake accessible in the existing hatch-back segment car. After finalizing the dimensions and MR fluid the four new design model for disc are considered for simulations. The brake are used several time during the dynamic condition so as to test the reliability of the Magneto-Rheological brake, the hysteresis analysis is also needed to be carried out by simulating it in a dynamic environment. For hysteresis analysis MATLAB Simulink is used for simulating the brake in dynamic condition with the help of Bouc-Wen Model. The main aim is to achieve a braking torque of MR brake near to the existing braking system of the vehicle.

Design and hysteresis behavior of magneto-rheological disc brake for hatchback segment commercial car

This work presents an optimised design for a magneto rheological fluid brake for all terrain vehicles. The actuator consists of a disk which is immersed in the magneto rheological fluid surrounded by an electromagnet. The braking torque is controlled by varying the DC current applied to the electromagnet. In the presence of a magnetic field, the magneto rheological fluid particle aligns in a chain like structure, thus increasing the viscosity. The shear stress generated causes friction in the surfaces of the rotating disk. Electromagnetic analysis of the proposed system is carried out using finite element based COMSOL multi-physics software and the amount of magnetic field generated is calculated with the help of COMSOL. The geometry is optimised and performance of the system in terms of braking torque is carried out. Proposed design reveals better performance in terms of braking torque from the existing literature.

https://iopscience.iop.org/article/10.1088/1757-899X/310/1/012127/pdf

Luckachan K George

Papers

Design and analysis of magneto rheological fluid brake for an all terrain vehicle

The influence of the geometry of V-gutter bluff body on transient vortex shedding

Transient Vortex Shedding Behaviour of Non-reacting Flow Over V-Gutter Bluff Bodies with Central Slit