Yasuyoshi Kaneko

Compact contactless power transfer system for electric vehicles

Electric vehicles (EVs) have been attracting considerable interest recently. A contactless power transfer system is required for EVs. Transformers can have single-sided or double-sided windings. Transformers with double-sided windings are expected to be more compact and lightweight than transformers with single-sided windings. A contactless power transfer system for EVs needs to have a high efficiency, a large air gap, good tolerance to misalignment and be compact and lightweight. In this paper, a novel transformer using series and parallel capacitors with rectangular cores and double-sided windings that satisfies these criteria has been developed, and its characteristics are described. It has an output power of 1.5 kW and an efficiency of 95% in the normal position. To reduce the cost of expensive ferrite cores, a transformer with split cores is also proposed.

A large air gap 3 kW wireless power transfer system for electric vehicles

A wireless power transfer system for electric vehicles is required to have high efficiency, a large air gap, and good tolerance for misalignment in the lateral direction and to be compact and lightweight. A new 3 kW transformer has been developed to satisfy these criteria using a novel H-shaped core and split primary capacitors. The design procedure based on the coupling factor k, the windings Q, and the core loss is described. An efficiency of 90% was achieved across a 200 mm air gap.

Small-size light-weight transformer with new core structure for contactless electric vehicle power transfer system

A contactless power transfer system for electric vehicles is required to have high efficiency, a large air gap, good tolerance to misalignment in the lateral direction, and be compact and lightweight. A new 1.5 kW transformer has been developed to satisfy these criteria using novel H-shaped cores, which is more efficient, more robust to misalignment, and lighter than previously employed rectangular cores, and its characteristics are described. An efficiency of 95% was achieved across a 70 mm air gap. The results of test at wide air gap of 100mm, temperature rise test and 3kW operation test are also presented.

Whole-Body Force Sensation by Force Sensor With Shell-Shaped End-Effector

This paper proposes a tactile-sensing mechanism for a robot. The mechanism is composed of a force-sensor device and an end-effector of shell shape. Since the end-effector plays the role of an outer shell, a force can be sensed at any position on the body. Due to the aspect of its intrinsic contact sensing, position of the single contact point is calculable without any sensor array. Another advantage is that the six-axis resultant force is measurable. This paper shows that the mechanism is also available for the end-effector with an angulated shape. The only condition for the shape is to be a convex hull. Some experimental results evaluate sources of error in practical measurement and show the validity of the proposed mechanism.

Neural network and fuzzy control of weld pool with welding robot

The sensing and control of weld pool depth in robotic welding are discussed. A neural network-based method for measuring the depth is proposed, since the depth cannot be directly measured in real time. The weld pool depth is estimated by using the information obtained from the welding side. The surface shape of the weld pool and the width of the groove gap can be measured during the welding. The weld pool depth can also be measured after the welding. Training data were constructed from these numerical data. When the width of the groove gap changes, the weld pool depth changes too. The feedforward control system for the variation of the groove gap width just under the electrode can be constructed by observing the groove gap width before the electrode. The feedback control system was constructed in order to keep the output of the neural network constant. The fuzzy control system was constructed from the feedback control part and the feedforward control part. The validity of a neuro-fuzzy controller was verified by welding experiments.<<ETX>>

A 10kW transformer with a novel cooling structure of a contactless power transfer system for electric vehicles

A contactless power transfer system for electric vehicles is required to have high efficiency, a large air gap, good tolerance to misalignment in the lateral direction, and to be compact and lightweight. A new 10kW transformer with double-sided winding for fast charging has been developed. The proposed transformer has a novel cooling structure using aluminum bars, aluminum junctions, and aluminum plates. In this paper, the design concept, specifications, and test results of the new transformer are described. The other feature of this transformer is its interoperability with a 3kW transformer. The interoperability test results are also shown.

Technology trends of wireless power transfer systems for electric vehicle and plug-in hybrid electric vehicle

A wireless power transfer system is desirable for the recharging of electric vehicles. The system for electric vehicles requires a high efficiency, a large air gap, and a good tolerance to lateral misalignment and needs to be compact and lightweight. This paper describes the characteristics of wireless power transfer system, the subject and solution in the case of applying to electric vehicles. Especially, the difference of characteristics of single-sided winding transformer and double-sided winding transformer is detailed. And new trends of the wireless power transfer system for electric vehicles are introduced.

A new he core transmitter of a contactless power transfer system that is compatible with circular core receivers and H-shaped core receivers

Contactless power transfer systems for electric vehicles contain two types of transformers (a pair consisting of a transmitter and a receiver): a rectangular (H-shaped) core double-sided winding transformer and a circular core single-sided winding transformer. Since the magnetic field structures of these two transformers differ greatly, these two types of transformers have been incompatible in the past, although a number of compatible receivers have recently been proposed. This paper proposes a novel He core transmitter that is compatible with both types of receivers. The He core transmitter adds a central magnetic pole by dividing the winding coil of the H-shaped core transmitter. This transmitter can change the magnetic field structure by changing the connections of divided windings and can transfer power to both types of receivers. Compatibility tests at 3 kW are carried out, and the test results are presented.

Whole-body force sensation by robot with outer shell

This paper proposes a force-sensing mechanism for a robot. The mechanism is composed of a force sensor device and an end-effector of shell-shape. Since the end-effector plays a role of an outer shell, force can be sensed at any positions on whole body. In other word, whole-body force sensation is realized. It is possible to calculate the position of a contact point without any sensor array. Hence costs and wirings are reduced. Another merit is that 6-axis resultant force is measurable in contrast with conventional tactile sensors. Experimental results of a mobile robot are shown to verify the validity of the proposed mechanism.

Methods for Reducing Leakage Electric Field of a Wireless Power Transfer System for Electric Vehicles

A wireless power transfer system for electric vehicles has to deal with the issue of high leakage levels of electric field. In this paper, we propose two methods for reducing the leakage electric field. First is the use of ferrite to reduce the emitted leakage electric field to the environment. Second is the changing of the pulse width of the inverter to reduce the harmonics of leakage electric field. We present the experimental results of the reduction effects of leakage electric field. We also compared the leakage electric field using series-parallel and series-series resonant capacitor topologies.