Integrated Battery Chargers

Integrated battery chargers (IBCs) have been proposed as a low-weight, low-volume, and high-power solution to conventional conductive chargers. However, the design of such chargers is complicated, requiring special components or control techniques to solve inherent issues (such as galvanic isolation, torque generation, and system reconfiguration) associated with their design. Solutions vary based on charging power, drive topology, and motor technology. This chapter introduces designs for IBCs, including solutions as proposed in the literature. It also presents challenges in their industrial adoption. Finally, the chapter presents opportunities for fleet charging applications using IBCs.

Implementation of robotic ankle–foot orthosis with an impedance-based assist-as-needed control strategy

In this paper, a robotic ankle–foot orthosis (AFO) is developed for individuals with a paretic ankle, and an impedance-based assist-as-needed controller is designed for the robotic AFO to provide adaptive assistance. First, a description of the robotic AFO hardware design is presented. Next, the design of the finite state machine is introduced, followed by an introduction to the modelling of the robotic AFO. Additionally, the control of the robotic AFO is presented. An impedance-based high-level controller that is composed of an ankle impedance based torque generation controller and an impedance controller is designed for the high-level control. A compensated low-level controller that is composed of a braking controller and a proportional-derivative controller with a compensation part is designed for the low-level control. Finally, a pilot study is conducted, and the experimental results demonstrate that with the proposed control algorithm, the robotic AFO has the potential for ankle rehabilitation by providing adaptive assistance. In the assisted condition with a high level of assistance, reductions of 8% and 20.1% of the root mean square of the tibialis anterior and lateral soleus activities are observed, respectively.

Wireless Torque and Power Transfer Using Multiple Coils with LCC-S Topology for Implantable Medical Drug Pump

In this paper, we propose a method of wirelessly torque transfer (WTT) and power (WPT) to a drug pump, one of implantable medical devices. By using the magnetic field generated by the WPT system to transfer torque and power to the receiving coil at the same time, applications that previously used power from the battery can be operated without a battery. The proposed method uses a receiving coil with magnetic material as a motor, and can generate torque in a desired direction using the magnetic field from the transmitting coil. The WPT system was analyzed using a topology that generates a constant current for stable torque generation. In addition, a method for detecting the position of the receiving coil without using additional power was proposed. Through simulations and experiments, it was confirmed that WTT and WPT were possible at the same time, and in particular, it was confirmed that WTT was stably possible.

Research on the mathematical modelling of the starting torque of self-lubricating spherical plain bearings

The starting torque of self-lubricating spherical plain bearings (SSPBs) is a key parameter for evaluating the performance of bearings. Therefore, the starting torque of SSPBs should be controlled to within an allowable range. In this paper, the starting torque generation mechanism is analyzed, and the critical load for the separation of the liner from the outer spherical surface of the inner ring is determined. A mathematical model of the starting torque is established; the experimental and theoretical results of the starting torque are compared and analyzed, and then the accuracy of the mathematical model is evaluated by the deterministic coefficient R2. The research reveals that a critical load exists for the starting torque. Below the critical load, the starting torque is dependent on the outer spherical radius of the inner ring, bearing wrap angle, and liner parameters such as the compressive elastic modulus, friction coefficient, and precompression of the liner; however, the starting torque is independent of the radial load. Above the critical load, the starting torque is also dependent on the radial load. The research results provide a theoretical basis for the design and application of bearings.

Native flagellar MS ring is formed by 34 subunits with 23-fold and 11-fold subsymmetries

The bacterial flagellar MS ring is a transmembrane complex acting as the core of the flagellar motor and template for flagellar assembly. The C ring attached to the MS ring is involved in torque generation and rotation switch, and a large symmetry mismatch between these two rings has been a long puzzle, especially with respect to their role in motor function. Here, using cryoEM structural analysis of the flagellar basal body and the MS ring formed by full-length FliF from Salmonella enterica, we show that the native MS ring is formed by 34 FliF subunits with no symmetry variation. Symmetry analysis of the C ring shows a variation with a peak at 34-fold, suggesting flexibility in C ring assembly. Finally, our data also indicate that FliF subunits assume two different conformations, contributing differentially to the inner and middle parts of the M ring and thus resulting in 23- and 11-fold subsymmetries in the inner and middle M ring, respectively. The internal core of the M ring, formed by 23 subunits, forms a hole of the right size to accommodate the protein export gate.

Cryo-EM structure of TFIIH/Rad4–Rad23–Rad33 in damaged DNA opening in nucleotide excision repair

The versatile nucleotide excision repair (NER) pathway initiates as the XPC–RAD23B–CETN2 complex first recognizes DNA lesions from the genomic DNA and recruits the general transcription factor complex, TFIIH, for subsequent lesion verification. Here, we present a cryo-EM structure of an NER initiation complex containing Rad4–Rad23-Rad33 (yeast homologue of XPC–RAD23B–CETN2) and 7-subunit coreTFIIH assembled on a carcinogen-DNA adduct lesion at 3.9–9.2 Å resolution. A ~30-bp DNA duplex could be mapped as it straddles between Rad4 and the Ssl2 (XPB) subunit of TFIIH on the 3' and 5' side of the lesion, respectively. The simultaneous binding with Rad4 and TFIIH was permitted by an unwinding of DNA at the lesion. Translocation coupled with torque generation by Ssl2 and Rad4 would extend the DNA unwinding at the lesion and deliver the damaged strand to Rad3 (XPD) in an open form suitable for subsequent lesion scanning and verification.