Supporting Uranus Exploration with Deployable ChipSat Probes

Since optical wireless power transmission (OWPT) transmits power by light, which has a narrow diffraction angle feature, it is a strong candidate for wireless power transmission systems supporting long ranges. To develop a realistic operational OWPT system, clarification of system level requirements is essential. In this study, to fill a gap between the concept/initial demonstration and an operational system, the required conditions were analyzed regarding the effects of beam alignment and shaping on the power generation ratio which is a system level efficiency factor with extension from the formerly reported one-dimensional analysis to three-dimensional to include errors in all degrees of freedom is presented. This extension is regarded as an indispensable methodology to evaluate the system level performance of general OWPT systems. Numerical requirements for beam alignment and shaping are derived for both non-cooperative and cooperative OWPT. In non-cooperative OWPT, the direction of the solar cell module is fixed, and the transmitter aligns its beam with the module. In cooperative OWPT, the module and transmitter mutually align in the same direction. Though the cooperative OWPT is more restrictive than the non-cooperative one, its advantages were clarified.

Section: Introductionmentioning

confidence: 99%

System Level Requirement Analysis of Beam Alignment and Shaping for Optical Wireless Power Transmission System by Semi–Empirical Simulation

Asaba

Miyamoto

2022

“…In the experiment with the substrate, the angle of the rotatable table (=attitude angle of the target) was φ = 110 deg. Considering that the irradiated beam is reflected by the target and directly enters the camera, like in Figure 16a, its attitude angle φ depends on the position and satisfies Equation (7).…”

Section: Positioning Of the Pv At Position Sets 1 2 Andmentioning

confidence: 99%

“…If the exact range data are provided externally, there would be an option to determine the target's position based on range information from the external ranging source combined with the internally estimated direction. In fact, the dominant contribution to the positioning error is removed by setting ∆R = 0 in Equation (7). Position accuracies were estimated using (exact) range information with the internal direction estimation.…”

Section: Position Estimation With External Ranging Informationmentioning

confidence: 99%

“…In the future, many power transmission systems to individual equipment are expected to become wireless [1], and optical wireless power transmission (OWPT) will play an important role [2][3][4]. Since it features light beams, it has an advantage of long-distance power transmission to photovoltaic devices (PVs) [5][6][7][8]. To increase the power generation efficiency in the target (PV), precise beam alignment and shaping depending on the target's position is necessary [9,10], and the PV's position and attitude needs to be determined from the light source before power transmission.…”

Section: Introductionmentioning

confidence: 99%

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Positioning of a Photovoltaic Device on a Real Two-Dimensional Plane in Optical Wireless Power Transmission by Means of Infrared Differential Absorption Imaging

Asaba,

Miyamoto

2023

In optical wireless power transmission (OWPT), detection and positioning of the photovoltaic device (PV) in real space is essential before power transmission. One of the candidates for the robust detection of PVs is differential absorption imaging, which has been proposed by the authors. In this method, raw images are captured using absorbable (λON) and non-absorbable (λOFF) wavelengths of the PV. Then, the PV is detected from the differential image of these. In this report, the positioning of a PV on a real two-dimensional plane was investigated by means of this differential imaging. Primarily, stereo imagery was utilized for positioning. Non-stereo positioning was also investigated, in which the azimuth angle (direction) was estimated from the position of the PV in the differential image, and ranging was performed using its apparent size. There are diffuse and non-diffuse (specular) options for the λOFF reflection of the rear surface of the PV. Positioning accuracy was measured with regard to this characteristic as well as the attitude angle. Especially for a PV with specular characteristics, even though its positioning accuracy was affected by its attitude angle, the accuracy could be improved by increasing the irradiation light power. On the other hand, direction determination was stable for a wide angular range of attitudes.

“…In the coming wireless society [1], Optical Wireless Power Transmission (OWPT) is expected to play an important role [2][3][4]. Since it irradiates light beam to photovoltaic device (PV) from light source, it has advantage of transmitting power to a long-distance target [5][6][7][8]. To increase power generation efficiency to irradiated power, sophisticated beam alignment and shaping combined with some relaxation strategy [9,10] is necessary.…”

Section: Introductionmentioning

confidence: 99%

Solar Cell Detection and Position, Attitude Determination by Differential Absorption Imaging in Optical Wireless Power Transmission

Asaba

Miyamoto

2023

In optical wireless power transmission, position, size, and attitude of photovoltaic device (PV) must be determined from light source. A method proposed in the previous report is based on selective absorption characteristics of PV, and it is detected by differentiating images of strongly absorbable wavelength and one not. In this study, using two infrared wavelengths, two kinds of targets were detected by differential absorption imaging. One was a GaAs substrate which simulates diffuse rear surface, and the other was a real GaAs PV. It was found that the substrate’s reflective characteristic was diffuse, and the solar cell’s was mainly non-diffuse and accompanied by small diffuse component supporting wide-angle reflection. Using this feature, the position of the GaAs solar cell could be determined within a wide range of angle. Its attitude could also be determined with an accuracy of ±10 degrees to its normal. The position of diffuse GaAs substrate could be determined within a wide range of angles, and its attitude determination was proposed by exploiting its varying apparent size with tilt angle. Broad reflection characteristics of the GaAs substrate enabled attitude determination for a wide-angle range, and determination around normal would be erroneous.