Twin-driven actuator with multi-layered disc magnetorheological fluid clutches for haptics

Abstract

Magnetorheological fluids are composite materials made of ferromagnetic particles, medium oils, and several types of additives. We have developed actuation systems for the fine haptic control of master–slave robots. In this study, we proposed a new structure of a magnetorheological fluid–based actuator suitable for haptic devices. For the basic structure of the actuator, we proposed a twin-driven magnetorheological fluid actuator using two multi-layered disc-type magnetorheological fluid clutches for haptics. We conducted performance measures for the magnetorheological fluid clutches for haptics with three commercially available magnetorheological fluids (i.e. 122EG, 132DG, and 140CG from Lord Corp.). The experimental results show that 132DG is a better material for force control. Then, we proposed two types of twin-driven magnetorheological fluid actuators (i.e. link type and belt type) and compared their performance. The results show that the averages of the time constant are 19.1 and 16.1 ms for the link type and belt type, respectively. Furthermore, the averages of torque error are 0.033 and 0.068 N m for the link type and belt type, respectively. However, the belt-type twin-driven magnetorheological fluid actuator is better if a large range of motion is required, while the link-type twin-driven magnetorheological fluid actuator is better if accurate torque control is required.

A Review on Structural Configurations of Magnetorheological Fluid Based Devices Reported in 2018–2020

“…Because of the large working area of the cooling liquid and MRF, the sealing requirements and production costs for this device are high. Based on the coupled operation mode, a multi-disc MRF clutch was presented, two of which are fixed on the casing and shaft, shown in Figure 5B (Kikuchi et al, 2020). Utilizing the clutch, a new actuator with flexible torque control can be assembled for the haptic device.…”

“…FIGURE 5 | (A) High-power MRF clutch(Wu et al, 2019). (B) Multi-layered disc MRF clutch and twin-driven MRF actuator(Kikuchi et al, 2020). (C) Hydrodynamic clutch with MRF(Olszak et al, 2019).…”

Haptic Interface with Twin-Driven MR Fluid Actuator for Teleoperation Endoscopic Surgery System

“…To investigate the effect of the haptic information in teleoperational endoscopic surgeries, we developed a haptic interface using the linkage type TD-MRA [13] and specific structure for the motion of endoscopic operations. In this section, this system is described.…”

“…However, their directly controllable torque is generally small. To improve the quality of haptic information in the robotic surgery system, we developed a twin-driven magnetorheological fluid (MRF) actuator (TD-MRA) [13] as a key component of the haptic interface. In this actuator, two high-performance MRF clutches [14] are utilized for torque transmission.…”

“…Hence, our TD-MRA adopted two H-MRCs to reduce the inertia and friction, as well as a flat gear mechanism to reduce unbalanced torques. In a previous study [13], we developed two types of TD-MRAs, using belt transmission (Belt-type TD-MRA) and parallel linkage (Link-type TD-MRA). Although both types have pros and cons, their torque/inertia ratio was up to 10,000 Nm/kgm 2 , which is at the same level as coreless motors.…”