Virtual needle insertion with haptic feedback using a hybrid actuator with DC servomotor and MR-brake with Hall-effect sensor

Mechatronics ◽  
2012 ◽  
Vol 22 (8) ◽  
pp. 1161-1176 ◽  
Author(s):  
Berk Gonenc ◽  
Hakan Gurocak
Author(s):  
Berk Gonenc ◽  
Hakan Gurocak

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 wide range of tissue properties and resistance forces accurately. In this research, we developed a hybrid haptic device made 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 alone, 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 stiff interaction forces yet cannot reflect fast dynamics that are encountered as the virtual scissors go through the tissue. The hybrid actuator developed in this work combines the two based on a control scheme that decomposes the actuator command signal into two branches considering each actuator's capabilities. It is implemented on a compact single degree-of-freedom (DOF) interface to simulate virtual tissue cutting with three different scissor types (Mayo, Metzenbaum, Iris) and four types of rat tissue (liver, muscle, skin, tendon). Results have shown close tracking of the desired force profile in all cases. Compared to just using a DC motor, the hybrid actuator provided a wider range of forces (up to 18 N) with fast response to render quick force variations without any instability for all simulated tissue and scissor types.


2008 ◽  
Vol 128 (2) ◽  
pp. 125-130
Author(s):  
Kan Akatsu ◽  
Nobuhiro Mitomo ◽  
Shinji Wakui

Machines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 101
Author(s):  
Leonardo Acho

The main objective of this paper is to present a position control design to a DC-motor, where the set-point is externally supplied. The controller is conceived by using vibrational control theory and implemented by just processing the time derivative of a Hall-effect sensor signal. Vibrational control is robust against model uncertainties. Hence, for control design, a simple mathematical model of a DC-Motor is invoked. Then, this controller is realized by utilizing analog electronics via operational amplifiers. In the experimental set-up, one extreme of a flexible beam attached to the motor shaft, and with a permanent magnet fixed on the other end, is constructed. Therefore, the control action consists of externally manipulating the flexible beam rotational position by driving a moveable Hall-effect sensor that is located facing the magnet. The experimental platform results in a low-priced device and is useful for teaching control and electronic topics. Experimental results are evidenced to support the main paper contribution.


Author(s):  
Thomas W. Anderson ◽  
Nathaniel A. Clark ◽  
Wesley E. Kotz ◽  
Briana D. Stremick ◽  
O¨zer Arnas ◽  
...  

Recent additions of armor have made light tactical vehicle turrets heavy enough that mechanical assistance is required for them to rotate. The Army’s solution is the Battery Powered Motorized Traversing Unit (BPMTU) which uses a joystick to traverse the turret. Use of the joystick distracts the gunner and prevents the gunner from continuously engaging the target while rotating the turret. This paper presents a modification to the weapon mount that allows the turret to be controlled by the position of the weapon itself and emphasizes the design process used to develop the inovation. With this design, the gunner can now maintain contact with a target, while rotating the turret, without fiddling with the joystick. The Weapon Activated and Controlled Turret (WACT) consists of two primary components; the bottom component is stationary relative to the turret and contains a Hall effect sensor and the top component rotates with the weapon and holds a linear magnet. As the position of the sensor relative to the magnet changes, the corresponding strength of the magnetic field also varies. This change in magnetic force induces a similar response in the output voltage of the Hall effect sensor, effectively translating rotational motion into an electric signal able to control the turret motor.


1999 ◽  
Author(s):  
Carlo A. Avizzano ◽  
Diego Ferrazzin ◽  
Giuseppe M. Prisco ◽  
Massimo Bergamasco

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 711
Author(s):  
Siya Lozanova ◽  
Ivan Kolev ◽  
Avgust Ivanov ◽  
Chavdar Roumenin

A new 2D (two-dimensional) in-plane sensitive Hall-effect sensor comprising two identical n-Si Greek-crosses is presented. Each of the crosses contains one central square contact and, symmetrically to each of their four sides, an outer contact is available. Outer electrode from one configuration is connected with the respective opposite contact from the other configuration, thus forming four parallel three-contact (3C) Hall elements. These original connections provide pairs of opposite supply currents in each of the cross-Hall structure. Also the obligatory load resistors in the outer contacts of 3С Hall elements are replaced by internal resistances of crosses themselves. The samples have been implemented by IC technology, using four masks. The magnetic field is parallel to the structures’ plane. The couples of opposite contacts of each Greek-cross are the outputs for the two orthogonal components of the magnetic vector at sensitivities S ≈ 115 V/AT whereas the cross-talk is very promising, reaching no more than 2.4%. The mean lowest detected magnetic induction B at a supply current Is = 3 mA over the frequency range f ≤ 500 Hz at a signal to noise ratio equal to unity, is Bmin ≈ 14 μT.


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