We present a novel pneumatic actuation system for generation of liquid metal droplets according to the so-called StarJet method. In contrast to our previous work, the performance of the device has been significantly improved: the maximum droplet generation frequency in continuous mode has been increased to fmax = 11 kHz (formerly fmax = 4 kHz). In addition, the droplet diameter has been reduced...

We present a novel pneumatic actuation system for generation of liquid metal droplets according to the so-called StarJet method. In contrast to our previous work [1, 2], the performance of the device has been significantly improved: The maximum droplet generation frequency in continuous-mode has been increased to fmax_=_11 kHz (formerly fmax_=_4 kHz). In addition, the droplet diameter has been ...

Magnetic resonance imaging (MRI) can be a very effective imaging modality for live guidance during surgical procedures. The rationale of MRI-guided surgery with robot-assistance is to perform surgical interventions utilizing “realtime” image feedback while minimize operation time and improves the surgical outcomes. However, challenges arise from electromagnetic compatibility within the high-fie...

In the remote controlled rehabilitation device, physical therapists must recognize the situation of the patient. The actuator in the device is also required to be flexible so as not to injure the body. In our previous study, the flexible pneumatic cylinder was proposed and tested. The flexible robot arm using the cylinders for human wrist rehabilitation was also developed. In the next step, it ...

In this paper, a novel pneumatic cylinder is proposed, named Magnetic Brake Cylinder. It is composed of a tank, a pneumatic cylinder, and a permanent magnet, and with this, the piston is held by the attractive force of the magnet until the pressure inside the tank is very high, offering a higher driving power than an ordinary cylinder when using the same pressure source. In addition, a control ...

The modeling of pneumatic actuators, also known as artificial muscles, has been the main focus in several research papers in the past [1, 2, 3, 4, 5]. At the Center for Intelligent Systems (CIS) at Vanderbilt University, we have been using pneumatic actuators for our Intelligent Soft Arm Control (ISAC, Figure 1). For the position control of a joint, driven by two artificial muscles, a physical ...

This paper reports an experimental evaluation of the following three different MRI-compatible actuators: a Shinsei ultrasonic motor a Nanomotion ultrasonic motor and a pneumatic cylinder actuator. We report the results of a study comparing the effect of these actuators on the signal to noise ratio (SNR) of MRJ images under a variety of experimental conditions. Evaluation was performed with the ...

This paper proposes a structure and control approach for the energy saving servo control of a pneumatic servo system. The energy saving approach is enabled by supplementing a standard four-way spool valve controlled pneumatic actuator with an additional two-way valve that enables flow between the cylinder chambers. The “crossflow” valve enables recirculation of pressurized air, and thus enables...

In this paper, a wavelet-based iterative learning control (WILC) scheme with Fuzzy PD feedback is presented for a pneumatic control system with nonsmooth nonlinearities and uncertain parameters. The wavelet transform is employed to extract the learnable dynamics from measured output signal before it can be used to update the control profile. The wavelet transform is adopted to decompose the ori...

This paper studies the evolutionary design of a fuzzy P+ID controller for an actual pneumatic muscle actuator system. The control of pneumatic muscles is a challenging problem because of their high degree of nonlinearity, time-varying parameters, and uncertainty. A fuzzy P+ID controller is constructed using an incremental fuzzy logic controller in place of the proportional term in a conventiona...